Reception method and terminal

Abstract

To appropriately synchronize a plurality of contents and display them.SOLUTION: A first data packet storing a first content via a first transmission path and a control packet storing URL information are received. A second data packet storing a second content via a second transmission path are received. It is determined whether or not one part of the first data packet is received at a predetermined time. In the case where it is determined that the first data packet is received, the first content and the second content are decoded. The decoded first and second contents are synchronized and displayed. In the case where it is determined that the first data packet is not received, an alternative data is acquired on the basis of the URL information, and the alternative data and the second content are decoded, and the decoded alternative data and the second content are displayed.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present disclosure relates to a receiving method and a terminal. [Background technology]

[0002] As a new approach, development is underway to realize a broadcasting and communication integrated service. A broadcasting and communication integrated service is a service that integrates broadcast program content and line content, in which "terminals receive broadcast program content transmitted from broadcast stations and content distributed by service providers via telecommunication lines, such as the Internet (herein, we call this "line content," but the terminology is not limited to this)."

[0003] To realize such a service, Patent Document 1 discloses a method for distributing real-time broadcast program content and line content to a terminal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2013 / 031556 [Patent Document 2] JP 2012-120140 A [Patent Document 3] JP 2012-129579 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, problems can arise when attempting to display multiple pieces of content in a time-synchronized manner, such as when displaying real-time broadcast program content and real-time line content.

[0006] Therefore, the present invention provides a packet receiving method and the like that can be used when a plurality of contents are displayed in a synchronized manner. [Means for solving the problem]

[0007] A receiving method according to the present disclosure includes receiving first data via broadcast, the first data being data in which some parity bits have been deleted from encoded bits generated by applying error correction encoding to information bits, receiving second data via broadcast before reception of the first data begins, the second data including the parity bits deleted when the first data was generated, and obtaining the information bits by performing error correction decoding on the received first data and second data, the first data being included in a different frame from the second data. Effect of the Invention

[0008] The receiving method and the like of the present invention can prevent problems caused by the data of one of the contents not being properly received when multiple contents are displayed synchronously. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of the relationship between broadcasting stations, telecommunication line providers, and terminals. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a transmission device owned by a broadcasting station and a telecommunications line provider. [Diagram 3] FIG. 3 is a diagram illustrating an example of the configuration of a terminal. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of a portion related to the error correction coding method of a transmission device of a telecommunications line provider. [Diagram 5] FIG. 5 is a diagram showing an example of the configuration of a portion of a transmission device of a telecommunications line provider that is related to an error correction coding method. [Figure 6] FIG. 6 is a diagram showing an example of a packet configuration method. [Figure 7] FIG. 7 is a diagram showing an example of a packet configuration method. [Figure 8] FIG. 8 is a diagram showing an example of a configuration in which a control information adding unit is provided before and after an error detection code adding unit. [Figure 9] FIG. 9 is a diagram showing an example of a packet transmission status and a packet reception status. [Figure 10] FIG. 10 is a diagram illustrating an example of a packet transmission status. [Figure 11] FIG. 11 is a diagram illustrating an example of a packet reception state. [Figure 12] FIG. 12 is a diagram illustrating an example of a packet reception state. [Figure 13] FIG. 13 is a diagram illustrating an example of a packet reception state. [Figure 14] FIG. 14 is a diagram illustrating an example of a processing flow of a packet (or frame) processing unit of the terminal. [Figure 15] FIG. 15 is a diagram illustrating an example of a processing flow of a packet (or frame) processing unit of the terminal. [Figure 16] FIG. 16 is a diagram showing an example of a packet transmission status and a packet reception status. [Figure 17] FIG. 17 is a diagram illustrating an example of a packet transmission status. [Figure 18] FIG. 18 is a diagram illustrating an example of a packet reception state. [Figure 19] FIG. 19 is a diagram illustrating an example of a packet reception state. [Figure 20] FIG. 20 is a diagram illustrating an example of a packet reception state. [Figure 21] FIG. 21 is a diagram showing a configuration example of a packet (or frame) processing unit in a transmission device owned by a broadcast station and a telecommunications line provider. [Figure 22] FIG. 22 is a diagram showing a configuration example when error correction decoding of a packet layer is performed in a packet (or frame) processing unit in a terminal. [Figure 23] FIG. 23 is a diagram showing an example of the configuration of a packet (or frame) processing unit in a terminal when error correction coding in the packet layer is not performed. [Figure 24] FIG. 24 is a diagram showing an example of the relationship between broadcasting stations, telecommunication line providers, and terminals. [Diagram 25] FIG. 25 is a diagram showing an example of the relationship between broadcasting stations, telecommunication line providers, and terminals. [Figure 26] FIG. 26 is a diagram showing an example of the configuration of a transmission device owned by a broadcasting station and a telecommunications line provider. [Figure 27] FIG. 27 is a diagram showing an example of the configuration of a transmission device owned by a broadcasting station and a telecommunications line provider. [Figure 28] FIG. 28 illustrates an example of the configuration of a terminal. [Figure 29] FIG. 29 illustrates an example of a packet transmission status. [Diagram 30] FIG. 30 is a diagram illustrating an example of a packet reception state. [Diagram 31] FIG. 31 is a diagram illustrating an example of a packet transmission status. [Diagram 32] FIG. 32 is a diagram illustrating an example of a packet reception state. [Diagram 33] FIG. 33 is a diagram illustrating an example of the configuration of a terminal. [Diagram 34] FIG. 34 is a diagram showing an example of the relationship between broadcasting stations, telecommunication line providers, and terminals. [Diagram 35] FIG. 35 is a diagram illustrating an example of a packet transmission status. [Diagram 36] FIG. 36 is a diagram showing an example of the configuration of a transmission device owned by a broadcasting station and a telecommunications line provider. [Figure 37] FIG. 37 is a diagram illustrating an example of the configuration of a terminal. [Figure 38] FIG. 38 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications line provider. [Figure 39] FIG. 39 is a diagram illustrating an example of the configuration of a terminal. [Diagram 40] FIG. 40 is a diagram showing an example of a packet transmission status. [Diagram 41] FIG. 41 is a diagram showing an example of the configuration of a transmission device owned by a broadcasting station and a telecommunications line provider. [Diagram 42]FIG. 42 is a diagram illustrating an example of the configuration of a terminal. [Diagram 43] FIG. 43 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications line provider. [Diagram 44] FIG. 44 is a diagram showing an example of a packet transmission status. [Diagram 45] FIG. 45 is a diagram illustrating an example of a packet transmission status. [Figure 46] FIG. 46 is a diagram showing an example of the configuration of a broadcasting station. [Figure 47] FIG. 47 is a diagram showing an example of the relationship between video packets and video and / or audio. [Figure 48] FIG. 48 is a diagram showing an example of the relationship between video packets and video and / or audio. [Figure 49] FIG. 49 is a diagram illustrating an example of the configuration of a terminal. [Figure 50] FIG. 50 is a diagram showing an example of a packet transmission status. [Figure 51] FIG. 51 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications line provider. [Figure 52] FIG. 52 is a diagram illustrating an example of the configuration of a terminal. [Diagram 53] FIG. 53 is a diagram showing an example of the configuration around the display unit. [Figure 54] FIG. 54 is a diagram showing an example of the configuration around the display unit. [Figure 55] FIG. 55 is a diagram showing an example of the configuration around the display unit. [Figure 56] FIG. 56 is a diagram showing an example of the configuration around the display unit. [Figure 57] FIG. 57 is a diagram showing an example of the configuration around the display unit. [Figure 58] FIG. 58 is a diagram showing an example of the configuration around the display unit. [Figure 59] FIG. 59 is a diagram showing an example of the configuration around the display unit. [Figure 60] FIG. 60 is a diagram showing an example of the configuration around the display unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Findings on which this disclosure is based) There is a demand for terminals to receive real-time broadcast program content and real-time line content with high quality. In this case, packet delays and packet losses are likely to be issues, especially in the case of line content. This point will be explained below.

[0011] Consider a case where a terminal receives real-time broadcast program content and real-time line content, and displays them on a display unit (display unit) equipped in the terminal, or on a display device (display) connected to the terminal. In this case, the real-time broadcast program content and the real-time line content are displayed separately. In this case, when displaying the line content, the display of the video can be controlled taking into account packet delays and packet losses of the line content.

[0012] However, when a terminal simultaneously displays real-time broadcast program content and real-time line content on a display unit (or a display device), a major issue arises in that the images of the broadcast program content and the line content are not synchronized in time.

[0013] Consider the case where a broadcasting station transmits real-time broadcast program content to a terminal. The broadcast program content is transmitted wirelessly (terrestrial digital broadcasting, satellite digital broadcasting, etc.) or via wired line (cable broadcasting, etc.). At this time, the quality of the program content may deteriorate depending on the conditions of the propagation path, but to overcome this, error correction codes are introduced to deal with poor propagation path conditions, thereby maintaining the quality of the program content at a high level. It is difficult to imagine a situation in which some of the information in the broadcast program content arrives with a delay.

[0014] On the other hand, in the case of line content transmitted to a terminal via a telecommunication line, for example, when a protocol such as UDP (User Datagram Protocol) is used, packet delays and packet losses can cause degradation in the quality of the line content. In particular, when real-time broadcast program content and real-time line content are simultaneously displayed on a display unit (or display device), several problems arise when the video of the broadcast program content and the video of the line content are synchronized in time.

[0015] For example, if a terminal delays the display of video content of a real-time broadcast program in consideration of the arrival delay of packets of line content, the terminal must be provided with a storage unit for data corresponding to the arrival delay, which creates a problem of an increase in the system scale of the terminal.

[0016] Furthermore, when the video of the line content is displayed in conjunction with the video display of the content of a real-time broadcast program, there is a high possibility that the video of the line content will be significantly distorted due to packet delays or packet losses of the line content.

[0017] The present disclosure aims to reduce the system scale of a transmission system and a terminal, and to achieve high-quality video display when real-time broadcast program content and real-time line content are displayed simultaneously on a display unit (or display device), and provides a transmission system and terminal etc. to achieve this.

[0018] A receiving method according to the present disclosure includes receiving first data via broadcast, the first data being data in which some parity bits have been deleted from encoded bits generated by applying error correction encoding to information bits, receiving second data via broadcast before reception of the first data begins, the second data including the parity bits deleted when the first data was generated, and obtaining the information bits by performing error correction decoding on the received first data and second data, the first data being included in a different frame from the second data.

[0019] A terminal according to the present disclosure is a terminal having a receiving unit and an error correction decoding unit, wherein the receiving unit receives first data via broadcast, the first data being data in which some parity bits have been deleted from coded bits generated by applying error correction coding to information bits, the receiving unit receives second data via broadcast before reception of the first data starts, the second data including the parity bits deleted when the first data was generated, the error correction decoding unit obtains the information bits by performing error correction decoding on the first data and the second data received by the receiving unit, and the first data is included in a different frame from the second data.

[0020] The receiving method of the present disclosure is a receiving method in which first data is received via broadcast, the first data being data in which some parity bits have been deleted from coded bits generated by applying error correction coding to information bits, and second data is received via broadcast before reception of the first data starts, the second data including the parity bits deleted when the first data was generated, and the information bits are obtained by performing error correction decoding on the received first data and second data.

[0021] A terminal according to the present disclosure is a terminal having a receiving unit and an error correction decoding unit, wherein the receiving unit receives first data via broadcast, the first data being data in which some parity bits have been deleted from coded bits generated by applying error correction coding to information bits, the receiving unit receives second data via broadcast before starting to receive the first data, the second data including the parity bits deleted when the first data was generated, and the error correction decoding unit obtains the information bits by performing error correction decoding on the first data and the second data received by the receiving unit.

[0022] The receiving method according to the present disclosure is a receiving method for receiving, via broadcast, first data having a number of bits greater than the number of information bits, which has been generated by a broadcasting station from coded bits generated by applying error correction coding to information bits, receiving, via broadcast, second data having a number of bits smaller than the number of information bits, which has been generated by the broadcasting station from the coded bits before reception of the first data starts, and performing error correction decoding on the received first data and second data, thereby obtaining the information bits.

[0023] A terminal according to the present disclosure is a terminal having a receiving unit and an error correction decoding unit, in which the receiving unit receives, via broadcast, first data having a number of bits greater than the number of information bits, which is generated by a broadcasting station from coded bits generated by applying error correction coding to information bits, and the receiving unit receives, via broadcast, second data having a number of bits smaller than the number of information bits, which is generated by the broadcasting station from the coded bits before reception of the first data begins, and the error correction decoding unit obtains the information bits by performing error correction decoding on the first data and the second data received by the receiving unit.

[0024] A method according to the present disclosure is a method for receiving and playing a first content and a second content, comprising: receiving a first data packet storing the first content and a control packet storing URL (Uniform Resource Locator) information via a first transmission path; receiving a second data packet storing the second content via a second transmission path; determining whether or not a portion of the first data packet has been received at a predetermined time; if it is determined that the first data packet has been received, decoding the first content and the second content, and displaying the decoded first content and the second content in synchronization; if it is determined that the first data packet has not been received, obtaining alternative data based on the URL information, decodes the alternative data and the second content, and displays the decoded alternative data and the second content.

[0025] Furthermore, a method according to the present disclosure is a method for receiving and playing a first content and a second content, comprising the steps of: receiving, via a first transmission path, a first data packet storing the first content, a parity packet generated from the first data packet, and a control packet storing URL (Uniform Resource Locator) information; receiving, via a second transmission path, a second data packet storing the second content; if a portion of the first data packet has not been received at a predetermined time, determining whether the first data packet can be decoded by a packet-level decoding process; if it is determined that the first data packet can be decoded, performing the packet-level decoding process to obtain the first data packet, decodes the first content and the second content, and displays the decoded first content and the second content in synchronization; if it is determined that the first data packet cannot be decoded, obtaining alternative data based on the URL information, decodes the alternative data and the second content, and displays the decoded alternative data and the second content.

[0026] According to the method disclosed herein, if a predetermined number or more of line data packets and line parity packets are received, decoding of the line content can be started, thereby improving the quality of the line content transmitted through a communication line where packet delays and packet drops may occur. Also, since the transmission time of the broadcast content is delayed by a predetermined time from the transmission time of the line content, the capacity of the memory unit for temporarily storing the broadcast content on the receiving side can be reduced compared to a case where the transmission time of the broadcast content is not delayed from the transmission time of the line content.

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0028] (Embodiment 1) Fig. 1 shows an example of the relationship between a broadcasting station, a telecommunications carrier, and a terminal in this embodiment. In Fig. 1, 101 indicates a site, and a baseball field or a soccer field is considered as an example. 102A and 102B indicate cameras. Assume that the cameras 102A and 102B are taking images from different angles, for example.

[0029] At this time, the broadcast station 103 receives the "first video and / or audio information" captured by the camera 102A, and the "first video and / or audio information" is transmitted to the terminal 105 via a wired connection such as a cable, or wirelessly.

[0030] Then, the broadcasting station 103 receives the "second video and / or audio information" captured by the camera 102B, and the "second video and / or audio information" is transmitted to the terminal 105 via the telecommunications line provider 104.

[0031] It should be noted that the “second video and / or audio information” may be transmitted directly to the telecommunications carrier 104 without going through the broadcast station 103, and then transmitted to the terminal 105.

[0032] Fig. 2 shows an example of the configuration of a broadcast station and a transmission device owned by a telecommunications carrier in this embodiment, with the portion surrounded by dotted line 240 being the broadcast station, and the portion surrounded by dotted line 250 being the transmission device owned by the telecommunications carrier. Note that control unit 232 may exist separately from the transmission device owned by the broadcast station or the telecommunications carrier, or may be provided by the broadcast station, or may be provided by the transmission device owned by the telecommunications carrier. Note that Fig. 2 shows a configuration diagram in the case where they exist separately.

[0033] The packet (or frame) processing unit 202 receives the "first video and / or audio information" 201 and the first control signal 211, performs packet (or frame) processing according to the first control signal 211, and outputs the first video and / or audio information 203 after the packet (or frame) processing. The detailed operation will be described later.

[0034] The physical layer error correction coding unit 204 receives as input the first video and / or audio information 203 after packet (or frame) processing and a first control signal 211, performs coding using an error correction code method (specific error correction code, coding rate) according to the first control signal 211, and outputs data 205 after error correction coding.

[0035] Modulation section 206 receives error-correction-coded data 205 and first control signal 211 as input, performs modulation using a modulation method in accordance with first control signal 211 , and outputs baseband signal 207 .

[0036] Transmitting section 208 receives baseband signal 207 and first control signal 211, performs signal processing based on a transmission method in accordance with first control signal 211, and outputs modulated signal 209, which is output as, for example, radio waves from antenna 210. Then, the data transmitted by modulated signal 209 is delivered to a terminal.

[0037] In the above description, an example of transmitting one modulated signal is described, but the present invention is not limited to this, and a transmission method of transmitting a plurality of modulated signals using a plurality of antennas at the same time and with the same frequency as shown in Patent Document 1, Patent Document 2, etc. may be used. In addition, as a transmission method, a single carrier method, a multicarrier method such as an OFDM (orthogonal frequency division multiplexing) method, a spread spectrum communication method, etc. are used. In addition, in FIG. 2, the broadcast station 240 is described as transmitting wirelessly, but a wired transmission method such as a cable may also be used.

[0038] The control unit 232 receives the second video and / or audio information 231 as input, and outputs the second video and / or audio information 212 and the second control signal 228. At this time, the second control signal 228 includes information related to a transmission method. The second video and / or audio information 212 is transmitted via the broadcast station 240.

[0039] The packet (or frame) processing unit 222 receives the second video and / or audio information 212, the second video and / or audio information 221 when it is directly delivered to the telecommunications line provider, and the second control signal 228 as input, and selects valid second video and / or audio information from the second video and / or audio information 212 and the second video and / or audio information 221 according to the second control signal 228, performs packet (or frame) processing on the selected information, and outputs the second video and / or audio information 223 after the packet (or frame) processing. The detailed operation will be described later.

[0040] The signal processing unit 224 receives the second video and / or audio information 223 after packet (or frame) processing and the second control signal 228, processes each layer (e.g., MAC (Media Access Control) layer, physical layer, etc., although of course, this is not limited to these) based on the second control signal 228, and outputs a processed signal 225.

[0041] Transmitting unit 226 receives processed signal 225 and second control signal 228, generates and outputs transmission signal 227 based on second control signal 228. Then, data transmitted in transmission signal 227 is delivered to the terminal.

[0042] The data transmitted by the transmission signal 227 may be delivered to the terminal by applying another transmission method or standard. For example, wireless LAN (Local Area Network), PLC (Power Line Communications), wireless transmission method using millimeter waves, cellular communication system, wireless MAN (Metropolitan Area Network), etc. can be mentioned, but are not limited to these. However, generally, the Internet Protocol is used, and TCP (Transmission Control Protocol) is used as the transfer protocol. , or UDP (user Datagram Protocol) will be used (TCP is one component of the suite, the other component being IP (Internet Protocol), and the entire suite is called TCP / IP).

[0043] Fig. 3 shows an example of the configuration of a terminal. An antenna 301 receives a modulated signal transmitted by a broadcast station, and a receiving unit 303 receives a received signal 302 by the antenna 301 as input, performs processing such as frequency conversion and quadrature demodulation, and outputs a baseband signal 304.

[0044] The time / frequency synchronization unit 305 receives the baseband signal 304 as input, extracts, for example, a preamble, pilot symbol, reference symbol, etc. contained in the modulated signal transmitted by the broadcasting station, performs time synchronization, frequency synchronization, frequency offset estimation, etc., and outputs a synchronization signal 306.

[0045] The channel estimation unit 307 receives the baseband signal 304 as input, extracts, for example, a preamble, pilot symbol, reference symbol, etc., contained in the modulated signal transmitted by the broadcast station, estimates the state of the propagation path (channel estimation), and outputs a channel estimation signal 308.

[0046] The control information extraction unit 309 receives the baseband signal 304 as input, extracts the control information symbols contained in the modulated signal transmitted by the broadcasting station, performs processing such as demodulation and error correction decoding of the control information symbols, and outputs a control information signal 310.

[0047] Demodulation section 311 receives baseband signal 304, synchronization signal 306, channel estimation signal 308, and control information signal 310 as input, and demodulates baseband signal 304 using synchronization signal 306 and channel estimation signal 308 based on information of the modulated signal included in control information signal 310, finds a log-likelihood ratio of each bit, and outputs log-likelihood ratio signal 312. The operation at this time is described in Patent Document 2, Patent Document 3, etc.

[0048] The physical layer error correction decoding unit 313 receives the log-likelihood ratio signal 312 and the control information signal 310 as input, performs error correction decoding based on information about the error correction code included in the control information signal 310 (e.g., information about the error correction code, code length (block length), coding rate, etc.), and outputs received data 314.

