Receiving 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 / communications integrated service. This service links broadcast program content with line content, in which "terminals receive broadcast program content transmitted from broadcast stations and content distributed by service providers via telecommunications lines, such as the Internet (herein referred to as "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] Japanese Patent Application Laid-Open No. 2012-120140 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-129579 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 reception method and the like that can be used when multiple pieces of content are displayed in synchronization. [Means for solving the problem]

[0007] The receiving method of the present disclosure includes receiving 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, 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, wherein the first data is included in a different frame from the second data. [Effects of the Invention]

[0008] The receiving method and the like of the present invention can prevent problems caused by inappropriate reception of data for one of the contents when a plurality of contents are displayed synchronously. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of the relationship between a broadcasting station, a telecommunications carrier, and a terminal. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of a transmission device owned by a broadcasting station and a telecommunications carrier. [Figure 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 an error correction coding method in a transmission device of a telecommunications carrier. [Figure 5] FIG. 5 is a diagram showing an example of the configuration of a portion related to an error correction coding method in a transmission device of a telecommunications carrier. [Figure 6] FIG. 6 is a diagram illustrating an example of a packet configuration method. [Figure 7] FIG. 7 is a diagram illustrating an example of a packet configuration method. [Figure 8] FIG. 8 shows an example of a configuration in which the control information adding unit is located before and after the 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 status. [Figure 12] FIG. 12 is a diagram illustrating an example of a packet reception status. [Figure 13] FIG. 13 is a diagram illustrating an example of a packet reception status. [Figure 14] FIG. 14 is a diagram illustrating an example of a processing flow of a packet (or frame) processing unit of a terminal. [Figure 15] FIG. 15 is a diagram illustrating an example of a processing flow of a packet (or frame) processing unit of a 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 status. [Figure 19] FIG. 19 is a diagram illustrating an example of a packet reception status. [Figure 20] FIG. 20 is a diagram illustrating an example of a packet reception status. [Figure 21] FIG. 21 is a diagram showing an example of the configuration of a packet (or frame) processing unit in a transmitting device owned by a broadcasting station and a telecommunications carrier. [Figure 22] FIG. 22 is a diagram showing an example of a configuration in which 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 a broadcasting station, a telecommunications carrier, and a terminal. [Figure 25] FIG. 25 is a diagram showing an example of the relationship between a broadcasting station, a telecommunications carrier, and a terminal. [Figure 26] FIG. 26 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier. [Figure 27] FIG. 27 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier. [Figure 28] FIG. 28 illustrates an example of the configuration of a terminal. [Figure 29] FIG. 29 is a diagram illustrating an example of a packet transmission status. [Figure 30] FIG. 30 is a diagram illustrating an example of a packet reception status. [Figure 31] FIG. 31 is a diagram illustrating an example of a packet transmission status. [Figure 32] FIG. 32 is a diagram illustrating an example of a packet reception status. [Figure 33] FIG. 33 is a diagram illustrating an example of the configuration of a terminal. [Figure 34] FIG. 34 is a diagram showing an example of the relationship between a broadcasting station, a telecommunications carrier, and a terminal. [Figure 35] FIG. 35 is a diagram illustrating an example of a packet transmission status. [Figure 36] FIG. 36 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier. [Figure 37] FIG. 37 illustrates 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 carrier. [Figure 39] FIG. 39 illustrates an example of the configuration of a terminal. [Figure 40] FIG. 40 is a diagram showing an example of a packet transmission status. [Figure 41] FIG. 41 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier. [Figure 42]FIG. 42 is a diagram illustrating an example of the configuration of a terminal. [Figure 43] FIG. 43 is a diagram showing an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier. [Figure 44] FIG. 44 is a diagram illustrating an example of a packet transmission status. [Figure 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 illustrates 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 carrier. [Figure 52] FIG. 52 is a diagram illustrating an example of the configuration of a terminal. [Figure 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 INVENTION

[0010] (Findings that formed the basis of this disclosure) There is a demand for high-quality reception of real-time broadcast program content and real-time line content at terminals. In particular, with line content, packet delays and packet loss are likely to become issues. 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 real-time line content are displayed separately. When displaying the line content, the video display 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 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 lines (cable broadcasting, etc.). In this case, 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 high quality of the program content. It is unlikely that some of the information in the broadcast program content will arrive with a delay.

[0014] On the other hand, when line content is transmitted to a terminal via a telecommunications line, for example, using a protocol such as UDP (User Datagram Protocol), 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 issues arise when the images of the broadcast program content and the line content are synchronized in time.

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

[0016] Furthermore, when video of line content is displayed in conjunction with video display of 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 the transmission system and 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, terminal, etc. to achieve this.

[0018] The receiving method of the present disclosure includes receiving 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, 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, wherein the first data is included in a different frame from the second data.

[0019] The 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, 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 begins, 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] The 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 of the present disclosure is a receiving method that 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, receives, via broadcast, second data having a number of bits less 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 obtains the information bits by performing error correction decoding on the received first data and second data.

[0023] The terminal according to the present disclosure is a terminal having a receiving unit and an error correction decoding unit, wherein the receiving unit receives, via broadcast, first data having a number of bits greater than the number of information bits, generated by a broadcasting station from coded bits generated by applying error correction coding to information bits; the receiving unit receives, via broadcast, second data having a number of bits less than the number of information bits, generated by the broadcasting station from the coded bits, prior to the start of reception of the first data; 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] The method disclosed herein is a method for receiving and playing first content and second content, which includes 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 at a predetermined time whether a portion of the first data packet has been received, and 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 with each other, and 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 first content and second content, the method including 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, and receiving, via a second transmission path, a second data packet storing the second content, and 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, and 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 with each other, and 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 of the present disclosure, decoding of line content can be started as soon as a predetermined number of line data packets and line parity packets have been received, thereby improving the quality of line content transmitted over 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 when 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 terminals in this embodiment. In Fig. 1, 101 indicates a site, and consider a baseball field or a soccer field as an example. 102A and 102B indicate cameras. Assume that cameras 102A and 102B are capturing images from different angles, for example.

[0029] At this time, the broadcasting 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 carrier 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] 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 which they exist separately.

[0033] Packet (or frame) processing unit 202 receives "first video and / or audio information" 201 and first control signal 211 as input, performs packet (or frame) processing according to first control signal 211, and outputs first video and / or audio information 203 after 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 the terminal.

[0037] Although the above description has been given using an example in which one modulated signal is transmitted, the present invention is not limited to this. Transmission methods such as those disclosed in Patent Documents 1 and 2 may be used, in which multiple modulated signals are transmitted at the same time and with the same frequency using multiple antennas. Furthermore, transmission methods may include a single carrier method, a multicarrier method such as OFDM (orthogonal frequency division multiplexing), a spread spectrum communication method, etc. Additionally, although FIG. 2 illustrates an example in which broadcast station 240 transmits wirelessly, a wired transmission method such as a cable may also be used.

[0038] The control unit 232 receives second video and / or audio information 231 as input, and outputs second video and / or audio information 212 and a 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 a broadcast station 240.

[0039] Packet (or frame) processing unit 222 receives second video and / or audio information 212, second video and / or audio information 221 as it arrives directly at the telecommunications carrier, and second control signal 228 as input, and selects valid second video and / or audio information from second video and / or audio information 212 and second video and / or audio information 221 using second control signal 228, performs packet (or frame) processing on the selected second video and / or audio information, and outputs packet (or frame) processed second video and / or audio information 223. 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 as input, processes each layer (for example, the MAC (Media Access Control) layer and the physical layer, etc., but of course, is not limited to these) based on the second control signal 228, and outputs a signal 225 after signal processing.

[0041] Transmitting section 226 receives processed signal 225 and second control signal 228 as input, generates and outputs transmission signal 227 based on second control signal 228. Then, the data transmitted by 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. Examples include, but are not limited to, a wireless LAN (Local Area Network), a PLC (Power Line Communications), a wireless transmission method using millimeter waves, a cellular communication system, and a wireless MAN (Metropolitan Area Network). However, the Internet Protocol is generally 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 is IP (Internet Protocol), and the entire suite is called TCP / IP).

[0043] An example of the configuration of a terminal is shown in Figure 3. Antenna 301 receives a modulated signal transmitted by a broadcast station, and receiving section 303 receives received signal 302 from antenna 301 as input, performs processing such as frequency conversion and quadrature demodulation, and outputs baseband signal 304.

[0044] The time / frequency synchronization unit 305 receives the baseband signal 304 as input, extracts, for example, preambles, pilot symbols, and reference symbols 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, a pilot symbol, a 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, calculates a log-likelihood ratio for each bit, and outputs log-likelihood ratio signal 312. Note that 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 in control information signal 310, and outputs packet (or frame) processed data 316. The detailed operation will be explained later.

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

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

[0052] The signal processing unit 355 receives the received signal 354 , separates it 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 explained later.

[0054] In the above description, an example has been given 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 the packet (or frame) processed data 316, the control information signal 310, the packet (or frame) processed data 359, and the control information 357 as input, generates data for displaying two images on the display unit 384, and outputs data 381.

[0056] The decoder 382 decodes the 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 from an external output terminal, and the audio signal 385 is output as sound from a speaker 386 or from an external output terminal.

