Transmission device, transmission method, reception device, and reception method

Abstract

The present disclosure relates to a transmission device, a transmission method, a reception device, and a reception method with which it is possible to partially receive a signal. Provided is a transmission device comprising: a generation unit that generates control information relating to propagation of broadcast content; and a transmission unit that transmits a broadcast stream including data constituting the broadcast content and control information by hierarchical propagation carried out using a segment structure obtained by dividing one channel into segments. The transmission unit propagates first division control information, from among first division control information and second division control information obtained by dividing the control information, in a first hierarchy, and propagates the second division control information in a second hierarchy. The first division control information includes control information relating to data propagated in the first hierarchy. An identifier composed of a preset fixed value is allocated to the first division control information. The present disclosure can be applied to, for example, a propagation system compatible with an ISDB-T next-generation broadcasting scheme.

Description

Transmitting device, transmitting method, receiving device, and receiving method

[0001] The present disclosure relates to a transmitting device, a transmitting method, a receiving device, and a receiving method, and more particularly to a transmitting device, a transmitting method, a receiving device, and a receiving method that are capable of partially receiving a signal.

[0002] ISDB-T (Integrated Services Digital Broadcasting - Terrestrial) is a broadcasting format used in Japan and other countries. In Japan, studies are underway to upgrade the next generation of terrestrial digital television broadcasting.

[0003] The next generation of ISDB-T is planned to provide broadcasting services by hierarchical transmission, similar to the current ISDB-T. The next generation of ISDB-T is planned to adopt the TLV (Type Length Value) multiplexing method and the MMT (MPEG Media Transport) method. For example, Patent Document 1 discloses technology related to the MMT method. Transmission control information used in the TLV multiplexing method, MMT method, etc. is transmitted by hierarchical transmission.

[0004] Japanese Patent Application Laid-Open No. 2015-207984

[0005] When providing broadcasting services using hierarchical transmission, there has been a demand for proposals for partially receiving signals transmitted in some of the hierarchical layers included in multiple hierarchical layers.

[0006] The present disclosure has been made in light of this situation, and makes it possible to partially receive signals.

[0007] A transmitting device according to one aspect of the present disclosure includes a generating unit that generates control information related to the transmission of broadcast content, and a transmitting unit that transmits a broadcast stream including data constituting the broadcast content and the control information by hierarchical transmission using a segment structure in which one channel is divided into segments, wherein the transmitting unit transmits the first divided control information in a first hierarchy and the second divided control information in a second hierarchy, of the first divided control information obtained by dividing the control information, and the first divided control information includes control information related to the data transmitted in the first hierarchy, and is a transmitting device to which an identifier consisting of a predetermined fixed value is assigned.

[0008] A transmission method according to one aspect of the present disclosure is a transmission method in which a transmitting device generates control information for transmitting broadcast content, transmits a broadcast stream including data constituting the broadcast content and the control information by hierarchical transmission using a segment structure in which one channel is divided into segments, and transmits the first divided control information in a first hierarchy and the second divided control information in a second hierarchy, the first divided control information including control information for the data transmitted in the first hierarchy, and is assigned an identifier consisting of a predetermined fixed value.

[0009] In a transmitting device and a transmitting method according to one aspect of the present disclosure, control information related to transmission of broadcast content is generated, a broadcast stream including data constituting the broadcast content and the control information is transmitted by hierarchical transmission using a segment structure in which one channel is divided into segments, and of first division control information and second division control information obtained by dividing the control information, the first division control information is transmitted in a first hierarchy and the second division control information is transmitted in a second hierarchy. Furthermore, the first division control information includes control information related to the data transmitted in the first hierarchy, and an identifier consisting of a preset fixed value is assigned to the first division control information.

[0010] A receiving device according to one aspect of the present disclosure comprises a receiving unit that receives a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, the broadcast stream being transmitted from a transmitting device by hierarchical transmission using a segment structure in which one channel is divided into segments, and a processing unit that processes the received broadcast stream, wherein the control information is divided into first division control information and second division control information, the first division control information being transmitted on a first layer and the second division control information being transmitted on a second layer, the first division control information including control information related to the data transmitted on the first layer, and an identifier consisting of a predetermined fixed value being assigned to it, and the processing unit acquires the first division control information included in the broadcast stream based on the fixed value that has been recorded in advance, and performs processing related to the data included in the broadcast stream based on the acquired first division control information.

[0011] A receiving method according to one aspect of the present disclosure includes a receiving device receiving a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, the broadcast stream being transmitted from a transmitting device by hierarchical transmission using a segment structure in which one channel is divided into segments, processing the received broadcast stream, dividing the control information into first division control information and second division control information, the first division control information being transmitted on a first layer and the second division control information being transmitted on a second layer, the first division control information including control information related to the data transmitted on the first layer, and an identifier consisting of a predetermined fixed value being assigned to the first division control information, and acquiring the first division control information included in the broadcast stream based on the pre-recorded fixed value, and processing the data included in the broadcast stream based on the acquired first division control information.

[0012] In a receiving device and a receiving method according to one aspect of the present disclosure, a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, the broadcast stream being transmitted from a transmitting device through hierarchical transmission using a segment structure in which one channel is divided into segments, is received, and the received broadcast stream is processed. The control information is divided into first division control information and second division control information, the first division control information being transmitted in a first hierarchy and the second division control information being transmitted in a second hierarchy, the first division control information including control information related to the data transmitted in the first hierarchy, and an identifier consisting of a preset fixed value being assigned to the first division control information, the first division control information included in the broadcast stream is acquired based on the pre-recorded fixed value, and the data included in the broadcast stream is processed based on the acquired first division control information.

[0013] The transmitting device and receiving device according to one aspect of the present disclosure may be independent devices or may be internal blocks constituting a single device.