[0049] Packet (or frame) processing unit 315 receives received data 314 and control information signal 310, processes packets (or frames) based on the information of control information signal 310, and outputs packet (or frame) processed data 316. The detailed operation will be described later.

[0050] In the above description, wireless transmission has been taken as an example, but a wired transmission method such as a cable may also be used. Also, an example of transmitting one modulated signal has been described, but the present invention is not limited to this, and a transmission method of transmitting multiple modulated signals using multiple antennas at the same time and with the same frequency, as shown in Patent Document 1, Patent Document 2, etc., may also be used. Also, as a transmission method, a single carrier method, a multicarrier method such as an OFDM (orthogonal frequency division multiplexing) method, a spread spectrum communication method, etc. are used, and the corresponding processing is performed in each section.

[0051] The receiving unit 353 receives a signal 352 transmitted via, for example, a cable connected to the connecting unit 351 , and outputs a received signal 354 .

[0052] The signal processing unit 355 receives the received signal 354 , separates the signal into information and control information, and outputs received data 356 and control information 357 .

[0053] Packet (or frame) processing unit 358 receives received data 356 and control information 357, performs packet (or frame) processing on the received data based on control information 357, and outputs packet (or frame) processed data 359. The detailed operation will be described later.

[0054] In the above description, a case has been described in which a transmission method compatible with the connection unit 351 is used, but either a wired communication method or a wireless communication method may be used.

[0055] The signal processing unit 380 receives as input the packet (or frame) processed data 316, the control information signal 310, the packet (or frame) processed data 359, and the control information 357, generates data for displaying two images on the display unit 384, and outputs data 381.

[0056] The decoder 382 decodes video and audio data and outputs a video signal 383 and an audio signal 385. The video signal 383 is output to a display unit 384 or is output from an external output terminal, and the audio signal 385 is output as sound from a speaker 386 or is output from the external output terminal.

[0057] Hereinafter, a transmission method will be described in which "the broadcasting station does not use error correction codes that enable recovery when a packet or frame loss occurs, but the telecommunications line operator's transmission device uses error correction codes that enable recovery when a packet or frame loss occurs."

[0058] 4 shows the configuration of the part related to the error correction coding method that enables recovery when a packet or frame loss occurs in a transmission device of a telecommunications carrier. (Here, it is called "error correction coding at the packet level", but the name is not limited to this.) The configuration of FIG. 4 is included in the packet (or frame) processing unit 222 in the transmission device 250 owned by the telecommunications carrier in FIG. 2.

[0059] The packet generating unit 402 receives the information 401 and the control information signal 414, and outputs an information packet 403 based on information about the packet size (the number of bits constituting one packet) contained in the control information signal 414. An example is shown in FIG. 4, and information packet #1, information packet #2,..., information packet #(n-1), and information packet #n are generated. (That is, information packet #k (k is an integer between 1 and n (n is an integer between 2 and 1)).) Also, if the number of information bits is insufficient to generate information packets #1 to #n, information packets #1 to #n are generated by inserting known data, for example.

[0060] The rearrangement unit 404 receives the information packet 403 and the control information signal 414, rearranges the data based on the information on the rearrangement method included in the control information signal 414, and outputs the rearranged data sequence 405. Note that rearrangement is not necessarily required. For example, information packets #1 to #n are received as input, and rearrangement is performed within the range of the bit sequence constituting the information packets #1 to #n.

[0061] Encoding unit 408 receives rearranged data sequence 405 and control information signal 414, performs encoding based on the error (erasure) correction coding method included in control information 414 (e.g., information on the error (erasure) correction coding method to be used, code length (block length), coding rate, etc.), and outputs parity packet 407. Note that an example is shown in FIG. 4, and parity packet #1, parity packet #2,..., parity packet #(h-1), and parity packet #h are generated (that is, parity packet #k (k is an integer between 1 and h (h is an integer between 1 and h)).

[0062] The error detection code adding unit 408 receives the parity packet 407, adds, for example, a CRC (Cyclic Redundancy Check) so that an error can be detected on a packet-by-packet basis, and outputs a parity packet 409 after the CRC is added. At this time, by adding the CRC, the receiving device can determine whether all the data in the packet is correct or whether the packet is lost. Note that, although the CRC is used as an example here, any code may be used as long as it is a block code or check code that allows determination as to whether all the data in the packet is correct or whether the packet is lost. Note that an example is shown in FIG. 4, and it is assumed that a parity packet #1 after the CRC is added, a parity packet #2 after the CRC is added, a parity packet #(h-1) after the CRC is added, and a parity packet #h after the CRC is added are generated (that is, a parity packet #k after the CRC is added (k is an integer between 1 and h (h is an integer between 1 and h)).

[0063] Similarly, the error detection code adding unit 410 receives the information packet 403, adds, for example, a CRC (Cyclic Redundancy Check) so that an error can be detected on a packet-by-packet basis, and outputs an information packet 411 after the CRC is added. At this time, by adding the CRC, the receiving device can determine whether all the data in the packet is correct or whether the packet is lost. Note that, although the CRC is used as an example here, any code may be used as long as it is a block code or check code that allows determination of whether all the data in the packet is correct or whether the packet is lost. Note that an example is shown in FIG. 4, and it is assumed that an information packet #1 after the CRC is added, an information packet #2 after the CRC is added, an information packet #(n-1) after the CRC is added, and an information packet #n after the CRC is added are generated (that is, an information packet #k after the CRC is added (k is an integer between 1 and n (n is an integer between 2 and 1)).

[0064] 4 may include control information (such as, but not limited to, information on the type of information, information on the coding method for video coding (frame rate, compression ratio, compression method) and the like). This will be described later.

[0065] Fig. 5 shows a configuration related to an error correction coding method that enables recovery when a packet or frame loss occurs in a transmission device of a telecommunications carrier, which is different from that in Fig. 4. The configuration in Fig. 5 is included in the packet (or frame) processing unit 222 in the transmission device 250 owned by the telecommunications carrier in Fig. 2.

[0066] Rearrangement section 502 receives information 501 and control information signal 510 as input, rearranges the data based on the rearrangement method information included in control information signal 510, and outputs rearranged information 503.

[0067] Encoding unit 504 receives rearranged information 503 and control information signal 510 as input, performs encoding based on the error (erasure) correction coding method (e.g., information on the error (erasure) correction coding method to be used, code length (block length), coding rate, etc.) included in control information 510, and outputs encoded data 505. In this case, the code used for encoding may be either a systematic code (a code in which the information sequence is included in the codeword as is) or a non-systematic code.

[0068] The packet generating unit 506 receives the encoded data 505 and the control information signal 510, and outputs a packet 507 based on information about the packet size (the number of bits constituting one packet) included in the control information signal 503. Note that an example is shown in FIG. 5, and packet #1, packet #2, ..., packet #(m-1), and information packet #m are generated. (That is, packet #k (k is an integer between 1 and m (m is an integer between 2 and 1)).) Also, if the number of information bits required to generate packets #1 to #m is insufficient, the encoding unit 504 performs encoding by, for example, inserting known data.

[0069] An error detection code adding unit 508 receives a packet 507 as input, adds, for example, a CRC (Cyclic Redundancy Check) so that an error can be detected on a packet-by-packet basis, and outputs a packet 509 after the CRC has been added. At this time, by adding the CRC, the receiving device can determine whether all data in the packet is correct or whether the packet has been lost. Note that, although the CRC is used as an example here, any code may be used as long as it is a block code or check code that allows determination as to whether all data in the packet is correct or whether the packet has been lost. Note that an example is shown in FIG. 5, and it is assumed that a packet #1 after the CRC has been added, a packet #2 after the CRC has been added, a packet #(m-1) after the CRC has been added, and a packet #m after the CRC has been added are generated (that is, a packet #k after the CRC has been added (k is an integer between 1 and m (m is an integer between 2 and 1)).

[0070] 5 may include control information (for example, information on the type of information, information on the coding method for video coding (frame rate, compression ratio, compression method), etc. (but not limited to these)). This will be described later.

[0071] The following describes an example of how the packets described above can be constructed.

[0072] Figure 6 shows an example of how the packets described above can be constructed. 601 is a CRC that can be used to detect errors.

[0073] 602 is "information about the number of packets obtained by error correcting code." For example, in the case of Fig. 4, the number of information packets is n and the number of parity packets is h, so this information is "n+h." Also, in the case of Fig. 5, the information about the number of packets obtained by error correcting code is "m."

[0074] 603 is "information on packet ID (identification)". For example, in the case of FIG. 4, the number of packets obtained by the error correction code is "n+h". Therefore, "0" to "n+h-1" are prepared as packet IDs. Then, any one of the identifiers "0" to "n+h-1" is given to each packet. Specifically, any one of the IDs "0" to "n+h-1" is given to each of the n information packets and the h parity packets shown in FIG. 4. In the case of FIG. 5, the number of packets obtained by the error correction code is "m". Therefore, "0" to "m-1" are prepared as packet IDs. Then, any one of the identifiers "0" to "m-1" is given to each packet. Specifically, any one of the IDs "0" to "m-1" is given to each of the m packets shown in FIG. 5.

[0075] Reference numeral 604 denotes control information other than "information on the number of packets obtained by error correction coding" and "packet ID (identification)". For example, information on the error correction coding method at the packet level, or if the packet length is variable, the number of bits (or number of bytes) of the packet length, may be used as the control information.

[0076] 605 is data, which is data to be transmitted to the terminal (here, for example, video and audio data).

[0077] Figure 7 shows an example of the above-described packet configuration method that is different from that shown in Figure 6. 701 is a CRC that can be used to detect errors.

[0078] Reference numeral 702 denotes first control information, and 703 denotes second control information. Examples of information belonging to the first control information and the second control information include, but are not limited to, "information on the number of packets obtained by error correction coding", "information on packet ID (identification)", information on the method of error correction coding at the packet level, and if the packet length is variable, the number of bits (or number of bytes) of the packet length.

[0079] 704 is data to be transmitted to the terminal (here, for example, video and audio data).

[0080] In this case, in FIG. 6, a data group consisting of “CRC” 601, “information regarding the number of packets obtained by error correction coding” 602, “packet ID (identifier) ​​information” 603, “control information” 604, and “data” 605 is regarded as “one packet with error detection code” in FIG. 4 and FIG. 5.

[0081] In the case of FIG. 7, the data group consisting of “CRC” 701, “first control information” 702, “second control information” 703, and “data” 704 is considered to be “one of the packets with error detection code” in FIG. 4 and FIG. 5.

[0082] In this case, the following four methods are considered as examples of packet configuration methods in FIG. 4 and FIG.

[0083] First method: As shown in Fig. 6, control information 604 and data 605 are packets before the error detection code is added in Fig. 4 and Fig. 5. Therefore, the control information 604 and data 605 are input to the error correction coding (coding unit 406 or coding unit 504). Meanwhile, information 602 on the number of packets obtained by the error correction coding, packet ID (identification) information 603, and CRC 601, which is an example of an error detection code, are added to the control information 604 and data 605 to form a packet with an error detection code.

[0084] If the number of packets obtained by error correction coding is, for example, 32, the packet ID will take a value from 0 to 31.

[0085] In this case, a control information adding unit is required either before or after the error detection code adding unit 408, 410, 508 in Fig. 4 and Fig. 5. The configuration is shown in Fig. 8.

[0086] 8 shows an example of a configuration in which a control information adding unit is provided before an error detection code adding unit. In the first method, a control information adding unit 802 receives control information 604 and data 605 (corresponding to 801), adds information 602 on the number of packets obtained by error correction coding and information 603 on the packet ID (identification), and outputs a data group 803.

[0087] An error detection code adding section 804 receives a data group 803 as input, adds a CRC 601, and outputs a packet 805 with an error detection code.

[0088] 8 shows an example of a configuration in which the control information adding unit is located after the error detection code adding unit. In the first method, the error detection code adding unit 812 receives the control information 604 and the data 605 (corresponding to 811), adds the CRC 601, and outputs a data group 813.

[0089] The control information addition unit 814 receives a data group 813 as input, adds information 602 regarding the number of packets obtained by error correction coding and packet ID (identification) information 603, and outputs a packet 815 with an error detection code.

[0090] Second method: As shown in Fig. 6, data 605 is the packet before the error detection code is added in Fig. 4 and Fig. 5. Therefore, the data 605 becomes the input of the error correction coding (coding unit 406 or coding unit 504). Meanwhile, information 602 on the number of packets obtained by the error correction coding, packet ID (identification) information 603, control information 604, and CRC 601, which is an example of an error detection code, are added to the data 605 to form a packet with an error detection code.

[0091] If the number of packets obtained by error correction coding is, for example, 32, the packet ID will take a value from 0 to 31.

[0092] In this case, a control information adding unit is required either before or after the error detection code adding unit 408, 410, 508 in Fig. 4 and Fig. 5. The configuration is shown in Fig. 8.

[0093] 8 shows an example of a configuration in which a control information adding unit is provided before an error detection code adding unit. In the second method, a control information adding unit 802 receives data 605 (corresponding to 801), adds information 602 on the number of packets obtained by error correction coding, packet ID (identification) information 603, and control information 604, and outputs a data group 803.

[0094] An error detection code adding section 804 receives a data group 803 as input, adds a CRC 601, and outputs a packet 805 with an error detection code.

[0095] 8 shows an example of a configuration in which the control information adding unit is located after the error detection code adding unit. In the second method, the error detection code adding unit 812 receives the data 605 (corresponding to 811), adds the CRC 601, and outputs the data group 813.

[0096] The control information addition unit 814 receives a data group 813 as input, adds information 602 regarding the number of packets obtained by error correction coding, packet ID (identification) information 603, and control information 604, and outputs a packet 815 with an error detection code.

[0097] Third method: As shown in Fig. 7, data 704 and second control information 703 are assumed to be a packet before the error detection code is added in Fig. 4 and Fig. 5. Therefore, the data 704 and second control information 703 are input to the error correction coding (coding unit 406 or coding unit 504). Meanwhile, the first control information 702 and CRC 701, which is an example of an error detection code, are added to the data 704 and second control information 703 to form a packet with an error detection code.

[0098] If the number of packets obtained by error correction coding is, for example, 32, the packet ID will take a value from 0 to 31.

[0099] In this case, a control information adding unit is required either before or after the error detection code adding unit 408, 410, 508 in Fig. 4 and Fig. 5. The configuration is shown in Fig. 8.

[0100] 8 shows an example of a configuration in which a control information adding unit is provided before an error detection code adding unit. In the case of the third method, a control information adding unit 802 receives data 704 and second control information 703 (corresponding to 801), adds first control information 702, and outputs data group 803.

[0101] An error detection code adding section 804 receives a data group 803 as input, adds a CRC 601, and outputs a packet 805 with an error detection code.

[0102] 8 shows an example of a configuration in which the control information adding unit is located after the error detection code adding unit. In the third method, the error detection code adding unit 812 receives the data 704 and the second control information 703 (corresponding to 811), adds the CRC 601, and outputs a data group 813.

[0103] A control information adding unit 814 receives the data group 813 as input, adds the first control information 702, and outputs a packet 815 with an error detection code.

[0104] Fourth method: As shown in Fig. 7, data 704 is a packet before the error detection code is added in Fig. 4 and Fig. 5. Therefore, the data 704 becomes an input for error correction coding (encoding unit 406 or encoding unit 504). Meanwhile, first control information 702, second control information 703, and CRC 701, which is an example of an error detection code, are added to the data 704 to form a packet with an error detection code.

[0105] If the number of packets obtained by error correction coding is, for example, 32, the packet ID will take a value from 0 to 31.

[0106] In this case, a control information adding unit is required either before or after the error detection code adding unit 408, 410, 508 in Fig. 4 and Fig. 5. The configuration is shown in Fig. 8.

[0107] 8 shows an example of a configuration in which a control information adding unit is provided before an error detection code adding unit. In the fourth method, a control information adding unit 802 receives data 704 (corresponding to 801), adds first control information 702 and second control information 703, and outputs a data group 803.

[0108] An error detection code adding section 804 receives a data group 803 as input, adds a CRC 601, and outputs a packet 805 with an error detection code.

[0109] 8 shows an example of a configuration in which the control information adding unit is located after the error detection code adding unit. In the fourth method, the error detection code adding unit 812 receives the data 704 (corresponding to 811), adds the CRC 601, and outputs a data group 813.

[0110] The control information adding section 814 receives the data group 813 as input, adds the first control information 702 and the second control information 703, and outputs a packet 815 with an error detection code.

[0111] Although not described above, each packet or some packets may contain information related to time. In this case, the information related to time may be contained in all packets, or may be contained in a specific packet.

[0112] Also, information about time may be included in the modulated signal transmitted by the broadcast station. In this case, the information about time may be included in all packets or frames, or may be included in a specific packet or frame.

[0113] The terminal uses the time information contained in the packet transmitted by the telecommunications carrier and the time information contained in the modulated signal transmitted by the broadcasting station to temporally synchronize the video transmitted by the telecommunications carrier and the video transmitted by the broadcasting station, and can display the two synchronized videos on the display unit equipped in the terminal, thereby reducing the possibility of causing discomfort to the viewer.

[0114] As explained above, the information transmitted by the telecommunications carrier includes information related to time, and the information transmitted by the broadcaster also includes information related to time, and by utilizing this information, the terminal can perform the decoding and display of the first and second images in a time synchronization manner. Also, the time information can be utilized for adjusting the timing of error correction decoding at the packet level as described in this embodiment.

[0115] Although the term "packet" is used above, other terms such as "frame" and "block" may also be used, and a "packet", "frame", and "block" are each made up of multiple bits.

[0116] Furthermore, the modulated signal transmitted by the broadcasting station does not necessarily have to have a packet-based data structure (it may be packet-based, although the packet length and the structure of the control information may or may not be the same as the structure of the packets transmitted by the telecommunications carrier).

[0117] Next, the timing of packets transmitted by the broadcasting station and the telecommunications carrier, and the reception state when the terminal receives the packets transmitted by the broadcasting station and the packets transmitted by the telecommunications carrier will be described. In the following description, it is assumed that the broadcasting station transmits packets, but information does not necessarily have to be transmitted in units of packets, and may be transmitted in units of frames or streams. To simplify the description, an example in which information is transmitted in units of packets will be described.

[0118] 900 in Fig. 9 shows an example of when a broadcasting station and a telecommunications carrier transmit information on two videos taken at the same time from different angles. In Fig. 9, the horizontal axis represents time. The broadcasting station transmits data on the first video, and the telecommunications carrier transmits data on the second video (the first and second videos are taken at the same time from different angles).

[0119] As shown in FIG. 9, the first video is assumed to be composed of packet "#1", packet "#2", packet "#3", packet "#4", packet "#5", packet "#6", and packet "#7", and the second video is assumed to be composed of packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7".

[0120] It should be noted that the first video does not consist only of packets "#1", "#2", "#3", "#4", "#5", "#6", and "#7", and the broadcasting station transmits the following packets in the same manner (however, this is not shown in FIG. 9).The second video does not consist only of packets "$1", "$2", "$3", "$4", "$5", "$6", and "$7", and the telecommunications carrier transmits the following packets in the same manner (however, this is not shown in FIG. 9).

[0121] In Figure 9, 900 shows a situation in which a broadcasting station and a telecommunications line provider transmit packets, with the broadcasting station transmitting packet "#1", packet "#2", packet "#3", packet "#4", packet "#5", packet "#6", and packet "#7", and the telecommunications line provider transmitting packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7".

[0122] In this case, it is assumed that packet “#1” and packet “$1” transmitted from time T1 shown in FIG. 9 are packets containing video from the same time, and that the broadcasting station and the telecommunications line provider are transmitting the packets.

[0123] 910 in Fig. 9 shows a state in which a terminal is receiving packets. Packets "#1", "#2", "#3", "#4", "#5", "#6", and "#7" transmitted by a broadcasting station will arrive consecutively if the broadcasting station transmits packets consecutively to the terminal in the same order. Therefore, as shown in Fig. 9, the terminal will receive packets "#1", "#2", "#3", "#4", "#5", "#6", and "#7", and reception will be completed at time point R1.

[0124] As described above, the telecommunications carrier transmits packets to the terminal using TCP (TCP / IP) or UDP. Therefore, even if the broadcasting station and the telecommunications carrier transmit information on two images from different angles at the same time as shown in 900 in Fig. 9, the packets transmitted by the telecommunications carrier may experience delays in the arrival of the packets and changes in the order in which the packets arrive as shown in 910 in Fig. 9. This is shown in 910 in Fig. 9. In this way, it is easy for the terminal to predict how the packets transmitted by the broadcasting station will arrive at the terminal, but it is difficult for the terminal to predict the arrival of the packets transmitted by the telecommunications carrier.

