JP6775075B2 - Data transmission systems, receivers, and programs - Google Patents

Description

The present invention relates to data transmission systems, receivers, and programs.

Currently, in digital broadcasting, data broadcasting content is transmitted using a data carousel transmission method (see Non-Patent Document 1) so that all files constituting the data broadcasting content can be received even if data reception is started from the middle. The constituent files are being transmitted. This data carousel transmission method is a method premised on transmission by MPEG2-TS. On the other hand, in future digital broadcasting for Super Hi-Vision, etc., it has been decided that MMT (Mpeg Media Transport; ISO / IEC 23008-1) will also be adopted as the transmission method, and in the MMT method, streams such as video will be adopted. Is transmitted as an MMTP (Mpeg Media Transport Protocol) packet.

"Data broadcasting coding method and transmission method standard in digital broadcasting ARIB STD-B24 5.8th edition (third volume)", Association of Radio Industries and Businesses, July 2013

However, the MMT method transmission has a problem that there is no transmission method capable of receiving all the content files no matter when the receiver starts data reception.

The present invention has been made in view of such circumstances, and in MMT method transmission, a data transmission system, a receiving device, and a data transmission system, a receiving device, which can ensure that all files are received at any time when data reception is started. And provide programs.

(1) The present invention has been made to solve the above-mentioned problems, and one aspect of the present invention is to acquire a file constituting the content and repeatedly send an MMTP packet containing the file constituting the content. A data transmission device for transmitting data, a control message generation device for transmitting an MMTP packet storing a table for storing a path name and an item ID for each of the files constituting the content, an MMTP packet transmitted by the data transmission device, and the above. It is provided with a multiplexing device that multiplexes the MMTP packet sent by the control message generator, and the packet ID of the MMTP packet that stores the files that make up the content is different from the packet ID of the MMTP packet that stores the table. The table is a data transmission system characterized by being a data asset management table.

(2) Further, another aspect of the present invention is the data transmission system according to (1), wherein the data transmission device acquires a file constituting the content, a file acquisition unit, and the file acquisition unit. The MMTP payload generation unit that stores the file acquired by the MMTP payload, the payload storage unit that stores the MMTP payload, and the MMTP payload stored in the payload storage unit are repeatedly stored in the MMTP packet and transmitted. It is equipped with a transmission unit.

(3) In another aspect of the present invention, an MMTP packet containing files constituting the content and a table storing the path name and item ID of each of the files constituting the content, which are repeatedly transmitted, are stored. It includes a receiving unit that receives the MMTP packet, and a file restoring unit that restores a file having a desired path name from the MMTP packet received by the receiving unit with reference to the table, and constitutes the content. Unlike the packet ID of the MMTP packet storing the file and the packet ID of the MMTP packet storing the table, the table is a receiving device characterized by being a data asset management table.

(4) In another aspect of the present invention, the computer stores the MMTP packet containing the files constituting the content, which are repeatedly transmitted, and the path name and item ID of each of the files constituting the content. It is a program for functioning as a receiving unit that receives an MMTP packet storing a table and a file restoring unit that restores a file with a desired path name from the MMTP packet received by the receiving unit with reference to the table. The program is different from the packet ID of the MMTP packet that stores the file constituting the content and the packet ID of the MMTP packet that stores the table, and the table is a data asset management table. ..

According to the present invention, in MMT transmission, it is possible to ensure that all files are received no matter when data reception is started.

It is a schematic block diagram which shows the structure of the content transmission system 10 by one Embodiment of this invention. It is a schematic diagram which shows the structural example of the IP data flow transmitted by the broadcasting equipment 11 in the same embodiment. It is a schematic diagram explaining the file transmission method by the broadcasting equipment 11 in the same embodiment. It is a schematic block diagram which shows the structure of the broadcasting equipment 11 in the same embodiment. It is a schematic block diagram which shows the structure of the control message generation apparatus 101 in the same embodiment. It is a schematic block diagram which shows the structure of the data transmission apparatus 104 in the same embodiment. It is a schematic block diagram which shows the structure of the receiving apparatus 12 in the same embodiment. It is a table which shows the data structure of the data transmission message in the same embodiment. It is a table which shows the data structure of the data directory management table in the same embodiment. It is a table which shows the data structure of the transmission arrangement information in the same embodiment. It is a table which shows the data structure of the data asset management table in the same embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing a configuration of a content transmission system 10 according to an embodiment of the present invention. The content transmission system 10 transmits content composed of one or a plurality of files (also referred to as multimedia content) using broadcast waves. The content transmission system 10 transmits by the MMT (MPEG Media Transport) method using TLV (Type Length Value) and IP (Internet Protocol) in order from the lower layer as the transmission data format.

