Transmitting device

Abstract

To make it possible to perform seamless reproduction at the time of switching a broadcast signal.SOLUTION: A receiving device receives a plurality of broadcast signals, and selects a broadcast signal of a target from the plurality of broadcast signals, on the basis of a result of processing with respect to the broadcast signal, and thus, it is possible to perform seamless reproduction at the time of switching the broadcast signal. The present technology, for example, can be applied to a receiver which is capable of receiving digital television broadcast.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present technology relates to a transmission device, and more particularly to a transmission device that is capable of performing seamless playback when switching broadcast signals. [Background technology]

[0002] For example, there is known a receiver that can receive a plurality of broadcast signals of simulcast programs, such as a one-segment broadcast program and a full-segment broadcast program (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-300910 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when switching between simulcast programs, video and audio disturbances can occur on receivers. Therefore, there has been a demand for a proposal to enable seamless playback when switching between received broadcast signals.

[0005] The present technology has been made in view of such circumstances, and makes it possible to perform seamless playback when switching between broadcast signals. [Means for solving the problem]

[0006] A receiving device according to a first aspect of the present technology is a receiving device including a receiving unit that receives a plurality of broadcast signals, and a control unit that selects a target broadcast signal from among the plurality of broadcast signals based on a result of processing the broadcast signals.

[0007] The receiving device according to the first aspect of the present technology may be an independent device or an internal block constituting a single device. Also, the data processing method according to the first aspect of the present technology is a data processing method corresponding to the receiving device according to the first aspect of the present technology described above.

[0008] In the receiving device and data processing method of the first aspect of the present technology, multiple broadcast signals are received, and a target broadcast signal is selected from the multiple broadcast signals based on the results of processing the broadcast signals.

[0009] A transmitting device according to a second aspect of the present technology is a transmitting device including a generating unit that generates video boundary information, which is information indicating the boundaries of the video of content of the same or corresponding content, and a transmitting unit that includes the video boundary information in a plurality of broadcast signals for transmitting the content, and transmits the video boundary information.

[0010] The transmitting device according to the second aspect of the present technology may be an independent device or an internal block constituting a single device. Also, the data processing method according to the second aspect of the present technology is a data processing method corresponding to the transmitting device according to the second aspect of the present technology described above.

[0011] In the transmitting device and data processing method of the second aspect of the present technology, video boundary information is generated, which is information indicating the video boundaries of content of the same or corresponding content, and the video boundary information is transmitted included in multiple broadcast signals for transmitting each of the content. [Effects of the Invention]

[0012] According to the first and second aspects of the present technology, playback can be performed seamlessly when broadcast signals are switched.

[0013] The effects described here are not necessarily limited to those described herein, and may be any of the effects described in this disclosure. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating a configuration of an embodiment of a transmission system to which the present technology is applied. [Figure 2] FIG. 1 illustrates an example of the configuration of a transmitting device. [Figure 3] FIG. 1 illustrates an example of the configuration of a receiving device. [Figure 4] FIG. 1 is a diagram illustrating the principle of seamless playback. [Figure 5] FIG. 10 is a diagram illustrating an example of the configuration of a receiving device that performs seamless playback. [Figure 6] 10A and 10B are diagrams illustrating examples of received signal quality and broadcast signal switching timing. [Figure 7] 10A and 10B are diagrams illustrating the relationship between physical layer frames and video signals when control is performed in units of physical layer frames. [Figure 8] FIG. 10 is a diagram illustrating an example of a data structure for each layer when an IP transmission method is adopted. [Figure 9] FIG. 10 is a diagram illustrating an example of the syntax of L1 basic information. [Figure 10] FIG. 10 is a diagram illustrating an example of the syntax of L1 detailed information. [Figure 11] FIG. 1 is a diagram showing the relationship between the physical layer and data handled in the upper layer. [Figure 12] FIG. 10 is a diagram showing the relationship between a physical layer frame and a video signal when control is performed in units of BB packets. [Figure 13] 10 is a diagram showing the relationship between BB packets and video signals when control is performed in units of BB packets. FIG. [Figure 14] FIG. 10 is a diagram illustrating an extension header of a BB packet. [Figure 15] FIG. 10 is a diagram illustrating an extension header of a BB packet. [Figure 16] FIG. 10 is a diagram illustrating an extension header of a BB packet. [Figure 17] FIG. 10 is a diagram illustrating an example of the syntax of video boundary information. [Figure 18] FIG. 10 is a diagram showing the relationship between layers and video signals when control is performed in layer units. [Figure 19]FIG. 10 is a diagram showing an example in which video boundary information is arranged in additional information (AC) related to broadcasting. [Figure 20] FIG. 10 is a diagram illustrating selection control of decoding targets according to the quality of received signals, etc. [Figure 21] 10 is a flowchart illustrating the flow of a first seamless playback process. [Figure 22] 10 is a flowchart illustrating the flow of a second seamless playback process. [Figure 23] FIG. 1 illustrates an example of the configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present technology will be described with reference to the drawings. The description will be made in the following order.

[0016] 1. System Configuration 2. Overview of this technology 3. Seamless playback control of this technology (1) Control in physical layer frames (2-1) Control on a per-BB packet basis (TDM) (2-2) Hierarchical control (FDM) (3) Selection control of decoding targets according to the quality of received signals, etc. 4. Seamless playback processing flow 5. Variations 6. Computer Configuration

[0017] <1. System configuration>

[0018] (Example of transmission system configuration) 1 is a diagram showing the configuration of an embodiment of a transmission system to which the present technology is applied. Note that a system refers to a logical collection of multiple devices.

[0019] 1, a transmission system 1 is made up of a transmitting device 10 and a receiving device 20. In this transmission system 1, data transmission is performed in accordance with a predetermined broadcasting format.

[0020] The transmitting device 10 is a transmitter compatible with a predetermined broadcasting system, and transmits content via a transmission path 30. For example, the transmitting device 10 transmits a broadcast stream including (components of) video, audio, etc., and signaling that constitute content such as a broadcast program, as a broadcast wave via the transmission path 30.

[0021] The receiving device 20 is a receiver compatible with a predetermined broadcasting system, and receives and outputs content transmitted from the transmitting device 10 via a transmission path 30. For example, the receiving device 20 receives broadcast waves from the transmitting device 10, processes the video, audio, etc. (components) and signaling that make up the content contained in the broadcast stream, and reproduces the video and audio of the content such as a broadcast program.

[0022] In addition, in the transmission system 1, the transmission path 30 may be, in addition to terrestrial waves (terrestrial broadcasting), for example, satellite broadcasting using a broadcasting satellite (BS) or a communications satellite (CS), or cable broadcasting (CATV) using a cable.

[0023] (Example of transmitter configuration) FIG. 2 is a diagram illustrating an example of the configuration of the transmission device 10 of FIG.

[0024] In FIG. 2, the transmitting device 10 is made up of a component processing unit 111, a signaling processing unit 112, a processing unit 113, and a modulation unit 114.

[0025] The component processing unit 111 acquires the content input thereto. Here, the content is composed of components such as video, audio, subtitles, etc. Furthermore, as the content, it is possible to prepare a plurality of pieces of the same or corresponding content, for example, pieces with different screen resolutions or pieces of audio only.

[0026] The component processing unit 111 processes (for example, encodes) the video and audio data of the content, and supplies the resulting video and audio signals to the processing unit 113.

[0027] The signaling processing unit 112 acquires data input thereto for generating control information used in demodulation processing, playback processing, etc. on the receiving device 20 side. The signaling processing unit 112 generates signaling (control information) based on the data for the control information and supplies it to the processing unit 113.

[0028] The processing unit 113 performs necessary processing on the video signal and audio signal supplied from the component processing unit 111 and the signaling supplied from the signaling processing unit 112, and supplies the resulting multiplexed stream to the modulation unit 114.

[0029] The modulation unit 114 performs modulation processing on the multiplexed stream supplied from the processing unit 113, and transmits the resulting signal via the antenna 121 as a broadcast signal.

[0030] The transmitting device 10 is configured as described above. For convenience of explanation, in Fig. 2, the transmitting device 10 is depicted as if it were made up of a single device, but the transmitting device 10 on the transmitting side can be a system made up of multiple devices having the functions of the blocks in Fig. 2.

[0031] (Example of receiving device configuration) FIG. 3 is a diagram showing an example of the configuration of the receiving device 20 of FIG.

[0032] 3, the receiving device 20 includes a control unit 210, a tuner 211, a demodulation unit 212, a filter 213, a decoding unit 214, and an output unit 215.

[0033] The control unit 210 is configured by, for example, a CPU (Central Processing Unit), a microprocessor, etc. The control unit 210 controls the operation of each unit of the receiving device 20.

[0034] The tuner 211 processes a broadcast signal in a predetermined frequency band received via the antenna 221 under the control of the control unit 210 , and supplies the resulting received signal to the demodulation unit 212 .

[0035] The demodulation unit 212 is configured by, for example, a demodulation LSI (Large Scale Integration) etc. The demodulation unit 212 performs demodulation processing on the received signal supplied from the tuner 211 under the control of the control unit 210, and supplies the resulting multiplexed stream to the filter 213.

[0036] The filter 213 processes the multiplexed stream supplied from the demodulation unit 212 under the control of the control unit 210 , and supplies the resulting video and audio signals to the decoding unit 214 .

[0037] The decoding unit 214 decodes the video signal and audio signal supplied from the filter 213 under the control of the control unit 210, and supplies the resulting video and audio data to the output unit 215. The filter 213 and the decoding unit 214 are configured, for example, from a main SoC (System On Chip) or the like.