[0125] For example, when a packet is received as shown in FIG. 9 at 910, the time when the terminal completes receiving the last packet from the broadcasting station is R1, and the time when the terminal completes receiving the last packet from the telecommunications carrier is R2. In many cases, R1 <R2となる。

[0126] However, since the first video and the second video are two videos taken at the same time from different angles, the viewer is likely to feel uncomfortable if the first video and the second video are not displayed in sync on the display unit 384 of the terminal in Fig. 3. For example, if the first video is an overall angle of the soccer game and the second video is an angle of an individual player, the viewer is likely to feel dissatisfied if the first video shows the moment when player A is shooting from an overall angle of the soccer game, while the second video shows the moment when the goal has already been scored.

[0127] If the first video and the second video are decoded at time R1, the first video will be displayed on the terminal, but because packets "$1", "$3", and "$6" have not arrived, it will be difficult for the terminal to display the second video with less distortion.

[0128] When the first image and the second image are decoded at time R2, the terminal needs to delay the time at which the first image is displayed in order to synchronize the display of the first image and the second image. Therefore, a memory unit (buffer) is required for the delay of the data of the first image. At this time, this method is acceptable if the amount of delay is small (or within a certain tolerance range), but in the case of TCP (TCP / IP) or UDP, the amount of delay is not constant, and if the terminal receives packets via a wireless LAN or the like, the amount of delay may become even larger. Therefore, when using this method to synchronize the display of the first image and the second image with less disturbance, the size of the memory unit of the terminal needs to be increased. Considering this point, when the terminal adopts a method of delaying the start time of decoding, it is desirable to introduce a method that can reduce image disturbance even if the delay time is shortened.

[0129] As one method for solving the above problem, we propose a transmission method as shown in Fig. 10. 1000 in Fig. 10 shows an example in which a broadcasting station and a telecommunications carrier transmit information on two videos from different angles at the same time, with the horizontal axis representing time. The difference from 900 in Fig. 9 is that the packets transmitted by the broadcasting station are delayed in consideration of the delay in arrival of the packets transmitted by the telecommunications carrier at the terminal. In Fig. 10, the telecommunications carrier starts transmitting packets from time T1. Then, packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7" are transmitted in sequence.

[0130] Therefore, the packet (or frame) processing units 202 and 222 in FIG. 2 have a packet (or frame) accumulation function for delaying the transmission of the generated packets, and can transmit the packets or frames after delaying by the accumulation capacity.

[0131] Then, the broadcasting station starts transmitting packets from time T2 (where T1 ≠ T2, here T1 < T2 is assumed, but T1 > T2 is also possible). Then, packets "#1", "#2", "#3", "#4", "#5", "#6", and "#7" are sequentially transmitted.

[0132] FIG. 11 shows an example (1100) of the packet reception status of the terminal when the broadcasting station and the telecommunications carrier transmit packets as shown in FIG. 10.

[0133] In FIG. 11, the terminal will receive packets "#1" to "#7" transmitted by the broadcasting station in the same manner as in FIG. 9. At this time, let the time when all packets are received be R2.

[0134] Then, the terminal will receive the packets transmitted by the telecommunications carrier. At this time, let the time when the terminal finishes receiving all the packets transmitted by the telecommunications carrier be R1. Then, because of the transmission as shown in FIG. 10, in the example of FIG. 11, R1 < R2 holds. Considering other examples, the difference between "the time when the terminal finishes receiving all the packets transmitted by the broadcasting station" and "the time when the terminal finishes receiving all the packets transmitted by the telecommunications carrier" is likely to be smaller compared to the case of transmitting packets as shown in FIG. 9. Therefore, there is a possibility that the circuit scale for packet accumulation and storage in the terminal can be reduced. In the case of FIG. 11, at time R2, the decoding of the first video and the second video may be started. However, the broadcasting station and the telecommunications carrier require a packet accumulation unit for delaying the transmission of packets, which leads to an increase in the circuit scale.

[0135] Since there are actually multiple (very many) terminals, the increase in the circuit scale of the terminals poses a greater challenge in terms of the increase in total circuit scale compared to the increase in circuit scale of the broadcasting station or the transmitting station of the telecommunications line operator. Therefore, the above-mentioned method is an effective way to suppress image distortion while suppressing the increase in circuit scale.

[0136] However, this does not mean that there will be no disturbance in the video. For example, the terminal may receive the packets as shown in Fig. 12, that is, the terminal may receive the packets sent by the telecommunications carrier with a delay, as shown in 910 in Fig. 9. In this case, compared to Fig. 9, the difference between "the point at which the terminal completes receiving all the packets sent by the broadcasting station" and "the point at which the terminal completes receiving all the packets sent by the telecommunications carrier" is smaller, but if decoding of the second video is started at the point at which packets "$3" and "$7" have been lost in order to display the first video and the second video in sync, disturbance in the second video will still occur.

[0137] Furthermore, in order to alleviate the second problem of image distortion, the amount of delay can be controlled on the transmitting side.

[0138] For example, the signal processing unit 380 of the terminal in Fig. 3 obtains information on the difference in arrival time (or statistical information thereof) between a packet transmitted by a broadcast station and a packet transmitted by a telecommunications carrier at the same time, and outputs the information as time difference information 399. Then, the time difference information 399 is transmitted from a transmitting device included in the terminal to, for example, the telecommunications carrier.

[0139] The transmitting device 250 of the telecommunications carrier in Fig. 2 includes a receiving unit and acquires the time difference information transmitted by the terminal (299 in Fig. 2). The packet (or frame) processing unit 202, 222 receives the time difference information 299 as an input, and controls the timing of transmission by changing the amount of the packet or frame storage unit, thereby outputting a packet or frame with a controlled amount of delay.

[0140] 2, it is difficult for the broadcast station 240 to control the amount of delay for each terminal (because of multicast). Therefore, the packet (or frame) processing unit 222 of the transmission device 250 of the telecommunications carrier controls the amount of delay for each terminal. However, when the transmission device 250 of the telecommunications carrier does not transmit packets individually to each terminal, that is, when multicasting, the broadcast station 240 may control the delay time (the timing of transmitting packets), or the telecommunications carrier may control the delay time (the timing of transmitting packets).

[0141] The case where "the transmission equipment of the telecommunications carrier uses an error correction code that allows recovery when a packet or frame loss occurs (error correction coding at the packet level)" will be described.

[0142] It is assumed that the telecommunications carrier wishes to transmit second video information consisting of 16384 x 4 = 65536 bits. In this case, the number of information bits constituting one packet is 16384 bits. (In addition, control information is transmitted separately as explained above.) This results in enough information bits to obtain 65536 / 16384 = 4 packets. At this time, as explained in Figures 4 and 5, an error correction code (error correction coding at the packet level) is used that enables recovery when a packet or frame loss occurs. The error correction code used at this time has a code length of 114688 bits and a coding rate of 4 / 7.

[0143] When the error correction code is a systematic code, for example, packets are generated as shown in FIG. 4, and when the error correction code is a non-systematic code, for example, packets are generated as shown in FIG. 5. In this case, when the second video information consisting of 65536 bits is encoded as shown in either FIG. 4 or FIG. 5, seven packets are generated (since the number of bits of information constituting one packet is 16384 bits). The seven packets are assumed to be packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7". In this case, if the terminal can receive a number of packets that is greater than the number of bits of information before encoding, that is, five packets or more, all packets can be restored. Therefore, as described above, for example, a broadcasting station and a telecommunication line operator transmit packets as shown in 901 in FIG. 9 (details are omitted as they are as described above).

[0144] At this time, the packet reception status of the terminal in Fig. 3 is assumed to be as shown in Fig. 13. And, at the time point Rc in Fig. 13, error correction code decoding is performed at the packet level. (That is, the packet (or frame) processing units 315, 358 of the terminal in Fig. 3 have a storage unit (buffer), and when the terminal receives a packet (or frame) from a broadcast station, the packet (or frame) processing unit 315 stores the packet or frame data in sequence and delays data processing. Then, after receiving all the packets and a certain period of time has passed, error correction decoding is performed at the packet level on the packets sent by the telecommunications carrier.)

[0145] At time point Rc in Fig. 13, the terminal has lost packets "$3" and "$6." (However, this is shown in Fig. 13 for ease of understanding.) However, as described above, since the terminal has obtained five or more packets, it is able to obtain all packets, that is, packets "$1," "$2," "$3," "$4," "$5," "$6," and "$7."

[0146] Therefore, the terminal can obtain the first and second images by decoding the first and second images after the time point Rc, and can therefore display the first and second images synchronously on the display unit. Therefore, the terminal does not need to wait until time point R2 shown in Fig. 13 at which all packets of the second image can be obtained.

[0147] By implementing the above, the waiting time for the terminal to obtain all packets of the second video is shortened, and the circuit scale of the memory unit for storing the packet or frame data of the first video can be significantly reduced. Furthermore, although video distortion has previously occurred at the terminal due to packet loss of the second video, it is now possible to obtain the effect that no video distortion occurs even if packet loss occurs within a specified range.

[0148] In the above description, it was stated that "the broadcasting station and the telecommunications carrier transmit packets as shown in 901 in FIG. 9", but for example, as shown in FIG. 10, the broadcasting station and the telecommunications carrier may transmit a packet (or frame) of a first video at the same time and a packet of a second video at the same time with a time difference. In this case, the terminal may receive a packet (or frame) transmitted by the broadcasting station and the telecommunications carrier as shown in FIG. 13 as described above. In this case, the terminal loses packets "$3" and "$6" at the time point Rc, but as described above, since the terminal has obtained five or more packets, it can obtain all packets, that is, packets "$1", "$2", "$3", "$4", "$5", "$6", and "$7".

[0149] Therefore, the terminal can obtain the first and second images by decoding the first and second images after the time point Rc, and can therefore display the first and second images synchronously on the display unit. Therefore, the terminal does not need to wait until time point R2 shown in Fig. 13 at which all packets of the second image can be obtained.

[0150] Next, there will be described the operation of the packet (or frame) processing unit 358 of the terminal in Fig. 3. Fig. 14 shows an example of a flowchart of the processing of the packet (or frame) processing unit 358 of the terminal.

[0151] For example, assume that the time point Rc in Fig. 13 is a specific time. Then, first, the following is confirmed.

[0152] (1) "Has the terminal completed receiving all packets (to perform video decoding) (or packets necessary to perform video decoding) (among the packets sent by the telecommunications carrier) before a specific time (point Rc)?"

[0153] If the answer is "yes," then if a systematic code is used for the packet-level encoding, the terminal does not perform packet-level decoding on the packets sent by the telecommunications carrier. Then, the terminal is able to start decoding the first video and the second video, so may start decoding. If a non-systematic code is used for the packet-level encoding, the terminal performs packet-level decoding on the packets sent by the telecommunications carrier. (Note that packet-level decoding may start at time Rc, or may start before that.) Then, the terminal is able to start decoding the first video and the second video, so may start decoding.

[0154] If no, continue below.

[0155] (2) "At a specific time (point Rc), has the terminal received the required number of packets (of packets sent by the telecommunications carrier) or more (here, five packets)?"

[0156] If "no," the terminal does not perform packet-level decoding because such decoding would not be able to recover the lost packets sent by the telecommunications carrier.

[0157] If the answer is "yes," the terminal performs packet-level decoding, since it can recover lost packets among those sent by the telecommunications carrier.Then, the terminal starts decoding the first and second images, since it is possible to do so.

[0158] It is also possible to implement FIG. 15, which is a simplification of FIG. 14. (FIG. 15 is characterized in that no determination is made before a specific time (time point Rc).)

[0159] "At a specific time (point Rc), has the terminal received at least the required number of packets (5 packets in this case) (out of the packets sent by the telecommunications carrier)?"

[0160] If "no," the terminal does not perform packet-level decoding because such decoding would not be able to recover the lost packets sent by the telecommunications carrier.

[0161] If the answer is "yes," the terminal performs packet-level decoding, since it can recover lost packets among those sent by the telecommunications carrier.Then, the terminal starts decoding the first and second images, since it is possible to do so.

[0162] However, although the above does not describe the introduction of error correction codes that enable restoration when packet or frame loss occurs at the broadcasting station, the implementation can be carried out in the same manner even if such codes are introduced.

[0163] Next, an embodiment in which the above explanation is applied to a frame unit of a modulated signal transmitted by a broadcast station will be described.

[0164] 1600 in Fig. 16 shows an example when a broadcast station and a telecommunications carrier transmit two pieces of video information of the same time and different angles. In Fig. 16, the horizontal axis represents time. In this case, the broadcast station transmits the first video data, and the telecommunications carrier transmits the second video data (the first video and the second video are assumed to be videos of the same time and different angles).

[0165] The difference between 1600 in Figure 16 and 900 in Figure 9 is that the first video transmitted by the broadcasting station is considered in frame units of the modulated signal when the broadcasting station applies a wireless transmission method or a wired transmission method.

[0166] As shown in 1600 of FIG. 16, the first video is assumed to be composed of frame "*1", and the second video is assumed to be composed of packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7".

[0167] The first video does not consist only of frame "*1", and the broadcasting station transmits subsequent frames in the same manner (however, this point is not mentioned in Fig. 16).The second video does not consist only of packets "$1", "$2", "$3", "$4", "$5", "$6", and "$7", and the telecommunications carrier transmits subsequent packets in the same manner (however, this point is not mentioned in Fig. 9).

[0168] In this case, it is assumed that the frame "※1" and packet "$1" transmitted from time T1 shown in FIG. 16 contain video from the same time, and that the broadcasting station and the telecommunications line provider are transmitting the frames and packets.

[0169] 1610 in Fig. 16 shows the state in which the terminal is receiving frames and packets. The terminal is receiving frame "*1" transmitted by the broadcast station. At this time, the terminal completes reception at time point R1.

[0170] As described above, the telecommunications carrier transmits packets to the terminal using TCP (TCP / IP) or UDP. Therefore, even if the broadcasting station and the telecommunications carrier transmit information on two videos from different angles at the same time as shown in 1600 of Fig. 16, the packets transmitted by the telecommunications carrier may experience delays in the arrival of the packets and changes in the order in which the packets arrive, as shown in 1610 of Fig. 16. This is shown in 1610 of Fig. 16. In this way, it is easy for the terminal to predict how the packets transmitted by the broadcasting station will arrive at the terminal, but it is difficult for the terminal to predict the arrival of the packets transmitted by the telecommunications carrier.

[0171] For example, when a packet is received as shown in FIG. 1610, the time when the terminal completes receiving the last packet from the broadcasting station is R1, and the time when the terminal completes receiving the last packet from the telecommunications carrier is R2. In many cases, R1 <R2となる。

[0172] However, since the first video and the second video are two videos taken at the same time from different angles, the viewer is likely to feel uncomfortable if the first video and the second video are not displayed in sync on the display unit 384 of the terminal in Fig. 3. For example, if the first video is an overall angle of the soccer game and the second video is an angle of an individual player, the viewer is likely to feel dissatisfied if the first video shows the moment when player A is shooting from an overall angle of the soccer game, while the second video shows the moment when the goal has already been scored.

[0173] If the first video and the second video are decoded at time R1, the first video will be displayed on the terminal, but because packets "$1", "$3", and "$6" have not arrived, it will be difficult for the terminal to display the second video with less distortion.

[0174] When the first image and the second image are decoded at time R2, the terminal needs to delay the time at which the first image is displayed in order to synchronize the display of the first image and the second image. Therefore, a memory unit (buffer) is required for the delay of the data of the first image. At this time, this method is acceptable if the amount of delay is small (or within a certain tolerance range), but in the case of TCP (TCP / IP) or UDP, the amount of delay is not constant, and if the terminal receives packets via a wireless LAN or the like, the amount of delay may become even larger. Therefore, when using this method to synchronize the display of the first image and the second image with less disturbance, the size of the memory unit of the terminal needs to be increased. Considering this point, when the terminal adopts a method of delaying the start time of decoding, it is desirable to introduce a method that can reduce image disturbance even if the delay time is shortened.

[0175] As one method for solving the above problem, we propose a transmission method as shown in Fig. 17. 1700 in Fig. 17 shows an example in which a broadcasting station and a telecommunications carrier transmit information on two videos from different angles at the same time, with the horizontal axis representing time. The difference from 1600 in Fig. 16 is that the frames transmitted by the broadcasting station are delayed, taking into consideration the arrival delay at the terminal of the packets transmitted by the telecommunications carrier. In Fig. 17, the telecommunications carrier starts transmitting packets from time T1. Then, packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7" are transmitted in sequence.

[0176] Therefore, the packet (or frame) processing units 202 and 222 in FIG. 2 have a packet (or frame) accumulation function for delaying the transmission of the generated packets, and can transmit the packets or frames after delaying by the accumulation capacity.

[0177] Then, the broadcasting station starts transmitting the frame at time T2 (where T1≠T2, here T1<T2 is assumed, but T1>T2 is also possible). And it transmits the frame "※1".

[0178] FIG. 18 shows an example (1800) of the packet reception status of the terminal when the broadcasting station and the telecommunications carrier transmit the packets as shown in FIG. 17.

[0179] In FIG. 18, the terminal will receive the frame "※1" transmitted by the broadcasting station in the same manner as in FIG. 16. At this time, let the time when reception is completed be R2.

[0180] Then, the terminal will receive the packets transmitted by the telecommunications carrier. At this time, let the time when the terminal finishes receiving all the packets transmitted by the telecommunications carrier be R1. Then, because of the transmission as shown in FIG. 17, in the example of FIG. 19, R1<R2 holds. Considering other examples, the difference between "the time when the terminal finishes receiving all the packets transmitted by the broadcasting station" and "the time when the terminal finishes receiving all the packets transmitted by the telecommunications carrier" is likely to be smaller compared to the case of transmitting the packets as shown in FIG. 16. Therefore, there is a possibility that the circuit scale for packet accumulation and storage in the terminal can be reduced. In the case of FIG. 19, at the time of time R2, the decoding of the first video and the second video may be started. However, the broadcasting station and the telecommunications carrier will require a packet accumulation unit for delaying the transmission of the packets, which will lead to an increase in the circuit scale.

[0181] Since there are actually multiple (very many) terminals, the increase in the circuit scale of the terminals poses a greater challenge in terms of the increase in total circuit scale compared to the increase in circuit scale of the broadcasting station or the transmitting station of the telecommunications line operator. Therefore, the above-mentioned method is an effective way to suppress image distortion while suppressing the increase in circuit scale.

[0182] However, this does not mean that there will be no disturbance in the video. For example, the terminal may receive the packets as shown in Fig. 19, that is, the terminal may receive the packets sent by the telecommunications carrier with a delay, as shown in 1610 in Fig. 16. In this case, compared to Fig. 16, the difference between "the point at which the terminal completes receiving all the packets sent by the broadcasting station" and "the point at which the terminal completes receiving all the packets sent by the telecommunications carrier" is smaller, but if decoding of the second video is started at the point at which packets "$3" and "$7" have been lost in order to display the first video and the second video in sync, disturbance in the second video will still occur.

[0183] Furthermore, in order to alleviate the second problem of image distortion, the amount of delay can be controlled on the transmitting side.

[0184] For example, the signal processing unit 380 of the terminal in Fig. 3 obtains information on the difference in arrival time (or statistical information thereof) between a frame transmitted by a broadcast station and a packet transmitted by a telecommunications carrier at the same time, and outputs the information as time difference information 399. Then, the time difference information 399 is transmitted from a transmitting device included in the terminal to, for example, the telecommunications carrier.

[0185] The transmitting device 250 of the telecommunications carrier in Fig. 2 includes a receiving unit and acquires the time difference information transmitted by the terminal (299 in Fig. 2). The packet (or frame) processing unit 202, 222 receives the time difference information 299 as an input, and controls the timing of transmission by changing the amount of the packet or frame storage unit, thereby outputting a packet or frame with a controlled amount of delay.

[0186] 2, it is difficult for the broadcast station 240 to control the amount of delay for each terminal (because of multicast). Therefore, the packet (or frame) processing unit 222 of the transmission device 250 of the telecommunications carrier controls the amount of delay for each terminal. However, when the transmission device 250 of the telecommunications carrier does not transmit packets individually to each terminal, that is, when multicasting, the broadcast station 240 may control the delay time (the timing of transmitting packets), or the telecommunications carrier may control the delay time (the timing of transmitting packets).

[0187] The case where "the transmission equipment of the telecommunications carrier uses an error correction code that allows recovery when a packet or frame loss occurs (error correction coding at the packet level)" will be described.

[0188] It is assumed that the telecommunications carrier wishes to transmit second video information consisting of 16384 x 4 = 65536 bits. In this case, the number of information bits constituting one packet is 16384 bits. (In addition, control information is transmitted separately as explained above.) This results in enough information bits to obtain 65536 / 16384 = 4 packets. At this time, as explained in Figures 4 and 5, an error correction code (error correction coding at the packet level) is used that enables recovery when a packet or frame loss occurs. The error correction code used at this time has a code length of 114688 bits and a coding rate of 4 / 7.