The content transmission system 10 includes a broadcasting facility 11, a receiving device 12, and an output device 13. The broadcasting equipment 11 repeatedly sends out the files constituting the content by using the broadcasting wave. This file includes a file containing character information such as HTML (HyperText Markup Language) file and control information, a file describing an application such as JavaScript (registered trademark), and a still image file such as JPEG (Joint Picture Experts Group). Audio files such as MPEG-2 audio can be included. The receiving device 12 receives the file delivered by the broadcasting equipment 11 and generates an image and an audio of the content by rendering, executing, and decoding the received file. The receiving device 12 generates an image signal representing an image of this content and an audio signal representing voice, and inputs the image signal to the output device 13. The output device 13 has a display device such as a liquid crystal display and a speaker, and displays an image represented by an image signal generated by the receiving device 12 and outputs a sound represented by the voice signal. The receiving device 12 and the output device 13 may be integrated.

FIG. 2 is a schematic diagram showing a configuration example of an IP data flow transmitted by the broadcasting equipment 11. In FIG. 2, one package P1 is transmitted by the IP data flow DF1 distributed from the broadcasting equipment 11. A data transmission message (Data_Transmission_Message) DTM1 (data transmission information) and a plurality of data assets DA1 and DA2 are transmitted in one package P1. The data transmission message DTM1 is a message defined by MMT, and in the present embodiment, "0x8002" is used as the message ID. Data assets DA1, DA2 are assets defined by MMT that transmit files constituting the contents as items I1, I2, .... Each asset is a bitstream stored in an MMTP packet having a specific packet ID (packet_id), and is also called a component or the like.

The data transmission message DTM1 stores a data directory management table (Data_Directory_Management_Table) DM1 (directory management information) and data asset management tables (Data_Asset_Management_Table) AM1 and AM2 (asset management information). The data directory management table DM1 associates the path name of the file constituting the content with the item ID (file identification information) of the file. The item ID is information that identifies a file that constitutes the content in the data flow in combination with the packet ID or the asset ID. In addition to these, the data directory management table DM also associates an IP data flow and a packet ID, but description thereof will be omitted here. The correspondence between the asset ID and the packet ID is described in the MP table in the PA message, which is a kind of control message.

Each of the data asset management tables AM1 and AM2 stores one corresponding asset ID and the item ID of the file stored in the data asset of the asset ID. As many data asset management tables as there are data assets are stored in the data transmission message.

Therefore, when the path name of the file is given, the item ID of the file is obtained from the data directory management table DM1. Further, the asset ID is obtained from the data asset management table AM1 that stores the obtained item ID. The item of the obtained item ID transmitted by the data asset of the asset ID is a file to which the path name is given.

FIG. 3 is a schematic diagram illustrating a file transmission method by the broadcasting equipment 11. As shown in FIG. 3, the broadcasting equipment 11 divides the file F1 to be transmitted into blocks F1a, F1b, ... Of predetermined sizes in order from the beginning. Then, the broadcasting equipment 11 adds MMTP payload headers PH1, PH2, ... To these blocks F1a, F1b, ..., To obtain MMTP payloads PL1, PL2, respectively. These MMTP payload headers PH1, PH2, ... Include an item ID, a fragmentation indicator (Fragmentation Indicator), and a fragment counter (fragment_counter). The item ID is the item ID of the file F1 of the block to which the MMTP payload header is added.

The fragmentation indicator takes four values from "0" to "3". When it is "0", it indicates that the file is completed only by the block to which the MMTP payload header is added. When it is "1", it indicates that the block to which the MMTP payload header is added is the beginning of the file. When it is "2", it means that the block to which the MMTP payload header is added is neither the beginning nor the end of the file. When it is "3", it indicates that the block to which the MMTP payload header is added is the end of the file. The fragment counter indicates how many more MMTPs are split from the same file.

The broadcasting equipment 11 adds MMTP packet headers H1 and H2 to the payloads PL1, PL2, ..., To obtain MMTP packets P1 and P2, respectively. These MMTP packet headers H1 and H2 include a packet ID, a packet sequence number, and a time stamp, respectively. The packet sequence number is a serial number assigned to the same packet ID. The time stamp indicates the time when the first byte of the MMTP packet is sent.