[0014] 1 is a block diagram showing an example configuration of an embodiment of a transmission system to which the present disclosure is applied. FIG. 2 is a block diagram showing an example configuration of an embodiment of the transmitting device of FIG. 1. FIG. 3 is a block diagram showing an example configuration of an embodiment of the receiving device of FIG. 1. FIG. 4 is a diagram showing an example configuration of a subframe when hierarchical transmission is performed. FIG. 5 is a diagram showing an example of a multi-layer frame configuration and asset allocation. FIG. 6 is a diagram showing an example of an allocation of control information and assets in a multi-layer frame configuration to which the present disclosure is applied. FIG. 7 is a diagram showing an example of MPT reference for a package using a package list table. FIG. 8 is a diagram showing an example configuration of a package list table. FIG. 9 is a diagram showing an example configuration of a PA message. FIG. 10 is a diagram showing an example configuration of an MPT. FIG. 11 is a diagram explaining transmission using the LDM method. FIG. 12 is a diagram showing an example configuration of a subframe when LDM transmission is performed. FIG. 13 is a diagram showing an example frame configuration and asset allocation for LDM transmission. FIG. 14 is a flowchart explaining a series of processing flows on the transmitting side and the receiving side. FIG. 15 is a block diagram showing an example configuration of a computer.

[0015] <System Configuration> Fig. 1 is a block diagram showing an example configuration of an embodiment of a transmission system to which the present disclosure is applied. In Fig. 1, the transmission system is composed of a transmitting device 10 and a receiving device 20. In the transmission system, a terrestrial digital television broadcasting broadcasting system can be adopted as the broadcasting system. Note that a system refers to a logical collection of multiple devices.

[0016] The transmitting device 10 transmits broadcast content such as broadcast programs produced by a broadcast station as broadcast signals. The transmitting device 10 performs necessary processing on control information and broadcast content data, and transmits the resulting broadcast signal from a transmitting antenna installed at a transmitting station.

[0017] The receiving device 20 is a device capable of receiving broadcast signals, such as a fixed receiver such as a television set or a mobile receiver such as a mobile phone. The receiving device 20 receives the broadcast signals transmitted from the transmitting device 10 via an antenna. The receiving device 20 performs necessary processing on the control information and data obtained from the received broadcast signals, thereby outputting video and audio of broadcast content such as a broadcast program.

[0018] Fig. 2 is a block diagram showing an example of the configuration of an embodiment of the transmitting device 10 of Fig. 1. In Fig. 2, the transmitting device 10 includes a processing unit 101 and a transmitting unit 102.

[0019] The processing unit 101 includes an encoder 111, a control information generating unit 112, and a multiplexing unit 113. Broadcast content data such as broadcast programs is input to the processing unit 101 from an external server connected via a network, storage built into the transmitting device 10, or the like. For example, the broadcast content includes 2K content corresponding to 2K video and 4K content corresponding to 4K video. The encoder 111 encodes the video data and audio data input as data constituting the broadcast content according to a predetermined encoding method, and supplies the encoded video data and audio data to the multiplexing unit 113.

[0020] The control information generator 112 generates control information and supplies it to the multiplexer 113. The control information generated here is control information related to the transmission of broadcast content, and is transport layer control information (e.g., MMT-SI, described later) used when processing data constituting the broadcast content in the transport layer, which is a layer higher than the physical layer in the protocol stack. The multiplexer 113 multiplexes the coded video data and audio data supplied from the encoder 111 with the control information supplied from the control information generator 112, and supplies the resulting multiplexed data (hereinafter also referred to as a broadcast stream) to the transmitter 102.

[0021] The transmitter 102 performs physical layer processing, such as encoding using error correction codes, on the multiplexed data supplied from the processor 101. The transmitter 102 constructs a physical layer frame using the data signal obtained by the physical layer processing and physical layer control information (e.g., TMCC information, which will be described later). The transmitter 102 performs necessary processing, such as IFFT (Inverse Fast Fourier Transform) and GI (Guard Interval) addition, to modulate the physical layer frame and generate a broadcast signal. The broadcast signal is transmitted from a transmitting antenna installed at the transmitting station.

[0022] Fig. 3 is a block diagram showing an example of the configuration of an embodiment of the receiving device 20 of Fig. 1. In Fig. 3, the receiving device 20 includes a receiving unit 201 and a processing unit 202.

[0023] The receiving unit 201 is composed of a tuner and a demodulation device (such as a demodulation LSI). The receiving unit 201 demodulates a physical layer frame by performing necessary processing such as GI removal and FFT (Fast Fourier Transform) on the broadcast signal received via the antenna. The receiving unit 201 acquires a data signal based on physical layer control information included in the physical layer frame and performs physical layer processing such as error correction using an error correction code. The receiving unit 201 supplies the multiplexed data (broadcast stream) obtained by the physical layer processing to the processing unit 202.

[0024] The processing unit 202 is configured with a main SoC (System on Chip) etc. The processing unit 202 has a demultiplexing unit 211, a control unit 212, a memory 213, and a decoder 214. The demultiplexing unit 211 separates the multiplexed data input thereto into video data, audio data, and control information, and supplies the video data and audio data to the decoder 214 and the control information to the control unit 212.

[0025] The control unit 212 controls the operation of each unit based on control information supplied from the demultiplexing unit 211. For example, the control unit 212 controls the demultiplexing process by the demultiplexing unit 211. The memory 213 is a non-volatile memory such as an NVRAM (Non Volatile RAM). The control unit 212 can read data (for example, a fixed value ID, which will be described later) recorded in the memory 213 and control the filtering process by the demultiplexing unit 211 based on the read data.

[0026] The decoder 214 receives the encoded video data and audio data from the demultiplexer 211. The decoder 214 decodes the encoded video data and audio data according to a predetermined decoding method and outputs the decoded video data and audio data to downstream circuits. As a result, in the receiving device 20, an image corresponding to the video data is displayed on the display and an audio corresponding to the audio data is output from the speaker, allowing the user to view broadcast content such as a broadcast program.