[0189] When the error correction code is a systematic code, for example, packets are generated as shown in FIG. 4, and when the error correction code is a non-systematic code, for example, packets are generated as shown in FIG. 5. In this case, when the second video information consisting of 65536 bits is encoded as shown in either FIG. 4 or FIG. 5, seven packets are generated (since the number of bits of information constituting one packet is 16384 bits). The seven packets are assumed to be packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7". In this case, if the terminal can receive a number of packets that is greater than the number of bits of information before encoding, that is, five packets or more, all packets can be restored. Therefore, as described above, for example, a broadcasting station and a telecommunication line operator transmit frames and packets as shown in 1601 of FIG. 16 (details are omitted as they are described above).

[0190] At this time, the packet reception status of the terminal in Fig. 3 is as shown in Fig. 20. And, at the time point Rc in Fig. 20, the error correction code is decoded at the packet level. (That is, the packet (or frame) processing units 315, 358 of the terminal in Fig. 3 have a storage unit (buffer), and when the terminal receives a frame from a broadcast station, the packet (or frame) processing unit 315 stores the frame data sequentially and delays the processing of the data. Then, after the reception of the frame is completed and a certain period of time has passed, the packet transmitted by the telecommunication line provider is decoded for error correction at the packet level.)

[0191] At time point Rc in Fig. 20, the terminal has lost packets "$3" and "$6." (However, this is shown in Fig. 20 for ease of understanding.) However, as described above, since the terminal has obtained five or more packets, it is able to obtain all packets, that is, packets "$1," "$2," "$3," "$4," "$5," "$6," and "$7."

[0192] Therefore, the terminal can obtain the first and second images by decoding the first and second images after the time point Rc, and can therefore display the first and second images synchronously on the display unit. Therefore, the terminal does not need to wait until time point R2 shown in Fig. 20 at which all packets of the second image can be obtained.

[0193] By implementing the above, the waiting time for the terminal to obtain all packets of the second video is shortened, and the circuit scale of the memory unit for storing the frame data of the first video can be significantly reduced. Furthermore, although video distortion has occurred at the terminal up until now due to packet loss of the second video, it is now possible to obtain the effect that no video distortion occurs even if packet loss occurs within a specified range.

[0194] In the above description, it was stated that "the broadcasting station and the telecommunications carrier transmit frames and packets as shown in 1601 of FIG. 16", but for example, as shown in FIG. 17, the broadcasting station and the telecommunications carrier may transmit a frame of a first video at the same time and a packet of a second video at the same time with a time difference. In this case, the terminal may receive packets (or frames) transmitted by the broadcasting station and the telecommunications carrier as shown in FIG. 20 as described above. In this case, too, at the time point Rc, the terminal has lost packets "$3" and "$6", but as described above, since the terminal has obtained five or more packets, it can obtain all packets, that is, packets "$1", "$2", "$3", "$4", "$5", "$6", and "$7".

[0195] Therefore, the terminal can obtain the first and second images by decoding the first and second images after the time point Rc, and can therefore display the first and second images synchronously on the display unit. Therefore, the terminal does not need to wait until time point R2 shown in Fig. 13 at which all packets of the second image can be obtained.

[0196] Next, there will be described the operation of the packet (or frame) processing unit 358 of the terminal in Fig. 3. Fig. 14 shows an example of a flowchart of the processing of the packet (or frame) processing unit 358 of the terminal.

[0197] For example, assume that the time point Rc in Fig. 20 is a specific time. Then, first, the following is confirmed.

[0198] (1) "Has the terminal completed receiving all packets (to perform video decoding) (or packets necessary to perform video decoding) (among the packets sent by the telecommunications carrier) before a specific time (point Rc)?"

[0199] If the answer is "yes," then if a systematic code is used for the packet-level encoding, the terminal does not perform packet-level decoding on the packets sent by the telecommunications carrier. Then, the terminal is able to start decoding the first video and the second video, so may start decoding. If a non-systematic code is used for the packet-level encoding, the terminal performs packet-level decoding on the packets sent by the telecommunications carrier. (Note that packet-level decoding may start at time Rc, or may start before that.) Then, the terminal is able to start decoding the first video and the second video, so may start decoding.

[0200] If no, continue below.

[0201] (2) "At a specific time (point Rc), has the terminal received the required number of packets (of packets sent by the telecommunications carrier) or more (here, five packets)?"

[0202] If "no," the terminal does not perform packet-level decoding because such decoding would not be able to recover the lost packets sent by the telecommunications carrier.

[0203] If the answer is "yes," the terminal performs packet-level decoding, since it can recover lost packets among those sent by the telecommunications carrier.Then, the terminal starts decoding the first and second images, since it is possible to do so.

[0204] It is to be noted that a simplified version of FIG. 14, shown in FIG. 15, may be implemented (FIG. 15 is characterized in that no determination is made before a specific time (time point Rc)).

[0205] "At a specific time (point Rc), has the terminal received at least the required number of packets (5 packets in this case) (out of the packets sent by the telecommunications carrier)?"

[0206] If "no," the terminal does not perform packet-level decoding because such decoding would not be able to recover the lost packets sent by the telecommunications carrier.

[0207] If the answer is "yes," the terminal performs packet-level decoding, since it can recover lost packets among those sent by the telecommunications carrier.Then, the terminal starts decoding the first and second images, since it is possible to do so.

[0208] However, although the above does not describe the introduction of error correction codes that enable restoration when packet or frame loss occurs at the broadcasting station, the implementation can be carried out in the same manner even if such codes are introduced.

[0209] In the present embodiment, the processing unit is described as a packet or a frame, but is not limited to this. Also, the delay caused by the storage unit does not have to be on a frame or packet basis, and the delay time may be generated at intervals of multiple frames or multiple packets.

[0210] The configuration of the packet (or frame processing units) 202, 222 in the transmission devices owned by the broadcast station and the telecommunications carrier in FIG. 2 in the above description will be described.

[0211] FIG. 21 shows an example of the configuration of the packet (or frame) processing units 202 and 222 in the transmitting devices owned by the broadcasting station and the telecommunications carrier in FIG.

[0212] The packet or frame generation unit 2102 receives as input video and / or audio information 2101 and a control signal 2105. The packet or frame generation unit 2102 performs processing based on the control signal 2105. For example, when performing error correction coding at the packet layer, the packet or frame generation unit 2102 performs processing as shown in FIG. 4 and FIG. 5 on the video and / or audio information 2101, and outputs packetized or framed data 2103. When packetizing or framing, the packet or frame generation unit 2102 packetizes or frames the video and / or audio information 2101, and outputs the packetized or framed data 2103.

[0213] Memory unit 2104 receives packetized or framed data 2103 and control signal 2105 as input, stores and delays packetized or framed data 2103 based on control signal 2105, and outputs delayed packetized or framed data 2106.

[0214] An example of the configuration of the memory unit 2104 is as shown in FIG. 21, in which memory blocks are connected in series, and the memory blocks store an input data group and, at that time, output the stored data group.

[0215] Next, the configuration of the packet (or frame) processing units 315 and 358 in the terminal of FIG. 3 will be described.

[0216] Fig. 22 shows an example of a configuration in which error correction decoding of a packet layer is performed in the packet (or frame) processing units 315 and 358 in the terminal in Fig. 3. Note that the operation will be described with reference to Fig. 20 as an example.

[0217] An error detection unit (eg, a CRC check unit) 2202 receives received data 2201 and a control signal 2208 as input.

[0218] For example, as shown in FIG. 20, when a packet is received, an error detection unit (e.g., a CRC check unit) 2202 performs error detection on packet “$2” and finds no error, so outputs packet “$2” as packet information 2203.

[0219] Similarly, an error detection unit (eg, a CRC check unit) 2202 performs error detection on packet “$4” and finds no error, so outputs packet “$4” as packet information 2203.

[0220] Furthermore, an error detection unit (eg, a CRC check unit) 2202 performs error detection on packet “$5” and finds no error, so outputs packet “$5” as packet information 2203.

[0221] Furthermore, an error detection unit (eg, a CRC check unit) 2202 performs error detection on packet “$7” and finds no error, so outputs packet “$7” as packet information 2203.

[0222] Furthermore, an error detection unit (eg, a CRC check unit) 2202 performs error detection on packet “$1” and finds no errors, so outputs packet “$1” as packet information 2203.

[0223] As explained above, since packet layer decoding is performed at time point Rc, the error detection unit (e.g., CRC check unit) 2202 will discard packets “$3” and “$6” even if it receives them.

[0224] The storage unit 2204 receives the packet information 2203 and the control signal 2208 as input, and controls the storage and output of packets based on the control signal 2208 .

[0225] For example, in the case of FIG. 20, packets "$2", "$4", "$5", "$7", and "$1" are input to the storage unit 2204, and therefore, packets "$2", "$4", "$5", "$7", and "$1" are stored. Then, when the control signal 2208 indicates the time point Rc, the storage unit 2204 is instructed to output the stored packets "$2", "$4", "$5", "$7", and "$1". Therefore, the storage unit 2204 outputs packets "$2", "$4", "$5", "$7", and "$1" as the stored packets 2205.

[0226] The packet layer decoder (erasure correction decoder) 2206 receives the stored packet 2205 and control signal 2208 as input. When the control signal 2208 indicates the time point Rc, the packet layer decoder (erasure correction decoder) 2206 performs erasure correction decoding (for example, when an LDPC (Low-Density Parity-Check) code is used as the error correction code, a belief propagation decoding such as sum-product decoding) using the packets "$2", "$4", "$5", "$7", and "$1" output by the memory unit 2204. At this time, the packet layer decoder (erasure correction decoder) 2206 can restore all information, and therefore outputs the received video and / or audio information 2207.

[0227] Note that, if error correction coding is performed in the packet layer in the transmission from the broadcasting station in Fig. 2, the operation in Fig. 22 will be slightly different from that described above. This point will be explained.

[0228] Broadcasting stations use wireless or wired transmission methods to transmit packets or frames to terminals, but due to fluctuations in the propagation path, not all packets can be received correctly at the terminal in Figure 3, even if error correction decoding is performed at the physical layer. For example, packet "#1" can be received without error, packet "#2" contains an error, packet "#3" can be received without error, and so on.

[0229] At this time, the error detection unit (e.g., CRC check unit) 2202 in Fig. 22 judges whether there is an error or not on a packet-by-packet basis using the error detection code. This results in a judgment that packet "#1" is correct, packet "#2" is erroneous, i.e., a packet loss, packet "#3" is correct, etc.

[0230] Then, packet layer decoding unit 2208 in FIG. 22 performs error correction decoding (erasure correction decoding) using the correct packets, restores the lost packets, and outputs received video and / or audio information 2207.

[0231] In the case where error correction coding in the packet layer is not performed in the transmission from the broadcasting station in Fig. 2, the configuration of packet (or frame) processing unit 315 in Fig. 3 is shown in Fig. 23. Note that the operation will be described using Fig. 20 as an example.

[0232] A storage unit 2302 receives received data 2301 and a control signal 2304 as input.

[0233] 20, when the terminal is receiving frame "*1", the received data of frame "*1" is input to storage unit 2302, which stores the data. Then, when control signal 2304 indicates that it is time Rc, storage unit 2302 outputs stored data 2303 (received data of frame "*1").

[0234] As described above, in this embodiment, a transmission method is described in which, for multi-angle first and second images, when a broadcasting station transmits the first image and a telecommunications line operator transmits the second image, error correction coding is performed at the packet level when transmitting the second image, thereby enabling a terminal to display synchronized first and second images and achieving the effect of producing images with less distortion.

[0235] In this embodiment, the receiving device and the antenna of the terminal may be separate. For example, the receiving device may have an interface for inputting, via a cable, a signal received by the antenna or a signal obtained by performing frequency conversion on the signal received by the antenna, and the receiving device performs the subsequent processing.

[0236] The data and information obtained by the receiving device is then converted into video and sound, and is displayed on a display (monitor), or the sound is output from a speaker. Furthermore, the data and information obtained by the receiving device may be subjected to signal processing related to video and sound (signal processing may not be performed), and may be output from an RCA terminal (video terminal, audio terminal), USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), digital terminal, etc., that the receiving device has.

[0237] (Embodiment 2) In this embodiment, a case will be described in which embodiment 1 is applied to a case in which there are multiple broadcasting stations or the broadcasting stations transmit information via multiple media (for example, satellite broadcasting, terrestrial broadcasting, cable broadcasting).

[0238] FIG. 24 shows an example of the relationship between broadcasting stations, telecommunication line providers, and terminals that differs from that in FIG. 1, and components that operate in the same manner as in FIG. 1 are given the same numbers.

[0239] 24, a distinctive feature is that in addition to a method in which broadcast station 103 transmits the angle (first video) captured by camera 102A to terminal 105 via the same route as in Fig. 1 (solid arrow from broadcast station 103 to terminal 105), there is also a method in which broadcast station 103 transmits to terminal 105 via a different route (dotted arrow from broadcast station 103 to terminal 105), and a method in which broadcast station 103 transmits to terminal 105 via repeater 2401. Although three routes exist in Fig. 24, the number of routes is not limited to this.

[0240] In Fig. 25, like Fig. 24, there is a method of transmitting the angle (first video) captured by camera 102A to terminal 105 via three routes, but a new broadcast station 2501 is also installed. Note that the same numbers are used for components that operate in the same way as in Figs. 1 and 24.

[0241] 25, in addition to the method in which broadcast station 103 transmits the angle (first video) captured by camera 102A to terminal 105 via the same route as in Fig. 1 (solid arrow from broadcast station 103 to terminal 105), there is also a method in which broadcast station 2501 transmits to terminal 105 via a different route (dotted arrow from broadcast station 2501 to terminal 105), and a method in which broadcast station 2501 transmits to terminal 105 via repeater 2401. Although three routes exist in Fig. 25, the number of routes is not limited to this.

[0242] Fig. 26 shows an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier in the states of Fig. 24 and Fig. 25, and the same numbers are used for components that operate in the same way as in Fig. 2. Therefore, the transmitting device 250 owned by the telecommunications carrier can perform all of the operations described in the first embodiment (such as packet level encoding and delayed transmission).

[0243] Transmitting device 2602 receives first video and / or audio information 2601 and control signal 2603 as input, determines a transmission method based on control signal 2603, and outputs modulated signal 2604, which is output from antenna 2605. Similarly, transmitting device 2612 receives first video and / or audio information 2601 and control signal 2613 as input, determines a transmission method based on control signal 2613, and outputs modulated signal 2614, which is output from antenna 2615.

[0244] The transmitting device 2622 receives the first video and / or audio information 2601 and the control signal 2623, determines a transmission method based on the control signal 2613, and outputs a modulated signal 2624. However, it is assumed that the modulated signal 2624 is transmitted to the terminal via a wire.

[0245] In this case, the transmitting devices 2602, 2612, and 2622 are transmitting devices related to the broadcasting station. Note that the characteristic operations of each transmitting device will be described later.

[0246] Figure 27 shows an example of the configuration of transmitting equipment owned by the broadcasting station and telecommunications line provider in Figures 24 and 25, which is different from that in Figure 26, and components that operate in the same way as in Figures 2 and 26 are given the same numbers.

[0247] FIG. 27 differs from FIG. 26 in that the first video and / or audio information is transmitted separately from the camera side to transmitting devices 2602, 2612, 2622. Therefore, 2701, 2712, 2721 in FIG. 27 are all the first video and / or audio information, and the operation of transmitting devices 2602, 2612, 2622 is the same as in FIG. 26.

[0248] In this case, the transmitting devices 2602, 2612, and 2622 are transmitting devices associated with the broadcasting station.

[0249] The characteristic operations of each transmitting device will be explained later.

[0250] Fig. 28 shows an example of the configuration of a terminal, and the same numbers are used for components that operate in the same way as in Fig. 3. 351 to 359 in Fig. 28 are components for receiving packets transmitted by a telecommunications carrier, just like in Fig. 3. These components perform the operations described in the first embodiment (packet level decoding, data storage, etc.).

[0251] Receiving device 2803 in Figure 28 is a device for receiving a modulated signal transmitted by transmitting device 2602 in Figures 26 and 27, receiving device 2813 is a device for receiving a modulated signal transmitted by transmitting device 2612 in Figures 26 and 27, and receiving device 2823 is a device for receiving a modulated signal transmitted by transmitting device 2622 in Figures 26 and 27.

[0252] The receiving device 2803 receives as input a received signal 2802 (a received signal of the modulated signal transmitted by the transmitting device 2602 in Figures 26 and 27) received by the antenna 2801, extracts the control information contained in the received signal, and performs processing such as demodulation, physical layer error correction decoding, (packet level decoding if packet level error correction coding has been performed), and outputs data 2704 after packet (or frame) processing and a control information signal 2705.

[0253] Similarly, receiving device 2813 receives received signal 2812 (a received signal of the modulated signal transmitted by transmitting device 2612 in Figures 26 and 27) via antenna 2811 as input, extracts control information contained in the received signal, and performs processing such as demodulation, physical layer error correction decoding, (packet level decoding if packet level error correction coding has been performed), and outputs packet (or frame) processed data 2714 and control information signal 2715.

[0254] The receiving device 2823 receives a received signal 2822 (a received signal of the modulated signal transmitted by the transmitting device 2622 in Figures 26 and 27) from a cable or the like connected to the connection unit 2821, extracts control information contained in the received signal, and performs processing such as demodulation, physical layer error correction decoding, (packet level decoding if packet level error correction coding has been performed), and outputs packet (or frame) processed data 2724 and a control information signal 2725.

[0255] At this time, the receiving devices 2803, 2813, and 2823 are not necessarily all operating at the same time. For example, if a broadcast channel selection unit is provided as an interface of the terminal, the receiving device associated with the channel set by the user using the selection unit will operate. The signal for achieving this is the selection signal 2850, and the receiving devices 2803, 2813, and 2823 will determine whether to operate based on the selection signal 2850.

[0256] The signal processing unit 380 receives the packet (or frame) processed data 2804, 2814, 2824, the control information signals 2805, 2815, 2825, and the selection signal 2850, and selects the valid packet (or frame) processed data based on the selection signal 2850.

[0257] In addition, signal processing unit 380 receives packet (or frame) processed data 359 and control information 357 as input, generates data for displaying two images on display unit 384 from valid packet (or frame) processed data and packet (or frame) processed data 359, and outputs data 381.

[0258] The characteristic operations of each receiving device will be explained later.

[0259] Next, problems that arise when transmitting primary video (and / or voice (audio) information) from the transmitting devices 2602, 2612, 2622 as shown in Fig. 26 and Fig. 27 will be described. Note that, in the following, it is assumed that the same packets are transmitted, but the packets transmitted by the transmitting devices 2602, 2612, 2622 may have different configurations, rather than the same packets. Furthermore, the primary video data transmitted from the transmitting devices 2602, 2612, 2622 may have different video (audio) encoding methods, frame rates, and video sizes (resolutions).

[0260] Fig. 29 shows an example of a situation in which the transmitting devices 2602, 2612, and 2622 in Fig. 26 and Fig. 27 transmit packets related to the primary video (and / or audio information) (2900 in Fig. 29). Note that in Fig. 29, the horizontal axis represents time.

[0261] The transmitting device 2602 in Figures 26 and 27 transmits packet "#0-1", packet "#0-2", packet "#0-3", packet "#0-4", packet "#0-5", packet "#0-6", and packet "#0-7". The transmitting device 2612 in Figures 26 and 27 transmits packet "#1-1", packet "#1-2", packet "#1-3", packet "#1-4", packet "#1-5", packet "#1-6", and packet "#1-7". The transmitting device 2622 in Figures 26 and 27 transmits packet "#2-1", packet "#2-2", packet "#2-3", packet "#2-4", packet "#2-5", packet "#2-6", and packet "#2-7".

[0262] In this case, it is assumed that the transmitting device 2602, the transmitting device 2612, and the transmitting device 2622 in FIGS. 26 and 27 all transmit packets at the same time from time T1.

[0263] FIG. 30 shows a state where the terminal in FIG. 28 receives packets when the transmitting devices 2602, 2612, and 2622 in FIG. 26 and FIG. 27 transmit packets as shown in FIG. 29 (3000 in FIG. 30).

[0264] As shown in FIG. 30, the time when the receiving device 2803 in FIG. 28 completes receiving packets "#0-7" is R1, the time when the receiving device 2813 in FIG. 28 completes receiving packets "#1-7" is R2, and the time when the receiving device 2823 in FIG. 28 completes receiving packets "#2-7" is R3. In this case, R1, R2, and R3 are different values, and the difference between them may be large. Note that in FIG. 30, it is assumed that the receiving devices 2803, 2813, and 2823 are operating simultaneously, but in reality, they do not need to operate simultaneously. In other words, when a user selects a channel (or a transmission medium (terrestrial broadcasting, cable broadcasting, satellite broadcasting)), only the receiving device corresponding to it will operate.