[0038] The output unit 215 is configured by, for example, an output interface circuit etc. The output unit 215 processes the video and audio data supplied from the decoding unit 214 and outputs it to a display device (not shown) or a speaker (not shown) etc. As a result, the receiving device 20 plays back content such as a broadcast program and outputs the video and audio.

[0039] In addition, in Figure 3, the receiving device 20 may have a display such as an LCD (Liquid Crystal Display) or an OLED (Organic Electroluminescence Display) and a speaker, and may output video and audio according to the data from the output unit 215.

[0040] The receiving device 20 is configured as described above.

[0041] 2. Overview of this technology

[0042] For example, ISDB-T (Integrated Services Digital Broadcasting - Terrestrial), a broadcasting system adopted in Japan and other countries, specifies two types of terrestrial digital television broadcasting: high-definition broadcasting using 12 segments (hereinafter referred to as full-segment broadcasting), which is primarily for fixed receivers, and "one-segment partial reception service for mobile phones and mobile terminals" (hereinafter referred to as one-segment broadcasting), which is primarily for mobile receivers and uses one segment. Furthermore, terrestrial digital television broadcasting also provides simulcast broadcasting, in which the same broadcast program (content) is broadcast on both full-segment and one-segment broadcasts.

[0043] In recent years, mobile receivers such as mobile phones and smartphones equipped with tuners for terrestrial digital television broadcasting, which are capable of receiving not only one-segment broadcasting but also so-called full-segment broadcasting, have become increasingly popular.

[0044] Some mobile receivers of this type are capable of switching the broadcast signal they receive depending on the reception environment, such as receiving full-segment broadcasts when the reception environment is good, and receiving one-segment broadcasts when the reception environment is poor. For example, full-segment broadcasts are HD resolution images (images corresponding to a screen resolution of approximately 1920 x 1080 pixels), while one-segment broadcasts are QVGA resolution images (images corresponding to a screen resolution of approximately 320 x 240 pixels).

[0045] However, when a mobile receiver switches the broadcast signal it receives depending on the reception environment, it may experience video and audio disturbances such as freezing and block errors.One of the causes of this phenomenon is, for example, a mismatch between the timing of switching signals processed in the physical layer of the broadcasting system's protocol stack and the boundaries of the GOP (Group of Pictures) structure obtained from the signals processed in the upper layer.

[0046] A GOP is made up of I-pictures, B-pictures, or P-pictures, and includes at least one I-picture. An I-picture is an image coded using only current image information. A B-picture is an image coded using current, past, and future image information. A P-picture is an image coded using current and past image information.

[0047] Meanwhile, the Advanced Television Systems Committee (ATSC), a broadcasting system adopted in the United States and other countries, is working on developing ATSC3.0, one of the next-generation terrestrial broadcasting standards. ATSC3.0 envisions operations in which multiple broadcast signals with different bit rates and robustness will be prepared, allowing receivers to switch between the broadcast signals they receive depending on the reception environment.

[0048] When operating in this manner, for example, 4K resolution video (video corresponding to a screen resolution of approximately 4000 x 2000 pixels) and audio can be transmitted at a high bit rate and low robustness, HD resolution video (video corresponding to a screen resolution of approximately 1920 x 1080 pixels) and audio can be transmitted at a medium bit rate and medium robustness, and only audio can be transmitted at a low bit rate and high robustness.

[0049] In this case, if the receiver's reception environment is good, it can select and receive 4K resolution video and audio broadcast signals, but if the reception environment is poor, it will have to select HD resolution video and audio, or in the worst case, select and receive only audio. In such cases, for example, when switching between 4K resolution video and HD resolution video, video and audio disturbances such as freezing may occur. One of the causes of this is that the timing of switching signals processed in the physical layer does not match the boundaries of the GOP structure obtained from the signals processed in the higher layer.

[0050] In this way, when broadcast signals are switched, if the timing of signal switching in the physical layer does not match the boundary of the video obtained from the signal in the higher layer, video and audio will be distorted. Therefore, this technology focuses on this point and proposes a method for suppressing video and audio distortion that occurs when broadcast signals are switched, and for seamless playback.

[0051] (Seamless playback principle) Here, the principle of seamless playback to which the present technology is applied will be described with reference to FIGS.

[0052] Figure 4 shows the relationship between the quality of the received signal and the number of receivable broadcast signals, with the horizontal axis representing time and the vertical axis representing the C / N ratio (Carrier to Noise Ratio). In Figure 4, the C / N ratio, represented by the solid line L, fluctuates over time.

[0053] 4, three types of broadcast signals are provided as broadcast signals that can be received by the receiving device 20, each with a different required bit rate and robustness. That is, a broadcast signal that transmits 4K resolution video and audio at a high bit rate and low robustness is represented by "4K" in the figure. Also, a broadcast signal that transmits HD resolution video and audio at a medium bit rate and medium robustness is represented by "HD" in the figure, and a broadcast signal that transmits only audio at a low bit rate and high robustness is represented by "audio" in the figure.

[0054] Although no specific values ​​are given here, this means that the bit rate increases in the order of low bit rate, medium bit rate, and high bit rate, and that the robustness increases in the order of low robustness, medium robustness, and high robustness.

[0055] Here, if the C / N ratio is high, the impact of noise on transmission is small, and the quality of the received signal can be said to be good. On the other hand, if the C / N ratio is low, the impact of noise is large, and the quality of the received signal can be said to be poor. Therefore, as shown in Figure 4, if the C / N ratio is high, it is possible to receive "4K," "HD," and "audio" broadcast signals, but if the C / N ratio is low, it is possible to receive "HD" and "audio" broadcast signals, and if the C / N ratio is even lower, it is only possible to receive "audio" broadcast signals.

[0056] In this way, in the receiving device 20, the broadcast signals that can be received change depending on the quality of the received signal, so even if the "4K" broadcast signal is being received when the quality of the received signal is good, if the quality of the received signal deteriorates, the "4K" broadcast signal cannot be received and the "HD" broadcast signal will be received. Conversely, even if the "HD" broadcast signal is being received when the quality of the received signal is slightly poor, the "4K" broadcast signal can be received when the quality of the received signal improves, so the "4K" broadcast signal will be received.

[0057] That is, the receiving device 20 switches the broadcast signal to be received in accordance with fluctuations in the C / N ratio, but as described above, when switching from 4K resolution video to HD resolution video or from HD resolution video to 4K resolution video, for example, video and audio disturbances may occur.The present technology suppresses video and audio disturbances when switching broadcast signals, enabling seamless playback.

[0058] The seamless playback control of the present technology can be roughly divided into cases where video boundary information, which is information indicating video boundaries (RAPs: Random Access Points), is used, and cases where video boundary information is not used.

[0059] In the case where video boundary information is used, video boundary information indicating a video boundary (RAP) is included in a signal processed in the physical layer. As a result, the receiving device 20 can switch the target broadcast signal based on this video boundary information, and the timing of the switching can be matched with the video boundary (RAP) obtained from the signal processed in the upper layer. The case where video boundary information is used will be described with reference to Figures 6 to 19.

[0060] On the other hand, in the case where video boundary information is not used, all of the multiple receivable broadcast signals are processed, and the signal to be decoded is selected based on information indicating the quality of the received signal, such as the C / N ratio, and information such as the error rate of the signal obtained by the demodulation process. Fig. 5 shows an example configuration of a receiving device 20 for realizing the case where video boundary information is not used. As shown in Fig. 5, when the case where video boundary information is not used is adopted, multiple systems of demodulators 212 and filters 213 are required to process multiple broadcast signals. The case where video boundary information is not used will be described with reference to Fig. 20.

[0061] 3. Seamless playback control using this technology

[0062] Next, seamless playback control of the present technology will be described, but first, a case where video boundary information is used will be described.

[0063] Here, the video boundary information can include, for example, the start position (position of I-picture) in a GOP period as a video boundary (RAP). This allows the receiving device 20 to match the timing of switching the target broadcast signal with a video boundary (RAP) such as a GOP structure boundary according to the quality of the received signal.

[0064] (Example of broadcast signal switching timing) FIG. 6 shows the quality of the received signal and the timing of switching the broadcast signal, with the horizontal axis representing time and the vertical axis representing the C / N ratio.

[0065] 6, the C / N ratio represented by the solid line L fluctuates over time, but assume that a user performs a channel (service) selection operation immediately before time t1. In this case, the C / N ratio is high between time t1 and time t2, and the quality of the received signal is good, so the receiving device 20 selects the "4K" broadcast signal ("S1" in the figure), and 4K video and audio are reproduced.

[0066] Thereafter, at time t2, when the C / N ratio gradually decreases and the quality of the received signal deteriorates, the receiving device 20 switches from the "4K" broadcast signal to the "HD" broadcast signal ("S2" in the figure), and HD video and audio are reproduced. At this time, the signal processed in the physical layer in the receiving device 20 (such as the demodulation unit 212) contains video boundary information, so by switching the signal processed in the physical layer at a timing according to this video boundary information, the timing coincides with the video boundary (for example, the boundary of the GOP structure) obtained from the signal processed in the higher layer.

[0067] This makes it possible for the downstream decoding unit 214 in the receiving device 20 to continuously decode the video signal and audio signal, and as a result, seamless playback is possible when switching from a "4K" broadcast signal ("S1" in the figure) to an "HD" broadcast signal ("S2" in the figure).