[0027] While the configuration of Fig. 1 described above illustrates a case where there is one receiving device 20, in reality, multiple receiving devices 20 may be provided, each of which may receive and process a broadcast signal transmitted from the transmitting device 10. Furthermore, in the configuration of Fig. 2 described above, the transmitting device 10 includes a processing unit 101 having an encoder 111, a control information generating unit 112, and a multiplexing unit 113, and a transmitting unit 102. However, these components (blocks) do not need to be provided within a single housing. For example, the transmitting device 10 may be configured as a transmission system (broadcast sending system) in which at least one of the components shown in Fig. 2 is provided in a separate device (broadcast server).

[0028] <Broadcasting method> In Japan, the Integrated Services Digital Broadcasting - Terrestrial (ISDB-T) method is used as the broadcasting method for terrestrial digital television broadcasting, but studies are being conducted to upgrade it to the next generation, and various technical methods are being considered. Hereinafter, the next generation method of ISDB-T will also be referred to as the advanced terrestrial broadcasting method. In the transmission system shown in Figure 1, the advanced terrestrial broadcasting method can be used as the broadcasting method for terrestrial digital television broadcasting.

[0029] The adoption of the TLV (Type Length Value) multiplexing method and MMT (MPEG Media Transport) method is being considered for the terrestrial broadcasting enhancement system, and MMT-SI (Signaling Information) and TLV-SI are planned to be used as control information for transmission. MMT-SI is control information related to the configuration of broadcast content, etc. MMT-SI is transmitted in MMTP (MMT Protocol) packets. TLV-SI is control information related to the multiplexing of IP packets. TLV-SI is transmitted in TLV packets.

[0030] In addition, the adoption of Orthogonal Frequency Division Multiplexing (OFDM), similar to the current ISDB-T system, is being considered for the Advanced Terrestrial Broadcasting System. In other words, the Advanced Terrestrial Broadcasting System will be able to use OFDM frames as the physical layer frame, similar to the ISDB-T system. Furthermore, the Advanced Terrestrial Broadcasting System is being considered for providing services using hierarchical transmission with a segment structure in which one channel is divided into segments, similar to the current ISDB-T system. However, compared to the current ISDB-T system, the Advanced Terrestrial Broadcasting System is being considered for increasing the number of segments used for signal transmission from 13 to 35, thereby increasing the number of segments.

[0031] The physical layer frame of the Advanced Terrestrial Broadcasting Standard consists of a frame synchronization signal section, a TMCC section, one or more subframe sections, and an extension section. The frame synchronization signal section transmits synchronization signals and TMCC (Transmission and Multiplexing Configuration Control) modulation parameters. The TMCC section transmits transmission control information, including information about the entire frame (such as time information) and modulation parameters for subframes and layers. The subframe section can be configured using frequency division multiplexing, time division multiplexing, or a combination of frequency division multiplexing and time division multiplexing to enable diverse hierarchical transmissions that take into account various reception environments. An extension section can be provided at the end of the physical layer frame to allow for future expansion.

[0032] Figure 4 is a diagram showing an example of a subframe configuration when hierarchical transmission is performed. Figure 4 shows a schematic diagram of a subframe configuration using frequency division multiplexing, in which the bandwidth of one channel is divided into multiple segments, with the horizontal direction in the diagram representing the frequency. As shown in Figure 4, subframes can provide broadcasting services through hierarchical transmission using layers A and B, each of which consists of one or more segments. For example, by transmitting subframes, it is possible to provide mobile reception services using layer A and fixed reception services using layer B.

[0033] Figure 5 is a diagram showing an example of a multi-layer frame structure and asset allocation. Figure 5 shows the synchronization signal, TMCC information, and subframe structure included in a physical layer frame. The subframe transmits control information and assets through hierarchical transmission in layers A and B. Assets are components that make up broadcast content, such as video and audio. As shown in Figure 5, in the subframe, MMT-SI, MPU1, and MPU2 are transmitted in layer A, and MPU3 and MPU4 are transmitted in layer B.

[0034] MMT-SI is control information (transport layer control information) related to MMT, a media transport method. MMT-SI includes a PA (Package Access) message. The PA message is the entry point of MMT-SI and transmits MMT-SI tables. The PA message includes an MP table (MPT: MMT Package Table). The MPT is a table containing information that configures a package, such as a list of assets and their locations. When multiple packages are multiplexed, the PA message further includes a Package List Table (PLT) in addition to the MPT. The Package List Table indicates the IP data flow and packet ID that transmits the PA message of the MMT package provided as a broadcast service, as well as a list of IP data flows that transmit IP services.

[0035] An MPU (Media Processing Unit) contains one or more access units and is a unit capable of decoding video and audio data by itself. An MPU consists of MPU metadata, which contains information about the overall configuration of the MPU, and sample data, which is encoded media data. A sequence number is assigned to each MPU that belongs to the same asset. MPUs can be distinguished from other MPUs by using an asset ID that identifies the asset and the MPU sequence number.

[0036] In this way, the MMT method defines components such as video and audio as assets, and assets are structured as a series of MPUs. The MPT included in the PA message, which is one of the MMT-SIs, indicates what assets content such as a broadcast program is made up of. In Figure 5, hierarchical layer A provides a broadcast service for 2K content, with control information (MMT-SI), 2K video data transmitted by MPU1 with asset ID 1, and audio data corresponding to the 2K video transmitted by MPU2 with asset ID 2. Furthermore, hierarchical layer B provides a broadcast service for 4K content, with 4K video data transmitted by MPU3 with asset ID 3, and stereophonic (3D audio) audio data corresponding to the 4K video transmitted by MPU4 with asset ID 4.