[0057] Here, we will explain a transmission method in which "broadcasting stations do not use error correction codes that enable recovery when packet or frame losses occur, but telecommunications carriers' transmission equipment uses error correction codes that enable recovery when packet or frame losses occur."

[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 transmitting device of a telecommunications carrier. (Here, this is called "error correction coding at the packet level," but the terminology is not limited to this.) The configuration of FIG. 4 is included in the packet (or frame) processing unit 222 in the transmitting device 250 owned by the telecommunications carrier in FIG. 2.

[0059] Packet generation unit 402 receives information 401 and control information signal 414 as input, and outputs information packet 403 based on information about packet size (the number of bits constituting one packet) contained in control information signal 414. An example is shown in FIG. 4, where 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 3))) Furthermore, 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 as input, rearranges the data based on the rearrangement method information 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 that constitutes the information packets #1 to #n.

[0061] Encoding section 408 receives rearranged data sequence 405 and control information signal 414 as input, performs encoding based on the error (erasure) correction coding scheme included in control information 414 (for example, information on the error (erasure) correction coding scheme 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) to enable error detection on a packet-by-packet basis, and outputs a parity packet 409 after the CRC has been added. By adding the CRC, the receiving device can determine whether all the data in the packet is correct or whether the packet has been lost. While a CRC is used as an example here, any block code or check code that can determine whether all the data in the packet is correct or whether the packet has been lost may be used. An example is shown in FIG. 4, which generates a parity packet #1 after the CRC has been added, a parity packet #2 after the CRC has been added, a parity packet #(h-1) after the CRC has been added, and a parity packet #h after the CRC has been added (i.e., a parity packet #k after the CRC has been added (k is an integer between 1 and h, inclusive (h is an integer greater than or equal to 1))).

[0063] Similarly, the error detection code adding unit 410 receives the information packet 403 as input, adds, for example, a CRC (Cyclic Redundancy Check) so that errors can be detected on a packet-by-packet basis, and outputs an information packet 411 after the CRC has been added. By adding the CRC, the receiving device can determine whether all the data in the packet is correct or whether the packet has been lost. While a CRC is used as an example here, any block code or check code that enables determination of whether all the data in the packet is correct or whether the packet has been lost may be used. An example is shown in FIG. 4, which generates an information packet #1 after the CRC has been added, an information packet #2 after the CRC has been added, an information packet #(n-1) after the CRC has been added, and an information packet #n after the CRC has been added (i.e., an information packet #k after the CRC has been added (k is an integer between 1 and n, inclusive (n is an integer between 2 and 1))).

[0064] Note that the information 401 in FIG. 4 may include control information (for example, information on the type of information, information on the video encoding format (frame rate, compression ratio, compression method), etc. (but not limited to these)). This will be explained 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 transmitting device of a telecommunications carrier, which is different from that shown in Fig. 4. The configuration shown in Fig. 5 is included in the packet (or frame) processing unit 222 in the transmitting 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 information on the rearrangement method included in control information signal 510, and outputs rearranged information 503.

[0067] Encoding section 504 receives rearranged information 503 and control information signal 510 as input, performs encoding based on the error (erasure) correction coding method (for example, 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] Packet generation unit 506 receives encoded data 505 and control information signal 510 as input, and outputs packet 507 based on information about the packet size (the number of bits constituting one packet) included in control information signal 503. An example is shown in FIG. 5, which generates packet #1, packet #2, ..., packet #(m-1), and information packet #m. (That is, packet #k (k is an integer between 1 and m (m is an integer between 2 and 3)).) Furthermore, if the number of information bits required to generate packets #1 to #m is insufficient, encoding is performed in encoding unit 504, for example, by inserting known data.

[0069] The error detection code adding unit 508 receives the packet 507 as input, adds, for example, a CRC (Cyclic Redundancy Check) so that errors can be detected on a packet-by-packet basis, and outputs a packet 509 after the CRC has been added. By adding the CRC, the receiving device can determine whether all the data in the packet is correct or whether the packet has been lost. While a CRC is used as an example here, any block code or check code that enables determination of whether all the data in the packet is correct or whether the packet has been lost may be used. An example is shown in FIG. 5, which generates 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 (i.e., a packet #k after the CRC has been added (k is an integer between 1 and m, inclusive, where m is an integer greater than or equal to 2)).

[0070] Note that information 501 in FIG. 5 may include control information (for example, information on the type of information, information on the encoding method for video encoding (frame rate, compression ratio, compression method), etc. (but not limited to these)). This point will be explained later.

[0071] An example of how the above-described packets are constructed will be described below.

[0072] Figure 6 shows an example of how the packets described above are constructed, where 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 "packet ID (identification) information." For example, in FIG. 4, the number of packets obtained by error correction coding is "n+h." Therefore, packet IDs (identifiers) ranging from "0" to "n+h-1" are prepared. Each packet is assigned one of the identifiers ranging from "0" to "n+h-1." Specifically, each of the n information packets and h parity packets shown in FIG. 4 is assigned one of the IDs ranging from "0" to "n+h-1." In FIG. 5, the number of packets obtained by error correction coding is "m." Therefore, packet IDs ranging from "0" to "m-1" are prepared. Each packet is assigned one of the identifiers ranging from "0" to "m-1." Specifically, each of the m packets shown in FIG. 5 is assigned one of the IDs ranging from "0" to "m-1."

[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, etc. 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 packet configuration method described above 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 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 error correction coding method 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 Figure 6, the data group consisting of "CRC" 601, "information about the number of packets obtained by error correction coding" 602, "packet ID (identifier) ​​information" 603, "control information" 604, and "data" 605 is considered to be "one packet with error detection code" in Figures 4 and 5.

[0081] In the case of Figure 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 Figures 4 and 5.

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

[0083] First method: 6, control information 604 and data 605 are packets before the error detection code is added in FIGS. 4 and 5. Therefore, the control information 604 and data 605 are input to the error correction coding (encoding unit 406 or encoding 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 between 0 and 31.

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

[0086] 8 shows an example of a configuration in which a control information adding unit is located 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 packet ID (identification), and outputs a data group 803.

[0087] An error detection code adding unit 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 the 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 information 603 regarding the packet ID (identification), 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, data 605 becomes the input to error correction coding (encoding unit 406 or encoding unit 504). Meanwhile, information 602 regarding the number of packets obtained by 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 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 between 0 and 31.

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

[0093] 8 shows an example of a configuration in which a control information adding unit is located before an error detection code adding unit. In the second method, a control information adding unit 802 receives data 605 (corresponding to 801) as input, 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 unit 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 the 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 the packets 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 (encoding unit 406 or encoding unit 504). Meanwhile, first control information 702 and a 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 between 0 and 31.

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

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

[0101] An error detection code adding unit 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] The 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 the packet before the error detection code is added in Fig. 4 and Fig. 5. Therefore, the data 704 becomes the 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 between 0 and 31.

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

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

[0108] An error detection code adding unit 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 unit 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 about time. In this case, the information about time may be contained in all packets, or may be contained in a specific packet.

[0112] Furthermore, 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 viewers.

[0114] As explained above, the information transmitted by telecommunications carriers includes information about time, and the information transmitted by broadcasters also includes information about time, and by utilizing this information, the terminal can perform temporal synchronization of the decoding and display of the first and second videos. Furthermore, this time information can also 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 "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, but the packet length and control information structure 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 broadcast station and the telecommunications carrier, and the reception status when the terminal receives the packets transmitted by the broadcast station and the packets transmitted by the telecommunications carrier will be explained. Note that in the following explanation, it is assumed that the broadcast 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 explanation, an example in which information is transmitted in units of packets will be explained.

[0118] 900 in Figure 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 Figure 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 Figure 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 subsequent packets in the same manner (however, this point is not shown in Figure 9). 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 shown in Figure 9).

[0121] 900 in Figure 9 shows a situation in which a broadcasting station and a telecommunications carrier transmit packets, where the broadcasting station transmits packet "#1", packet "#2", packet "#3", packet "#4", packet "#5", packet "#6", and packet "#7", and the telecommunications carrier transmits packet "$1", packet "$2", packet "$3", packet "$4", packet "$5", packet "$6", and packet "$7".

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

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

[0124] As mentioned above, telecommunications carriers transmit packets to terminals using TCP (TCP / IP) or UDP. Therefore, even if a broadcasting station and a telecommunications carrier transmit information on two videos from different angles at the same time, as shown in 900 of 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 of FIG. 9. This is shown in 910 of FIG. 9. In this way, it is easy for a terminal to predict how a packet transmitted by a broadcasting station will arrive at the terminal, but it is difficult for a terminal to predict the arrival of a packet transmitted by a telecommunications carrier.

[0125] For example, when a packet is received as shown in 910 in Figure 9, if 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, viewers are 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 a full angle of the soccer game and the second video is an angle of an individual player, viewers are likely to feel dissatisfied if the first video shows the full angle of the soccer game and shows the moment when player A is shooting, 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 minimal distortion.