[0068] Thereafter, between time t2 and time t4, the receiving device 20 continues to select the "HD" broadcast signal ("S2" and "S3" in the figure) depending on the quality of the received signal, and HD video and audio are reproduced.

[0069] Furthermore, at time t4, when the C / N ratio increases and the quality of the received signal improves, the receiving device 20 switches from the "HD" broadcast signal ("S3" in the figure) to the "4K" broadcast signal ("S4" in the figure), and 4K video and audio are reproduced. At this time, in the receiving device 20 (the demodulation unit 212, etc.), the signal processed in the physical layer is switched at a timing according to video boundary information included in the signal processed in the physical layer, so that the timing coincides with the video boundaries (for example, boundaries of the GOP structure) obtained from the signal processed in the higher layer.

[0070] This makes it possible for the downstream decoding unit 214 in the receiving device 20 to continuously decode the video signal and audio signal, and as a result, seamless playback is possible when switching from an "HD" broadcast signal ("S3" in the figure) to a "4K" broadcast signal ("S4" in the figure).

[0071] The explanation for the subsequent time periods will be omitted as it would be repetitive, but when the receiving device 20 switches the broadcast signal according to the quality of the received signal, it switches the broadcast signal according to the video boundary information contained in the signal processed in the physical layer, making it possible to match the timing of the broadcast signal switching with the video boundary (RAP), thereby enabling seamless playback.

[0072] In this way, the receiving device 20 can perform seamless playback by using the video boundary information. Here, the video boundary information can be included in signals processed in the physical layer, such as the preamble of a physical layer frame, the header of a physical layer packet (a demodulated baseband packet), or additional information related to broadcasting. A control method according to the placement position of the video boundary information will be described below.

[0073] (1) Control in physical layer frames

[0074] (Relationship between physical layer frame and video signal) FIG. 7 is a diagram showing the relationship between physical layer frames and video signals when broadcast signals are switched in accordance with the quality of the received signal in units of physical layer frames, which are units for transmitting data.

[0075] 7, the upper part shows the configuration of the physical layer frame, and the lower part shows the configuration of the video signal. In addition, the time direction in FIG. 7 is from left to right in the figure. Note that these relationships are also the same in other corresponding figures described later.

[0076] In Figure 7, streams for "4K" video and audio signals, "HD" video and audio signals, and "audio" audio signals are provided to transmit three types of broadcast signals. In other words, these streams are streams of the same or corresponding content. In these streams, the positions indicated by arrows P1 and P2 in the figure are video boundaries ("RAP" in the figure), such as the start position in a GOP period (the position of an I-picture).

[0077] When these streams are transmitted as broadcast signals, they are transmitted in physical layer frame units. For example, in ATSC 3.0, a physical layer frame is composed of a bootstrap (BS), a preamble, and a data portion.

[0078] The bootstrap corresponds to, for example, the P1 symbol constituting the T2 frame of DVB-T2 (Digital Video Broadcasting - Second Generation Terrestrial), and the preamble corresponds to, for example, the P2 symbol constituting the T2 frame of DVB-T2. Therefore, the bootstrap can also be said to be a preamble. The frame length of the physical layer frame is, for example, 100 to 200 ms.

[0079] In the physical layer frame, the data portion includes data for each PLP (Physical Layer Pipe).

[0080] That is, a "4K" video signal and audio signal stream is transmitted as a PLP with a PLPID of "1" (hereinafter also referred to as PLP#1). In the "4K" stream transmitted by PLP#1, data 4K-1, whose position indicated by arrow P1 in the figure is the boundary (RAP) of the video, is divided into data 4K-11, data 4K-12, and data 4K-13 along its time axis, and are respectively included in the data portions of physical layer frames F-1 to F-3.

[0081] The "HD" video and audio signal streams are transmitted as a PLP with a PLPID of "2" (hereinafter also referred to as PLP#2). In the "HD" stream transmitted by PLP#2, data HD-1, whose video boundary (RAP) is indicated by arrow P1 in the figure, is divided into data HD-11, data HD-12, and data HD-13 along the time axis, and are included in the data portions of physical layer frames F-1 to F-3, respectively.

[0082] The "audio" audio signal stream is transmitted as a PLP with a PLPID of "3" (hereinafter also referred to as PLP#3). In the "audio" stream transmitted by PLP#3, data A-1, whose position indicated by arrow P1 in the figure corresponds to the video boundary (RAP), is divided into data A-11, data A-12, and data A-13 along its time axis, and are respectively included in the data portions of physical layer frames F-1 to F-3.

[0083] Although this will not be repeated and will not be explained further, the position indicated by arrow P2 in the figure is the boundary (RAP) of the image for data 4K-2, data HD-2, and data A-2, and the divided data will similarly be included in physical layer frames (not shown) from physical layer frame F-3 onwards.

[0084] 7, the period of the video boundary (for example, the GOP period) and an integer multiple of the period of the physical layer frame are equal to each other. Therefore, for example, by including video boundary information indicating the video boundary (RAP) in the preamble of a physical layer frame (physical layer frame F-1) including data (data 4K-11, HD-11, and A-11) corresponding to a video boundary (RAP) such as the start (I picture) of a GOP period, it is possible to indicate that the physical layer frame (physical layer frame F-1) includes data corresponding to the video boundary (RAP).

[0085] As a result, when the receiving device 20 switches broadcast signals in accordance with the quality of the received signal, for example, by processing the physical layer frame F-1 containing video boundary information, the timing of the switch coincides with the video boundary ("RAP" in the figure) of the data 4K-1 or data HD-1 processed in the higher layer (position indicated by arrow P1 in the figure). As a result, the receiving device 20 can perform seamless playback when switching, for example, from a "4K" broadcast signal to an "HD" broadcast signal or from an "HD" broadcast signal to a "4K" broadcast signal.

[0086] Furthermore, by using the video boundary information included in the preamble of the physical layer frame, seamless playback becomes possible by operating only one circuit (the demodulator 212 and the filter 213), so that the circuit can be operated to a minimum extent and low power consumption can be achieved. For example, since a demodulation LSI has a large circuit scale and consumes a lot of power, the effect of reducing power consumption by operating only one circuit to a minimum extent is very significant.

[0087] As will be explained in more detail later, when ATSC 3.0 uses ROUTE as the transport protocol, streaming delivery conforms to MPEG-DASH, in which video and audio streams are transmitted as segment files. Since a segment file contains a RAP (Random Access Point) at its beginning, in the example of Figure 7, the video boundary (RAP) corresponds to the beginning of the segment file, and seamless playback can be achieved by switching between segment files.

[0088] (Example of data structure) By the way, it is expected that more advanced services will be provided by adopting an IP transmission method that uses IP (Internet Protocol) packets used in the field of communications for digital television broadcasting, rather than the currently widely used MPEG2-TS (Transport Stream) method. For example, it has been decided that the IP transmission method will be adopted in ATSC3.0, one of the next-generation terrestrial broadcasting standards.

[0089] FIG. 8 is a diagram showing an example of a data structure for each layer when the IP transmission method is adopted.

[0090] In FIG. 8, a layer 1 (L1) which is a physical layer, a layer 2 (L2) which is a layer above the layer 1, and a layer 3 (L3) which is a layer above the layer 2 form a hierarchical structure.

[0091] IP packets are processed as Layer 3 data. An IP packet consists of an IP header and a payload. A UDP packet is stored in the payload of an IP packet. In other words, an IP packet can also be said to be an IP / UDP packet. The payload of an IP / UDP packet stores video and audio data of the content, signaling data as control information, and so on.

[0092] Generic packets are processed as data for Layer 2. Generic packets consist of a generic header and a payload. One or more IP / UDP packets are placed in the payload of the generic packet and encapsulated.

[0093] BB packets (Baseband Packets) are processed as data for Layer 1. A BB packet consists of a BBP header (Baseband Packet Header) and a payload. One or more generic packets are placed in the payload of the BB packet and encapsulated. Furthermore, in Layer 1, data obtained by scrambling one or more BB packets is mapped to an FEC frame, and parity for error correction in the physical layer is added.

[0094] Here, the physical layer frame of layer 1 is composed of a bootstrap, a preamble, and a data section. Data obtained by performing physical layer processing (modulation processing) such as performing bit interleaving on multiple FEC frames, performing mapping processing, and further performing interleaving in the time direction and frequency direction is mapped into the data section of the physical layer frame.

[0095] The preamble of the physical layer frame contains signaling. For example, ATSC 3.0 specifies L1 signaling as the signaling included in the preamble. L1 signaling consists of L1 basic signaling and L1 detail signaling.

[0096] Comparing the L1 basic information and the L1 detailed information, the L1 basic information is composed of approximately 200 bits, while the L1 detailed information is composed of 400 to several thousand bits, so they differ in size. Also, in the preamble of the physical layer frame, the L1 basic information and the L1 detailed information are read in that order, so the L1 basic information is read before the L1 detailed information. Furthermore, the L1 basic information differs from the L1 detailed information in that it is transmitted more robustly.

[0097] (L1 Basic Information Configuration) FIG. 9 is a diagram showing an example of the syntax of L1 basic signaling.

[0098] Note that the details of the L1 basic information are described in "Table 9.2 L1-Basic Signaling Fields and Syntax" in the following Non-Patent Document 1. Therefore, the syntax in Fig. 9 describes an excerpt of the L1 basic information that is particularly relevant to this technology.

[0099] Non-patent document 1: ATSC Candidate Standard: Physical Layer Protocol (A / 322) Doc. S32-230r45 6 April 2016

[0100] The 1-bit L1B_RAP_EXIST_FLAG is a flag indicating whether video boundary information exists in the L1 detailed information.