[0037] In the advanced terrestrial broadcasting system, it is being considered to provide a fixed reception service (layer B) and a mobile reception service (layer A) through hierarchical transmission, similar to the current ISDB-T system. However, since the transmission capacity of layer A is limited to approximately 1 to 2 Mbps, if all control information is placed on layer A, the transmission capacity allocated to video and audio data will be limited. Therefore, in this disclosure, in order to perform hierarchical transmission without placing pressure on the transmission capacity of layer A, which has a limited transmission capacity, in the advanced terrestrial broadcasting system, cross-sectional control information is divided and placed on layers A and B, respectively, thereby performing hierarchical transmission without placing pressure on the transmission capacity of layer A, which has a limited transmission capacity. In addition, by assigning a predetermined fixed value (hereinafter also referred to as a fixed value ID) to the identifier of the control information transmitted on layer A, partial signal reception on layer A alone is possible when performing hierarchical transmission.

[0038] Figure 6 is a diagram showing an example of the arrangement of control information and assets in a multi-layer frame configuration to which the present disclosure is applied. In Figure 6, the square within the dashed frame on layer A indicates the control information of MMT-SI transmitted on layer A, and the square within the dashed line on layer B indicates the control information of MMT-SI transmitted on layer B. Furthermore, the letters within the control information square indicate the name, and the value written above the name indicates the ID. Note that in Figure 6 and other figures, the PA message may be abbreviated as "PA" and the package list table as "PLT."

[0039] For example, MMT-SI in layer A and MMT-SI in layer B each include PA messages that are divided from a PA message (hereinafter also referred to as divided PA messages), but the divided PA messages in layer A are assigned a message ID of 0x8010, and the divided PA messages in layer B are assigned a message ID of 0x0000. Also, MMT-SI in layer A and MMT-SI in layer B each include MPTs that are divided from an MPT (hereinafter also referred to as divided MPTs), but the divided MPTs in layer A are assigned a table ID of 0x11, and the divided MPTs in layer B are assigned a table ID of 0x20.

[0040] The MMT-SI in layer A includes a divided PA message (PA) assigned a message ID of 0x8010, and a divided MPT (MPT) assigned a table ID of 0x11. The MMT-SI in layer B includes a divided PA message (PA) assigned a message ID of 0x0000, a divided MPT (MPT) assigned a table ID of 0x20, and a package list table (PLT) assigned a table ID of 0x80. Here, the MMT-SI in layer A refers only to data transmitted in layer A, i.e., assets transmitted by MPU1 and MPU2 in layer A. Furthermore, the IDs assigned to the divided PA messages and divided MPTs included in the MMT-SI in layer A are preset fixed value IDs. In other words, the message ID assigned to the divided PA message in layer A is a fixed value ID of 0x8010. Furthermore, the table ID assigned to the divided MPT in layer A is a fixed value ID of 0x11.

[0041] In this way, by assigning fixed value IDs to the divided PA messages and divided MPTs transmitted in layer A, receiving device 20 can perform filtering processing based on the pre-recorded fixed value IDs to acquire the divided PA messages and divided MPTs transmitted in layer A. Specifically, in receiving device 20, by pre-recording a fixed value ID (0x8010) in memory 213, demultiplexing unit 211 can, under control of control unit 212, filter the divided PA messages to which the message ID of 0x8010 is assigned as the fixed value ID to acquire the divided PA messages transmitted in layer A. Similarly, by pre-recording a fixed value ID (0x11) in memory 213, demultiplexing unit 211 can filter the divided MPTs to which the table ID of 0x11 is assigned as the fixed value ID to acquire the divided MPTs transmitted in layer A.

[0042] As a result, receiving device 20 can partially receive the layer A signal from layers A and B, acquire the divided PA message and divided MPT of layer A from the received signal, and acquire the 2K video data and audio data corresponding to the 2K video transmitted by MPU1 and MPU2 on layer A. In this way, by dividing the control information (the MMT-SI PA message and MPT) and transmitting the divided control information (divided control information with a data size smaller than the complete control information) on layers A and B separately, it is possible to realize a multi-layer broadcasting service without putting a strain on the transmission capacity of layer A, which has a limited transmission capacity. Furthermore, by assigning a fixed ID to the divided control information, receiving device 20 can acquire the divided control information by filtering based on the pre-recorded fixed ID and identify the target asset, thereby enabling independent reception (partial reception) of the signal of one layer (layer A) of multiple layers (layer A and layer B).

[0043] Here, in Figure 6, as shown by the arrow pointing from the box in the package list table (PLT) included in the MMT-SI on the B layer to the box in the divided PA message (PA) included in the MMT-SI on the A layer, the PA message is indirectly specified by the package list table.

[0044] Specifically, as shown in Figure 7, the PA message shown on the left side of the figure is transmitted by an MMTP packet with a packet ID of 0x0000. When multiple packages are multiplexed, this PA message includes a package list table. The package list table provides a list of packet IDs of MMTP packets that transmit PA messages containing MPTs of other packages. Therefore, by analyzing the package list table, the receiving device 20 can identify, from the package ID, the MMTP packet that transmits the PA message containing the MPT that is the entry point for that service.

[0045] Fig. 8 is a diagram showing an example of the configuration of a package list table (PLT). As shown in Fig. 8, the package list table includes table_id indicating the identifier of the package list table included in the MMT-SI table, version indicating the version of the table, length indicating the table length in terms of the number of data bytes that follow this field, and num_of_package indicating the number of packages whose location information is to be described in the table.

[0046] Within the loop corresponding to the number of packages, MMT_package_id_length, which indicates the length of the package ID, is placed, followed by MMT_package_id_byte according to the package ID length and MMT_general_location_info(). MMT_package_id_byte indicates the package ID. MMT_general_location_info() indicates the location information for transmitting the PA message of the package indicated by the package ID. In other words, for indirectly specified PA messages, location information is specified for each package ID.

[0047] The package list table includes num_of_ip_delivery, which indicates the number of IP services (number of IP delivery flows) for which location information is listed in the table. Within the loop corresponding to the number of IP delivery flows, transport_file_id, which indicates a label for uniquely identifying the file to be transmitted, and location_type, which indicates the type of location information (location type), are placed.