[0128] If the first video and the second video are decoded at time R2, the terminal needs to delay the time at which the first video is displayed in order to synchronize the display of the first video and the second video. Therefore, a memory (buffer) is required to accommodate the delay of the first video data. This method is acceptable if the delay is small (or within a certain tolerance). However, in the case of TCP (TCP / IP) or UDP, the delay is not constant. Furthermore, if the terminal receives packets via a wireless LAN or the like, the delay may be even greater. Therefore, to synchronize the display of the first video and the second video with minimal distortion using this method, the terminal's memory must be large. Considering this, if a terminal employs a method for delaying the start time of decoding, it is desirable to introduce a technique that can reduce video distortion even with a short delay.

[0129] As one method for solving the above problem, we propose a transmission method as shown in Figure 10. 1000 in Figure 10 shows an example in which a broadcasting station and a telecommunications carrier transmit information on two videos taken from different angles at the same time, with the horizontal axis representing time. This differs from 900 in Figure 9 in that the packets transmitted by the broadcasting station are delayed to take into account the delay in arrival of the packets transmitted by the telecommunications carrier at the terminal. In Figure 10, the telecommunications carrier begins transmitting packets at 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 conceivable). 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 the time of 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 total increase in circuit scale than the increase in the circuit scale of the broadcasting station or the transmitting station of a 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 video distortion will not occur. For example, as shown in Figure 12, the terminal may receive packets sent by the telecommunications carrier with a delay, as shown at 910 in Figure 9. In this case, compared to Figure 9, the difference between "the point at which the terminal has received all packets sent by the broadcast station" and "the point at which the terminal has received all packets sent by the telecommunications carrier" is smaller. However, 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 and second videos in synchronization, distortion of the second video will still occur.

[0137] Furthermore, the second problem of image distortion can be alleviated by controlling the amount of delay on the transmitting side.

[0138] For example, signal processing unit 380 of the terminal in Fig. 3 obtains information regarding 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, time difference information 399 is transmitted from a transmitting device provided in the terminal to, for example, the telecommunications carrier.

[0139] The transmitting device 250 of the telecommunications carrier in Fig. 2 is equipped with 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 and controls the transmission timing by changing the amount of the packet or frame memory, thereby outputting a packet or frame with a controlled delay amount.

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

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

[0142] Assume 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. In this case, as explained in Figures 4 and 5, an error correction code (packet-level error correction coding) is used to enable recovery when a packet or frame loss occurs. The error correction code used in this case has a code length of 114688 bits and a coding rate of 4 / 7.

[0143] If the error correction code is a systematic code, packets are generated as shown in FIG. 4, for example. If the error correction code is a non-systematic code, packets are generated as shown in FIG. 5, for example. In this case, when encoding the second video information consisting of 65,536 bits as shown in either FIG. 4 or FIG. 5, seven packets are generated (since the number of bits constituting one packet is 16,384 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 a terminal can receive five or more packets, a number greater than the number of bits of information before encoding, all packets can be restored. Therefore, as mentioned above, for example, a broadcasting station and a telecommunications carrier may transmit packets as shown in 901 in FIG. 9 (details are omitted as they are explained 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 time point Rc in Fig. 13, error correction decoding is performed at the packet level. (That is, packet (or frame) processing units 315, 358 of the terminal in Fig. 3 have a storage unit (buffer), and when the terminal receives packets (or frames) from the broadcast station, packet (or frame) processing unit 315 stores the packet or frame data sequentially and delays data processing. Then, after receiving all 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 Rc in Figure 13, the terminal has lost packets "$3" and "$6." (However, this is shown in Figure 13 for clarity.) However, as mentioned above, since the terminal has received five or more packets, it is able to receive 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 time 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 R2 shown in Figure 13, when 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 packet or frame data of the first video can be significantly reduced. Furthermore, although packet loss of the second video previously caused video distortion at the terminal, this method can also have the effect of preventing video distortion even if packet loss occurs within a specified range.

[0148] In the above explanation, it was stated that "the broadcast station and the telecommunications carrier transmit packets as shown in 901 in FIG. 9." However, for example, as shown in FIG. 10, the broadcast station and the telecommunications carrier may transmit a first video packet (or frame) and a second video packet at the same time, with a time lag. In this case, the terminal may receive packets (or frames) transmitted by the broadcast station and the telecommunications carrier, as shown in FIG. 13, as described above. In this case, too, at time Rc, the terminal has lost packets "$3" and "$6." However, as described above, since the terminal has received five or more packets, it can obtain all packets, i.e., 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 time 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 R2 shown in Figure 13, when all packets of the second image can be obtained.

[0150] Next, there will be explained 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, let the time point Rc in Fig. 13 be a specific time. Then, first, the following confirmation is made.

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

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

[0154] If no, continue below.

[0155] (2) "At a specific time (time Rc), has the terminal received more than the required number of packets (5 packets in this case) (among the packets sent by the telecommunications carrier)?"

[0156] If "no," the terminal does not perform packet-level decoding because packet-level 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, which allows it to recover lost packets sent by the telecommunications carrier. Then, the terminal begins decoding the first and second videos, as it is able to do so.

[0158] It should 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)).

[0159] "At a specific time (point Rc), has the terminal received more than the required number of packets (five 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 packet-level 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, which allows it to recover lost packets sent by the telecommunications carrier. Then, the terminal begins decoding the first and second videos, as it is able to do so.

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

[0163] Next, an implementation when the above explanation is applied to a frame unit of a modulated signal transmitted by a broadcasting station will be described.

[0164] 1600 in Fig. 16 shows an example in which a broadcast station and a telecommunications carrier transmit two pieces of video information from different angles at the same time. 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 and second videos are assumed to be videos from different angles at the same time).

[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 Figure 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] It should be noted that the first video does not consist of only frame "*1," and the broadcasting station transmits subsequent frames in the same manner (however, this point is not mentioned in Figure 16).The second video does not consist of only 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 Figure 9).

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

[0169] 1610 in Figure 16 shows the terminal receiving frames and packets. It receives frame "*1" transmitted by the broadcast station. At this time, the terminal completes reception at time R1.

[0170] As described above, telecommunications carriers transmit packets to terminals using TCP (TCP / IP) or UDP. Therefore, even if a broadcasting station and a 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 be delayed in arrival and the order in which the packets arrive may be changed, as shown in 1610 of FIG. 16. This is shown in 1610 of FIG. 16. In this way, it is easy for a terminal to predict how a packet transmitted by a broadcasting station will arrive at the terminal, but it is difficult for a terminal to predict the arrival of a packet transmitted by a telecommunications carrier.

[0171] For example, when a packet is received as shown in 1610 in Figure 16, if 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, viewers are 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 a full angle of the soccer game and the second video is an angle of an individual player, viewers are likely to feel dissatisfied if the first video shows the full angle of the soccer game and shows the moment when player A is shooting, 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 minimal distortion.

[0174] If the first video and the second video are decoded at time R2, the terminal needs to delay the time at which the first video is displayed in order to synchronize the display of the first video and the second video. Therefore, a memory (buffer) is required to accommodate the delay of the first video data. This method is acceptable if the delay is small (or within a certain tolerance). However, in the case of TCP (TCP / IP) or UDP, the delay is not constant. Furthermore, if the terminal receives packets via a wireless LAN or the like, the delay may be even greater. Therefore, to synchronize the display of the first video and the second video with minimal distortion using this method, the terminal's memory must be large. Considering this, if a terminal employs a method for delaying the start time of decoding, it is desirable to introduce a technique that can reduce video distortion even with a short delay.

[0175] As one method for solving the above problem, we propose a transmission method as shown in Figure 17. 1700 in Figure 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 Figure 16 is that the frames transmitted by the broadcasting station are delayed to take into account the arrival delay of the packets transmitted by the telecommunications carrier at the terminal. In Figure 17, the telecommunications carrier begins transmitting packets at 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 conceivable). And it transmits the frame "※1".

[0178] FIG. 18 shows an example (1800) of the reception status of the packets at 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 as in the case of 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 has completed 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 has completed receiving all the packets transmitted by the broadcasting station" and "the time when the terminal has completed 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, it is possible that the circuit scale for packet accumulation and storage at the terminal can be reduced. In the case of FIG. 19, at the time point 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 total increase in circuit scale than the increase in the circuit scale of the broadcasting station or the transmitting station of a 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 video distortion will not occur. For example, as shown in Figure 19, the terminal may receive packets sent by the telecommunications carrier with a delay, as shown at 1610 in Figure 16. In this case, compared to Figure 16, the difference between the "point at which the terminal has received all packets sent by the broadcast station" and the "point at which the terminal has received all packets sent by the telecommunications carrier" is smaller. However, 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 and second videos in synchronization, distortion of the second video will still occur.

[0183] Furthermore, the second problem of image distortion can be alleviated by controlling the amount of delay 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 provided in the terminal to, for example, the telecommunications carrier.

[0185] The transmitting device 250 of the telecommunications carrier in Fig. 2 is equipped with 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 and controls the transmission timing by changing the amount of the packet or frame memory, thereby outputting a packet or frame with a controlled delay amount.

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

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

[0188] Assume 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. In this case, as explained in Figures 4 and 5, an error correction code (packet-level error correction coding) is used to enable recovery when a packet or frame loss occurs. The error correction code used in this case has a code length of 114688 bits and a coding rate of 4 / 7.