[0101] For example, when "0" is set as L1B_RAP_EXIST_FLAG, it indicates that the L1 detailed information does not include video boundary information. On the other hand, when "1" is set as L1B_RAP_EXIST_FLAG, it indicates that the L1 detailed information includes video boundary information.

[0102] Explanation of flags other than L1B_RAP_EXIST_FLAG will be omitted here.

[0103] (L1 detailed information configuration) FIG. 10 is a diagram illustrating an example of the syntax of L1 detail signaling.

[0104] Note that the L1 detailed information is described in detail in "Table 9.8 L1-Detail Signaling Fields and Syntax" in the above-mentioned Non-Patent Document 1. Therefore, the syntax in Fig. 10 describes an excerpt of the L1 detailed information that is particularly relevant to the present technology.

[0105] For example, if "1" is set as L1B_RAP_EXIST_FLAG in the L1 basic information of Figure 9, this indicates that video boundary information exists, so in the L1 detailed information of Figure 10, a 1-bit RAP and an 8-bit AdaptationSet are placed as video boundary information.

[0106] The 1-bit RAP is a flag that indicates whether the corresponding physical layer frame contains a video boundary (RAP). For example, if "0" is set as RAP, it indicates that the corresponding physical layer frame does not contain a video boundary (RAP).

[0107] On the other hand, if "1" is set as RAP, it indicates that the corresponding physical layer frame contains a video boundary (RAP). In other words, in this case, the data portion of the corresponding physical layer frame contains, for example, data of an I-picture located at the beginning of a GOP period.

[0108] The 8-bit AdaptationSet specifies an AdaptationSet that includes a video boundary (RAP). Here, the AdaptationSet corresponds to an AdaptationSet element described in MPD (Media Presentation Description) metadata, which is used for streaming distribution compliant with MPEG-DASH (Dynamic Adaptive Streaming over HTTP).

[0109] That is, MPD metadata describes a hierarchical structure of Period elements, AdaptationSet elements, Representation elements, etc. Period elements are units for describing the configuration of content such as broadcast programs. AdaptationSet elements or Representation elements are used for each stream such as video, audio, and subtitles, and can describe the attributes of each stream.

[0110] Specifically, the AdaptationSet element represents streams encoded from various sources. To allow the receiving device 20 to select one of the streams according to a parameter such as a bit rate, a Representation element is placed within the AdaptationSet element, listing multiple streams with different parameters such as a bit rate. Typically, the AdaptationSet element and the Representation element correspond to a single stream, such as a video, audio, or subtitle stream.

[0111] For example, ATSC3.0 is expected to use ROUTE (Real-Time Object Delivery over Unidirectional Transport) as the transport protocol, in which case streaming will be compliant with MPEG-DASH. In this case, the AdaptationSet placed in the L1 detailed information can identify the stream that contains the video boundary (RAP).

[0112] Explanations other than RAP and AdaptationSet will be omitted here.

[0113] In addition, in FIGS. 9 and 10, when uimsbf (unsigned integer most significant bit first) is specified as the format, it means that a bit operation is performed and the data is treated as an integer.

[0114] (Relationship between the physical layer and higher layers) FIG. 11 is a diagram showing the relationship between the physical layer and the data handled in the upper layer.

[0115] As mentioned above, ATSC 3.0 is expected to use ROUTE (Real-Time Object Delivery over Unidirectional Transport) as the transport protocol. ROUTE is an extension of FLUTE (File Delivery over Unidirectional Transport), a protocol suitable for unidirectional multicast transfer of binary files. ROUTE sessions can be used to transmit video, audio, subtitle components, signaling, and other data.

[0116] 11, a broadcast stream in a predetermined frequency band (e.g., 6 MHz) includes PLP#0, PLP#1, and PLP#2. PLP#0 includes a low-level signaling (LLS) stream. However, the LLS stream is stored in IP packets and transmitted.

[0117] Here, ATSC3.0 specifies LLS (Low Level Signaling) and SLS (Service Layer Signaling) as signaling. LLS is signaling acquired prior to SLS, and SLS for each service is acquired according to the information included in the LLS. The LLS includes, for example, metadata such as SLT (Service List Table). SLT metadata includes basic information indicating the configuration of streams and services in a broadcast network, such as information necessary for selecting a service.

[0118] PLP#1 includes, for example, a "4K" stream provided as Service#1. The "4K" stream includes video signals (Video Segments), audio signals (Audio Segments), and SLS (Service Signaling), and is identified by the IP address, port number, PLP ID, etc. included in the SLT metadata.

[0119] The SLS is signaling for each service and includes metadata such as a User Service Bundle Description (USBD), a Service-based Transport Session Instance Description (S-TSID), and a Media Presentation Description (MPD).

[0120] The USBD metadata includes information such as where to get other metadata.

[0121] S-TSID metadata is an ATSC3.0 extension of LSID (LCT Session Instance Description) and is control information for the ROUTE protocol. S-TSID metadata can also identify the EFDT (Extended FDT) transmitted in the ROUTE session. EFDT is an extension of the FDT (File Delivery Table) introduced in FLUTE and is control information for transmission.

[0122] As described above, MPD metadata is control information for video and audio files used for streaming distribution conforming to MPEG-DASH. Here, MPEG-DASH is a streaming distribution standard conforming to OTT-V (Over The Top Video), and is a standard for adaptive streaming distribution using a streaming protocol based on HTTP (Hypertext Transfer Protocol).

[0123] The MPEG-DASH standard specifies a manifest file for describing metadata, which is control information for video and audio files, and a file format for transmitting video content. Here, the former manifest file is called MPD (Media Presentation Description), and the latter file format is also called segment format.

[0124] When ROUTE is used as the transport protocol, the MP4 file format is expected to be used as the streaming file format. The MP4 file format is a derivative of the ISO Base Media File Format (ISOBMFF) defined in ISO / IEC 14496-12.

[0125] When selecting a channel, the receiving device 20 identifies the stream to be played from the IP address, port number, and PLP ID of the service to be selected (Service #1) in accordance with the SLT metadata acquired in advance. Furthermore, the receiving device 20 analyzes the MPD metadata and S-TSID metadata transmitted on the SLS channel among the LCT channels of the ROUTE session for the stream to be played, and acquires video and audio streams (segment files) transmitted on the AV (Audio Video) channel in accordance with the analysis results. As a result, the receiving device 20 plays back the 4K video and audio provided as Service #1.

[0126] In addition, ATSC3.0 also assumes the use of MMT (MPEG Media Transport) as a transport protocol together with ROUTE. In the example of Figure 11, the service provided as Service#2 in PLP#2 complies with the MMT method.

[0127] As described above, in the control on a physical layer frame basis, by including video boundary information indicating video boundaries (RAPs) as L1 signaling in the preamble of the physical layer frame, the receiving device 20 can switch the target broadcast signal based on this video boundary information, thereby matching the timing of the switching with the video boundaries (RAPs) obtained from the signal processed in the upper layer. This allows the receiving device 20 to perform seamless playback when switching broadcast signals.

[0128] In the above description of control on a physical layer frame-by-frame basis, we have described a case where time division multiplexing (TDM) is used as a method for multiplexing multiple broadcast signals, such as ATSC 3.0, but the same can be done with frequency division multiplexing (FDM).

[0129] That is, when frequency division multiplexing (FDM) is adopted, a predetermined frequency band (for example, 6 MHz) is frequency-divided into multiple segments, and hierarchical transmission is performed using the band of each of one or more segments. In this case, for each layer consisting of the frequency band of one or more segments obtained by frequency division, it is possible to transmit content of the same or corresponding content, such as "4K," "HD," or "audio."

[0130] Even when such a frequency division multiplexing (FDM) method is adopted, by including image boundary information, which is information indicating image boundaries (RAPs), in the signaling of the physical layer frame, the receiving device 20 can switch the target broadcast signal based on this image boundary information, and thereby align the timing of the switching with the image boundaries (RAPs) obtained from the signal processed in the upper layer.

[0131] For example, ISDB-T uses frequency division multiplexing (FDM), dividing one channel's frequency band (6 MHz) into 13 segments, with the central segment being used to transmit one-segment broadcast signals for mobile receivers and the remaining 12 segments being used to transmit broadcast signals for fixed receivers. Even in this case, by using video boundary information indicating the video boundaries (RAPs), for example, when switching between full-segment and one-segment broadcast signals depending on the reception environment on a mobile receiver, seamless playback can be achieved without any disruption to the video or audio.

[0132] (2-1) Control on a per-BB packet basis (TDM)

[0133] In the above-described control in units of physical layer frames, video boundary information is included in the L1 signaling of the preamble, assuming that the period of the video boundary (e.g., the GOP period) is equal to an integer multiple of the period of the physical layer frames. However, if the period of the video boundary is different from the integer multiple of the period of the physical layer frames, control in units of physical layer frames is not possible. Therefore, next, a control method for when the period of the video boundary is not an integer multiple of the period of the physical layer frames will be described.

[0134] However, as mentioned earlier, there are two methods for multiplexing multiple broadcast signals: time division multiplexing (TDM) and frequency division multiplexing (FDM).Here, we will first explain the control method when time division multiplexing (TDM) is used, with reference to Figures 12 to 17, and then explain the control method when frequency division multiplexing (FDM) is used, with reference to Figures 18 and 19.

[0135] (Relationship between physical layer frame and video signal) FIG. 12 is a diagram showing the relationship between physical layer frames and video signals when broadcast signals are switched in accordance with the quality of the received signal in units of BB packets, which are demodulated baseband packets.