[0265] In this case, if the terminal displays only the first video (and / or sound (audio) information), there is no problem. However, as described in the first embodiment, if the first video and the second video are displayed in synchronization, issues arise in terms of the circuit scale of the terminal.

[0266] As described in the first embodiment, the terminal synchronizes the second video (and / or audio information) transmitted via the telecommunications carrier with the first video (and / or audio information) in time and displays the video on the display unit so that the user does not feel uncomfortable about the multi-angle video. At this time, the user selects a channel (or a transmission medium (terrestrial broadcasting, cable broadcasting, satellite broadcasting)), and only the corresponding receiving device operates. However, as described above (see FIG. 30), the arrival time of the packets of the first video (and / or audio information) differs greatly depending on the channel selected by the user (terminal). Therefore, particularly when the user (terminal) selects a channel (channel transmitting the first video) whose arrival time differs greatly from that of the packets of the second video, the terminal will have a large circuit in the memory unit for synchronizing the videos.

[0267] In order to solve this problem, taking into consideration the time difference in packet arrival in Fig. 30, the transmitting devices 2602, 2612, and 2622 that transmit the first video (and / or voice (audio) information) in Fig. 26 and Fig. 27 are made to transmit the information of the first video (and / or voice (audio) information) at different timings. This is shown in Fig. 31.

[0268] As in Fig. 31, transmitting device 2602 in Fig. 26 and Fig. 27 starts transmitting packets of the first video (and / or voice (audio) information) at time point T0. Then, transmitting device 2612 in Fig. 26 and Fig. 27 starts transmitting packets of the first video (and / or voice (audio) information) at time point T1, and transmitting device 2622 in Fig. 26 and Fig. 27 starts transmitting packets of the first video (and / or voice (audio) information) at time point T2.

[0269] FIG. 32 shows how packets arrive at the receiving device of the terminal in FIG. 28 when the transmitting devices 2602, 2612, and 2622 in FIGS. 26 and 27 transmit packets as in FIG.

[0270] As shown in Fig. 32, the time when the receiving device 2823 in Fig. 28 completes receiving packet "#2-7" is Z1, and the time when the receiving device 2823 in Fig. 28 completes receiving packet "#1-7" is Z2. In this case, it is assumed that the receiving device 2803 in Fig. 28 receives packet "#0-7" between times Z1 and Z2.

[0271] As can be seen by comparing Fig. 30 and Fig. 32, because the timing of transmitting packets of the first video (and / or voice (audio) information) is adjusted by transmitting devices 2602, 2612, 2622 in Fig. 26 and Fig. 27 as in Fig. 31, the arrival time difference of packets of the first video (and / or voice (audio) information) arriving at receiving devices 2803, 2813, 2823 of the terminal, respectively, is smaller than that in Fig. 30. This provides the effect of reducing the circuit scale of the memory unit of the terminal.

[0272] In other words, the receiving device of the terminal can have a smaller memory circuit for temporally synchronizing the first video (and / or voice (audio) information) and the second video transmitted by the transmitting device 2602 in Figures 26 and 27, and can have a smaller memory circuit for temporally synchronizing the first video (and / or voice (audio) information) and the second video transmitted by the transmitting device 2612 in Figures 26 and 27, and can have a smaller memory circuit for temporally synchronizing the first video (and / or voice (audio) information) and the second video transmitted by the transmitting device 2622 in Figures 26 and 27.

[0273] In addition, in Fig. 32, it is assumed that the receiving devices 2803, 2813, and 2823 are operating simultaneously, but in reality, they do not have to operate simultaneously. In other words, when a user selects a channel (or a transmission medium (terrestrial broadcasting, cable broadcasting, satellite broadcasting)), only the receiving device corresponding to the channel operates.

[0274] Note that the packet processing, signal processing, and decoding processing for displaying the first video (and / or voice (audio) information) transmitted by the transmitting device 2602 in Fig. 26 and Fig. 27 and the packets of the second video transmitted by the telecommunications carrier in a time-synchronized manner can be realized by implementing them in the same manner as described in embodiment 1. The packets of the second video are decoded at the packet level, and the processing method is as described in embodiment 1.

[0275] Similarly, the packet processing, signal processing, and decoding processing for displaying the first video (and / or voice (audio) information) transmitted by the transmitting device 2612 in Fig. 26 and Fig. 27 and the packets of the second video transmitted by the telecommunication line carrier in a time-synchronized manner can be realized by implementing the same method as described in embodiment 1. The packets of the second video are decoded at the packet level, and the processing method is as described in embodiment 1.

[0276] Also, the packet processing, signal processing, and decoding processing for displaying the first video (and / or voice (audio) information) transmitted by the transmitting device 2622 in Fig. 26 and Fig. 27 and the packets of the second video transmitted by the telecommunication line carrier in a time-synchronized manner can be realized by implementing them in the same manner as described in embodiment 1. The packets of the second video are decoded at the packet level, and the processing method is as described in embodiment 1.

[0277] As described in the first embodiment, in order to further reduce the problem of the disturbance of the second image, the amount of delay may be controlled on the transmitting side.

[0278] For example, the signal processing unit 380 of the terminal in Fig. 28 obtains information on the difference (or statistical information thereof) in arrival time between a frame transmitted by each broadcasting station (transmitting devices 2602, 2612, 2622 shown in Figs. 26 and 27) and a packet transmitted by a telecommunications carrier at the same time, and outputs the information as time difference information 399. Then, the time difference information 399 is transmitted from the transmitting device included in the terminal to, for example, the telecommunications carrier.

[0279] The transmitting device 250 of the telecommunication line provider in Fig. 26 and Fig. 27 has a receiving unit and acquires the time difference information transmitted by the terminal (299 in Fig. 2). Then, the packet (or frame) processing unit 202, 222 receives the time difference information 299 as an input, and controls the timing of transmission by changing the amount of the packet or frame storage unit, thereby outputting a packet or frame with a controlled amount of delay.

[0280] 26 and 27, it is difficult for each broadcasting station (transmitting devices 2602, 2612, 2622 shown in Fig. 26 and 27) to control the amount of delay for each terminal. (Because of multicast) Therefore, the packet (or frame) processing unit 222 of the transmitting device 250 of the telecommunications line provider controls the amount of delay for each terminal. However, when the transmitting device 250 of the telecommunications line provider does not transmit packets individually to each terminal, that is, when multicasting, each broadcasting station (transmitting devices 2602, 2612, 2622 shown in Fig. 26 and 27) may control the delay time (packet transmission timing), or the telecommunications line provider may control the delay time (packet transmission timing).

[0281] As another method, the terminal may automatically select a channel transmitted by a broadcast station. For example, as shown in Figs. 26 and 27, the first video (and / or sound (audio) information) information is transmitted by transmitting devices 2602, 2612, and 2622. The configuration of a terminal when performing automatic selection is shown in Fig. 33. In Fig. 33, the same numbers are used for components that operate in the same way as in Figs. 3 and 28, and detailed explanations will be omitted.

[0282] In FIG. 33, signal processing unit 380 outputs signal 3301 including information regarding the delay time between the first video (and / or audio information) packets (or frames) and the second video packets output by receiving device 2803, the delay time between the first video (and / or audio information) packets (or frames) and the second video packets output by receiving device 2813, and the delay time between the first video (and / or audio information) packets (or frames) and the second video packets output by receiving device 2823.

[0283] A delay time analysis unit 3302 receives a signal 3301 as input, and outputs information 3303 of packets (2804, 2814, 2824) suitable for displaying the primary video and secondary video in temporal synchronization.

[0284] The selection unit 3306 receives as input information 3303 of packets (2804, 2814, 2824) suitable for displaying the first video and the second video in time synchronization, information 3304 of a channel set by the user, and a control signal 3305, and selects either information 3303 of packets (2804, 2814, 2824) suitable for displaying the first video and the second video in time synchronization or information 3304 of a channel set by the user according to the control signal 3305, and outputs the selected signal as a selection signal 3307. Note that when information 3303 of packets (2804, 2814, 2824) suitable for displaying the first video and the second video in time synchronization is selected according to the control signal 3305, the result of the analysis by the delay time analysis unit 3302 is reflected.

[0285] Then, the receiving devices 2803, 2813, and 2823 determine whether or not to operate based on the selection signal 3307.

[0286] This makes it possible for the terminal to automatically select the channel transmitted by the broadcast station.

[0287] As described above, in this embodiment, when a broadcast station transmits the first video and a telecommunications carrier transmits the second video for the multi-angle first and second videos, error correction coding is performed at the packet level during transmission of the second video, and each broadcast station controls the timing of transmitting the information on the first video. Furthermore, the terminal has a function that allows it to select a broadcast station from which to obtain the first video. This allows the terminal to display synchronized first and second videos, and also provides the effect of providing videos with less distortion.

[0288] (Embodiment 3) In the first and second embodiments, a transmission method has been described in which, for a multi-angle first video and a second video, a broadcasting station transmits the first video and a telecommunications carrier transmits the second video, and error correction coding is performed at the packet level when transmitting the second video. In this case, the telecommunications carrier transmits packets of the second video by TCP (TCP / IP) or UDP, and introduces packet-level error correction coding to reduce the effects of packet delays and packet losses.

[0289] However, even if packet-level error correction codes are introduced, packet delays and packet losses have an effect, albeit small, which causes image distortion. In particular, when a terminal receives packets of the second image via wireless communication such as wireless LAN or a cellular communication system, the image distortion may become significant, and viewers are likely to feel uncomfortable when the image is distorted.

[0290] In this embodiment, a method for reducing the discomfort felt by the user due to this image disturbance will be described.

[0291] Fig. 34 shows an example of the relationship between a broadcasting station, a telecommunications carrier, and a terminal in this embodiment. The same numbers are used for components that operate in the same way as in Fig. 1. In Fig. 34, 101 indicates a site, and a baseball field and a soccer field are considered as examples. 102A and 102B indicate cameras. Assume that the cameras 102A and 102B are taking images from different angles, for example.

[0292] At this time, the broadcast station 103 receives the "first video and / or audio information" captured by the camera 102A, and the "first video and / or audio information" is transmitted to the terminal 105 via a wired connection such as a cable, or wirelessly.

[0293] Then, the broadcasting station 103 receives the "second video and / or audio information" captured by the camera 102B, and the "second video and / or audio information" is transmitted to the terminal 105 via the telecommunications line provider 104.

[0294] It should be noted that the “second video and / or audio information” may be transmitted directly to the telecommunications carrier 104 without going through the broadcast station 103, and then transmitted to the terminal 105.

[0295] Furthermore, the information provider 3401 provides information to the broadcasting station, and the broadcasting station transmits information based on this information to the terminal together with the "first video and / or audio information."

[0296] Fig. 35 shows an example 3500 of the transmission status of packets transmitted by a broadcasting station and a telecommunication line carrier in this embodiment. However, as shown in the second embodiment, a plurality of broadcasting stations can transmit packets of the first video, and Fig. 35 shows only a transmission packet (frame) of one broadcasting station. However, as in the second embodiment, the contents described below can also be implemented in the case where a plurality of transmitting stations transmit the first video packets.

[0297] As in the first and second embodiments, the broadcasting station transmits the "first video and / or audio information" and the electric carrier transmits the "second video and / or audio information."

[0298] In Figure 35, the first video packet group transmitted by the broadcasting station and the second video packet group transmitted by the telecommunications line provider are videos of the same time, and as described in embodiments 1 and 2, the terminal will display the first video and the second video on the display unit in synchronization with each other.

[0299] In addition to the packets of the first video, the broadcasting station transmits "text information (message information)", and / or "still image information", and / or "URL (Uniform Resource Locator) information" as shown in FIG. 35. This information is used when the terminal is unable to restore the information of the first video and, as a result, has difficulty in displaying the first video on the display unit, and a screen replacing the first video is displayed on the display unit of the terminal. Similarly, this information is used when the terminal is unable to restore the information of the second video and, as a result, has difficulty in displaying the second video on the display unit, and a screen replacing the second video is displayed on the display unit of the terminal.

[0300] In FIG. 35, the broadcasting station transmits "text information (electronic message information)", "still image information", and "URL (Uniform Resource Locator) information", but it does not have to transmit all of the information. It may transmit one of "text information (electronic message information)", "still image information", and "URL (Uniform Resource Locator) information", or it may transmit two of "text information (electronic message information)", "still image information", and "URL (Uniform Resource Locator) information".

[0301] In addition, these pieces of information do not have to be always included in each transmission frame, for example, these pieces of information may be transmitted for each set of frames. Therefore, the timing of transmitting these pieces of information may be arbitrary.

[0302] Figure 36 shows the configuration of the transmitting equipment of the broadcasting station and the telecommunications line provider when transmitting the information of Figure 35. Components that operate in the same manner as in Figure 2 are given the same numbers, and the implementation method is the same as that explained in the first and second embodiments, so the explanation is omitted.

[0303] Packet (or frame) processing unit 3602 receives character information (message information), and / or still image information, and / or URL information 3601, and first control signal 211 as input, performs packetization and framing based on first control signal 211, and outputs information after packet (or frame) processing 3603.

[0304] The physical layer error correction coding unit 3604 receives the information 3603 after packet (or frame) processing and the first control signal 211 as input, performs error correction coding based on the information on the physical layer error correction coding method contained in the first control signal 211, and outputs data 3605 after error correction coding.

[0305] The modulation section 206 receives the error correction coded data 205, 3605 and the first control signal 211 as input, and performs mapping on the error correction coded data 205, 3605 based on the information on the frame structure and the information on the modulation method and transmission method included in the first control signal 211, and outputs a baseband signal 207.

[0306] Figure 37 shows an example of the configuration of a receiving device of a terminal that receives a signal transmitted as in Figure 36, and components that operate in the same manner as in Figure 3 are given the same numbers.The implementation method is the same as that explained in embodiments 1 and 2, so the explanation is omitted.

[0307] Demodulation section 311 receives baseband signal 304, synchronization signal 306, channel estimation signal 308, and control information signal 310 as input, and demodulates baseband signal 304 using synchronization signal 306 and channel estimation signal 308 based on information about the frame structure and information about the modulation method and transmission method included in control information signal 310, and outputs log-likelihood ratio signal 312 and “log-likelihood ratio signal 3701 of character information (telegram information), and / or still image information, and / or URL information.”

[0308] The physical layer error correction decoding unit 3702 receives as input the "log likelihood ratio signal 3701 of character information (telegram information), and / or still image information, and / or URL information" and the control information signal 310, performs decoding based on information relating to the error correction encoding method contained in the control information signal 310, and outputs "received data 3703 of character information (telegram information), and / or still image information, and / or URL information."

[0309] The packet (or frame) processing unit 3704 receives "received data 3703 of character information (electronic message information), and / or still image information, and / or URL information" and control information signal 310, performs packet (or frame) processing based on the control information signal 310, and outputs "character information (electronic message information), and / or still image information, and / or URL information 3705 after packet (or frame) processing."

[0310] The decoder 3706 receives as input “character information (message information), still image information, and / or URL information 3705 after packet (or frame) processing”, decodes the character information (message information), still image information, or URL information, and outputs display screen information 3707.

[0311] At this time, the decoder 3706 operates as follows. In the case of "character information (electronic message information)", the display screen information 3707 becomes "character information (electronic message information) to be displayed on the display unit". In the case of "still image information", the display screen information 3707 becomes "still image information to be displayed on the display unit". In the case of "URL information", information from the URL destination (3708) is obtained and output.

[0312] The signal processor 380 determines whether or not a synchronized image of the first and second images has been obtained, and outputs the determination result 3700.

[0313] Display unit 384 receives video signal 383, display screen information 3707, and determination result 3700 as input, and displays video signal 383 if determination result 3700 indicates that "synchronized images of the first and second images have been obtained." If determination result 3700 indicates that "synchronized images of the first and second images have not been obtained," and the display unit 384 displays display screen information 3707 in place of the first image and also displays the second image if the first image has not been obtained. If the second image has not been obtained, display screen information 3707 is displayed in place of the second image.

[0314] Figure 38 shows the configuration of the transmitting equipment of the broadcasting station and the telecommunications line provider when transmitting the information of Figure 35, and components that operate in the same manner as in Figures 2 and 36 are given the same numbers, and the implementation method is the same as that explained in embodiment 1, embodiment 2, and Figure 36, so the explanation is omitted.

[0315] Figure 38 differs from Figure 36 in that the physical layer error correction code used when transmitting the first video packet group in Figure 35 is the same as the physical layer error correction code used when transmitting character information (telegram information) and / or still image information and / or URL information. Therefore, Figure 38 does not have physical layer error correction coding unit 3604 in Figure 36, and physical layer error correction coding unit 204 also performs coding of character information (telegram information) and / or still image information and / or URL information.

[0316] Figure 39 shows an example of the configuration of a receiving device of a terminal when the information of Figure 35 is transmitted in Figure 38, and components that operate in the same manner as in Figures 3 and 37 are given the same numbers, and the implementation method is the same as that explained in embodiment 1, embodiment 2, and Figure 37, so the explanation is omitted.

[0317] Figure 39 differs from Figure 38 in that the physical layer error correction code used when transmitting the first video packet group in Figure 35 is the same as the physical layer error correction code used when transmitting character information (message information) and / or still image information and / or URL information. Therefore, Figure 39 does not have physical layer error correction decoding unit 3702 in Figure 37, and physical layer error correction decoding unit 313 also performs decoding of character information (message information) and / or still image information and / or URL information.

[0318] In the transmission frame of the broadcasting station in Fig. 35, an example is shown in which the "first packet group", "text information (telegram information)", and "still image information" are transmitted in a time-division manner, but the present invention is not limited to this example, and in a multi-carrier transmission method, or in a case where multiple channels exist on the frequency axis, the "first packet group", "text information (telegram information)", and "still image information" may be transmitted in a frequency-division manner. In addition, both time division and frequency division may be used in combination.

[0319] Fig. 40 shows an example 4000 of the transmission status of transmission packets by broadcasting stations and telecommunication line providers different from Fig. 35. However, as shown in the second embodiment, a plurality of broadcasting stations can transmit packets of the first video, and Fig. 40 shows only the transmission packets (frames) of one broadcasting station. However, as in the second embodiment, it is possible to implement the contents described below even in the case where a plurality of transmitting stations transmit the first video packets.

[0320] As in the first and second embodiments, the broadcasting station transmits the "first video and / or audio information" and the electric carrier transmits the "second video and / or audio information."

[0321] In Figure 40, the first video packet group transmitted by the broadcasting station and the second video packet group transmitted by the telecommunications line provider are videos of the same time, and as described in embodiments 1 and 2, the terminal will display the first video and the second video on the display unit in synchronization with each other.

[0322] The telecommunications carrier shall transmit, in addition to the packets of the second video, "text information (message information)", and / or "still image information", and / or "URL (Uniform Resource Locator) information" as shown in FIG. 40. This information is used when the terminal is unable to restore the information of the first video and, as a result, it is difficult to display the first video on the display unit, and a screen replacing the first video is displayed on the display unit of the terminal. Similarly, this information is used when the terminal is unable to restore the information of the second video and, as a result, it is difficult to display the second video on the display unit, and a screen replacing the second video is displayed on the display unit of the terminal.

[0323] In FIG. 40, the telecommunications line provider transmits "text information (electronic message information)", "still image information", and "URL (Uniform Resource Locator) information", but it is not necessary to transmit all of the information. The telecommunications line provider may transmit one of "text information (electronic message information)", "still image information", and "URL (Uniform Resource Locator) information", or may transmit two of "text information (electronic message information)", "still image information", and "URL (Uniform Resource Locator) information".

[0324] In addition, these pieces of information do not have to be always included in each transmission frame, for example, these pieces of information may be transmitted for each set of frames. Therefore, the timing of transmitting these pieces of information may be arbitrary.

[0325] When transmitting a frame as shown in FIG. 40, information provider 3401 in FIG. 34 provides information about telecommunications line provider 104 as shown by the dotted line, and telecommunications line provider 104 transmits that information to terminal 105 as shown by the dotted line.

[0326] Figure 41 shows the configuration of the transmitting equipment of the broadcasting station and the telecommunications line provider when transmitting the information of Figure 40, and the same numbers are used for components that operate in the same manner as in Figure 2, and the implementation method is the same as that explained in the first and second embodiments, so the explanation is omitted.

[0327] The packet (or frame) processing unit 4102 receives as input character information (message information), and / or still image information, and / or URL information 4101, and the second control signal 228, performs packetization and framing based on the second control signal 228, and outputs information after packet (or frame) processing 4103.