[0189] If the error correction code is a systematic code, packets are generated as shown in FIG. 4, for example. If the error correction code is a non-systematic code, packets are generated as shown in FIG. 5, for example. In this case, when encoding the second video information consisting of 65,536 bits as shown in either FIG. 4 or FIG. 5, seven packets are generated (since the number of bits constituting one packet is 16,384 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 a terminal can receive five or more packets, a number greater than the number of bits of information before encoding, all packets can be restored. Therefore, as mentioned above, for example, a broadcasting station and a telecommunications carrier transmit frames and packets as shown in 1601 in FIG. 16 (details are omitted as they are explained above).

[0190] At this time, it is assumed that the packet reception status of the terminal in Fig. 3 is as shown in Fig. 20. And, at time point Rc in Fig. 20, error correction decoding is performed at the packet level. (That is, 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, packet (or frame) processing unit 315 stores the frame data sequentially and delays data processing. Then, after completion of frame reception and a certain period of time has passed, error correction decoding is performed at the packet level on the packet sent by the telecommunications carrier.)

[0191] At time Rc in Figure 20, the terminal has lost packets "$3" and "$6." (However, this is shown in Figure 20 for clarity.) However, as mentioned above, since the terminal has received 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 time 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 R2 shown in Figure 20, when 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, which has the effect of significantly reducing the circuit size of the memory unit for storing frame data of the first video. Furthermore, while packet loss of the second video previously caused video distortion at the terminal, this has the effect of preventing video distortion even if packet loss occurs within a specified range.

[0194] In the above explanation, it was stated that "the broadcast station and the telecommunications carrier transmit frames and packets as shown in 1601 of FIG. 16." However, for example, as shown in FIG. 17, the broadcast 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 lag. In this case, the terminal may receive packets (or frames) transmitted by the broadcast station and the telecommunications carrier, as shown in FIG. 20, as explained above. In this case, too, at time Rc, the terminal has lost packets "$3" and "$6." However, as described above, since the terminal has received five or more packets, it can obtain all packets, i.e., 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 time 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 R2 shown in Figure 13, when all packets of the second image can be obtained.

[0196] Next, there will be explained 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, let the time point Rc in Fig. 20 be a specific time. Then, first, the following confirmation is made.

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

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

[0200] If no, continue below.

[0201] (2) "At a specific time (time Rc), has the terminal received more than the required number of packets (5 packets in this case) (among the packets sent by the telecommunications carrier)?"

[0202] If "no," the terminal does not perform packet-level decoding because packet-level 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, which allows it to recover lost packets sent by the telecommunications carrier. Then, the terminal begins decoding the first and second videos, as it is able to do so.

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

[0205] "At a specific time (point Rc), has the terminal received more than the required number of packets (five 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 packet-level 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, which allows it to recover lost packets sent by the telecommunications carrier. Then, the terminal begins decoding the first and second videos, as it is able to do so.

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

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

[0210] The configuration of 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 shown 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 then performs processing based on the control signal 2105. For example, when performing packet layer error correction coding, the packet or frame generation unit 2102 processes the video and / or audio information 2101 as shown in FIGS. 4 and 5, 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] The memory unit 2104 receives packetized or framed data 2103 and a control signal 2105 as input, stores the packetized or framed data 2103 based on the control signal 2105, delays it, and outputs the delayed packetized or framed data 2106.

[0214] An example of the configuration of the memory unit 2104 is as shown in Figure 21, where memory blocks are connected in series, and the memory blocks store input data groups and then output the stored data groups.

[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 the configuration when error correction decoding of the packet layer is performed in the packet (or frame) processing units 315 and 358 in the terminal of Fig. 3. The operation will be explained using Fig. 20 as an example.

[0217] An error detection unit (for example, 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 errors, so outputs packet “$2” as packet information 2203.

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

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

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

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

[0223] As explained above, since the packet layer is decoded at time 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 Figure 20, packets "$2", "$4", "$5", "$7", and "$1" are input to memory unit 2204, which therefore stores packets "$2", "$4", "$5", "$7", and "$1". Then, when control signal 2208 indicates time point Rc, memory unit 2204 is instructed to output the stored packets "$2", "$4", "$5", "$7", and "$1". Therefore, memory unit 2204 outputs packets "$2", "$4", "$5", "$7", and "$1" as stored packets 2205.

[0226] Packet layer decoder (erasure correction decoder) 2206 receives stored packet 2205 and control signal 2208 as input.Then, when control signal 2208 indicates time Rc, packet layer decoder (erasure correction decoder) 2206 uses packet "$2", packet "$4", packet "$5", packet "$7" and packet "$1" output from memory 2204 to perform erasure correction decoding (for example, when using LDPC (Low-Density Parity-Check) code as error correction code, belief propagation decoding such as sum-product decoding).At this time, packet layer decoder (erasure correction decoder) 2206 can restore all information, so it outputs received video and / or audio information 2207.

[0227] It should be noted 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 below.

[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 physical layer error correction decoding is performed. 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 determines whether or not there is an error on a packet-by-packet basis using the error detection code. This results in a determination that packet "#1" is correct, packet "#2" is in error (i.e., packet loss), packet "#3" is correct, etc.

[0230] Then, the 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 of 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 explained using Fig. 20 as an example.

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

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

[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 carrier transmits the second image, error correction coding is performed at the packet level when the second image is transmitted. This allows a terminal to display synchronized first and second images, and also has 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 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 then performs the subsequent processing.

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

[0237] (Embodiment 2) In this embodiment, we will explain the case where embodiment 1 is applied to a case where there are multiple broadcasting stations or where broadcasting stations transmit information via multiple media (e.g., satellite broadcasting, terrestrial broadcasting, cable broadcasting).

[0238] FIG. 24 shows an example of the relationship between broadcasting stations, telecommunications carriers, and terminals that differs from that shown in FIG. 1, and the same numbers are used for components that operate in the same way as in FIG.

[0239] 24, the distinctive features are 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, as in 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 separate 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 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 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] Figure 26 shows an example of the configuration of a transmitting device owned by a broadcasting station and a telecommunications carrier in the states of Figures 24 and 25, and the same numbers are used for components that operate in the same way as in Figure 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] Transmitting device 2622 receives first video and / or audio information 2601 and control signal 2623, determines a transmission method based on control signal 2613, and outputs modulated signal 2624. Note that modulated signal 2624 is assumed to be transmitted to the terminal via a wired connection.

[0245] In this case, the transmitting devices 2602, 2612, and 2622 are transmitting devices related to the broadcasting station. Note that the characteristic operation of each transmitting device will be explained 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 Figure 26, and parts that operate in the same way as in Figures 2 and 26 are given the same numbers.

[0247] Figure 27 differs from Figure 26 in that the first video and / or audio information is transmitted separately from the camera side to transmitting devices 2602, 2612, and 2622. Therefore, 2701, 2712, and 2721 in Figure 27 are all the first video and / or audio information, and the operation of transmitting devices 2602, 2612, and 2622 is the same as in Figure 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 components that operate in the same way as in Fig. 3 are assigned the same numbers. As in Fig. 3, 351 to 359 in Fig. 28 are components that receive packets sent by a telecommunications carrier. These components perform the operations described in the first embodiment (such as packet-level decoding and data storage).

[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 a received signal 2802 (a received signal of the modulated signal transmitted by the transmitting device 2602 in Figures 26 and 27) via the antenna 2801 as input, extracts the control information contained in the received signal, and performs processing such as demodulation, physical layer error correction decoding (or packet level decoding if packet level error correction coding is performed), and outputs packet (or frame) processed data 2704 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 the control information contained in the received signal, and performs processing such as demodulation, physical layer error correction decoding (or packet level decoding if packet level error correction coding is 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 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 is performed), and outputs packet (or frame) processed data 2724 and a control information signal 2725.

[0255] At this time, it is not necessarily the case that all of the receiving devices 2803, 2813, and 2823 are operating at the same time. For example, if a broadcast channel selection unit is provided as an interface for the terminal, the receiving device associated with the channel set by the user using the selection unit will operate. The signal that realizes 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 packet (or frame) processed data 2804, 2814, 2824, control information signals 2805, 2815, 2825, and a selection signal 2850 as input, and selects valid packet (or frame) processed data based on the selection signal 2850.

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

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

[0259] Next, issues that arise when primary video (and / or voice (audio) information) is transmitted from transmitting devices 2602, 2612, and 2622 as shown in Figures 26 and 27 will be described. Note that, although the following description will be made assuming that the same packets are transmitted, the packets transmitted by transmitting devices 2602, 2612, and 2622 may not be the same packets and may have different configurations. Furthermore, the primary video data transmitted from transmitting devices 2602, 2612, and 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 Figs. 26 and 27 transmit packets related to the primary video (and / or audio information) (2900 in Fig. 29). 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", and 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] At this time, it is assumed that the transmitting devices 2602, 2612, and 2622 in FIGS. 26 and 27 all transmit packets at the same time from time T1.