[0136] In Fig. 12, streams for "4K" video and audio signals, "HD" video and audio signals, and "audio" audio signals are provided to transmit three types of broadcast signals. In other words, these streams are streams of the same or corresponding content. In these streams, the positions indicated by arrows P1 and P2 in the figure are video boundaries ("RAP" in the figure), such as the start position in a GOP period (the position of an I-picture).

[0137] That is, the "4K" stream transmitted in PLP#1 has a different GOP period for each video boundary (RAP) indicated by arrows P1 and P2, so that, for example, data 4K-1, data 4K-2, and data 4K-3 are data for different GOP periods. Similarly, in the "HD" stream transmitted in PLP#2, data HD-1, data HD-2, and data HD-3 are data for different GOP periods.

[0138] Here, in the example of Figure 12, in the "4K" stream, data 4K-2 is divided along the time axis and is included in the data portions of physical layer frames F-1 to F-3, respectively. However, since the GOP period does not match an integer multiple of the period of the physical layer frames, data 4K-12 of physical layer frame F-1 includes, as data for PLP#1, data 4K-2 as well as part of data 4K-1.

[0139] Furthermore, data 4K-22 in physical layer frame F-2 includes only data 4K-2 as data for PLP#1, and data 4K-23 in physical layer frame F-3 includes data 4K-2 as well as part of data 4K-3 as data for PLP#1.

[0140] In the "HD" stream, data HD-2 is divided along the time axis and is included in the data portions of physical layer frames F-1 to F-3, respectively. However, since the GOP period does not match an integer multiple of the period of the physical layer frames, data HD-12 of physical layer frame F-1 includes, as data for PLP#2, data HD-2 as well as part of data HD-1.

[0141] Data HD-22 of physical layer frame F-2 contains only data HD-2 as data of PLP#2. Furthermore, data HD-23 of physical layer frame F-3 contains data HD-2 as data of PLP#2, as well as part of data HD-3.

[0142] In the "audio" stream, data A-2 is divided along the time axis and is included in the data portions of physical layer frames F-1 to F-3, respectively. However, since the GOP period does not match an integer multiple of the period of the physical layer frames, data A-12 in physical layer frame F-1 includes, as data for PLP#3, data A-2 as well as part of data A-1.

[0143] Also, data A-22 in physical layer frame F-2 includes only data A-2 as data for PLP#3, and data A-23 in physical layer frame F-3 includes part of data A-3 as data for PLP#3 in addition to data A-2.

[0144] 12, the period of the video boundaries (GOP period) does not match an integer multiple of the period of the physical layer frames. In this case, even if the above-mentioned control is performed in units of physical layer frames, it is not possible to match the timing of switching the signals processed in the physical layer with the video boundaries (GOP structure boundaries) obtained from the signals processed in the higher layer.

[0145] Therefore, here, by performing control in BB packet units, which are even finer units than physical layer frame units, it is possible to match the timing of switching signals processed in the physical layer with the boundaries of the images (boundaries of the GOP structure) obtained from the signals processed in the higher layer, even if the period of the image boundaries (GOP period) does not match an integer multiple of the period of the physical layer frames.

[0146] (Relationship between BB packets and video signals) FIG. 13 is a diagram showing the relationship between BB packets and video signals when broadcast signals are switched in accordance with the quality of the received signal in units of BB packets, which are demodulated baseband packets.

[0147] In FIG. 13, the physical layer frames F-1 to F-3 in the upper row correspond to the physical layer frames F-1 to F-3 shown in FIG.

[0148] That is, data 4K-12 in physical layer frame F-1 includes data 4K-1 and data 4K-2 in the "4K" stream as data for PLP#1. Also, in physical layer frame F-1, data HD-12 includes data HD-1 and data HD-2 in the "HD" stream as data for PLP#2, and data A-12 includes data A-1 and A-2 in the "audio" stream as data for PLP#3.

[0149] Similarly, for physical layer frames from physical layer frame F-1 onwards, such as physical layer frame F-2 and physical layer frame F-3, data for the "4K", "HD", and "audio" streams are included as data within the same GOP period or data spanning GOP periods.

[0150] Here, looking at physical layer frame F-1, data 4K-12 included in its data portion corresponds to BB packet 4K-12-1, BB packet 4K-12-2, and BB packet 4K-12-3. That is, as shown in the above-mentioned FIG. 8, the BB packet is a packet of layer 1 (physical layer), and is one or more packets (baseband packets after demodulation) obtained by processing the data portion of the physical layer frame. Therefore, by controlling in BB packet units in processing at the physical layer, it is possible to align the timing with the period of the video boundary (GOP period) in units finer than when controlling in physical layer frame units.

[0151] Similarly, data HD-12 included in the data portion of physical layer frame F-1 corresponds to BB packets HD-12-1 to HD-12-3, and data A-12 corresponds to BB packets A-12-1 to A-12-3. Therefore, by controlling in BB packet units in processing at the physical layer, it is possible to align the timing with the video boundary period (GOP period) even if the video boundary period (GOP period) does not match an integer multiple of the physical layer frame period.

[0152] Furthermore, among the multiple BB packets included in the data section of the physical layer frame F-1, if we look at BB packet 4K-12-1 of data 4K-12, BB packet 4K-12-1 is composed of a BBP header and a payload. In addition to the header, the BBP header can also contain an optional field and an extension field. By including video boundary information indicating a video boundary (RAP) in this BBP header, it can be indicated that the BB packet to which the BBP header is added contains data corresponding to the video boundary (RAP).

[0153] For example, when data 4K-12 included in the data section of physical layer frame F-1 corresponds to BB packets 4K-12-1 to 4K-12-3, assume that, among the data of the "4K" stream (Figure 12), data 4K-1 is stored in BB packet 4K-12-1, and data 4K-2 is stored in BB packets 4K-12-2 and BB packet 4K-12-3.

[0154] In this case, the data 4K-2 stored in BB packet 4K-12-2 corresponds to data corresponding to a video boundary (RAP) such as the beginning of a GOP period (I picture), so by including video boundary information in the header of this BB packet 4K-12-2, it can be indicated that the BB packet 4K-12-2 contains data corresponding to a video boundary (RAP).

[0155] As a result, when the receiving device 20 switches broadcast signals according to the quality of the received signal, for example, by processing the BB packet 4K-12-2 containing video boundary information, the timing of the switch coincides with the video boundary (RAP) of the data 4K-2 or data HD-2 processed in the upper layer (the position indicated by the arrow P1 in the figure). As a result, when the receiving device 20 switches, for example, from a "4K" broadcast signal to an "HD" broadcast signal or from an "HD" broadcast signal to a "4K" broadcast signal, seamless playback is possible.

[0156] Furthermore, by using the video boundary information included in the header of the BB packet, seamless playback is possible by operating only one circuit (the demodulator 212 and the filter 213), so that the circuit can be operated to a minimum extent and low power consumption can be achieved. For example, since a demodulation LSI has a large circuit scale and consumes a lot of power, the effect of reducing power consumption by operating only one circuit to a minimum extent is very significant.

[0157] As mentioned above, when ROUTE is used as the transport protocol in ATSC 3.0, streaming delivery conforms to MPEG-DASH, in which video and audio streams are transmitted as segment files. Since a segment file includes a RAP at its beginning, in the example of Figure 12, the video boundary (RAP) corresponds to the beginning of the segment file, and seamless playback can be achieved by switching between segment files.

[0158] (Video boundary information is placed in the BB packet extension header) Next, an example in which video boundary information is placed in a BB packet extension header will be described with reference to FIGS.

[0159] Figure 14 shows the structure of a BB packet (Baseband Packet). In Figure 14, the BB packet is composed of a BBP header and a payload. In addition to a 1- or 2-byte header, the BBP header can also contain an optional field and an extension field.

[0160] That is, when "0" is set as the 1-bit mode in the header, 7-bit pointer information (Pointer (LSB)) is placed. The pointer information is information for indicating the position of the generic packet placed in the payload of the BB packet. For example, when the data of the generic packet placed at the end of a BB packet is placed across to the next BB packet, the position information of the generic packet placed at the beginning of the next BB packet can be set as the pointer information.

[0161] Furthermore, when "1" is set as the mode (MODE), in addition to the 7-bit pointer information (Pointer (LSB)), 6-bit pointer information (Pointer (MSB)) and a 2-bit optional flag (OPTI: OPTIONAL) are placed. The optional flag is information indicating whether or not to place an optional field and an extension field to extend the header.

[0162] That is, as shown in Figure 15, if the optional field and extension field are not extended, the optional flag is set to "00". Also, if a 1-byte optional field and extension field are extended, the optional flag is set to "01", resulting in short extension mode (box A in the figure). On the other hand, if a 2-byte optional field and extension field are extended, the optional flag is set to "10" or "11", resulting in long extension mode or mixed extension mode (box B in the figure).

[0163] The optional field begins with 3-bit extension type information (EXT_TYPE), which contains information about the extension field type, as shown in FIG.

[0164] That is, when a counter for extension length information (EXT_Length (LSB)) is placed in the extension field, the extension type information is set to "000". Also, when video boundary information is placed in the extension field, the extension type information is set to "001". This video boundary information includes RAP, Adaptation Set, and Sequence Number.

[0165] FIG. 17 shows an example of the syntax of the video boundary information included in the header of the BB packet.