[0328] The signal processing unit 224 receives as input the second video and / or audio information 223 after packet (or frame) processing, the information 4103 after packet (or frame) processing, and the second control signal 228, performs signal processing to generate a transmission signal based on the information of the telecommunications line provider's transmission frame of Figure 40 contained in the second control signal 228, and outputs the processed signal 225.

[0329] Figure 42 shows an example of the configuration of a receiving device of a terminal that receives a signal transmitted as in Figure 41, and components that operate in the same manner as in Figure 3 are given the same numbers, and the implementation method is the same as that explained in embodiments 1 and 2, so the explanation is omitted.

[0330] The signal processing unit 355 receives the received signal 354, separates it into a second video packet group, control information, character information (telegram information), still image information, and URL information, and outputs received data (second video packet group) 356, control information 357, and a "log-likelihood ratio signal 4202 of character information (telegram information), and / or still image information, and / or URL information."

[0331] The packet (or frame) processing unit 4203 receives as input the "log likelihood ratio signal 4202 of character information (email information), and / or still image information, and / or URL information" and control information 357, performs signal processing based on information regarding the transmission method and error correction coding method included in the control information 357, and outputs "received data 4204 of character information (email information), and / or still image information, and / or URL information."

[0332] The decoder 4205 receives as input “received data 4204 of character information (message information), still image information, and / or URL information after packet (or frame) processing”, decodes the character information (message information), still image information, or URL information, and outputs display screen information 4206.

[0333] At this time, the decoder 4205 operates as follows: In the case of "character information (electronic message information)", the display screen information 4206 becomes "character information (electronic message information) to be displayed on the display unit". In the case of "still image information", the display screen information 4206 is "still image information to be displayed on the display unit". In the case of "URL information", information from the URL destination (4210) is obtained and output.

[0334] The signal processor 380 determines whether or not a synchronized image of the first and second images has been obtained, and outputs the determination result 4201.

[0335] Display unit 384 receives video signal 383, display screen information 4206, and determination result 4201 as input, and displays video signal 383 if determination result 4201 indicates that "synchronized images of the first and second images have been obtained." If determination result 4201 indicates that "synchronized images of the first and second images have not been obtained," and the first image has not been obtained, display screen information 4206 is displayed in place of the first image, and the second image is also displayed. If the second image has not been obtained, display screen information 4206 is displayed in place of the second image.

[0336] As described above, when a disturbance occurs in the display of the first and second images in a multi-angle display, by displaying information in place of the images that may be disturbed, it is possible to obtain the effect of increasing the likelihood of reducing the discomfort felt by the user.

[0337] (Embodiment 4) In the first and second embodiments, a transmission method has been described in which, for a multi-angle first video and a second video, a broadcasting station transmits the first video and a telecommunications carrier transmits the second video, and error correction coding is performed at the packet level when transmitting the second video. In this case, the telecommunications carrier transmits packets of the second video by TCP (TCP / IP) or UDP, and introduces packet-level error correction coding to reduce the effects of packet delays and packet losses.

[0338] However, when the first video transmitted by the broadcasting station and the data transmitted by the telecommunication carrier are synchronized in time, there are cases where erasure correction code (error correction coding at the packet level) does not need to be introduced. This embodiment will explain this point.

[0339] Fig. 43 shows an example of the configuration of the transmitting device of the broadcasting station and the telecommunication line provider in this embodiment. In Fig. 43, the same numbers are used for components that operate in the same way as in Fig. 2. Control unit 232 receives transmission data 4300 as input, and outputs transmission data 4301 and second control signal 228. The detailed operation will be described later with reference to Fig. 44.

[0340] Control information generator 4303 receives transmission data 4301 and transmission data 4302, and generates and outputs control information 4302. Note that detailed operations will be described later with reference to FIG.

[0341] Packet (or frame) processing unit 222 receives transmission data 4301, transmission data 4302 when it is directly delivered to the telecommunications line provider, and second control signal 228 as input, selects valid transmission data from transmission data 4301 and transmission data 4302 according to second control signal 228, performs packet (or frame) processing, and outputs packet (or frame) processed data 4304. Details of the operation will be described later with reference to FIG.

[0342] FIG. 44 shows an example 4400 of the transmission status of packets transmitted by a broadcasting station and a transmitting device of a telecommunications carrier in this embodiment. When a broadcasting station transmits "first video packet group #1" (4401), the telecommunications carrier transmits control information 4405 and "second video packet group #1" (4406). At this time, erasure correction coding (error correction coding at the packet level) for generating "second video packet group #1" (4406) is performed in the transmitting device of the telecommunications carrier shown in FIG. 43. And, the control information 4405 includes "information indicating that erasure correction coding (error correction coding at the packet level) has been performed".

[0343] When the broadcasting station shown in Fig. 43 transmits "first video packet group #2" (4402), the telecommunications carrier transmits control information 4407 and "second video packet group #2" (4408). At this time, the transmission device of the telecommunications carrier shown in Fig. 43 does not perform erasure correction coding (error correction coding at the packet level) to generate "second video packet group #2" (4406). And, the control information 4405 includes "information indicating that erasure correction coding (error correction coding at the packet level) has not been performed."

[0344] As described above, when transmitting the packet of the second image, erasure correction coding (error correction coding at packet level) may or may not be performed. For example, when the compression rate of the image coding is high and / or the number of pictures is small (that is, data size is small), the number of packets to be transmitted can be reduced, so the control information generating unit 4303 of Fig. 43 will determine that "erasure correction coding is not performed". Conversely, when the compression rate of the image coding is low and / or the number of pixels is large (that is, data size is large), the number of packets to be transmitted increases, so the control information generating unit 4303 of Fig. 43 will determine that "erasure correction coding is performed".

[0345] When the broadcasting station shown in FIG. 43 transmits "first video packet group #3" (4403), the telecommunications carrier transmits control information 4409 and "data packet group" (4410). At this time, the data of the "data packet group" (4410) is "text information", "still image information", "URL information", etc. At this time, erasure correction coding (error correction coding at the packet level) is not performed in the transmitting device of the telecommunications carrier shown in FIG. 43 to generate the "data packet group" (4410). And, the control information 4409 includes "information indicating that erasure correction coding (error correction coding at the packet level) has not been performed."

[0346] In the case where the data of the "data packet group" (4410) is "text information", "still image information", "URL information" or the like, the amount of data to be transmitted is small compared to video data, so the control information generating unit 4303 of Fig. 43 will determine that "erasure correction coding is not performed".

[0347] Note that information on whether erasure correction coding is performed is included in control information 4302.

[0348] Therefore, as described above, the packet (or frame) processing unit 222 of Figure 43 judges whether to carry out erasure correction coding for data based on the information of "whether to carry out erasure correction coding" contained in control information 4302, and carries out processing based on whether to carry out erasure correction coding or not.

[0349] Figure 42 shows an example of the configuration of a receiving device of a terminal that receives signals transmitted as shown in Figures 43 and 44, and the implementation method is the same as that described in embodiments 1, 2, and 3.

[0350] Signal processing unit 355 receives received signal 354 as input, determines the type of information (video data, or text information (telegram information), or still image information, or URL information) sent by the telecommunications line provider from the control information (symbol) in Figure 44, and outputs received data (second video packet group) 356, control information 357, and "log-likelihood ratio signal 4202 of text information (telegram information), and / or still image information, and / or URL information."

[0351] The packet (or frame) processing unit 4203 receives as input the "log likelihood ratio signal 4202 of character information (telegram information), and / or still image information, and / or URL information" and control information 357, and if the information type information of the control information 357 is character information (telegram information), still image information, or URL information, performs signal processing based on information on the transmission method, error correction encoding method, etc., and outputs "received data 4204 of character information (telegram information), and / or still image information, and / or URL information."

[0352] The decoder 4205 receives as input “received data 4204 of character information (message information), still image information, and / or URL information after packet (or frame) processing”, decodes the character information (message information), still image information, or URL information, and outputs display screen information 4206.

[0353] At this time, the decoder 4205 operates as follows. In the case of "character information (email information)", the display screen information 4206 becomes "character information (email information) to be displayed on the display unit". In the case of "still image information", the display screen information 4206 becomes "still image information to be displayed on the display unit". In the case of "URL information", information from the URL destination (4210) is obtained and output.

[0354] Packet (or frame) processing unit 358 receives received data 356 and control information 357 as input. When the information of the type of information contained in control information 357 indicates that it is the second image, and further obtains the information that erasure correction code is applied, performs erasure correction decoding (packet level error correction decoding).And, when obtains the information that erasure correction decoding is not applied, does not perform erasure correction decoding (packet level error correction decoding).

[0355] The signal processing unit 380 determines whether or not the second video has been obtained from the control information (symbols) in FIG.

[0356] Display unit 384 receives video signal 383, display screen information 4206, and determination result 4201 as input, and if determination result 4201 indicates that "a second video has been obtained," it displays video signal 383. If determination result 4201 indicates that "a second video has not been obtained," it displays display screen information 4206.

[0357] As described above, by switching between applying and not applying erasure correction coding (error correction coding at the packet level), the terminal can achieve both high data reception quality and improved data transmission speed (when erasure correction coding is applied, the data transmission speed will decrease).

[0358] (Embodiment 5) In the first to fourth embodiments, the application examples of erasure correction code (packet level error correction coding) have been described. In the present embodiment, another application example of erasure correction code (packet level error correction coding) will be described.

[0359] Fig. 45 shows the state of packets transmitted by a broadcasting station in this embodiment, with the horizontal axis representing time. In Fig. 45, 4501 is a pre-transmitted packet group, and a terminal that receives this packet group (4501) will temporarily store this packet group (4501). Note that even if a terminal receives pre-transmitted packet group 4501 and performs packet-level error correction decoding, it will not be able to obtain video (and audio). (The characteristics of this will be explained in detail later.) This has the characteristic that the reception time period of a program including video can be uniquely set.

[0360] Reference numeral 4502 denotes a video packet group, and the terminal is capable of displaying video (and audio) by obtaining the video packet group 4502. (The characteristics of this case will be explained in detail later.) The terminal also performs packet-level error correction decoding using the video packet group 4502 and the stored pre-transmission packet group 4501, thereby achieving higher data (packet) reception quality and enabling the video to be decoded with less video distortion.

[0361] Therefore, both a terminal that holds pretransmission packet group 4501 and a terminal that does not hold pretransmission packet group 4501 can decode the video by obtaining video packet group 4502.

[0362] Figure 46 shows an example of the configuration of a broadcasting station that enables the broadcasting station to transmit packets as shown in Figure 45, and components that operate in the same way as in Figure 2 are given the same numbers and their explanations are omitted.

[0363] Packet (or frame) processing unit 202 receives first video and / or audio information 201 and first control signal 211 as input, performs packet-level error correction coding based on first control signal 211, and outputs first video and / or audio information 203 after packet (or frame) processing. In this embodiment, first video and / or audio information 203 after packet (or frame) processing is made up of pre-transmission packet group 4501 and video packet group 4502 in FIG. In this case, pre-transmission packet group 4501 and video packet group 4502 in Figure 45 do not show control information (information necessary for the terminal to perform processing such as demodulation, decoding, signal processing, etc.), but when the broadcasting station transmits pre-transmission packet group 4501, it also transmits control information (the control information is included in pre-transmission packet group 4501), and when the broadcasting station transmits video packet group 4502, it also transmits control information (the control information is included in video packet group 4502).

[0364] Packet sorting unit 4600 receives first video and / or audio information 203 after packet (or frame) processing and first control signal 211 as input, and if first control signal 211 indicates that "the transmission method as in FIG. 45 is adopted", it outputs pre-transmission (transmission) packet group 4602 and video packet group 4603. If first control signal 211 indicates that "the transmission method as in FIG. 45 is not adopted", it outputs packet group 4601.

[0365] Pre-transmission (transmission) packet storage unit 4604 receives pre-transmission packet group 4602 and first control signal 211, and temporarily stores the pre-transmission packet group (however, if operation is possible without storage, storage is not performed). Then, based on first control signal 211, pre-transmission (transmission) packet storage unit 4604 outputs the stored pre-transmission packet group as pre-transmission packet group 4605.

[0366] Video packet storage unit 4607 receives video packet group 4603 and first control signal 211, and temporarily stores the video packet group. Then, based on first control signal 211, video packet storage unit 4607 outputs the stored video packet group as video packet group 4608.

[0367] Physical layer error correction coding unit 204 receives packet group 4601, advance (transmission) packet group 4605, video packet group 4608, and first control signal 211 as input, and if first control signal 211 indicates that "the transmission method as shown in Figure 45 is not adopted", performs physical layer error correction coding on packet group 4601, and outputs data 205 after error correction coding.

[0368] When first control signal 211 indicates that "a transmission method as shown in Figure 45 is to be adopted", physical layer error correction coding unit 204 outputs error correction coded data obtained by applying physical layer error correction coding to pre- (transmission) packet group 4605, and error correction coded data obtained by applying physical layer error correction coding to video packet group 4608, according to the frame of Figure 45.

[0369] Next, the relationship between the advance (transmission) packet group 4602 (4605) (4501), the video packet group 4603 (4608) (4502), and the first video and / or audio information 201 will be described.

[0370] FIG. 47 shows an example of the relationship between packet groups 4602 (4605) (4501), video packet groups 4603 (4608) (4502), and the first video and / or audio information 201. Further, FIG. 48 shows an example of the relationship different from that in FIG. 47, namely, the relationship between packet groups 4602 (4605) (4501), video packet groups 4603 (4608) (4502), and the first video and / or audio information 201.

[0371] In FIG. 47, 4701 indicates the "first video and / or audio information", and let the number of bits of the "first video and / or audio information" 4701 be X bits (X is a natural number). Then, when using an organizing code in error correction coding at the packet level, by encoding the "first video and / or audio information" 4701, the "first video and / or audio information" 4702 and parity 4703 are obtained. Note that the "first video and / or audio information" 4701 and the "first video and / or audio information" 4702 are the same data. Therefore, the number of bits of the "first video and / or audio information" 4702 is X bits (X is a natural number). And let the number of bits of the parity 4703 be Y bits (Y is a natural number), and the relationship Y < X is assumed to hold.

[0372] Then, it is assumed that the video packet group 4502 in FIG. 45 is generated from the "first video and / or audio information" 4702, and the pre-transmission packet group 4501 in FIG. 45 is generated from the parity 4703 (for example, in each packet, additional information such as control information may be added).

[0373] When the video packet group and the pre-transmission packet group are generated as shown in FIG. 47, the above-mentioned "even if the terminal receives the pre-transmission packet group 4501 and performs error correction decoding at the packet level, it is impossible to obtain the video (and audio)" is satisfied (because Y < X).

[0374] Also, from the configuration of the video packet group in FIG. 47, it will satisfy the above-mentioned "The terminal can display video (and audio) by obtaining the video packet group 4502.", and can also realize the above-mentioned "The terminal can obtain higher reception quality of data (packets) by performing packet-level error correction decoding using the video packet group 4502 and the pre-transmission packet group 4501 stored in memory, and can decode the video with less video distortion."

[0375] In FIG. 48, 4801 indicates "information of the first video and / or audio", and let the number of bits of "information of the first video and / or audio" 4801 be X bits (X is a natural number).

[0376] Then, when using systematic codes or non-systematic codes in error correction coding at the packet level, assume that by encoding "information of the first video and / or audio" 4801, "first data" 4802 and "second data" 4803 are obtained.

[0377] Note that let the number of bits of "first data" 4802 be Z bits (Z is a natural number), and assume that Z>X holds. And let the number of bits of "second data" 4803 be Y bits (Y is a natural number), and assume that the relationship Y<X holds.

[0378] Then, assume that the video packet group 4502 in FIG. 45 is generated from "first data" 4802, and the pre-(transmission) packet group 4501 in FIG. 45 is generated from "second data" 4803 (for example, in each packet, additional information such as control information may be added).

[0379] When the video packet group and the pre-transmission packet group are generated as shown in FIG. 48, it will satisfy the above-mentioned "Even if the terminal receives the pre-transmission packet group 4501 and performs packet-level error correction decoding, it cannot obtain video (and audio)" (because Y<X is satisfied).

[0380] Furthermore, the configuration of the video packet group in FIG. 48 satisfies the above-mentioned "The terminal is capable of displaying video (and audio) by obtaining video packet group 4502.", and also realizes the above-mentioned "The terminal can obtain higher data (packet) reception quality by performing packet-level error correction decoding using video packet group 4502 and stored pre-transmitted packet group 4501, making it possible to decode video with less video distortion."

[0381] FIG. 49 shows an example of the configuration of a terminal that receives a group of packets transmitted as shown in FIG. 45, and components that operate in the same way as in FIG. 3 are given the same numbers and their explanations are omitted.

[0382] The storage unit 4901 receives the received data 314 and the control information signal 310, and if the control information signal 310 indicates that "the received data 314 is data of the prior (transmission) packet group 4501 in FIG. 45", it stores the received data 314. Then, when instructed, the storage unit 4901 outputs the data stored in the storage unit (stored data 4902).

[0383] The packet (or frame) processing unit 315 receives the received data 314, the stored data 4902, and the control information signal 310 as input.

[0384] When the control information signal 310 indicates that “the received data 314 is data of the advance (transmitted) packet group 4501 in FIG.

[0385] The case where the control information signal 310 indicates that "the received data 314 is data of the video packet group 4502 in FIG. 45."

[0386] When the memory unit 4901 stores the pre-transmitted packet group 4501 of FIG. 45, the packet (or frame) processing unit 315 performs packet-level error correction decoding using the received data 314 and the stored data 4902, and outputs the data 316 after packet (or frame) processing.

[0387] If the memory unit 4901 does not store the pre-transmitted packet group 4501 of FIG. 45, the packet (or frame) processing unit 315 performs packet-level error correction decoding using the received data 314, and outputs the data 316 after packet (or frame) processing.

[0388] If the control information signal 310 indicates "not the transmission method of Figure 45", the packet (or frame) processing unit 315 performs packet (or frame) processing based on the control information signal 310, and outputs data 316 after packet (or frame) processing.

[0389] By implementing the above, the terminal can obtain high data reception quality, and it is possible to obtain the effect of constructing a highly flexible broadcasting system (multicast system).

[0390] In the above, the case where the advance (transmission) packet is transmitted by the broadcast station has been described, but the present invention is not limited to this method, and therefore, hereinafter, a case where another transmission method is used will be described.

[0391] FIG. 50 shows the state of packets transmitted by the transmitting device of the broadcasting station and the telecommunication carrier in this embodiment, with the horizontal axis being time. In FIG. 50, 5001 is a pre-transmitted packet group, and this packet group (5001) is transmitted by the transmitting device of the telecommunication carrier. Then, a terminal that receives this packet group (5001) temporarily stores this packet group (5001). Note that even if a terminal receives the pre-transmitted packet group 5001 and performs packet-level error correction decoding, it is assumed that it is not possible to obtain video (and audio). (The characteristics of this case will be explained in detail later.) This has the characteristic that the receiving time period of a program including video can be uniquely set.

[0392] Reference numeral 5002 denotes a video packet group, and this packet group (5002) is transmitted by a broadcast station. The terminal is then able to display video (and audio) by receiving video packet group 5002. (The characteristics of this case will be explained in detail later.) The terminal also performs packet-level error correction decoding using video packet group 5002 and stored pre-transmitted packet group 5001, thereby achieving higher data (packet) reception quality and enabling video decoding with less video distortion.

[0393] Therefore, both a terminal that holds pretransmitted packet group 5001 and a terminal that does not hold pretransmitted packet group 5001 can decode the video by obtaining video packet group 5002.

[0394] Figure 51 shows an example of the configuration of a transmitting device of a broadcasting station and a telecommunications line provider that enables the transmitting device of the broadcasting station and the telecommunications line provider to transmit packets as shown in Figure 50. Components that operate in the same manner as in Figure 2 are given the same numbers and their explanations are omitted.

[0395] The packet (or frame) processing unit 202 receives the first video and / or audio information 201 and the first control signal 211 as input, performs packet-level error correction coding based on the first control signal 211, and outputs the first video and / or audio information 203 after packet (or frame) processing.

[0396] In this embodiment, the first video and / or audio information 203 after packet (or frame) processing is composed of pre-transmission packet group 5001 and video packet group 5002 in Fig. 50. At this time, pre-transmission packet group 5001 and video packet group 5002 in Fig. 50 do not show control information (information required for a terminal to perform processing such as demodulation, decoding, and signal processing), but when a transmission device of a telecommunications line provider transmits pre-transmission packet group 5001, it also transmits control information (control information is included in pre-transmission packet group 5001), and when a broadcasting station transmits video packet group 5002, it also transmits control information (control information is included in video packet group 5002).

[0397] Packet sorting unit 5100 receives first video and / or audio information 203 after packet (or frame) processing and first control signal 211 as input, and if first control signal 211 indicates that "a transmission method like that of FIG. 50 is adopted", it outputs pre-transmission (transmission) packet group 5103 and video packet group 5102. If first control signal 211 indicates that "a transmission method like that of FIG. 50 is not adopted", it outputs packet group 5101.