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

[0264] As shown in FIG. 30, R1 denotes the time when receiving device 2803 in FIG. 28 completes receiving packets "#0-7," R2 denotes the time when receiving device 2813 in FIG. 28 completes receiving packets "#1-7," and R3 denotes the time when receiving device 2823 in FIG. 28 completes receiving packets "#2-7." In this case, R1, R2, and R3 are different values, and the differences between them can be large. Note that FIG. 30 assumes that 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 transmission medium (terrestrial broadcasting, cable broadcasting, satellite broadcasting)), only the corresponding receiving device 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 explained in the first embodiment, if the first video and the second video are displayed in synchronization, issues arise in terms of the circuit size of the terminal.

[0266] As explained in the first embodiment, the terminal attempts to display the video on the display unit by temporally synchronizing the second video (and / or sound (audio) information) transmitted via the telecommunications carrier with the first video (and / or sound (audio) information) so that the user does not feel uncomfortable with the multi-angle video. At this time, the user selects a channel (or 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 sound (audio) information) varies 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 require a large circuit in its memory unit for video synchronization.

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

[0268] As shown 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 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 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 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 from a comparison of 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, and 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, and 2823 of the terminal is smaller than in Fig. 30. This has 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 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 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 transmitting device 2622 in Figures 26 and 27.

[0273] 32, it is assumed that 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 transmission medium (terrestrial broadcasting, cable broadcasting, satellite broadcasting)), only the corresponding receiving device will operate.

[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 Figures 26 and 27 in time synchronization with the packets of the second video transmitted by the telecommunications carrier can be realized by implementing the same methods as those described in embodiment 1. The packets of the second video are decoded at the packet level, and the processing method is the same as that 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 Figures 26 and 27 in time synchronization with the packets of the second video transmitted by the telecommunications carrier can be realized by implementing the same methods as those described in embodiment 1. The packets of the second video are decoded at the packet level, and the processing method is the same as that described in embodiment 1.

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

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

[0278] For example, signal processing unit 380 of the terminal in Fig. 28 obtains information regarding the difference (or statistical information thereof) in arrival time between a frame transmitted by each broadcast 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, time difference information 399 is transmitted from a transmitting device included in the terminal to, for example, a telecommunications carrier.

[0279] 26 and 27, the transmitting device 250 of the telecommunications carrier is equipped with 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 and controls the transmission timing by changing the amount of the packet or frame memory, thereby outputting a packet or frame with a controlled delay.

[0280] 26 and 27, it is difficult for each broadcasting station (transmitting devices 2602, 2612, 2622 shown in FIGS. 26 and 27) to control the amount of delay for each terminal. Therefore (due to multicast), packet (or frame) processing unit 222 of transmitting device 250 of the telecommunications carrier controls the amount of delay for each terminal. However, if transmitting device 250 of the telecommunications carrier does not transmit packets individually to each terminal, that is, if multicast is used, each broadcasting station (transmitting devices 2602, 2612, 2622 shown in FIGS. 26 and 27) may control the delay time (packet transmission timing), or the telecommunications carrier 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, it is assumed that transmitting devices 2602, 2612, and 2622 transmit information on the first video (and / or sound (audio) information). The configuration of a terminal when automatic selection is performed is shown in Fig. 33. Note that in Fig. 33, components that operate in the same way as in Figs. 3 and 28 are assigned the same numbers, and detailed description thereof will be omitted.

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

[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 time synchronization.

[0284] 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 the channel set by the user, and 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 the channel set by the user according to control signal 3305, and outputs the selected signal as 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 control signal 3305, the result of the analysis by delay time analysis unit 3302 is reflected.

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

[0286] This allows 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 multi-angle first and second videos, packet-level error correction coding is performed during transmission of the second video, and each broadcast station controls the timing of transmitting the information for the first video. Furthermore, the terminal has a function that enables it to select the broadcast station from which to obtain the first video. This allows the terminal to display synchronized first and second videos, and also achieves the effect of reducing image distortion.

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

[0289] However, even if packet-level error correction codes are introduced, packet delays and packet losses still have a small effect, causing video distortion. In particular, when a terminal receives packets of the second video via wireless communication such as a wireless LAN or a cellular communication system, the video distortion can become significant, and viewers are likely to find the video distortion unpleasant.

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

[0291] Figure 34 shows an example of the relationship between a broadcasting station, a telecommunications carrier, and a terminal in this embodiment. Components that operate in the same way as in Figure 1 are given the same numbers. In Figure 34, 101 indicates a site, and as an example, consider a baseball field or a soccer field. 102A and 102B indicate cameras. Assume that cameras 102A and 102B are capturing images from different angles, for example.

[0292] At this time, the broadcasting 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 carrier 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 broadcast station and a telecommunications carrier in this embodiment. However, as shown in the second embodiment, multiple broadcast stations can transmit packets of the first video, and Fig. 35 shows only the transmission packets (frames) of one broadcast station. However, as in the second embodiment, it is also possible to implement the contents described below in the case where multiple 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 from the same time, and as described in embodiments 1 and 2, the terminal will synchronize the first video and the second video on the display unit.

[0299] In addition to the packets of the first video, the broadcast 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 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 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 Figure 35, the broadcasting station transmits "text information (telegram 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 (telegram information)," "still image information," and "URL (Uniform Resource Locator) information," or it may transmit two of "text information (telegram information)," "still image information," and "URL (Uniform Resource Locator) information."

[0301] Furthermore, this information does not have to be included in every frame of a transmission frame, and for example, this information may be transmitted for every several frames. Therefore, the timing of transmitting this information is not limited.

[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, and the same numbers are used for components that operate in the same way as in Figure 2, and the implementation method is the same as that explained in embodiments 1 and 2, so 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 3603 after packet (or frame) processing.

[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 included in the first control signal 211, and outputs data 3605 after error correction coding.

[0305] Modulation section 206 receives error correction coded data 205, 3605 and first control signal 211 as input, and performs mapping on error correction coded data 205, 3605 based on information about the frame structure and information about the modulation method and transmission method included in first control signal 211, and outputs 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 shown in Figure 36, and components that operate in the same way as in Figure 3 are given the same numbers.The implementation method is the same as that described in embodiments 1 and 2, so the description will be omitted.

[0307] Demodulation unit 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 regarding 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 (message information), and / or still image information, and / or URL information" and the control information signal 310, performs packet (or frame) processing based on the control information signal 310, and outputs "character information (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) and / or 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, decoder 3706 operates as follows: In the case of "character information (electronic message information)", display screen information 3707 becomes "character information (electronic message information) to be displayed on the display unit". In the case of "still image information", display screen information 3707 becomes "still image information to be displayed on the display unit". In the case of "URL information", information (3708) from the URL destination is obtained and output.

[0312] The signal processing unit 380 determines whether synchronized images of the first and second images have 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 first image has not been obtained, display screen information 3707 is displayed and the second image is also displayed in place of the first image. 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 operator when transmitting the information of Figure 35, and the same numbers are used for components that operate in the same way as in Figures 2 and 36, and the implementation method is the same as that explained in embodiment 1, embodiment 2, and Figure 36, so explanation will be omitted.

[0315] Figure 38 differs from Figure 36 in that the physical layer error correction code used when transmitting the first group of video packets 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 the physical layer error correction coding unit 3604 in Figure 36, and the 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 parts that operate in the same way 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 explanation is omitted.

[0317] Figure 39 differs from Figure 38 in that the physical layer error correction code used when transmitting the first group of video packets 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 39 does not have the physical layer error correction decoding unit 3702 in Figure 37, and physical layer error correction decoding unit 313 also performs decoding of character information (telegram 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. In a multi-carrier transmission system, when there are multiple channels on the frequency axis, etc., the "first packet group," "text information (telegram information)," and "still image information" may be transmitted in a frequency-division manner. Also, both time division and frequency division may be used in combination.

[0319] Fig. 40 shows an example 4000 of the transmission status of packets transmitted by a broadcasting station and a telecommunications carrier different from those in Fig. 35. However, as shown in the second embodiment, multiple 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 also possible to implement the contents described below when multiple 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 from the same time, and as described in embodiments 1 and 2, the terminal will synchronize the first video and the second video on the display unit.

[0322] In addition to the packets of the second video, the telecommunications carrier shall transmit "text information (message information)," and / or "still image information," and / or "URL (Uniform Resource Locator) information," as shown in Figure 40. This information is used when the terminal is unable to restore the information of the first video and, as a result, has difficulty 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 displaying 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 Figure 40, the telecommunications carrier sends "text information (electronic message information)," "still image information," and "URL (Uniform Resource Locator) information," but it is not necessary to send all of the information; it may send one of "text information (electronic message information)," "still image information," and "URL (Uniform Resource Locator) information," or it may send two of "text information (electronic message information)," "still image information," and "URL (Uniform Resource Locator) information."

[0324] Furthermore, this information does not have to be included in every frame of a transmission frame, and for example, this information may be transmitted for every several frames. Therefore, the timing of transmitting this information is not limited.

[0325] When transmitting a frame as shown in Figure 40, information provider 3401 in Figure 34 provides information about telecommunications carrier 104 as shown by the dotted line, and telecommunications carrier 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 way as in Figure 2, and the implementation method is the same as that explained in embodiments 1 and 2, so explanation will be 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 4103 after packet (or frame) processing.

[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, and performs signal processing to generate a transmission signal based on the information on the transmission frame of the telecommunications line provider 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 shown in Figure 41, and components that operate in the same way 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 explanation is omitted.