The broadcasting equipment 11 repeatedly sends out these MMTP packets P1, P2, ... However, the broadcasting equipment 11 assigns the packet sequence number and the time stamp of the MMTP packet header to the values at that time each time the packet is transmitted. For example, the broadcasting equipment 11 assigns a value to the packet sequence number so as to be a continuous number from the packet sequence number of the same packet ID transmitted immediately before.

The receiving device 12 receives these MMTP packets P1, P2, P3, ..., And constructs files F1, files F2, .... At this time, for example, it is assumed that the receiving device 12 starts receiving from the MMPT packet P3. Since the MMTP packets P1, P2, P3 ... Are repeatedly transmitted, the receiving device 12 receives the MMTP packets P1, P2 to be transmitted again after receiving the MMTP packets P3 and later. Therefore, the receiving device 12 can receive all of the MMTP packets P1, P2, ..., And construct all the files F1, F2, ... That constitute the content. The same applies when the reception of the MMTP packet in the middle fails due to a transmission error or the like.

FIG. 4 is a schematic block diagram showing the configuration of the broadcasting equipment 11. The broadcasting equipment 11 includes a control message generation device 101, a video transmission device 102, an audio transmission device 103, a data transmission device 104, a multiplexing device 105, and a distribution device 106. The control message generation device 101 generates an MMTP packet containing a data transmission message. The data transmission message associates the information indicating the path name of the file constituting the content with the information regarding the arrangement of the file in the transmission line. This association is performed between the data directory management table stored in the data transmission message and the data asset management table. The control message generation device 101 may also generate an MMTP packet that stores a control message such as a PA message that stores the MP table.

The video transmission device 102 generates an MMTP packet containing video assets. The voice transmission device 103 generates an MMTP packet containing voice assets. The data transmission device 104 generates an MMTP packet containing an asset (data asset) for transmitting a file constituting the content as an item. The files that make up the content include files that include character information such as HTML files and control information, files that describe applications such as JavaScript (registered trademark), still image files such as PEG, and audio files such as MPEG-2 audio. and so on. The multiplexing device 105 multiplexes the MMTP packets generated by each of the control message generation device 101, the video transmission device 102, the audio transmission device 103, and the data transmission device 104. The multiplexing device 105 generates an IP data flow for transmitting the multiplexed MMTP packet. The distribution device 106 (distribution unit) generates a TLV stream for transmitting the IP data flow generated by the multiplexing device 105, and distributes the TLV stream using a broadcast wave.

FIG. 5 is a schematic block diagram showing the configuration of the control message generation device 101. The control message generation device 101 includes a directory management table generation unit 111, an asset management table generation unit 112, and a data transmission message generation unit 113. The directory management table generation unit 111 generates a directory management table that associates the path names of all the files constituting the content with the information regarding the arrangement of those files in the transmission line.

When the file is transmitted by the broadcasting equipment 11, the directory management table uses the package ID of the package in which the file is transmitted and the item ID associated with the file as information regarding the arrangement in the transmission line. It is stored. Further, the directory management table stores information on the arrangement in the transmission line even when the file is transmitted by multicast or unicast via the IP network, but the details will be omitted.

The asset management table generation unit 112 generates an asset management table that stores information regarding the arrangement of files that are transmitted in the same package as this table among the files that make up the content. The information regarding the arrangement in the transmission line stored in the asset management table is the asset ID of the data asset associated with the asset management table and the item ID of the file stored in the data asset. The data transmission message generation unit 113 generates a data transmission message that stores the directory management table generated by the directory management table generation unit 111 and the asset management table generated by the asset management table generation unit 112.

FIG. 6 is a schematic block diagram showing the configuration of the data transmission device 104. The data transmission device 104 includes a file acquisition unit 141, an MMTP payload generation unit 142, a payload storage unit 143, an MMTP packet generation unit 144, and a data asset transmission unit 145. The MMTP packet generation unit 144 and the data asset transmission unit 145 function as a transmission unit 146. The file acquisition unit 141 acquires the files that make up the content. The MMTP payload generation unit 142 divides the file acquired by the file acquisition unit 141 into a predetermined size or less, adds an MMTP payload header, and generates an MMTP payload. The MMTP payload generation unit 142 stores the generated MMTP payload in the payload storage unit 143.

The MMTP packet generation unit 144 reads the MMTP payload stored in the payload storage unit 143 and adds an MMTP packet header to the read MMTP payload to generate an MMTP packet. The MMTP packet generation unit 144 repeats reading all the MMTP payloads to be sent and generating MMTP packets. At this time, the MMTP packet generation unit 144 allocates values so that the packet sequence numbers in the MMTP packet header are consecutive numbers. When the MMTP packet generation unit 144 generates the MMTP packet, the data asset transmission unit 145 outputs the MMTP packet.