[0166] The 1-bit RAP is a flag indicating that the corresponding BB packet contains a video boundary (RAP). For example, if "0" is set as the RAP, it indicates that the corresponding BB packet does not contain a video boundary (RAP).

[0167] On the other hand, if "1" is set as RAP, it indicates that the corresponding BB packet contains a video boundary (RAP). In other words, in this case, the payload of the corresponding BB packet contains, for example, data of an I-picture placed at the beginning of the GOP period.

[0168] The 8-bit AdaptationSet specifies an AdaptationSet that includes a video boundary (RAP). As described above, the AdaptationSet corresponds to the AdaptationSet element described in the MPD metadata that is used for streaming distribution conforming to MPEG-DASH. The AdaptationSet can identify a stream that includes a video boundary (RAP).

[0169] The 15-bit Sequence Number specifies the sequence number of the BB packet. This sequence number is incremented by 1 for each BB packet, regardless of whether there is a video boundary (RAP). Note that by using the sequence number, it is possible to identify corresponding BB packets, for example, between different PLPs.

[0170] Returning to the explanation of Fig. 16, when private user data is placed in the extension field, the extension type information is set to "110". Furthermore, when the extension field is padded, the extension type information is set to "111". In Fig. 16, the extension type information of "010" to "101" is a reserved area for future extensions.

[0171] As described above, in the control on a BB packet basis when the time division multiplexing (TDM) method is adopted, by including video boundary information indicating video boundaries (RAPs) in the header of the BB packet, the receiving device 20 can switch the target broadcast signal based on this video boundary information, and the timing of the switching can be matched with the video boundaries (RAPs) obtained from the signal processed in the upper layer. This allows the receiving device 20 to perform seamless playback when switching broadcast signals.

[0172] (2-2) Hierarchical control (FDM)

[0173] Next, we will explain a control method when the period of the video boundary (GOP period) does not match an integer multiple of the period of the physical layer frame, namely, when frequency division multiplexing (FDM) is used as the multiplexing method for multiple broadcast signals.

[0174] (Relationship between layers and video signals) FIG. 18 is a diagram showing the relationship between layers and video signals when broadcast signals are switched in accordance with the quality of the received signal for each layer when hierarchical transmission is performed.

[0175] Here, when frequency division multiplexing (FDM) is adopted, a predetermined frequency band (for example, 6 MHz) is divided into multiple segments, and hierarchical transmission can be performed using the bands of one or multiple segments. For example, in ISDB-T, the frequency band of one channel (6 MHz) is divided into 13 segments, and the central frequency band of the single segment is used to transmit broadcast signals for one-segment broadcasting intended for mobile receivers, and the remaining 12 frequency band segments are used to transmit broadcast signals for broadcasting intended for fixed receivers.

[0176] The upper part of Fig. 18 shows the configuration of each layer when hierarchical transmission is performed in the transmission system 1 (Fig. 1), with the horizontal direction representing time and the vertical direction representing frequency. In the example of Fig. 18, three layers, layer 1, layer 2, and layer 3, are configured using frequency bands of one or more segments obtained by frequency division.

[0177] The bottom part of Figure 18 shows the configuration of a video signal, similar to Figure 7 above, but with "4K" video signal and audio signal streams transmitted on Layer 1. Furthermore, "HD" video signal and audio signal streams are transmitted on Layer 2, and "audio" audio signal streams are transmitted on Layer 3. Therefore, for example, Layer 2 will have a larger number of segments than Layer 3, and Layer 1 will have a larger number of segments than Layer 2.

[0178] Here, in each of the "4K", "HD", and "audio" streams, the positions indicated by arrows P1 and P2 in the figure are image boundaries (RAPs), such as the first position in the GOP period (position of the I-picture), but by including image boundary information indicating the image boundaries (RAPs) for each layer, it is possible to identify the image boundaries (RAPs).

[0179] As a result, when receiving device 20 switches broadcast signals according to the quality of the received signal, by processing (detecting) the video boundary information transmitted for each layer, the timing of the switch coincides with the boundary (RAP) of the GOP structure of data 4K-2 or data HD-2 processed in the higher layer (the position indicated by arrow P1 in the figure). As a result, receiving device 20 can perform seamless playback when, for example, switching from a "4K" broadcast signal transmitted on layer 1 to an "HD" broadcast signal transmitted on layer 2, or switching from an "HD" broadcast signal transmitted on layer 2 to a "4K" broadcast signal transmitted on layer 1.

[0180] (Image boundary information is placed in additional information about the broadcast) Next, with reference to FIG. 19, an example of arranging video boundary information in additional information (AC) related to broadcasting will be described.

[0181] Figure 19 shows the configuration of an OFDM segment, with the horizontal direction representing carrier numbers and the vertical direction representing OFDM symbol numbers. Here, in OFDM (Orthogonal Frequency Division Multiplexing), a large number of orthogonal subcarriers are provided within a transmission band, and digital modulation is performed.

[0182] The OFDM segment in Fig. 19 includes TMCC and AC. TMCC (Transmission Multiplexing Configuration Control) is transmission control information for performing demodulation processing, decoding processing, etc. in receiving device 20 in hierarchical transmission in which multiple transmission parameters are mixed. AC (Auxiliary Channel) is additional information related to broadcasting. The same number of AC1s exist in all segments. For example, this additional information (AC(AC1)) can include video boundary information.

[0183] FIG. 19 shows an example of the syntax of video boundary information included in additional information (AC) related to broadcasting.

[0184] A 1-bit RAP is a flag that indicates that the segment contains a video boundary (RAP). For example, if "1" is set as RAP, it indicates that the segment contains a video boundary (RAP).

[0185] The 8-bit AdaptationSet specifies the AdaptationSet that includes the video boundary (RAP). The AdaptationSet can identify the stream that includes the video boundary (RAP). The 15-bit Sequence Number specifies the sequence number.

[0186] As described above, when frequency division multiplexing (FDM) is used for layer-by-layer (segment-by-segment) control, the additional information (AC), which allows segment-by-segment designation, includes video boundary information indicating video boundaries (RAPs). The receiving device 20 switches the target broadcast signal based on the video boundary information included in the additional information (AC), thereby matching the timing of the switching with the video boundaries (RAPs) obtained from the signal processed in the upper layer. This allows the receiving device 20 to perform seamless playback when switching broadcast signals.

[0187] Note that the video boundary information is not limited to the additional information (AC) related to the broadcast, but may be included in other control information such as transmission control information (TMCC).

[0188] (3) Selection control of decoding targets according to the quality of received signals, etc.

[0189] Next, a case where video boundary information is not used will be described with reference to Fig. 20. Fig. 20 is a diagram for explaining selection control of decoding targets according to the quality of received signals and the like.

[0190] 20, receiving device 20 is composed of tuner 211, demodulation units 212-1 to 212-3, filters 213-1 to 213-3, selection unit 220, and decoding unit 214. However, in the configuration example of receiving device 20 in FIG. 20, illustration of control unit 210 and output unit 215 is omitted, but selection unit 220 is a part of the function of control unit 210.

[0191] Tuner 211 processes broadcast signals in a predetermined frequency band received via antenna 221 under the control of control unit 210, and supplies the resulting received signals to demodulation units 212-1 to 212-3.

[0192] Here, for example, when "4K", "HD", and "audio" broadcast signals are received as broadcast signals transmitted from the transmitting device 10, the "4K" received signal is supplied to the demodulation unit 212-1, the "HD" received signal is supplied to the demodulation unit 212-2, and the "audio" received signal is supplied to the demodulation unit 212-3.

[0193] The demodulation unit 212-1 performs demodulation processing on the received signal supplied from the tuner 211 under the control of the control unit 210, and supplies the resulting "4K" stream to the filter 213-1. The filter 213-1 processes the "4K" stream from the demodulation unit 212-1 under the control of the control unit 210. As a result, "4K" video signals and audio signals are obtained.

[0194] The demodulation unit 212-2 demodulates the received signal supplied from the tuner 211 under the control of the control unit 210, and supplies the resulting "HD" stream to the filter 213-2. The filter 213-2 processes the "HD" stream from the demodulation unit 212-2 under the control of the control unit 210. As a result, "HD" video and audio signals are obtained.

[0195] The demodulation unit 212-3 demodulates the received signal supplied from the tuner 211 under the control of the control unit 210, and supplies the resulting "audio" stream to the filter 213-3. The filter 213-3 processes the "audio" stream from the demodulation unit 212-3 under the control of the control unit 210. As a result, an "audio" audio signal is obtained.

[0196] At this time, the control unit 210 is supplied with the processing results obtained by the processing of the tuner 211 and the processing results obtained by the processing of the demodulation units 212-1 to 212-3. The control unit 210 selects a signal to be decoded based on at least one of the processing results from the tuner 211 and the demodulation unit 212.

[0197] That is, the control unit 210 obtains, as a processing result, information indicating the quality of the received signal, such as the C / N ratio, and the error rate of the signal obtained by the demodulation process, and can select a signal to be decoded based on this information. Based on the selection result of the signal to be decoded, the control unit 210 controls the selection unit 220 so that the signal to be selected is supplied to the decoding unit 214.

[0198] When a "4K" signal is selected as the signal to be decoded, the control unit 210 causes the "4K" video signal and audio signal from the filter 213-1 to be supplied to the decoding unit 214. The decoding unit 214 decodes the "4K" video signal and audio signal supplied from the filter 213-1. As a result, the receiving device 20 reproduces 4K video and audio.