[0330] Signal processing unit 355 receives received signal 354, separates it into a second group of video packets, control information, character information (telegram information), still image information, and URL information, and outputs received data (second group of video packets) 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 (telegram information), and / or still image information, and / or URL information" and control information 357, performs signal processing based on information on the transmission method and error correction coding method contained in the control information 357, and outputs "received data 4204 of character information (telegram 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 processing unit 380 determines whether or not synchronized images of the first and second images have 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 if determination result 4201 indicates that "synchronized images of the first and second images have been obtained," it displays video signal 383. If determination result 4201 indicates that "synchronized images of the first and second images have not been obtained," and if the first image has not been obtained, it displays display screen information 4206 and also displays the second image in place of the first image. If the second image has not been obtained, it displays display screen information 4206 in place of the second image.

[0336] As described above, when a disturbance occurs in the display of the first and second multi-angle images, by displaying information to replace 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] (Fourth embodiment) In the first and second embodiments, a transmission method has been described in which, for multi-angle first and second videos, a broadcast station transmits the first video and a telecommunications carrier transmits the second video, and packet-level error correction coding is performed when transmitting the second video. In this case, the telecommunications carrier transmits packets of the second video using TCP (TCP / IP) or UDP, and packet-level error correction coding is introduced to reduce the effects of packet delays and packet loss.

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

[0339] Figure 43 shows an example of the configuration of the transmitting devices of a broadcasting station and a telecommunications carrier in this embodiment. In Figure 43, components that operate in the same way as in Figure 2 are given the same numbers. Control unit 232 receives transmission data 4300 as input, and outputs transmission data 4301 and second control signal 228. The detailed operation will be explained later using Figure 44.

[0340] Control information generator 4303 receives transmission data 4301 and transmission data 4302 as input, and generates and outputs control information 4302. The detailed operation will be explained later using FIG.

[0341] Packet (or frame) processing unit 222 receives transmission data 4301, transmission data 4302 when it reaches the telecommunications carrier directly, and second control signal 228 as input, selects valid transmission data from transmission data 4301 and transmission data 4302 based on second control signal 228, performs packet (or frame) processing, and outputs packet (or frame) processed data 4304. The detailed operation will be explained later using FIG.

[0342] Figure 44 shows an example 4400 of the transmission status of packets transmitted by the transmitting device of a broadcasting station and a telecommunications carrier in this embodiment. When the 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, the transmitting device of the telecommunications carrier shown in Figure 43 is assumed to perform erasure correction coding (packet level error correction coding) to generate "second video packet group #1" (4406). And, the control information 4405 is assumed to include "information indicating that erasure correction coding (packet level error correction coding) 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 transmitting 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 explained above, when sending the packet of second video, erasure correction coding (error correction coding at packet level) may or may not be carried out.For example, when the compression rate of video coding is high and / or the number of pictures is small (that is, data size is small), the number of packets to be sent can be reduced, so the control information generating unit 4303 of Figure 43 will determine that "erasure correction coding is not carried out".On the contrary, when the compression rate of video coding is low and / or the number of pixels is large (that is, data size is large), the number of packets to be sent will be increased, so the control information generating unit 4303 of Figure 43 will determine that "erasure correction coding is carried out".

[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] When the data of "data packet group" (4410) is "text information", "still picture information", "URL information" etc., the amount of data to be sent is small compared with video data, so the control information generating unit 4303 of Figure 43 will judge that "do not carry out erasure correction coding".

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

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

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

[0354] Packet (or frame) processing unit 358 receives data 356 and control information 357 as input, and when the information of the type of information that contains in control information 357 indicates that it is second image, and when obtain the information that erasure correction code is applied, carry out erasure correction decoding (packet level error correction decoding).And when obtain the information that erasure correction decoding is not applied, do not carry out erasure correction decoding (packet level error correction decoding).

[0355] The signal processing unit 380 determines whether the second video has been obtained from the control information (symbol) 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 mentioned above, by switching between applying erasure correction code (packet level error correction coding) and not applying it, terminal can achieve both high data reception quality and improvement of data transmission speed (when applying erasure correction code, data transmission speed will be reduced).

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

[0359] Figure 45 shows packets transmitted by a broadcasting station in this embodiment, with the horizontal axis representing time. In Figure 45, 4501 is a pre-transmitted packet group, and a terminal that receives this packet group (4501) temporarily stores 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 case will be explained in detail later.) This has the advantage that the reception time slot for a program that includes video can be uniquely set.

[0360] Reference numeral 4502 denotes a group of video packets, and the terminal is able to display video (and audio) by obtaining the group of video packets 4502. (The characteristics of this case will be explained in detail later.) Furthermore, the terminal can obtain higher data (packet) reception quality by performing packet-level error correction decoding using the group of video packets 4502 and the stored group of pre-transmitted packets 4501, making it possible to decode video 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 packet (or frame) processed first video and / or audio information 203. In this embodiment, packet (or frame) processed first video and / or audio information 203 is made up of pre-transmission packet group 4501 and video packet group 4502 in Fig. 45. At this time, although the pre-transmission packet group 4501 and the video packet group 4502 in Figure 45 do not show control information (information necessary for the terminal to perform processes such as demodulation, decoding, and signal processing), when the broadcasting station transmits the pre-transmission packet group 4501, it also transmits control information (the control information is included in the pre-transmission packet group 4501), and when the broadcasting station transmits the video packet group 4502, it also transmits control information (the control information is included in the 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 "a transmission method like that of FIG. 45 is to be adopted," it outputs pre-transmission (transmission) packet group 4602 and video packet group 4603. If first control signal 211 indicates that "a transmission method like that of FIG. 45 is not to be 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 as input, 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] The physical layer error correction coding unit 204 receives as input a packet group 4601, a pre-transmission (transmission) packet group 4605, a video packet group 4608, and a first control signal 211, and if the first control signal 211 indicates that "the transmission method shown in Figure 45 is not adopted," it performs physical layer error correction coding on the packet group 4601 and outputs data 205 after error correction coding.

[0368] When the first control signal 211 indicates that "a transmission method as shown in Figure 45 is adopted," the physical layer error correction coding unit 204 outputs error correction coded data obtained by applying physical layer error correction coding to the pre-transmission (transmission) packet group 4605, and error correction coded data obtained by applying physical layer error correction coding to the 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 among packet groups 4602 (4605) (4501), video packet groups 4603 (4608) (4502), and the first video and / or audio information 201. FIG. 48 shows an example, different from FIG. 47, of the relationship among “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”. Let the number of bits of “the first video and / or audio information” 4701 be X bits (X is a natural number). In error correction coding at the packet level, when using an organizing code, 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). Let the number of bits of parity 4703 be Y bits (Y is a natural number), and assume that the relationship Y < X holds.

[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 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, it satisfies the above-mentioned “even if the terminal receives the pre-transmission packet group 4501 and performs error correction decoding at the packet level, it cannot obtain the video (and audio)” (because Y < X is satisfied).

[0374] Also, from the configuration of the video packet group in FIG. 47, it satisfies 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 "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).

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

[0377] 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] And 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). <00,01293> When the video packet group and the pre-transmission packet group are generated as shown in FIG. 48, it satisfies 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 Figure 48 satisfies the above-mentioned condition, "The terminal is capable of displaying video (and audio) by obtaining video packet group 4502.", and also realizes the above-mentioned condition, "The terminal can obtain higher data (packet) reception quality by performing packet-level error correction decoding using video packet group 4502 and the 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] Storage unit 4901 receives received data 314 and control information signal 310 as input, and if control information signal 310 indicates that "received data 314 is data of prior (transmission) packet group 4501 in FIG. 45," it stores received data 314. Then, when instructed to do so, 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 (transmission) packet group 4501 in FIG.

[0385] When 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 Figure 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 packet (or frame) processed data 316.

[0387] If the memory unit 4901 does not store the pre-transmitted packet group 4501 of Figure 45, the packet (or frame) processing unit 315 performs packet-level error correction decoding using the received data 314 and outputs 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 broadcast station transmits the advance (transmission) packet has been described, but the present invention is not limited to this method. Therefore, hereinafter, the case where other transmission methods are used will be described.

[0391] FIG. 50 shows packets transmitted by the transmitting devices of the broadcasting station and the telecommunications carrier in this embodiment, with the horizontal axis representing time. In FIG. 50, 5001 denotes a pre-transmitted packet group, and this packet group (5001) is transmitted by the transmitting device of the telecommunications carrier. A terminal that receives this packet group (5001) temporarily stores this packet group (5001). Note that even if a terminal receives pre-transmitted packet group 5001 and performs packet-level error correction decoding, it will not be able to obtain video (and audio). (The characteristics of this case will be explained in detail later.) This has the advantage that the reception time slot for a program containing video can be uniquely set.

[0392] Reference numeral 5002 denotes a group of video packets, and this group of packets (5002) is transmitted by a broadcast station. The terminal is then able to display video (and audio) by receiving the group of video packets 5002 (the characteristics of this case will be explained in detail later). Furthermore, the terminal can obtain higher data (packet) reception quality by performing packet-level error correction decoding using the group of video packets 5002 and the stored group of pre-transmitted packets 5001, making it possible to decode video with less video distortion.