[0048] A location type of 0x01 indicates an IPv4 data flow, and contains ipv4_src_addr, which indicates the source address of the IPv4 data flow, ipv4_dst_addr, which indicates the destination address of the IPv4 data flow, and dst_port, which indicates the destination port number of the IP data flow. A location type of 0x02 indicates an IPv6 data flow, and contains ipv6_src_addr, which indicates the source address of the IPv6 data flow, ipv6_dst_addr, which indicates the destination address of the IPv6 data flow, and dst_port, which indicates the destination port number of the IP data flow.

[0049] A location type of 0x05 means URL, and contains URL_length, which indicates the byte length of the URL (URL length) when location information is indicated by URL, and URL_byte, which corresponds to the URL length. URL_byte indicates the URL of the IP service. Within the loop corresponding to the number of IP delivery flows, descriptor_loop_length, which indicates the total byte length of the subsequent descriptor (descriptor length), and descriptor(), which corresponds to the descriptor length, are placed. descriptor() is an area (descriptor area) for a descriptor that indicates detailed information about the IP service.

[0050] Returning to Figure 7, the package list table included in the PA message shown on the left side of the figure indirectly specifies the PA message, as indicated by the three arrows pointing from the package list table box to the PA message box. For example, assume that the PA message and MPT enclosed in dashed-dotted box A in Figure 7 are a divided PA message and divided MPT included in MMT-SI in layer A of Figure 6. Furthermore, the divided PA message including the package list table and MPT in Figure 7 is included in MMT-SI in layer B of Figure 6.

[0051] At this time, fixed value IDs (0x8010, 0x11) are assigned to the divided PA messages and divided MPTs included in the MMT-SI in layer A, so receiving device 20 can acquire the PA messages and MPTs (divided PA messages and divided MPTs) in frame A in Fig. 7 by performing filtering processing based on the fixed value IDs, and can acquire the assets in frame A in Fig. 7 based on the acquired MPTs (divided MPTs). In other words, receiving device 20 can acquire the divided PA messages and divided MPTs (PA messages and MPTs in frame A in Fig. 7) included in the MMT-SI in layer A, regardless of indirect designation by the package list table included in the MMT-SI in layer B.

[0052] The PA message and the MPT will be described in detail with reference to Figures 9 to 11. Figure 9 is a diagram showing an example of the configuration of a PA message. As shown in Figure 9, the PA message includes a message_id field indicating the identifier of the message, a version field indicating the version of the PA message, and a length field indicating the length from immediately after this field to the end of the message payload.

[0053] In a PA message, number_of_tables indicating the number of tables to be stored in the PA message is placed in the extension field, and table_id, table_version, and table_length are placed in a loop corresponding to the number of tables. table_id indicates the identifier of the table to be stored in the PA message. table_version indicates the version of the table to be stored in the PA message. table_length indicates the length of the table to be stored in the PA message. Furthermore, in a PA message, table() corresponding to the table length is placed in the message payload. table() is the field for the table to be stored in the PA message.

[0054] Fig. 10 is a diagram showing an example of the configuration of an MPT. As shown in Fig. 10, the MPT includes a table_id field indicating the identifier of the table, a version field indicating the version of the table, and a length field indicating the table length in terms of the number of data bytes that follow this field.

[0055] Figure 11 is a diagram showing an example of table identifier allocation for MMT-SI. As shown in Figure 11, table IDs related to MPTs (MP tables) are specified as 0x11 to 0x1F and 0x20. If the target MPT is a complete MPT, 0x20 is specified. If it is described by several MPTs, 0x11 to 0x1F is specified according to the subset. In Figure 6, the divided MPT in tier A is a divided MPT, so the table ID set as a fixed value ID is 0x11.

[0056] Returning to Figure 10, the MPT includes MPT_mode, which indicates the operation when the MPT is divided into subsets, MMT_package_id_length, which indicates the byte length of the package ID, MMT_package_id_byte, which indicates the package ID arranged according to the package ID length, MPT_descriptors_length, which indicates the length of the MPT descriptor area, and MPT_descriptors_byte, which is an area for storing MPT descriptors according to the MPT descriptor length.

[0057] The MPT table also includes number_of_assets, which indicates the number of assets for which the table provides information. Within the loop corresponding to the number of assets, there are identifier_type, which indicates the ID system of the MMTP packet flow; asset_id_scheme, which indicates the format of the asset ID; asset_id_length, which indicates the length of the asset ID; and asset_id_byte, which is the area for the asset ID corresponding to the asset ID length.

[0058] Also placed within the loop are asset_type, which indicates the type of asset; asset_clock_relation_flag, which indicates whether the asset has a clock information field; location_count, which indicates the number of location information pieces for the asset; MMT_general_location_info(), which is an area for asset location information arranged according to the number of locations; asset_descriptors_length, which indicates the total byte length of the subsequent descriptors; and asset_descriptors_byte, which is an area for storing asset descriptors arranged according to the asset descriptor length.

[0059] As described above, by assigning a fixed value ID to the division control information (divided PA message, divided MPT) transmitted in layer A, the receiving device 20 can acquire the division control information transmitted in layer A based on the fixed value ID, and therefore can partially receive the signal transmitted in layer A. Note that the IDs of the divided PA message and divided MPT transmitted in layer A may both be fixed value IDs, or at least one of the IDs of the divided PA message and the divided MPT may be a fixed value ID. For example, as shown in FIG. 7 , if the divided MPT can be acquired, the target asset can be identified. Therefore, the ID of the divided MPT of the divided PA message and divided MPT transmitted in layer A may be set as a fixed value ID to acquire the divided MPT. Alternatively, for example, if the table included in the divided PA message is only the divided MPT, the divided MPT included in the divided PA message may be acquired using the divided PA message as a fixed value ID.