[0398] In FIG. 51, the broadcasting station is configured to include packet (or frame) processing unit 202 and packet distribution unit 5100, but this is not limited to this. A transmitting device of a telecommunications line provider may include packet (or frame) processing unit 202 and packet distribution unit 5100, or another device may include packet (or frame) processing unit 202 and packet distribution unit 5100.

[0399] Video packet storage unit 5104 receives video packet group 5102 and first control signal 211, and temporarily stores the video packet group. Then, based on first control signal 211, video packet storage unit 5104 outputs the stored video packet group as video packet group 5105.

[0400] Physical layer error correction coding unit 204 receives packet group 5101, video packet group 5105, and first control signal 211 as input, and if first control signal 211 indicates that "the transmission method as shown in Figure 50 is not adopted", performs physical layer error correction coding on packet group 5101, and outputs data 205 after error correction coding.

[0401] When the first control signal 211 indicates that "a transmission method as shown in Figure 50 is to be adopted", the physical layer error correction coding unit 204 outputs error correction coded data obtained by applying physical layer error correction coding to the video packet group 5105 according to the frame of Figure 50.

[0402] Signal processing unit 224 in the telecommunications carrier's transmitting device receives as input post-packet (or frame) processing information 223, pre- (transmission) packet group 5103, first control signal 211, and second control signal 228, and if first control signal 211 indicates that "a transmission method as shown in Figure 50 will be adopted," it performs signal processing on pre- (transmission) packet group 5103 in accordance with the frame of Figure 50, and outputs post-signal processing signal 225.

[0403] In other cases, based on the information of the second control signal 228, the signal processor 224 performs signal processing on the packet (or frame) processed information 223, and outputs the processed signal 225.

[0404] Next, the relationship between the advance (transmission) packet group 5103 (5001), the video packet group 5102 (5105) (5002), and the first video and / or audio information 201 will be described.

[0405] FIG. 47 shows an example of the relationship among packet group 5103 (5001), video packet group 5102 (5105) (5002), and the first video and / or audio information 201. Further, FIG. 48 shows an example of the relationship different from that in FIG. 47, i.e., the relationship among packet group 5103 (5001), video packet group 5102 (5105) (5002), and the first video and / or audio information 201.

[0406] In FIG. 47, 4701 indicates "the first video and / or audio information", and the number of bits of "the first video and / or audio information" 4701 is set to X bits (X is a natural number). When using an organizing code in error correction coding at the packet level, by encoding "the first video and / or audio information" 4701, "the first video and / or audio information" 4702 and parity 4703 are obtained. Note that "the first video and / or audio information" 4701 and "the first video and / or audio information" 4702 are the same data. Thus, the number of bits of "the first video and / or audio information" 4702 is X bits (X is a natural number). And let the number of bits of parity 4703 be Y bits (Y is a natural number), and the relationship Y < X holds.

[0407] Then, it is assumed that the video packet group 5002 in FIG. 50 is generated from "the first video and / or audio information" 4702, and the pre-transmission packet group 5001 in FIG. 50 is generated from parity 4703 (for example, in each packet, additional information such as control information may be added).

[0408] When the video packet group and the pre-transmission packet group are generated as shown in FIG. 47, the condition that "even if the terminal receives the pre-transmission packet group 5001 and performs error correction decoding at the packet level, it cannot obtain the video (and audio)" is satisfied (because Y < X).

[0409] Also, from the configuration of the video packet group in FIG. 47, it is satisfied that "the terminal can display video (and audio) by obtaining the video packet group 5002." Also, it is possible to realize "the terminal can obtain higher reception quality of data (packets) by performing packet-level error correction decoding using the video packet group 5002 and the pre-transmission packet group 5001 stored in memory, and can decode the video with less video distortion."

[0410] In FIG. 48, 4801 indicates "the information of the first video and / or audio", and let the number of bits of "the information of the first video and / or audio" 4801 be X bits (X is a natural number).

[0411] And in error correction coding at the packet level, when using systematic codes or non-systematic codes, it is assumed that "the first data" 4802 and "the second data" 4803 are obtained by encoding "the information of the first video and / or audio" 4801 (for example, in each packet, additional information such as control information may be added).

[0412] Let the number of bits of "the first data" 4802 be Z bits (Z is a natural number), and assume that Z>X holds. And let the number of bits of "the second data" 4803 be Y bits (Y is a natural number), and assume that the relationship Y<X holds.

[0413] Then, it is assumed that the video packet group 5002 in FIG. 50 is generated from "the first data" 4802, and the pre-transmission packet group 5001 in FIG. 50 is generated from "the second data" 4803.

[0414] When the video packet group and the pre-transmission packet group are generated as shown in FIG. 48, it is satisfied that "the terminal cannot obtain video (and audio) even if it receives the pre-transmission packet group 5001 and performs packet-level error correction decoding" (because Y<X is satisfied).

[0415] Furthermore, the configuration of the video packet group in Figure 48 satisfies the above-mentioned "The terminal is capable of displaying video (and audio) by obtaining video packet group 5002.", and also realizes the above-mentioned "The terminal can obtain higher data (packet) reception quality by performing packet-level error correction decoding using video packet group 5002 and stored pre-transmitted packet group 5001, making it possible to decode video with less video distortion."

[0416] FIG. 52 shows an example of the configuration of a terminal that receives a group of packets transmitted as shown in FIG. 50, and components that operate in the same manner as in FIG. 3 are given the same numbers and their explanations are omitted.

[0417] The storage unit 5201 receives the control information signal 310, the received data 356, and the control information 357 as input, and if the control information 357 indicates that "the received data 356 is data of the prior (transmission) packet group 5001 in FIG. 50", it stores the received data 356. Then, when instructed by the control information signal 310, the storage unit 5201 outputs the data stored in the storage unit (stored data 5202).

[0418] A packet (or frame) processing unit 358 receives received data 314 and control information 357, and if the control information 357 indicates "not the transmission method of Figure 50", performs packet (or frame) processing based on the control information 357, and outputs data 359 after packet (or frame) processing.

[0419] The packet (or frame) processing unit 315 receives the received data 314, the stored data 5202, and the control information signal 310 as input.

[0420] The case where the control information signal 310 indicates that "the received data 314 is data of the video packet group 5002 in FIG. 50."

[0421] When the memory unit 5201 stores the pre-transmitted packet group 5001 of FIG. 50, the packet (or frame) processing unit 315 performs packet-level error correction decoding using the received data 314 and the stored data 5202, and outputs the data 316 after packet (or frame) processing.

[0422] If the memory unit 5201 does not store the pre-transmitted packet group 5001 of FIG. 50, the packet (or frame) processing unit 315 performs packet-level error correction decoding using the received data 314, and outputs the packet (or frame) processed data 316.

[0423] If the control information signal 310 indicates "not the transmission method of Figure 50", the packet (or frame) processing unit 315 performs packet (or frame) processing based on the control information signal 310, and outputs data 316 after packet (or frame) processing.

[0424] By implementing the above, the terminal can obtain high data reception quality, and it is possible to obtain the effect of constructing a highly flexible broadcasting system (multicast system).

[0425] Naturally, the broadcasting station may use a transmission method other than that of this embodiment, and in such a case, the broadcasting station will switch between the transmission method of this embodiment and the transmission method other than that of this embodiment.

[0426] (Embodiment 6) In the first to fifth embodiments, a configuration in which the terminal is equipped with a display unit has been described. However, the configuration of the terminal is not limited to this configuration, and a configuration in which the terminal is equipped with a display unit and is connectable to another device having a display unit (called a display device), a configuration in which the terminal does not have a display unit, etc. are conceivable.

[0427] The detailed configuration of a terminal in the case where the terminal is used to implement the first to fifth embodiments will be described below.

[0428] First, a configuration in which a terminal is provided with a display device and can be connected to another device having a display unit (called a display device) will be described.

[0429] FIG. 53 shows an example of the configuration around the display unit in the terminals of FIGS. 3, 28, 33, 37, 39, 52, etc., and the same numbers are used for components that operate in the same way as in FIG. 3.

[0430] Decoder 382 receives data 381 and control signal 5301 as input. If control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs, for example, video data after decoding of the "first video and / or audio information" as 383 in Fig. 53, and audio data after decoding of the "first video and / or audio information" as 385 in Fig. 53. At this time, display unit 384 displays the first video.

[0431] In addition, since the control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, the decoder 382 outputs the video data after decoding of the "second video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "second video and / or audio information" as 5303 in FIG. 53. The video data after decoding of the "second video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "second video and / or audio information" as 5303 in FIG. 53 are delivered to the display device 5306 via the connection unit 5304. (Note that the connection 5305 may be either wireless or wired.) The display device 5306 displays the second video (note that the second audio may be played from a speaker).

[0432] Another example will be described.

[0433] Decoder 382 receives data 381 and control signal 5301 as input. If control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs, for example, video data after decoding of the "second video and / or audio information" as 383 in Fig. 53, and audio data after decoding of the "second video and / or audio information" as 385 in Fig. 53. At this time, display unit 384 displays the second video.

[0434] In addition, since the control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, the decoder 382 outputs the video data after decoding of the "first video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "first video and / or audio information" as 5303 in FIG. 53. The video data after decoding of the "first video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "first video and / or audio information" as 5303 in FIG. 53 are delivered to the display device 5306 via the connection unit 5304. (Note that the connection 5305 may be either wireless or wired.) The display device 5306 displays the first video (note that the first audio may be played from a speaker).

[0435] As in the above example, either the first image or the second image may be displayed on the display unit 384, and either the first image or the second image may be displayed on the display device 5306. The display method may be controlled by, for example, the control signal 5301.

[0436] Note that the control signal 5301 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on the display unit 384 as described in the other embodiments. The control signal 5301 may also include control information for adjusting the display timing of the display unit 384 and the display device 5306.

[0437] Figure 54 shows an example of the configuration around the display unit in terminals such as Figures 3, 28, 33, 37, 39, and 52, and parts that operate in the same way as in Figures 3 and 53 are given the same numbers.

[0438] Data separation unit (which may be called a "data control unit") 5402 receives data 381 and control signal 5401. If control signal 5401 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5402 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "first video and / or audio information" as data 5407, and outputs the data related to the "second video and / or audio information" as data 5403.

[0439] Then, decoder 382 receives data 5407, performs decoding, and the first video is displayed on display unit 384.

[0440] Moreover, data related to the "second video and / or audio information" is delivered to the display device 5306 via the connection unit 5404. (Note that the connection 5305 may be either wireless or wired.) The display device 5306 displays the second video (note that the second audio may be played from a speaker).

[0441] Another example will be described.

[0442] Data separation unit (which may be called a "data control unit") 5402 receives data 381 and control signal 5401. If control signal 5401 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5402 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "second video and / or audio information" as data 5407, and outputs the data related to the "first video and / or audio information" as data 5403.

[0443] Then, the decoder 382 receives the data 5407, decodes it, and the second video is displayed on the display unit 384.

[0444] Moreover, data related to the "first video and / or audio information" is delivered to the display device 5306 via the connection unit 5404. (Note that the connection 5305 may be either wireless or wired.) The display device 5306 displays the first video (note that the first audio may be played from a speaker).

[0445] As in the above example, either the first image or the second image may be displayed on the display unit 384, and either the first image or the second image may be displayed on the display device 5306. The display method may be controlled by, for example, the control signal 5401.

[0446] Note that the control signal 5401 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on the display unit 384 as described in the other embodiments. The control signal 5401 may also include control information for adjusting the display timing of the display unit 384 and the display device 5306.

[0447] In the case of FIG. 54, the display device 5308 has a video decoder.

[0448] FIG. 55 shows an example of the configuration of the periphery of the display unit in the terminal of FIG. 42 etc., and the same numbers are used for components that operate in the same manner as in FIG. 3 and FIG.

[0449] When the terminal has the configuration of FIG. 55, the display unit 384 will perform any one of the following: "display a first image", "display a second image", "display both the first image and the second image", "display {first image} and {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}", "display {second image} and {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}".

[0450] Then, display device 5510 will perform any one of the following: "display a first video", "display a second video", "display both the first video and the second video", "display {first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", "display {second video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}".

[0451] Decoder 382 receives data 381 and control signal 5504. If control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs, for example, video data after decoding of the "first video and / or audio information" as 383 in Fig. 55, and audio data after decoding of the "first video and / or audio information" as 385 in Fig. 55. At this time, display unit 384 displays the first video.

[0452] In addition, since control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs the decoded video data of the "second video and / or audio information" as 5501 in Figure 55, and the decoded audio data of the "second video and / or audio information" as 5502 in Figure 55.

[0453] Then, the decoded video data of the "second video and / or audio information" 5501 in Fig. 55, and the decoded audio data of the "second video and / or audio information" 5302 in Fig. 55 are delivered to a display device 5510 via a selection unit 5505 and a connection unit 5508. (Note that connection 5509 may be either wireless or wired.) The display device 5510 displays the second video (note that the second audio may be played from a speaker).

[0454] Another example will be described.

[0455] Decoder 382 receives data 381 and control signal 5504. If control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs, for example, video data after decoding of the "second video and / or audio information" as 383 in Fig. 55, and audio data after decoding of the "second video and / or audio information" as 385 in Fig. 55. At this time, display unit 384 displays the second video.

[0456] In addition, since control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs the decoded video data of the "first video and / or audio information" as 5501 in FIG. 55, and the decoded audio data of the "first video and / or audio information" as 5502 in FIG. 55.

[0457] Then, the decoded video data of the "first video and / or audio information" 5501 in Fig. 55, and the decoded audio data of the "first video and / or audio information" 5302 in Fig. 55 are delivered to a display device 5510 via a selection unit 5505 and a connection unit 5508. (Note that connection 5509 may be either wireless or wired.) The display device 5510 displays the first video (note that the first audio may be played from a speaker).

[0458] Decoder 4205 receives as input “received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing”, information 4210 from the URL, and control signal 5504 .

[0459] When the control signal 5504 indicates that either "received data 4204 of character information (message information) after packet (or frame) processing, and / or still image information, and / or URL information" or information 4210 from the URL is to be displayed on the display unit 384, information 4206 on the display screen is output.

[0460] When the control signal 5504 indicates that either "received data 4204 of character information (message information) after packet (or frame) processing, and / or still image information, and / or URL information" or information 4210 from the URL is to be displayed on the display device 5510, information 5503 on the display screen is output.

[0461] Selection unit 5505 receives signals 5501 , 5502 , 5505 and control signal 5504 as input, and outputs display information to be displayed on display device 5510 and sound information to be played from the speaker as 5506 , 5507 based on control signal 5504 .

[0462] The signals 5506 , 5507 are then transmitted via connection 5508 to a display device 5510 .

[0463] As in the above example, a plurality of screens may be displayed on the display unit 384, or the terminal may transmit a portion of the display information to the display device 5306, which then displays the video (or screen). The display method may be controlled by, for example, the control signal 5504.

[0464] Control signal 5504 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on display unit 384 as described in other embodiments. Control signal 5504 may also include control information for adjusting the display timing of display unit 384 and display device 5510.

[0465] FIG. 56 shows an example of the configuration of the periphery of the display unit in the terminal of FIG. 42 etc., and the same reference numbers are used for components that operate in the same manner as in FIG. 3 and FIG.

[0466] When the terminal has the configuration of FIG. 56, the display unit 384 will perform any one of the following: "display a first image", "display a second image", "display both the first image and the second image", "display {first image} and {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}", "display {second image} and {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}".

[0467] Then, display device 5510 will perform any one of the following: "display a first video", "display a second video", "display both the first video and the second video", "display {first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", "display {second video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}".

[0468] Data separation unit (data control unit) 5602 receives data 381 and control signal 5601. When control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5602 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "first video and / or audio information" as data 5603, and outputs the data related to the "second video and / or audio information" as data 5604.

[0469] Then, the decoder 382 receives the data 5407, performs decoding, and the first image becomes a candidate for display on the display unit 384 (the image to be displayed on the display unit 384 is selected from among the candidate images based on the determination result 4201).

[0470] Then, data related to the "second video and / or audio information" is delivered to the display device 5613 via the selection unit 5608 and the connection unit 5611. (Note that the connection 5612 may be either wireless or wired.) The display device 5613 displays the second video (note that the second audio may be played from a speaker).

[0471] Another example will be described.

[0472] Data separation unit (data control unit) 5602 receives data 381 and control signal 5601. When control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5602 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "second video and / or audio information" as data 5603, and outputs the data related to the "first video and / or audio information" as data 5604.

[0473] Then, the decoder 382 receives the data 5407, performs decoding, and the second image becomes a candidate for display on the display unit 384 (the image to be displayed on the display unit 384 is selected from among the candidate images based on the determination result 4201).

[0474] Then, data related to the "first video and / or audio information" is delivered to the display device 5613 via the selection unit 5608 and the connection unit 5611. (Note that the connection 5612 may be either wireless or wired.) The display device 5613 displays the first video (note that the first audio may be played from a speaker).

[0475] Data separation unit (data control unit) 5605 receives as input “received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing”, information from the URL 4210, and control signal 5601.

[0476] When control signal 5601 indicates that either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL is to be displayed on display unit 384, data separation unit (data control unit) 5605 outputs either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL as signal 5606.

[0477] When control signal 5601 indicates that either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL is to be displayed on display device 5510, data separation unit (data control unit) 5605 outputs either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL as signal 5607.

[0478] A selection unit 5608 receives signals 5604 and 5607 and a control signal 5601 as input, and outputs display information to be displayed on a display device 5613 and sound information to be output from a speaker as signals 5609 and 5610 based on the control signal 5601 .

[0479] The signals 5609 , 5610 are then transmitted via connection 5611 to a display device 5613 .

[0480] As in the above example, a plurality of screens may be displayed on the display unit 384, or the terminal may transmit a portion of the display information to the display device 5613, which then displays the video (or screen). The display method may be controlled by, for example, the control signal 5601.

[0481] Note that control signal 5601 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on display unit 384 as described in other embodiments. Control signal 5601 may also include control information for adjusting the display timing of display unit 384 and display device 5613.

[0482] In the above example, an embodiment in which the terminal has a display unit and can be connected to another display device has been described, but in this case, even in a case different from the above example, two images may be displayed by using both the display unit of the terminal and the other display device. For example, an image transmitted by a broadcaster may be displayed on the display unit of the terminal, and an image, text information, or still image (which may include text) linked to the image may be displayed on the other display device. Also, an image transmitted by a broadcaster may be displayed on the other display device, and an image, text information, or still image (which may include text) linked to the image may be displayed on the display unit of the terminal. In addition, when transmitting data, the transmission method described in the fifth embodiment may be applied.

[0483] Next, a configuration in which the terminal does not have a display unit will be described.

[0484] Figure 57 shows an example of the configuration around the display unit of a terminal such as Figures 3, 28, 33, 37, 39, and 52, and parts that operate in the same way as in Figures 3 and 53 are given the same numbers.

[0485] The decoder 382 receives as input data 381 and control signal 5301. When the control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, the decoder 382 outputs, for example, video data after decoding of the "first video and / or audio information" as 383 in Fig. 53, and audio data after decoding of the "first video and / or audio information" as 385 in Fig. 53, which are transmitted to the display device 5703 via the connection unit 5701, and the display device 5703 displays the first video and outputs the audio (note that the connection 5702 may be either wireless or wired).

[0486] In addition, since the control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, the decoder 382 outputs the video data after decoding of the "second video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "second video and / or audio information" as 5303 in FIG. 53. The video data after decoding of the "second video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "second video and / or audio information" as 5303 in FIG. 53 are delivered to the display device 5306 via the connection unit 5304 (note that the connection 5305 may be either wireless or wired). The display device 5306 displays the second video (note that the second audio may be played from a speaker).

[0487] Another example will be described.

[0488] The decoder 382 receives as input data 381 and control signal 5301. When the control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, the decoder 382 outputs, for example, video data after decoding of the "second video and / or audio information" as 383 in Fig. 53, and audio data after decoding of the "second video and / or audio information" as 385 in Fig. 53, which are transmitted to the display device 5703 via the connection unit 5701, and the display device 5703 displays the second video and outputs the audio (note that the connection 5702 may be either wireless or wired).

[0489] In addition, since the control signal 5301 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, the decoder 382 outputs the video data after decoding of the "first video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "first video and / or audio information" as 5303 in FIG. 53. The video data after decoding of the "first video and / or audio information" as 5302 in FIG. 53, and the audio data after decoding of the "first video and / or audio information" as 5303 in FIG. 53 are delivered to the display device 5306 via the connection unit 5304 (note that the connection 5305 may be either wireless or wired). The display device 5306 displays the first video (note that the first audio may be played from a speaker).