[0199] When an "HD" signal is selected as the signal to be decoded, the control unit 210 supplies the "HD" video signal and audio signal from the filter 213-2 to the decoding unit 214. The decoding unit 214 decodes the "HD" video signal and audio signal supplied from the filter 213-2. As a result, the receiving device 20 reproduces HD video and audio.

[0200] When a "voice" signal is selected as the signal to be decoded, the control unit 210 causes the "voice" audio signal from the filter 213-3 to be supplied to the decoding unit 214. The decoding unit 214 decodes the "voice" audio signal supplied from the filter 213-3. As a result, only the audio is reproduced in the receiving device 20.

[0201] Here, when switching the signal to be decoded, the control unit 210 switches the stream described in the AdaptationSet element of the MPD metadata based on information about the segment file obtained by processing the filters 213-1 to 213-3 (for example, a template or an ISOBMFF timestamp), thereby enabling the stream to be switched without causing any disturbance in the video or audio.

[0202] As a result, in the receiving device 20, seamless playback can be performed when switching from a "4K" broadcast signal to an "HD" broadcast signal, or from an "HD" broadcast signal to a "4K" broadcast signal, depending on the quality of the received signal, as shown in the lower part of Fig. 20. Note that the control method for switching streams using information about segment files and MPD metadata described here is just one example, and other control methods may be used as long as seamless playback is possible.

[0203] In the example of Figure 20, a configuration is shown in which multiple systems (three systems) of demodulators 212 and filters 213 are provided, but by having the demodulators 212 and filters 213 operate in a time-division manner, it is possible to perform equivalent processing using one system or fewer systems of demodulators 212 and filters 213.

[0204] <4. Seamless playback processing flow>

[0205] Next, the flow of seamless playback processing realized in the transmission system of FIG. 1 will be described with reference to the flowcharts of FIGS.

[0206] (First seamless playback process) First, the flow of the first seamless playback process will be described with reference to the flowchart in FIG.

[0207] This first seamless playback process corresponds to the case where video boundary information is used. In Fig. 21, the processes of steps S111 to S113 are processes on the transmitting side executed by the transmitting device 10 in Fig. 1. Furthermore, the processes of steps S211 to S220 are processes on the receiving side executed by the receiving device 20 in Fig. 1.

[0208] In step S111, the signaling processing unit 112 generates video boundary information indicating video boundaries (RAPs) according to the stream to be processed.

[0209] In step S112, the modulation unit 114 processes the multiplexed stream generated by the processing unit 113 to generate a physical layer frame. However, the multiplexed stream includes streams of the same or corresponding content, such as "4K", "HD", and "audio" streams.

[0210] In addition, the modulation unit 114 performs processing so that video boundary information indicating the video boundary (RAP) of each content is included in units of either physical layer frames, BB packets, or layer units, depending on the stream to be processed.

[0211] That is, when control is performed in units of physical layer frames, video boundary information is included in the L1 signaling included in the preamble of the physical layer frame. When control is performed in units of BB packets, video boundary information is included in the header of the BB packet. Furthermore, when control is performed in units of layers (segments), video boundary information is included in additional information (AC) related to broadcasting.

[0212] The physical layer frame generated in the process of step S112 is transmitted as a broadcast signal via the transmission path 30 (S113). However, for convenience of explanation, it is expressed here as if streams of the same or corresponding content, such as "4K", "HD", and "audio" streams, are transmitted as multiple broadcast signals for each stream.

[0213] In step S211, the tuner 211 receives the broadcast signal transmitted from the transmitting device 10 via the antenna 221 under the control of the control unit 210.

[0214] In step S212, the control unit 210 determines whether the quality of the broadcast signal (received signal) received in the process of step S211 has changed. Here, for example, the quality of the received signal can be determined by comparing the C / N ratio obtained from the received signal with a predetermined threshold.

[0215] If it is determined in step S212 that the quality of the received signal has not changed, the process proceeds to step S213. In step S213, demodulation unit 212 processes a physical layer frame obtained from the broadcast signal received in the process of step S211. The data obtained from the physical layer frame is processed by filter 213 to obtain a video signal and an audio signal.

[0216] In step S214, the decoding unit 214 decodes the video signal and audio signal obtained in the process of step S213. The video and audio data decoded by the decoding unit 214 is output by the output unit 215, and, for example, HD video and audio are reproduced.

[0217] In step S215, it is determined whether or not to end the process. If it is determined not to end the process in step S215, the process returns to step S211. Then, steps S211 to S215 are repeated until it is determined in the determination process of step S212 that the quality of the received signal has changed, and playback of, for example, HD video and audio continues.

[0218] Thereafter, if it is determined in step S212 that the quality of the received signal has changed, the process proceeds to step S216. In step S216, the demodulation unit 212 processes the physical layer frame obtained from the broadcast signal.

[0219] In step S217, under the control of the control unit 210, the demodulation unit 212 detects image boundary information based on the signal processed in the physical layer, which is obtained in the processing of step S216.

[0220] That is, when control is performed in units of physical layer frames, video boundary information is detected from L1 signaling included in the preamble of the physical layer frame. When control is performed in units of BB packets, video boundary information is detected from the header of the BB packet. When control is performed in units of layers (segments), video boundary information is detected from additional information (AC) related to broadcasting.

[0221] In step S218, the control unit 210 determines whether or not video boundary information has been detected from the signal processed in the physical layer, based on the detection result obtained in the process of step S217.

[0222] If it is determined in step S218 that video boundary information has not been detected, the process proceeds to step S219. In step S219, the decoding unit 214 decodes the video signal and audio signal obtained in the process of step S216. The video and audio data decoded by the decoding unit 214 is output by the output unit 215, and playback of, for example, HD video and audio continues.

[0223] When the process of step S219 ends, the process returns to step S216. Then, the processes of steps S216 to S219 are repeated until it is determined in the determination process of step S218 that video boundary information has been detected, and playback of, for example, HD video and audio continues.

[0224] If it is determined in step S218 that video boundary information has been detected, the process proceeds to step S220. In step S220, the control unit 210 controls the tuner 211 or the demodulation unit 212 to switch the broadcast signal received from the transmitting device 10. Here, for example, the broadcast signal is switched from an "HD" broadcast signal to a "4K" broadcast signal in response to a change in the quality of the received signal.

[0225] When the broadcast signal is switched in the process of step S220, the process proceeds to step S213. In steps S213 and S214, the physical layer frame obtained from the switched broadcast signal is processed, and the video signal and audio signal are decoded, so that, for example, 4K video and audio are played, and the video of the same content is switched from HD resolution video to 4K resolution video.

[0226] Here, the determination process of step S218 ensures that the timing of switching the signal processed in the physical layer by the process of step S220 coincides with the boundary (RAP) of the video processed in step S214. Therefore, for example, when the C / N ratio increases and the quality of the received signal improves, there is no disruption in the video or audio when switching from HD resolution video to 4K resolution video, and playback is smooth.

[0227] The above-described process is repeated until it is determined in step S215 that the process should be terminated. If it is determined in step S215 that the process should be terminated, the first seamless playback process in FIG. 21 is terminated.

[0228] The flow of the first seamless playback process has been described above.

[0229] (Second seamless playback process) Next, the flow of the second seamless playback process will be described with reference to the flowchart in FIG.

[0230] This second seamless playback process corresponds to a case where video boundary information is not used. In Fig. 22, the processes of steps S131 and S132 are processes on the transmitting side executed by the transmitting device 10 in Fig. 1. Also, the processes of steps S231 to S235 are processes on the receiving side executed by the receiving device 20 in Fig. 1.

[0231] In step S131, the multiplexed stream generated by the processing unit 113 is processed to generate a physical layer frame. However, the multiplexed stream includes streams of the same or corresponding content, such as "4K", "HD", and "audio" streams.

[0232] The physical layer frame generated in the process of step S131 is transmitted as a broadcast signal via the transmission path 30 (S132).

[0233] In step S231, the tuner 211 receives the broadcast signal transmitted from the transmitting device 10 via the antenna 221 under the control of the control unit 210.

[0234] In step S232, demodulation units 212-1 to 212-3 process physical layer frames obtained from the broadcast signals received in the process of step S231. The signals obtained from the physical layer frames are processed by filters 213-1 to 213-3 to obtain video signals and audio signals.

[0235] Here, for example, a "4K" signal is processed by a demodulator 212-1 and a filter 213-1. Also, for example, a "HD" signal is processed by a demodulator 212-2 and a filter 213-2, and a "audio" signal is processed by a demodulator 212-3 and a filter 213-3.

[0236] In step S233, the control unit 210 selects a signal to be decoded from the signals output from the filters 213-1 to 213-3 based on, for example, information indicating the quality of the received signal, such as the C / N ratio, and information such as the error rate of the signal obtained by the demodulation process.

[0237] In step S234, the decoding unit 214 decodes any one of the signals output from the filters 213-1 to 213-3 based on the result of the selection of the decoding target obtained in the process of step S233.

[0238] Here, for example, if a "4K" signal is selected as the signal to be decoded, the "4K" video signal and audio signal from the filter 213-1 are decoded. As a result, the receiving device 20 reproduces 4K video and audio.

[0239] Furthermore, for example, when an "HD" signal is selected as the signal to be decoded, the "HD" video signal and audio signal are decoded from the filter 213-2. As a result, the receiving device 20 reproduces HD video and audio. Furthermore, for example, when an "audio" signal is selected as the signal to be decoded, the "audio" audio signal is decoded from the filter 213-3. As a result, the receiving device 20 reproduces only audio.

[0240] In step S235, it is determined whether or not the process should be ended. If it is determined in step S235 that the process should not be ended, the process returns to step S231, and the processes in steps S231 to S235 are repeated.