[0060] <LDM System> The introduction of a layered division multiplexing system (hereinafter also referred to as LDM system) is being considered for advanced terrestrial broadcasting. Fig. 12 is a diagram explaining transmission using the LDM system. In Fig. 12, the vertical axis represents signal level and the horizontal axis represents frequency.

[0061] Figure 12 shows the frequency band of one channel, and each frequency band is composed of multiple segments (for example, 35 segments in the terrestrial broadcasting advanced standard). As shown in Figure 12, in transmission using the LDM method, broadcast signals can be transmitted by overlapping them in the same frequency band using a high-power layer as the upper layer (UL) and a low-power layer as the lower layer (LL). When introducing the LDM method to provide a multi-stream broadcast service, a first stream broadcast signal can be transmitted in the high-power layer (UL) and a second stream broadcast signal can be transmitted in the low-power layer (LL).

[0062] For example, a multi-stream broadcasting service can provide video with a resolution corresponding to a signal that can be demodulated on the receiving side. More specifically, video with a resolution corresponding to a signal that can be demodulated is provided based on a carrier-to-noise ratio (CN ratio) that varies depending on the reception environment of the receiving device 20. Transmission using the LDM method enables efficient transmission of video with different resolutions.

[0063] Fig. 13 is a diagram showing an example of a subframe configuration when LDM transmission is performed. Fig. 13 shows a schematic diagram of a subframe configuration when layer A is assigned to UL and LL, with the horizontal direction in the diagram representing frequency and the vertical direction in the diagram representing power.

[0064] Figure 14 is a diagram showing an example of a frame configuration and asset allocation for LDM transmission. Figure 14 shows the configuration of a synchronization signal, TMCC information, and subframe included in a physical layer frame, and the subframe transmits control information and assets by LDM transmission on the UL layer A (UL-A) and LL layer A (LL-A). As shown in Figure 14, in the subframe, MMT-SI, MPU1, and MPU2 are transmitted on the UL layer A (UL-A), and MPU3 and MPU4 are transmitted on the LL layer A (LL-A).

[0065] Even when LDM transmission is performed, the control information (PA message, MPT) can be divided, and the divided control information can be transmitted for each power layer by dividing it into the UL layer A (UL-A) and the LL layer A (LL-A), as in Fig. 6. Specifically, the MMT-SI for the UL layer A (UL-A) includes a divided PA message assigned a message ID of 0x8010 and a divided MPT assigned a table ID of 0x11. The MMT-SI for the LL layer A (LL-A) includes a divided PA message assigned a message ID of 0x0000, a divided MPT assigned a table ID of 0x20, and a package list table (PLT) assigned a table ID of 0x80.

[0066] However, the MMT-SI in the UL A layer (UL-A) only references assets transmitted by MPU1 and MPU2 in the UL A layer (UL-A). Furthermore, the IDs assigned to the segmented PA messages and segmented MPTs included in the MMT-SI in the UL A layer (UL-A) are pre-set fixed IDs. Specifically, the message ID assigned to the segmented PA messages in the UL A layer (UL-A) is a fixed ID of 0x8010. Furthermore, the table ID assigned to the segmented MPT in the UL A layer (UL-A) is a fixed ID of 0x11.

[0067] In this way, by assigning fixed ID values ​​(0x8010, 0x11) to the IDs assigned to the divided PA messages and divided MPTs transmitted on the UL layer A (UL-A), the receiving device 20 can perform filtering processing based on the pre-recorded fixed ID values ​​(0x8010, 0x11). The receiving device 20 can obtain the divided PA messages and divided MPTs transmitted on the UL layer A (UL-A) through filtering processing, and can obtain the video data of the 2K video and the audio data of the sound corresponding to the 2K video transmitted by MPU1 and MPU2 on the UL layer A (UL-A).

[0068] As described above, by assigning a fixed ID to the divided control information, the receiving device 20 can acquire the divided control information by filtering based on the fixed ID and identify the target asset. As a result, it becomes possible to independently receive (partially receive) a signal of one power hierarchical layer (UL-A) among multiple power hierarchical layers (UL-A, LL-A) transmitted by LDM.

[0069] <Processing on the transmitting side and receiving side> Fig. 15 is a flowchart illustrating a series of processing steps on the transmitting side and receiving side. In Fig. 15, steps S11 to S13 are processing steps executed by the transmitting device 10 in Fig. 2, and steps S21 to S23 are processing steps executed by the receiving device 20 in Fig. 3.

[0070] In step S11, the control information generator 112 generates control information such as MMT-SI. For example, the control information generator 112 generates MMT-SI (divided PA message, divided MPT, etc.) for layer A of hierarchical transmission and MMT-SI (divided PA message, divided MPT, etc.) for layer B.

[0071] In step S12, the multiplexing unit 113 multiplexes the data and control information. For example, the multiplexing unit 113 multiplexes the 2K video data of MPU1, the audio data of MPU2, and the MMT-SI of layer A. The multiplexing unit 113 also multiplexes the 4K video data of MPU3, the audio data of MPU4, and the MMT-SI of layer B.

[0072] In step S13, the transmitting unit 102 constructs a physical layer frame using the data signal obtained by processing the multiplexed data and physical layer control information such as TMCC information, modulates the physical layer frame, and transmits the terrestrial broadcast signal.

[0073] In step S21, the receiving unit 201 receives a terrestrial broadcast signal via an antenna. The receiving unit 201 demodulates the received terrestrial broadcast signal to extract a physical layer frame, and outputs the resulting multiplexed data to the processing unit 202.

[0074] In step S22, the control unit 212 acquires control information by controlling the filtering process by the multiplexing unit 211 based on the fixed value ID read from the memory 213. In step S23, the control unit 212 performs processing related to the data based on the acquired control information.