[0490] As in the above example, either the first image or the second image may be displayed on the display device 5306, and the display device 5306 may also display either the first image or the second image. The display method may be controlled by, for example, the control signal 5301.

[0491] Note that control signal 5301 may include control information that allows switching between displaying the first video and the second video as described above and displaying the first video and the second video on display unit 384 as described in other embodiments. Control signal 5301 may also include control information for adjusting display device 5306 and the display timing of display device 5306.

[0492] Figure 58 shows an example of the configuration around the display unit in terminals such as Figures 3, 28, 33, 37, 39, and 52, and parts that operate in the same way as in Figures 3, 53, and 54 are given the same numbers.

[0493] Data separation unit (which may be called a "data control unit") 5402 receives data 381 and control signal 5401. If control signal 5401 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5402 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "first video and / or audio information" as data 5407, and outputs the data related to the "second video and / or audio information" as data 5403.

[0494] Then, the decoder 382 receives the data 5407 as input, and outputs the decoded data (video, audio) 383, 395. Then, the decoded data (video, audio) 383, 395 and the data 5407 are transmitted to the display device 5803 via a connection unit 5801 (note that the connection 5802 may be either wireless or wired), and the display device 5803 displays the first video (note that the first audio may be played from a speaker).

[0495] Moreover, data related to the "second video and / or audio information" is delivered to the display device 5306 via the connection unit 5404. (Note that the connection 5305 may be either wireless or wired.) The display device 5306 displays the second video (note that the second audio may be played from a speaker).

[0496] Another example will be described.

[0497] Data separation unit (which may be called a "data control unit") 5402 receives data 381 and control signal 5401. If control signal 5401 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5402 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "second video and / or audio information" as data 5407, and outputs the data related to the "first video and / or audio information" as data 5403.

[0498] Then, the decoder 382 receives the data 5407 as input, and outputs the decoded data (video, audio) 383, 395. Then, the decoded data (video, audio) 383, 395 and the data 5407 are transmitted to the display device 5803 via a connection unit 5801 (note that the connection 5802 may be either wireless or wired), and the display device 5803 displays the second video (note that the second audio may be played from a speaker).

[0499] Moreover, data related to the "first video and / or audio information" is delivered to the display device 5306 via the connection unit 5404. (Note that the connection 5305 may be either wireless or wired.) The display device 5306 displays the first video (note that the first audio may be played from a speaker).

[0500] As in the above example, either the first image or the second image may be displayed on the display device 5803, and either the first image or the second image may be displayed on the display device 5306. The display method may be controlled by, for example, the control signal 5401.

[0501] Control signal 5401 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on display device 5803 as described in other embodiments. Control signal 5401 may also include control information for adjusting the display timing of display device 5803 and display device 5306.

[0502] In the case of FIG. 58, the display device 5308 has a video decoder.

[0503] FIG. 59 shows an example of the configuration of the periphery of the display unit in a terminal such as FIG. 42, and components that operate in the same manner as in FIG. 3, FIG. 42, and FIG. 55 are given the same numbers.

[0504] When the terminal has the configuration of FIG. 59, the display device 5903 will perform any one of the following: "display a first video", "display a second video", "display both the first video and the second video", "display {a first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", "display {a second video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}".

[0505] Then, display device 5510 will perform any one of the following: "display a first video", "display a second video", "display both the first video and the second video", "display {first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", "display {second video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}".

[0506] Decoder 382 receives data 381 and control signal 5504. If control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs, for example, video data after decoding of the "first video and / or audio information" as 383 in Fig. 59, and audio data after decoding of the "first video and / or audio information" as 385 in Fig. 59.

[0507] Then, the signals 383, 385, and 4206 are transmitted to the display device 5903 via a connection 5901 (note that the connection 5902 may be either wireless or wired).

[0508] In addition, since control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs the decoded video data of the "second video and / or audio information" as 5501 in Figure 59, and the decoded audio data of the "second video and / or audio information" as 5502 in Figure 59.

[0509] Then, the decoded video data of the "second video and / or audio information" 5501 in Fig. 59, and the decoded audio data of the "second video and / or audio information" 5302 in Fig. 59 are delivered to a display device 5510 via a selection unit 5505 and a connection unit 5508. (Note that connection 5509 may be either wireless or wired.) The display device 5510 displays the second video (note that the second audio may be played from a speaker).

[0510] Another example will be described.

[0511] Decoder 382 receives data 381 and control signal 5504. If control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs, for example, video data after decoding of the "second video and / or audio information" as 383 in Fig. 59, and audio data after decoding of the "second video and / or audio information" as 385 in Fig. 59.

[0512] Then, the signals 383, 385, and 4206 are transmitted to the display device 5903 via a connection 5901 (note that the connection 5902 may be either wireless or wired).

[0513] In addition, since control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, decoder 382 outputs the decoded video data of the "first video and / or audio information" as 5501 in Figure 59, and the decoded audio data of the "first video and / or audio information" as 5502 in Figure 59.

[0514] Then, the decoded video data of the "first video and / or audio information" 5501 in Fig. 59 and the decoded audio data of the "first video and / or audio information" 5302 in Fig. 59 are delivered to a display device 5510 via a selection unit 5505 and a connection unit 5508. (Note that connection 5509 may be either wireless or wired.) The display device 5510 displays the first video (note that the first audio may be played from a speaker).

[0515] Decoder 4205 receives as input “received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing”, information 4210 from the URL, and control signal 5504 .

[0516] When the control signal 5504 indicates that either "received data 4204 of character information (message information) after packet (or frame) processing, and / or still image information, and / or URL information" or information 4210 from the URL is to be displayed, information 4206 on the display screen is output.

[0517] When the control signal 5504 indicates that either "received data 4204 of character information (message information) after packet (or frame) processing, and / or still image information, and / or URL information" or information 4210 from the URL is to be displayed on the display device 5510, information 5503 on the display screen is output.

[0518] Selection unit 5505 receives signals 5501 , 5502 , 5505 and control signal 5504 as input, and outputs display information to be displayed on display device 5510 and sound information to be played from the speaker as 5506 , 5507 based on control signal 5504 .

[0519] The signals 5506 , 5507 are then transmitted via connection 5508 to a display device 5510 .

[0520] As in the above example, a plurality of screens may be displayed on the display device 5510, or the terminal may transmit a portion of the display information to the display device 5306, which then displays the video (or screen). The display method may be controlled by, for example, the control signal 5504.

[0521] Control signal 5504 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on display unit 384 as described in other embodiments. Control signal 5504 may also include control information for adjusting the display timing of display unit 384 and display device 5510.

[0522] FIG. 60 shows an example of the configuration of the periphery of the display unit in the terminal of FIG. 42 etc., and the same numbers are used for components that operate in the same manner as in FIG. 3, FIG. 42 and FIG.

[0523] When the terminal has the configuration of FIG. 56, the display device 6003 will perform any one of the following: "display a first video", "display a second video", "display both the first video and the second video", "display {a first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", "display {a second video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}".

[0524] Then, display device 5510 will perform any one of the following: "display a first video", "display a second video", "display both the first video and the second video", "display {first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", "display {second video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}", or "display {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}".

[0525] Data separation unit (data control unit) 5602 receives data 381 and control signal 5601. When control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5602 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "first video and / or audio information" as data 5603, and outputs the data related to the "second video and / or audio information" as data 5604.

[0526] Then, the decoder 382 receives the data 5407, decodes it, and outputs the data 383 of the first video and the audio data 385.

[0527] Then, data related to the "second video and / or audio information" is delivered to the display device 5613 via the selection unit 5608 and the connection unit 5611. (Note that the connection 5612 may be either wireless or wired.) The display device 5613 displays the second video (note that the second audio may be played from a speaker).

[0528] Another example will be described.

[0529] Data separation unit (data control unit) 5602 receives data 381 and control signal 5601. When control signal 5504 indicates that the "first video and / or audio information" and the "second video and / or audio information" are to be displayed on separate display units, data separation unit (data control unit) 5602 separates data 381 into data related to the "first video and / or audio information" and data related to the "second video and / or audio information", outputs the "second video and / or audio information" as data 5603, and outputs the data related to the "first video and / or audio information" as data 5604.

[0530] Then, the decoder 382 receives the data 5407, decodes it, and outputs the secondary video data 383 and audio data 385.

[0531] Then, data related to the "first video and / or audio information" is delivered to the display device 5613 via the selection unit 5608 and the connection unit 5611. (Note that the connection 5612 may be either wireless or wired.) The display device 5613 displays the first video (note that the first audio may be played from a speaker).

[0532] Data separation unit (data control unit) 5605 receives as input “received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing”, information from the URL 4210, and control signal 5601.

[0533] When control signal 5601 indicates that either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL is to be displayed on display unit 384, data separation unit (data control unit) 5605 outputs either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL as signal 5606.

[0534] When control signal 5601 indicates that either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL is to be displayed on display device 5510, data separation unit (data control unit) 5605 outputs either "received data 4204 of character information (message information) and / or still image information and / or URL information after packet (or frame) processing" or information 4210 from the URL as signal 5607.

[0535] A selection unit 5608 receives signals 5604 and 5607 and a control signal 5601 as input, and outputs display information to be displayed on a display device 5613 and sound information to be output from a speaker as signals 5609 and 5610 based on the control signal 5601 .

[0536] The signals 5609 , 5610 are then transmitted via connection 5611 to a display device 5613 .

[0537] The connection unit 5901 is connected (5902) to a display device 5903, and the display device 5903 displays video and outputs audio from a speaker (note that the connection 5902 may be either wireless or wired).

[0538] As in the above example, a plurality of screens may be displayed on the display device 5903, or the terminal may transmit a portion of the display information to the display device 5613, which then displays the video (or screen). The display method may be controlled by the control signal 5601, for example.

[0539] Control signal 5601 may include control information for switching between displaying the first video and the second video as described above and displaying the first video and the second video on display device 5903 as described in other embodiments. Control signal 5601 may also include control information for adjusting the display timing of display device 5903 and display device 5613.

[0540] In the above example, an embodiment in which the terminal can be connected to the first display device and the second display device has been described, but in this case, even in a case different from the above example, two images may be displayed by using both the first display device and the second display device. For example, an image transmitted by a broadcaster may be displayed on the first display device, and an image, text information, or a still image (which may include text) linked to the image may be displayed on the second display device. Also, an image transmitted by a broadcaster may be displayed on the second display device, and an image, text information, or a still image (which may include text) linked to the image may be displayed on the first display device. In addition, when transmitting data, a transmission method such as that described in the fifth embodiment may be applied.

[0541] By implementing the above, the terminal can obtain high data reception quality, and it is possible to obtain the effect of constructing a highly flexible broadcasting system (multicast system).

[0542] Naturally, the broadcasting station may use a transmission method other than that of this embodiment, and in such a case, the broadcasting station will switch between the transmission method of this embodiment and the transmission method other than that of this embodiment.

[0543] (Supplementary Note 1) In this specification, the expression "video (and / or audio information)" is used, but the main embodiment assumes that the information being sent / received includes video information.

[0544] In this specification, the term "audio" is used, but the same implementation can be carried out even if the "audio" is audio, sound, or the like.

[0545] In this specification, as the configuration of the receiving device of the terminal, for example, in Figures 3, 28, 33, 37, 39, 42, 49, 52, etc., a display unit is described, but the terminal does not have to have a display unit. In this case, for example, the terminal may have a configuration of "a terminal having a terminal for outputting video and / or audio data" or "a terminal having a storage unit (hard disk, semiconductor memory, disk) for recording video and / or audio data" (in this case, the video and / or audio data may be the data itself obtained by the terminal through a receiving operation, or may be data obtained by converting the format of the data obtained by the terminal through a receiving operation).

[0546] Furthermore, as the configuration of the receiving device of the terminal, for example, Figures 3, 28, 33, 37, 39, 42, 49, 52, etc. show a display unit, but when the terminal does not have a display unit, the terminal can have an output unit that outputs "video and / or audio data", and by connecting the display device of this output unit, the user can view the video and / or audio.

[0547] Of course, the embodiments and other contents described in this specification may be combined in combination.

[0548] Furthermore, each embodiment and other contents are merely examples. For example, even if a "modulation method, error correction coding method (error correction code to be used, code length, coding rate, etc.), control information, etc." is given as an example, it is possible to implement the same configuration even if a different "modulation method, error correction coding method (error correction code to be used, code length, coding rate, etc.), control information, etc." is applied.

[0549] In addition to data (information), each packet and each frame may also include symbols for transmitting control information (such as information regarding the transmission method), preambles for performing demodulation, pilot symbols, reference symbols, unique words, postambles, and other symbols (however, these symbols may be named in any way, and it is their function itself that is important).

[0550] In this specification, the broadcast station transmits data wirelessly, and the transmission method at that time may be any transmission method, such as a single carrier transmission method, a multicarrier transmission method such as an OFDM (Orthogonal Frequency Division Multiplexing) method, a transmission method using a spread spectrum communication method, a transmission method in which multiple modulated signals are transmitted at the same time and at the same frequency by performing precoding or space-time (or time-frequency) coding (for example, space-time block codes). The broadcast station may also use a method of transmitting data using a wire such as a cable.

[0551] In this specification, an example is described in which data transmitted by a transmitting device of a telecommunications carrier is transmitted by wire, but a method of transmitting data wirelessly may also be used. Also, a method using both wired and wireless transmission may also be used.

[0552] In this specification, the receiving device and the antenna of the terminal may be separate. For example, the receiving device may have an interface that inputs, via a cable, a signal received by the antenna or a signal that has been frequency-converted from the signal received by the antenna, and the receiving device performs subsequent processing.

[0553] The data and information obtained by the receiving device is then converted into video and sound, and is displayed on a display (monitor), or the sound is output from a speaker. Furthermore, the data and information obtained by the receiving device may be subjected to signal processing related to video and sound (signal processing may not be performed), and may be output from an RCA terminal (video terminal, audio terminal), USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), HDMI (registered trademark) 2.0 digital terminal, etc., that the receiving device has.

[0554] In this specification, the receiving device may be a communication device such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, a base station, etc. Also, the transmitting device and the receiving device in this disclosure may be a device having a communication function, and may be in a form that allows the device to be connected via some interface to a device for executing an application, such as a television, a radio, a personal computer, or a mobile phone.

[0555] In addition, the present disclosure is not limited to each embodiment, and can be implemented with various modifications. For example, in each embodiment, the case where the communication is performed as a communication device is described, but the present disclosure is not limited to this, and the communication method can also be implemented as software.

[0556] Both the transmitting antenna of the transmitting device and the receiving antenna of the receiving device, which are illustrated as one antenna in the drawings, may be configured with a plurality of antennas.

[0557] For example, a program for executing the above communication method is stored in a ROM (Read Only Memory). Alternatively, the program may be stored in a local memory (RAM) and run by a CPU (Central Processing Unit).

[0558] In addition, a program for executing the above-mentioned communication method may be stored in a computer-readable storage medium, and the program stored in the storage medium may be recorded in the computer's RAM (Random Access Memory), causing the computer to operate according to the program.

[0559] Each of the configurations of the above-mentioned embodiments may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be individually implemented as single chips, or may be implemented as a single chip that includes all or part of the configurations of each embodiment.

[0560] Here, we refer to it as LSI, but depending on the level of integration, it may also be called IC (Integrated Circuit), system LSI, super LSI, or ultra LSI. Also, the method of integration is not limited to LSI, but may be realized by dedicated circuits or general-purpose processors. It is also possible to use FPGA (Field Programmable Gate Array), which can be programmed after LSI manufacturing, or reconfigurable processors, which can reconfigure the connections and settings of circuit cells inside LSI.

[0561] Furthermore, if an integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a different derived technology, it is natural that such technology may be used to integrate the functional blocks. The application of biotechnology, etc. is also a possibility.

[0562] (Supplementary Note 2) In the above embodiments 1 to 3, an example has been given in which a broadcast station and a telecommunications carrier each transmit content via one or multiple routes (transmission media). However, it goes without saying that the control of transmission timing described in the above embodiments 1 to 3 can also be applied in cases in which, for example, a broadcast station transmits content using multiple transmission media, or a telecommunications carrier transmits content via multiple routes.

[0563] For example, telecommunications carrier #1 and telecommunications carrier #2 may transmit content via multiple routes (transmission media), or broadcast station #1 and broadcast station #2 may transmit content via multiple routes (transmission media). Note that although there are two transmitting stations, more than two broadcast stations may transmit content via multiple routes (transmission media).

[0564] Furthermore, for example, when a telecommunications carrier (transmitting station, base station) transmits content via multiple different routes including a first route and a second route, a transmitting device owned by the telecommunications carrier may control the transmission timing of either or both of a packet group transmitted via a first route and a packet group transmitted via a second route, depending on the difference between a first time from when the transmitting device transmits data until the data arrives at a terminal via the first route and a second time from when the transmitting device transmits data until the data arrives at a terminal via the second route (i.e., multiple communication routes are used and time division is performed (however, at least some packets may be transmitted simultaneously), and the packet group is delivered to the terminal. However, the packet group will include information indicating whether error correction coding at the packet level has been performed or not, as shown in this specification).

[0565] Here, the first route and the second route may be the same as long as at least a part of the route is different. In addition, if a difference occurs in the time from when the transmitting device transmits data to when the data arrives at the terminal due to the use of different transmission media or different protocols between some relay devices, the routes may be regarded as different routes even if the devices on the routes are all the same, and the transmission timing may be controlled.

[0566] On the other hand, even if the data actually passes through different relay devices, if the difference in time between when the data is transmitted from the transmitting device and when the data arrives at the terminal is small, the routes may be treated as the same route. For example, if content is actually transmitted through three or more routes, but the three or more routes can be classified into a first group in which the time between when the data is transmitted from the transmitting device and when the data arrives at the terminal is included in a first range, and a second group in which the time between when the data is transmitted from the transmitting device and when the data arrives at the terminal is included in a second range different from the first range, the first group and the second group may be regarded as the first route and the second route, respectively, to control the transmission timing.

[0567] Furthermore, the transmitting device that transmits the packet group along the first route and the transmitting device that transmits the packet group along the second route may be the same or different.

[0568] This makes it possible to prevent disturbances in the contents being played back in synchronization, and also to reduce the scale of the circuitry in the terminal.

[0569] In addition, in the above embodiments 1 to 3, an example has been described in which a broadcasting station and a telecommunications carrier transmit a first and a second multi-angle video captured by multiple cameras, respectively. However, the content to be transmitted does not have to be a first and a second multi-angle video. If it is necessary to play back data transmitted via each path in a synchronized manner, the effect of suppressing the occurrence of disruptions to the content to be played back in a synchronized manner can be obtained by controlling the transmission timing as described in embodiments 1 to 3.

[0570] For example, audio and video that are played back in synchronization may be transmitted over different paths, or encoded data generated by encoding video may be separated into a first stream and a second stream, and the separated first stream and second stream may be transmitted over different paths. Here, the first stream may include first-layer encoded data that can be played back alone as low-quality video, and the second stream may include second-layer encoded data that can be played back as high-quality video in combination with the first-layer encoded data, or both the first stream and the second stream may include encoded data that needs to be played back in combination with encoded data included in the other stream. Furthermore, the second stream may include encoded data that is the same as at least a portion of the encoded data included in the first stream.

[0571] It goes without saying that the method of controlling transmission timing described in this supplementary appendix 2 may be implemented in combination with any one or more of the fourth to sixth embodiments.

[0572] In this disclosure, the examples of services provided by multicast have been mainly described, but it goes without saying that the present disclosure can be applied to services provided by unicast. In other words, a group of packets may be transmitted by multiple telecommunications carriers via multiple routes, and at this time, terminal feedback may be provided to each telecommunications carrier, and the telecommunications carrier may accept a request to retransmit packets. [Industrial Applicability]

[0573] INDUSTRIAL APPLICABILITY The present disclosure is useful, for example, in transmitting high-quality video information in a broadcasting and communication cooperation service. [Explanation of symbols]

[0574] 102A, 102B Camera 103 Broadcasting Station 104 Telecommunications Line Providers 105 Terminals

Claims

1. receiving first data via broadcast, the first data being data obtained by deleting some parity bits from coded bits generated by performing error correction coding on information bits; The second data is received by broadcasting before the reception of the first data is started, and the second data includes a parity bit that was deleted when the first data was generated; performing error correction decoding on the received first data and second data to obtain the information bits; The first data is included in a different frame than the second data. Receiving method.

2. A terminal including a receiving unit and an error correction decoding unit, The receiving unit receives first data by broadcasting, and the first data is data obtained by deleting some parity bits from encoded bits generated by performing error correction encoding on information bits; The receiving unit receives second data by broadcasting before starting reception of the first data, and the second data includes a parity bit that was deleted when the first data was generated; the error correction decoding unit performs error correction decoding on the first data and the second data received by the receiving unit to obtain the information bits; The first data is included in a different frame than the second data. Terminal.

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