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

[0394] Figure 51 shows an example of the configuration of the transmitting equipment of a broadcasting station and a telecommunications carrier that enables the transmitting equipment of a broadcasting station and a telecommunications carrier to transmit packets as shown in Figure 50. Components that operate in the same way 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, first video and / or audio information 203 after packet (or frame) processing is made up 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 indicate control information (information necessary for a terminal to perform processes such as demodulation, decoding, and signal processing), but when a transmission device of a telecommunications carrier transmits pre-transmission packet group 5001, it also transmits control information (the 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 (the 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 to be 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 to be adopted," it outputs packet group 5101.

[0398] In Figure 51, the broadcasting station is configured to have packet (or frame) processing unit 202 and packet distribution unit 5100, but this is not limited to this. The transmitting device of a telecommunications line provider may also have packet (or frame) processing unit 202 and packet distribution unit 5100, or another device may have 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] The physical layer error correction coding unit 204 receives as input the packet group 5101, the video packet group 5105, and the first control signal 211, and if the first control signal 211 indicates that "the transmission method shown in Figure 50 is not adopted," it performs physical layer error correction coding on the packet group 5101 and outputs the error correction coded data 205.

[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 in which physical layer error correction coding has been applied 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 information 223 after packet (or frame) processing, pre-transmission (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 (transmission) packet group 5103 according to the frame of Figure 50 and outputs signal 225 after signal processing.

[0403] In other cases, based on the information of the second control signal 228, the signal processing unit 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 between packet group 5103(5001), video packet group 5102(5105)(5002), and the first video and / or audio information 201. Also, FIG. 48 shows an example of "the relationship between packet group 5103(5001), video packet group 5102(5105)(5002), and the first video and / or audio information 201", which is different from that in FIG. 47.

[0406] In FIG. 47, 4701 indicates "the first video and / or audio information". 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 organization 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). Let the number of bits of parity 4703 be Y bits (Y is a natural number), and assume that 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, it will satisfy the above-mentioned "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)" (because Y < X is satisfied).

[0409] 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 5002." Also, it can realize the above-mentioned "The terminal can obtain higher reception quality of data (packets) and decode the video in a state with less video distortion by performing packet-level error correction decoding using the video packet group 5002 and the pre-transmission packet group 5001 stored in memory."

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

[0412] 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.

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

[0414] 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 5001 and performs packet-level error correction decoding, it cannot obtain video (and audio)" (because Y < X is satisfied).

[0415] Furthermore, the configuration of the video packet group in Figure 48 satisfies the above-mentioned condition "The terminal is capable of displaying video (and audio) by obtaining video packet group 5002.", and also realizes the above-mentioned condition "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, and can 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] Storage unit 5201 receives control information signal 310, received data 356, and control information 357 as input, and if control information 357 indicates that "received data 356 is data of prior (transmission) packet group 5001 in FIG. 50," it stores received data 356. Then, when instructed by control information signal 310, storage unit 5201 outputs the data stored in the storage unit (stored data 5202).

[0418] Packet (or frame) processing unit 358 receives received data 314 and control information 357 as input, and if control information 357 indicates that the transmission method is not that of Figure 50, performs packet (or frame) processing based on 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.

[0420] When 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 Figure 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 packet (or frame) processed data 316.

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

[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 that 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 other possible configurations are possible, such as 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), and a configuration in which the terminal does not have a display unit.

[0427] The detailed configuration of a terminal when the first to fifth embodiments are implemented using a terminal with such a configuration will be described below.

[0428] First, a description will be given of a configuration in which a terminal is provided with a display device and can be connected to another device (called a display device) that has a display unit.

[0429] Figure 53 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 Figure 3 are given the same numbers.

[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, the decoded video data of the "first video and / or audio information" as 383 in FIG. 53, and the decoded audio data 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 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 the decoded video data of the "second video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "second video and / or audio information" as 5303 in FIG. 53. Then, the decoded video data of the "second video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "second video and / or audio information" as 5303 in FIG. 53 are delivered to display device 5306 via connection unit 5304. (Note that connection 5305 may be either wireless or wired.) Display device 5306 displays the second video (note that the second audio may be played from a speaker).

[0432] Another example is given below.

[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, the decoded video data of the "second video and / or audio information" as 383 in FIG. 53, and the decoded audio data 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 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 the decoded video data of the "first video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "first video and / or audio information" as 5303 in FIG. 53. Then, the decoded video data of the "first video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "first video and / or audio information" as 5303 in FIG. 53 are delivered to display device 5306 via connection unit 5304. (Note that connection 5305 may be either wireless or wired.) 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 video or the second video may be displayed on the display unit 384, and either the first video or the second video may be displayed on the display device 5306. The display method may be controlled by, for example, the control signal 5301.

[0436] Control signal 5301 may include control information that enables 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 the display timing of display unit 384 and display device 5306.

[0437] Figure 54 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.

[0438] Data separation unit (which may be called "data control unit") 5402 receives as input 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", and outputs the "first video and / or audio information" as data 5407 and the data related to the "second video and / or audio information" as data 5403, for example.

[0439] Then, decoder 382 receives data 5407, decodes it, and the primary video is displayed on display unit 384.

[0440] Furthermore, 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 is given below.

[0442] Data separation unit (which may be called "data control unit") 5402 receives as input 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," and outputs the "second video and / or audio information" as data 5407 and the data related to the "first video and / or audio information" as data 5403.

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

[0444] Furthermore, 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 video or the second video may be displayed on the display unit 384, and either the first video or the second video may be displayed on the display device 5306. The display method may be controlled by, for example, the control signal 5401.

[0446] Control signal 5401 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 5401 may also include control information for adjusting the display timing of display unit 384 and 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 of a terminal such as that shown in FIG. 42, and components that operate in the same manner as those shown in FIGS. 3 and 42 are given the same numbers.

[0449] When the terminal has the configuration of FIG. 55, the display unit 384 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 {the first video} and {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}," "display {the second video} 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, the display device 5510 will perform any of the following: "display the first video," "display the second video," "display both the first video and the second video," "display {the first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}," "display {the 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, the decoded video data of the "first video and / or audio information" as 383 in FIG. 55, and the decoded audio data 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 display device 5510 via selection unit 5505 and connection unit 5508. (Note that connection 5509 may be either wireless or wired.) Display device 5510 displays the second video (note that the second audio may be played from a speaker).

[0454] Another example is given below.

[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, the decoded video data of the "second video and / or audio information" as 383 in FIG. 55, and the decoded audio data 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 Figure 55, and the decoded audio data of the "first video and / or audio information" as 5502 in Figure 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 display device 5510 via selection unit 5505 and connection unit 5508. (Note that connection 5509 may be either wireless or wired.) 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] Selector 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 output from 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, multiple screens may be displayed on display unit 384, or the terminal may transmit part of the display information to display device 5306, which then displays the video (or screen). The display method may be controlled by control signal 5504, for example.

[0464] Control signal 5504 may include control information that enables 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 of a terminal such as that shown in FIG. 42, and components that operate in the same manner as those in FIGS. 3 and 42 are given the same numbers.

[0466] When the terminal has the configuration of FIG. 56, the display unit 384 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 {the first video} and {a display screen based on character information (electronic message information), and / or still image information, and / or URL information}," "display {the second video} 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, the display device 5510 will perform any of the following: "display the first video," "display the second video," "display both the first video and the second video," "display {the first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}," "display {the 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 as input data 381 and control signal 5601. 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, 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," and outputs the "first video and / or audio information" as data 5603 and the data related to the "second video and / or audio information" as data 5604.

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

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

[0471] Another example is given below.

[0472] Data separation unit (data control unit) 5602 receives as input data 381 and control signal 5601. 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, 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," and outputs the "second video and / or audio information" as data 5603 and the data related to the "first video and / or audio information" as data 5604.

[0473] Then, decoder 382 receives data 5407, decodes it, and the second video becomes a candidate for display on display unit 384 (based on determination result 4201, the video to be displayed on display unit 384 is selected from the candidate videos).

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

[0475] The data separation unit (data control unit) 5605 receives as input the "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 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 and 5610 are then transmitted via connection 5611 to a display device 5613 .

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

[0481] Control signal 5601 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 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 has been described in which the terminal is equipped with a display unit and can be connected to another display device. However, in cases different from the above example, two videos may be displayed using both the display unit of the terminal and another display device. For example, a video transmitted by a broadcaster may be displayed on the display unit of the terminal, and a video, text information, or still image (which may include text) linked to the video may be displayed on another display device. Also, a video transmitted by a broadcaster may be displayed on another display device, and a video, text information, or still image (which may include text) linked to the video may be displayed on the display unit of the terminal. In addition, when transmitting data, the transmission method described in embodiment 5 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] Decoder 382 receives data 381 and control signal 5301. 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, the decoded video data of the "first video and / or audio information" as 383 in Fig. 53 and the decoded audio data of the "first video and / or audio information" as 385 in Fig. 53, which are transmitted to display device 5703 via connection unit 5701, and display device 5703 displays the first video and outputs the audio (note that connection 5702 may be either wireless or wired).

[0486] In addition, since 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 the decoded video data of the "second video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "second video and / or audio information" as 5303 in FIG. 53. The decoded video data of the "second video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "second video and / or audio information" as 5303 in FIG. 53 are delivered to display device 5306 via connection unit 5304 (note that connection 5305 may be wireless or wired). Display device 5306 displays the second video (note that the second audio may be played from a speaker).