[0075] For example, if fixed value IDs of 0x8010 and 0x11 are recorded in memory 213, control unit 212 controls the filtering process by multiplexer 211 based on the fixed value IDs of 0x8010 and 0x11 to acquire a divided PA message assigned a message ID (fixed value ID) of 0x8010 and a divided MPT assigned a table ID (fixed value ID) of 0x11, which are included in MMT-SI of layer A (S22). Based on the acquired divided PA message and divided MPT, control unit 212 controls the filtering process by multiplexer 211 to input the 2K video data of MPU1 of layer A and the audio data of MPU2 of audio from the multiplexer 211 to decoder 214 (S23). Then, in receiving device 20, decoding process is performed by decoder 214, and 2K video corresponding to the video data is displayed on the display, and audio corresponding to the audio data is output from the speaker.

[0076] Although the above description has been given of an advanced terrestrial broadcasting system, which is the next generation system of ISDB-T, as a broadcasting system for terrestrial digital television broadcasting, the present disclosure may be applied to other broadcasting systems. Furthermore, the present disclosure is not limited to terrestrial waves (terrestrial broadcasting), and may be applied to broadcasting systems such as broadcasting satellites (BS), communications satellites, or cable broadcasting (CATV: Common Antenna Television).

[0077] In the above description, the receiving device 20 is a television receiver, but the fixed receiver may be, for example, an electronic device such as a set-top box (STB), a recording device, a game console, or a personal computer (PC). Furthermore, the receiving device 20 is a mobile phone, but the mobile receiver may be, for example, an electronic device such as a smartphone or a tablet computer. Furthermore, the receiving device is not limited to a fixed receiver or a mobile receiver, but may be, for example, an in-vehicle device mounted in a vehicle, such as an in-vehicle television, or a wearable computer, such as a head-mounted display (HMD).

[0078] Furthermore, in a transmission system to which the present disclosure is applied, a server having various functions connected to a communication line such as the Internet may be provided, so that a receiving device 20 having communication functions can access the server via the communication line to perform two-way communication, and receive and process various data such as content and applications.

[0079] In this specification, "2K video" refers to video corresponding to a screen resolution of approximately 1920 x 1080 pixels, and "4K video" refers to video corresponding to a screen resolution of approximately 3840 x 2160 pixels. In the above explanation, 2K content of 2K video and 4K content of 4K video were described as broadcast content transmitted hierarchically in the terrestrial broadcasting advanced standard. However, the terrestrial broadcasting advanced standard may also transmit content with even higher image quality, such as 8K video. "8K video" refers to video corresponding to a screen resolution of approximately 7680 x 4320 pixels.

[0080] The fixed value (fixed value ID) assigned to the identifier of the control information can be any value from 0x11 to 0x1F assigned to the subset MP table of the MPT (MP table) shown in FIG.

[0081] <Computer Configuration> 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. Fig. 16 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes by a program.

[0082] In the computer, 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 storage unit 1008, a communication unit 1009, and a drive 1010 are connected to the input / output interface 1005.

[0083] The input unit 1006 includes a keyboard, a mouse, a microphone, etc. The output unit 1007 includes a display, a speaker, etc. The storage 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 semiconductor memory, a magnetic disk, an optical disk, or a magneto-optical disk.

[0084] In a computer configured as described above, the CPU 1001 loads a program recorded in the ROM 1002 or memory 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.

[0085] The program executed by the computer (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.

[0086] In a computer, the program can be installed in the storage 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 storage unit 1008. Alternatively, the program can be installed in advance in the ROM 1002 or the storage unit 1008.

[0087] The processing performed by a computer according to a program includes processing that is executed in parallel or individually (for example, parallel processing or object-based processing). In addition, the program may be processed by a single computer (processor) or may be distributed among multiple computers.

[0088] It should be noted that the embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, the effects described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0089] The present disclosure can also be configured as follows.

[0090] (1) A transmitting device comprising: a generating unit that generates control information related to transmission of broadcast content; and a transmitting unit that transmits a broadcast stream including data constituting the broadcast content and the control information by hierarchical transmission using a segment structure in which one channel is divided into segments, wherein the transmitting unit transmits, of first divided control information and second divided control information obtained by dividing the control information, the first divided control information in a first layer and the second divided control information in a second layer, wherein the first divided control information includes control information related to the data to be transmitted in the first layer and is assigned an identifier consisting of a preset fixed value. (2) The transmitting device according to (1), wherein the control information includes MMT-SI, and the first divided control information includes the first MPT of first and second MPTs obtained by dividing an MPT included in the MMT-SI, and the second divided control information includes the second MPT. (3) The transmission device according to (1) or (2), wherein the control information includes MMT-SI, wherein the first division control information includes the first PA message among a first PA message and a second PA message obtained by dividing a PA message included in the MMT-SI, and wherein the second division control information includes the second PA message. (4) The transmission device according to any of (1) to (3), wherein the first layer is used for a first service, wherein the second layer is used for a second service different from the first service, and wherein the first layer and the second layer have different transmission capacities. (5) The transmission device according to any of (1) to (3), wherein the transmitter multiplexes the first layer transmitting the first division control information and the second layer transmitting the second division control information at different power levels using an LDM scheme.(6) A transmission method in which a transmitting device generates control information regarding the transmission of broadcast content, transmits a broadcast stream including data constituting the broadcast content and the control information by hierarchical transmission using a segment structure in which one channel is divided into segments, transmits the first divided control information in a first hierarchy and the second divided control information in a second hierarchy, and the first divided control information includes control information regarding the data transmitted in the first hierarchy and is assigned an identifier consisting of a preset fixed value. (7) A receiving device comprising: a receiving unit that receives a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, the broadcast stream being transmitted from a transmitting device by hierarchical transmission using a segment structure in which one channel is divided into segments; and a processing unit that processes the received broadcast stream, wherein the control information is divided into first division control information and second division control information, the first division control information being transmitted in a first hierarchy and the second division control information being transmitted in a second hierarchy, the first division control information including control information related to the data transmitted in the first hierarchy and assigned an identifier consisting of a predetermined fixed value, the processing unit acquiring the first division control information included in the broadcast stream based on the fixed value that was recorded in advance, and performing processing related to the data included in the broadcast stream based on the acquired first division control information. (8) The receiving device according to (7), wherein the control information includes MMT-SI, wherein the first division control information includes the first MPT among a first MPT and a second MPT obtained by dividing an MPT included in the MMT-SI, and the second division control information includes the second MPT. (9) The receiving device according to (7) or (8), wherein the control information includes MMT-SI, wherein the first division control information includes the first PA message among a first PA message and a second PA message obtained by dividing a PA message included in the MMT-SI, and the second division control information includes the second PA message.(10) The receiving device according to any one of (7) to (9), wherein the first layer is used for a first service, the second layer is used for a second service different from the first service, and the first layer and the second layer have different transmission capacities. (11) The receiving device according to any one of (7) to (9), wherein the first layer transmitting the first division control information and the second layer transmitting the second division control information are multiplexed at different powers using an LDM method. (12) A receiving method in which a receiving device receives a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, the broadcast stream being transmitted from a transmitting device by hierarchical transmission using a segment structure in which one channel is divided into segments; processes the received broadcast stream; divides the control information into first division control information and second division control information, the first division control information being transmitted in a first hierarchy and the second division control information being transmitted in a second hierarchy; the first division control information includes control information related to the data transmitted in the first hierarchy and is assigned an identifier consisting of a preset fixed value; acquires the first division control information included in the broadcast stream based on the pre-recorded fixed value; and performs processing related to the data included in the broadcast stream based on the acquired first division control information.