[0241] By repeating steps S231 to S235, the signal to be decoded selected in the processing of step S233 is decoded. When switching the signal to be decoded, the control unit 210 switches the stream described in the AdaptationSet element of the MPD metadata based on information about the segment file obtained by the processing of filters 213-1 to 213-3 (for example, a template or an ISOBMFF timestamp), thereby making it possible to switch the stream without causing any disturbance in the video or audio.

[0242] For example, in the receiving device 20, playback can be performed seamlessly when switching from a "4K" broadcast signal to an "HD" broadcast signal, or from an "HD" broadcast signal to a "4K" broadcast signal, depending on the quality of the received signal, etc.

[0243] If it is determined in the determination process of step S235 that the process is to be ended, the second seamless playback process of FIG. 22 is ended.

[0244] The flow of the second seamless playback process has been described above.

[0245] <5. Variations>

[0246] The above explanation has focused on ISDB (particularly ISDB-T), a system adopted in Japan etc., and ATSC (particularly ATSC3.0), a system adopted in the United States etc., as digital television broadcasting standards, but the present invention may also be applied to DVB (Digital Video Broadcasting), a system adopted by European countries etc. Also, the above explanation has been given using ATSC3.0, which employs an IP transmission system, as an example, but the present invention is not limited to IP transmission systems and may also be applied to other systems such as the MPEG2-TS (Transport Stream) system.

[0247] In addition, the digital television broadcasting standard can be applied to terrestrial broadcasting, satellite broadcasting using broadcasting satellites (BS) and communications satellites (CS), and wired broadcasting such as cable television (CATV).

[0248] Furthermore, the names of the signaling, packets, etc. described above are merely examples, and other names may be used. However, the difference between these names is merely a formal difference, and does not mean that the actual content of the target signaling, packets, etc. is different. For example, a BB packet (Baseband Packet) may be called a BB stream (Baseband Stream). Also, for example, a Generic packet may be called an ALP (ATSC Link-layer Protocol) packet. Also, the terms frame and packet may be used interchangeably.

[0249] In the above description, the content has been described as a broadcast program, but it is not limited to this and can include any content, such as videos, music, e-books, games, advertisements, etc. Furthermore, the content is not limited to broadcast programs and may be content distributed via communication. Furthermore, some of the components that make up the content may be distributed via communication.

[0250] Furthermore, the present technology can also be applied to transmission paths other than broadcast networks, i.e., predetermined standards (standards other than digital television broadcast standards) that are defined assuming the use of communication lines (communication networks) such as the Internet or a telephone network. In that case, a communication line such as the Internet or a telephone network is used as the transmission path 30 of the transmission system 1 (FIG. 1), and the transmitting device 10 can be a server provided on the Internet. Then, the communication server and the receiving device 20 perform bidirectional communication via the transmission path 30 (communication line).

[0251] <6. Computer Configuration>

[0252] The above-described series of processes can be executed by hardware or software. When the series of processes is executed by software, a program constituting the software is installed in a computer. Figure 23 is a diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes by a program.

[0253] In the computer 1000, a CPU (Central Processing Unit) 1001, a ROM (Read Only Memory) 1002, and a RAM (Random Access Memory) 1003 are interconnected by a bus 1004. An input / output interface 1005 is further connected to the bus 1004. An input unit 1006, an output unit 1007, a recording unit 1008, a communication unit 1009, and a drive 1010 are connected to the input / output interface 1005.

[0254] The input unit 1006 includes a keyboard, a mouse, a microphone, etc. The output unit 1007 includes a display, a speaker, etc. The recording unit 1008 includes a hard disk, a non-volatile memory, etc. The communication unit 1009 includes a network interface, etc. The drive 1010 drives a removable recording medium 1011 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

[0255] In the computer 1000 configured as described above, the CPU 1001 loads a program recorded in the ROM 1002 or the recording unit 1008 into the RAM 1003 via the input / output interface 1005 and the bus 1004 and executes it, thereby performing the above-mentioned series of processes.

[0256] The program executed by the computer 1000 (CPU 1001) can be provided by being recorded on a removable recording medium 1011 such as a package medium, for example. The program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

[0257] In the computer 1000, the program can be installed in the recording unit 1008 via the input / output interface 1005 by inserting the removable recording medium 1011 into the drive 1010. The program can also be received by the communication unit 1009 via a wired or wireless transmission medium and installed in the recording unit 1008. Alternatively, the program can be installed in the ROM 1002 or the recording unit 1008 in advance.

[0258] Here, in this specification, the processing performed by a computer according to a program does not necessarily have to be performed chronologically in the order described in the flowchart. In other words, the processing performed by a computer according to a program also includes processing executed in parallel or individually (for example, parallel processing or object-based processing). Furthermore, the program may be processed by one computer (processor), or may be processed in a distributed manner by multiple computers.

[0259] It should be noted that the embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible within the scope of the present technology.

[0260] The present technology can also be configured as follows.

[0261] (1) a receiving unit for receiving a plurality of broadcast signals; a control unit that selects a target broadcast signal from the plurality of broadcast signals based on a result of processing the broadcast signal; A receiving device comprising: (2) the plurality of broadcast signals each transmitting the same or corresponding content; The control unit switches the target broadcast signal based on image boundary information that is information indicating an image boundary of the content. A receiving device as described in (1). (3) The plurality of broadcast signals are transmitted by time division multiplexing (TDM), The image boundary information is included in the header of the demodulated baseband packet. (2) A receiving device according to the present invention. (4) The plurality of broadcast signals are transmitted by frequency division multiplexing (FDM), The image boundary information is included in the additional information in units of segments. (2) A receiving device according to the present invention. (5) The image boundary information is included in the preamble of the physical layer frame. (2) A receiving device according to the present invention. (6) The video boundary information includes information for identifying a stream that includes a boundary of the video. A receiving device according to any one of (2) to (5). (7) further comprising a plurality of demodulation units for demodulating the plurality of broadcast signals; The control unit switches the target broadcast signal based on the demodulation results of the plurality of demodulation units. A receiving device as described in (1). (8) The video boundary information is information indicating the beginning of a GOP (Group of Pictures) cycle. A receiving device according to any one of (2) to (6). (9) The plurality of broadcast signals each have a different bit rate and robustness. A receiving device according to any one of (1) to (8). (10) A data processing method for a receiving device, comprising: The receiving device: Receives multiple broadcast signals, Selecting a target broadcast signal from among the plurality of broadcast signals based on the results of processing the broadcast signal. A data processing method comprising the steps. (11) a generating unit that generates video boundary information that indicates a boundary of a video of the same or corresponding content; a transmitting unit that transmits the video boundary information by including it in a plurality of broadcast signals for transmitting the content; A transmitting device comprising: (12) The plurality of broadcast signals are transmitted by time division multiplexing (TDM); The image boundary information is included in the header of a baseband packet before modulation. The transmitting device according to (11). (13) The plurality of broadcast signals are transmitted using frequency division multiplexing (FDM); The image boundary information is included in the additional information in units of segments. The transmitting device according to (11). (14) The image boundary information is included in the preamble of the physical layer frame. The transmitting device according to (11). (15) The video boundary information includes information for identifying a stream that includes a boundary of the video. A transmitting device according to any one of (11) to (14). (16) The video boundary information is information indicating the beginning of a GOP period. A transmitting device according to any one of (11) to (15). (17) The plurality of broadcast signals each have a different bit rate and robustness. A transmitting device according to any one of (11) to (16). (18) A data processing method for a transmitting device, comprising: The transmitting device: generating video boundary information that indicates the boundaries of videos of the same or corresponding content; The video boundary information is transmitted by being included in a plurality of broadcast signals for transmitting the content. A data processing method comprising the steps. [Explanation of symbols]

[0262] 1 transmission system, 10 transmitting device, 20 receiving device, 30 transmission path, 111 component processing section, 112 signaling processing section, 113 processing section, 114 modulation section, 210 control section, 211 tuner, 212 demodulation section, 213 filter, 214 decoding section, 215 output section, 1000 computer, 1001 CPU

Claims

1. a control unit that controls transmission of video boundary information, which is information indicating a boundary between videos of the same or corresponding content, in a plurality of signals that transmit the content, the video boundary information is information transmitted in a physical layer and indicates a boundary of a video of the content that is processed in a layer higher than the physical layer; The upper layer is a layer that processes data to be stored in a predetermined packet included in a frame of the physical layer. Transmitting device.

2. The content is delivered in accordance with MPEG-DASH (Dynamic Adaptive Streaming over HTTP), The video boundary information includes information corresponding to an AdaptationSet element described in MPD (Media Presentation Description) metadata, The predetermined packet includes an IP packet. The transmitting device according to claim 1 .

3. the plurality of signals are transmitted by time division multiplexing (TDM); The image boundary information is included in the header of a baseband packet before modulation. The transmitting device according to claim 1 .

4. The multiple signals are transmitted using frequency division multiplexing (FDM). transmitted by The image boundary information is included in the additional information in units of segments. The transmitting device according to claim 1 .

5. The image boundary information is included in the preamble of the physical layer frame. The transmitting device according to claim 1 .

6. The video boundary information includes information for identifying a stream that includes a boundary of the video. The transmitting device according to claim 1 .

7. The video boundary information is information indicating the beginning of a GOP (Group of Pictures) cycle. The transmitting device according to claim 1 .

8. The plurality of signals each have a different bit rate and robustness. The transmitting device according to claim 1 .

Images