[0487] Another example is given below.

[0488] Decoder 382 receives data 381 and control signal 5301. 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, the decoded video data of the "second video and / or audio information" as 383 in Fig. 53 and the decoded audio data of the "second video and / or audio information" as 385 in Fig. 53, which are transmitted to display device 5703 via connection unit 5701, and display device 5703 displays the second video and outputs the audio (note that connection 5702 may be either wireless or wired).

[0489] In addition, since 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 the decoded video data of the "first video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "first video and / or audio information" as 5303 in FIG. 53. Then, the decoded video data of the "first video and / or audio information" as 5302 in FIG. 53 and the decoded audio data of the "first video and / or audio information" as 5303 in FIG. 53 are delivered to display device 5306 via connection unit 5304 (note that connection 5305 may be wireless or wired). 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 video or the second video may be displayed on the display device 5306, and the display device 5306 may also display either the first video or the second video. The display method may be controlled by, for example, the control signal 5301.

[0491] Control signal 5301 may include control information that enables 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 of a terminal such as Figures 3, 28, 33, 37, 39, and 52, and parts that operate in the same way as Figures 3, 53, and 54 are given the same numbers.

[0493] Data separation unit (which may be called "data control unit") 5402 receives as input 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", and outputs the "first video and / or audio information" as data 5407 and the data related to the "second video and / or audio information" as data 5403, for example.

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

[0495] Furthermore, 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 is given below.

[0497] Data separation unit (which may be called "data control unit") 5402 receives as input 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," and outputs the "second video and / or audio information" as data 5407 and the data related to the "first video and / or audio information" as data 5403.

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

[0499] Furthermore, 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 video or the second video may be displayed on the display device 5803, and either the first video or the second video 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 that enables 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 of a terminal such as that shown in FIG. 42, and components that operate in the same manner as those shown in FIGS. 3, 42, and 55 are given the same numbers.

[0504] When the terminal has the configuration of FIG. 59, the display device 5903 will perform any of the following: "display a first video," "display a second video," "display both the first video and the second video," "display {the first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}," "display {the 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, the display device 5510 will perform any of the following: "display the first video," "display the second video," "display both the first video and the second video," "display {the first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}," "display {the 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, the decoded video data of the "first video and / or audio information" as 383 in Fig. 59, and the decoded audio data 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 display device 5510 via selection unit 5505 and connection unit 5508. (Note that connection 5509 may be either wireless or wired.) Display device 5510 displays the second video (note that the second audio may be played from a speaker).

[0510] Another example is given below.

[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, the decoded video data of the "second video and / or audio information" as 383 in Fig. 59, and the decoded audio data 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 display device 5510 via selection unit 5505 and connection unit 5508. (Note that connection 5509 may be either wireless or wired.) 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] Selector 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 output from 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, multiple screens may be displayed on display device 5510, or the terminal may transmit part of the display information to display device 5306, which then displays the video (or screen). The display method may be controlled by control signal 5504, for example.

[0521] Control signal 5504 may include control information that enables 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 of a terminal such as that shown in FIG. 42, and components that operate in the same manner as those shown in FIGS. 3, 42, and 56 are given the same numbers.

[0523] When the terminal has the configuration of FIG. 56, the display device 6003 will perform any of the following: "display a first video," "display a second video," "display both the first video and the second video," "display {the first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}," "display {the 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, the display device 5510 will perform any of the following: "display the first video," "display the second video," "display both the first video and the second video," "display {the first video} and {a display screen based on text information (electronic message information), and / or still image information, and / or URL information}," "display {the 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 as input data 381 and control signal 5601. 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, 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," and outputs the "first video and / or audio information" as data 5603 and the data related to the "second video and / or audio information" as data 5604.

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

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

[0528] Another example is given below.

[0529] Data separation unit (data control unit) 5602 receives as input data 381 and control signal 5601. 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, 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," and outputs the "second video and / or audio information" as data 5603 and the data related to the "first video and / or audio information" as data 5604.

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

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

[0532] The data separation unit (data control unit) 5605 receives as input the "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 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 and 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, multiple screens may be displayed on display device 5903, or the terminal may transmit part of the display information to display device 5613, which then displays the video (or screen). The display method may be controlled by control signal 5601, for example.

[0539] Control signal 5601 may include control information that enables 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 a terminal can be connected to a first display device and a second display device has been described. However, in a case different from the above example, both the first display device and the second display device may be used to display two images. For example, a video transmitted by a broadcaster may be displayed on the first display device, and a video, text information, or a still image (which may include text) linked to the video may be displayed on the second display device. Also, a video transmitted by a broadcaster may be displayed on the second display device, and a video, text information, or a still image (which may include text) linked to the video may be displayed on the first display device. In addition, a transmission method such as that described in the fifth embodiment may be applied to data transmission.

[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 that 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 is based on the assumption that the information being sent / received includes video information.

[0544] In this specification, the term "voice" is used, but the same implementation is possible even if the "voice" 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 can be configured as "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's receiving operation, or may be data obtained by converting the format of the data obtained by the terminal's receiving operation).

[0546] Furthermore, as the configuration of the receiving device of the terminal, for example, Figures 3, 28, 33, 37, 39, 42, 49, and 52 show a display unit, but when the terminal does not have a display unit, the terminal has 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] Naturally, the embodiments and other contents described in this specification may be combined and implemented.

[0548] Furthermore, each embodiment and other contents are merely examples, and 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 exemplified, 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 contain symbols for transmitting control information (such as information about the transmission method), preambles for 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 may be any method, such as a single-carrier transmission method, a multi-carrier transmission method such as OFDM (Orthogonal Frequency Division Multiplexing), a transmission method using a spread spectrum communication method, a transmission method in which multiple modulated signals are transmitted at the same time and frequency by performing precoding or space-time (or time-frequency) coding (e.g., space-time block codes).The broadcast station may also transmit data via a wired line such as a cable.

[0551] Although the present specification describes an example in which data transmitted by a transmitting device of a telecommunications carrier is transmitted via a wired connection, the present specification also provides a method for transmitting data wirelessly, or a method that uses both wired and wireless transmission.

[0552] In this specification, the receiving device and the antenna of the terminal may be separate devices. 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 then performs subsequent processing.

[0553] The data and information obtained by the receiving device are then converted into video and sound, which are then displayed on a display (monitor) or output from a speaker. Furthermore, the data and information obtained by the receiving device may undergo signal processing for video and sound (or may not require signal processing) and 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., which the receiving device has.

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

[0555] The present disclosure is not limited to the embodiments and can be implemented with various modifications. For example, in the embodiments, the case where the communication method 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] The single antenna shown in the drawings, both the transmitting antenna of the transmitting device and the receiving antenna of the receiving device, may be configured with multiple antennas.

[0557] For example, a program for executing the above communication method may be stored in advance in a ROM (Read Only Memory). Alternatively, the program may be stored in a memory (memory) and run by a CPU (Central Processor 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 RAM (Random Access Memory) of the computer, causing the computer to operate in accordance with the program.

[0559] Each configuration of the above-described 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 configuration of each embodiment.

[0560] Here, we refer to LSI, but depending on the level of integration, it may also be called IC (Integrated Circuit), system LSI, super LSI, or ultra LSI. Furthermore, the method of integration is not limited to LSI; it can also be realized using dedicated circuits or general-purpose processors. It is also possible to use FPGAs (Field Programmable Gate Arrays), which can be programmed after LSI manufacturing, or reconfigurable processors, which allow the connections and settings of circuit cells within LSI to be reconfigured.

[0561] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0562] (Supplementary Note 2) In the above embodiments 1 to 3, we have taken as an example a case where a broadcasting station and a telecommunications carrier each transmit content via one or more routes (transmission media), but it goes without saying that the control of transmission timing described in the above embodiments 1 to 3 can also be applied to cases where, for example, a broadcasting 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 the first route and a packet group transmitted via the second route, depending on the difference between a first time from when the transmitting device transmits the data until it arrives at the terminal via the first route and a second time from when the transmitting device transmits the data until it arrives at the 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 whether error correction coding at the packet level has been performed, as shown in this specification).

[0565] Here, the first route and the second route may be the same in other parts as long as at least a part of the route is different. Also, if different transmission media or protocols are used between some relay devices, which causes a difference in the time it takes for data to arrive at the terminal after it is sent from the transmitting device, the routes may be considered to be different even if all the devices on the routes are the same, and transmission timing may be controlled accordingly.

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

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

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

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

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

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

[0572] Although this disclosure has been described with a focus on examples of services provided by multicast, it goes without saying that the present disclosure can also be applied to services provided by unicast. That is, a group of packets may be transmitted by multiple carriers over multiple routes, and in this case, terminal feedback may be provided to each carrier, and the carrier may accept requests for packet retransmission. [Industrial Applicability]

[0573] 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; receiving second data via broadcasting before starting reception of the first data, the second data including a parity bit 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 from the second data. Receiving method.

2. A terminal including a receiving unit and an error correction decoding unit, the receiving unit receives 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 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 from the second data. Terminal.

Images