[0091] REFERENCE SIGNS LIST 10 Transmitting device, 20 Receiving device, 101 Processing section, 102 Transmitting section, 111 Encoder, 112 Control information generating section, 113 Multiplexing section, 201 Receiving section, 202 Processing section, 211 Demultiplexing section, 212 Control section, 213 Memory, 214 Decoder

Claims

1. A transmission device comprising: a generation unit that generates control information related to the transmission of broadcast content; and a transmission unit that transmits a broadcast stream including data constituting the broadcast content and the control information by hierarchical transmission with a segment structure in which one channel is segmented into segments, wherein the transmission unit transmits the first divided control information obtained by dividing the control information in a first layer and the second divided control information in a second layer, the first divided control information includes control information related to the data transmitted in the first layer, and an identifier consisting of a preset fixed value is assigned.

2. The transmission device according to claim 1, wherein the control information includes MMT-SI, the first divided control information includes the first MPT among the first MPT and the second MPT obtained by dividing the MPT included in the MMT-SI, and the second divided control information includes the second MPT.

3. The transmission device according to claim 1, wherein the control information includes MMT-SI, the first divided control information includes the first PA message among the first PA message and the second PA message obtained by dividing the PA message included in the MMT-SI, and the second divided control information includes the second PA message.

4. The transmission device according to claim 1, wherein the first layer is used in a first service, the second layer is used in a second service different from the first service, and the transmission capacities of the first layer and the second layer are different.

5. The transmission device according to claim 1, wherein the transmission unit multiplexes, using the LDM method, the first layer that transmits the first divided control information and the second layer that transmits the second divided control information with different powers.

6. A transmission method in which a transmission device generates control information related to the transmission of broadcast content, and transmits a broadcast stream including data constituting the broadcast content and the control information by hierarchical transmission with a segment structure obtained by dividing one channel into segments. Among first divided control information and second divided control information obtained by dividing the control information, the first divided control information is transmitted in a first layer, and the second divided control information is transmitted in a second layer. The first divided control information includes control information related to the data transmitted in the first layer, and an identifier consisting of a preset fixed value is assigned thereto.

7. A receiving device comprising: a receiving unit that receives a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, which is transmitted by hierarchical transmission with a segment structure obtained by dividing one channel into segments from a transmission device; and a processing unit that processes the received broadcast stream. Among first divided control information and second divided control information obtained by dividing the control information, the first divided control information is transmitted in a first layer, and the second divided control information is transmitted in a second layer. The first divided control information includes control information related to the data transmitted in the first layer, and an identifier consisting of a preset fixed value is assigned thereto. The processing unit acquires the first divided control information included in the broadcast stream based on a fixed value recorded in advance, and performs processing related to the data included in the broadcast stream based on the acquired first divided control information.

8. The receiving device according to claim 7, wherein the control information includes MMT-SI, the first divided control information includes a first MPT among a first MPT and a second MPT obtained by dividing an MPT included in the MMT-SI, and the second divided control information includes the second MPT.

9. The receiving device according to claim 7, wherein the control information includes MMT-SI, the first divided control information includes a first PA message among a first PA message and a second PA message obtained by dividing a PA message included in the MMT-SI, and the second divided control information includes the second PA message.

10. The first layer is used in the first service, the second layer is used in a second service different from the first service, and the transmission capacities of the first layer and the second layer are different. The receiving apparatus according to claim 7.

11. The first layer for transmitting the first divided control information and the second layer for transmitting the second divided control information are multiplexed with different powers using the LDM method. The receiving apparatus according to claim 7.

12. A receiving method in which a receiving apparatus receives a broadcast stream including data constituting broadcast content and control information related to the transmission of the broadcast content, which is transmitted by hierarchical transmission with a segment structure in which one channel is segmented from a transmitting apparatus, processes the received broadcast stream, and among the first divided control information and the second divided control information obtained by dividing the control information, the first divided control information is transmitted in a first layer, the second divided control information is transmitted in a second layer, the first divided control information includes control information related to the data transmitted in the first layer, and an identifier consisting of a preset fixed value is assigned, obtains the first divided control information included in the broadcast stream based on the fixed value recorded in advance, and performs processing related to the data included in the broadcast stream based on the obtained first divided control information.

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