FIG. 7 is a schematic block diagram showing the configuration of the receiving device 12. The receiving device 12 includes a broadcast receiving unit 201, a separating unit 202, a designated acquisition unit 203, a receiving control unit 204, a control message processing unit 205, a video decoding unit 206, an audio decoding unit 207, a data rendering unit 208, and a video synthesis unit 209. It includes a voice synthesis unit 210 and a file restoration unit 211. The broadcast receiving unit 201 receives the broadcast wave transmitted by the broadcast equipment 11 and detects the TLV stream from the received broadcast wave. The broadcast receiving unit 201 extracts the IP data flow stored in the detected TLV stream and inputs it to the separation unit 202.

Separation unit 202 extracts MMTP packets from the input IP data flow. The separation unit 202 inputs the MMTP packet of the packet ID specified by the reception control unit 204 to the control message processing unit 205, the video decoding unit 206, the audio decoding unit 207, and the file restoration unit 211, respectively. The designation acquisition unit 203 acquires the designation of the content by the user. In the present embodiment, the content is specified by pressing the button corresponding to the package ID of the package for transmitting the content by using the remote controller of the receiving device 12. The designation acquisition unit 203 detects the pressed button and inputs the package ID corresponding to the button to the reception control unit 204.

The reception control unit 204 determines the IP data flow to be received according to the package ID input from the designated acquisition unit 203, and instructs the broadcast reception unit 201 to receive the IP data flow. Further, the reception control unit 204 instructs the separation unit 202 of the packet ID of the MMTP packet to be input to each unit according to the packet ID of each asset constituting the package input from the control message processing unit 205.

The control message processing unit 205 extracts control messages such as a data transmission message and a PA message from the MMTP packet input from the separation unit 202. The control message processing unit 205 acquires the packet ID of the asset constituting the package from the PA message and inputs it to the reception control unit 204. Further, the control message processing unit 205 acquires the correspondence between the path name of the file constituting the content and the item ID from the data transmission message, and inputs the correspondence to the file restoration unit 211.

The video decoding unit 206 extracts and decodes the video data stored in the MMTP packet input from the separation unit 202. The video decoding unit 206 inputs the video signal obtained by decoding to the video synthesis unit 209. The voice decoding unit 207 extracts and decodes the voice data stored in the MMTP packet input from the separation unit 202. The voice decoding unit 207 inputs the voice signal obtained by decoding to the voice synthesis unit 210. The data rendering unit 208 is, for example, an HTML browser, and the file restoration unit 211 renders, executes, decodes, or the like the restored file to generate an image signal and an audio signal. Since the file restored by the file restoration unit 211 is a file transmitted by the data transmission device 104, a file including character information such as an HTML file and control information, and an application such as JavaScript (registered trademark) are described. Includes files, still image files such as JPEG, and audio files such as MPEG-2 audio.

The video compositing unit 209 synthesizes the video signal from the video decoding unit 206 and the video signal from the data rendering unit 208, and outputs the combined video signal. The voice synthesis unit 210 synthesizes the voice signal from the voice decoding unit 207 and the voice signal from the data rendering unit 208, and outputs the combined voice signal.

The file restoration unit 211 restores a file from the MMTP packet input from the separation unit 202. For example, as shown in FIG. 3, when the file is divided into MMTP packets P1, P2, P3, ... And repeatedly transmitted, even if the file restoration unit 211 starts receiving from the MMTP packet P3, the following MMTP packets P1 and P2 can be received and the file can be restored by repeating. The file restoration unit 211 specifies the path name of the restored file by referring to the correspondence between the path name input from the control message processing unit 205 and the item ID. The file restoration unit 211 inputs the file with the path name specified by the data rendering unit 208 to the data rendering unit 208.

In the table, FIG. 8 shows No. Is a column indicating the serial number of the row in the table. The data structure is a column indicating the data structure of the data transmission message. The number of bits is a column indicating the number of bits of the data structure. The bit string notation is a column indicating the data format of the data structure of the number of bits. Uimsbf in bit string notation is an abbreviation for unsigned integer most significant bit first, and means an unsigned integer and the most significant bit is the first.

In FIG. 8, No. "Data_Transmission_message () {" in 1 is hereinafter referred to as No. Up to 14 "}" indicates that the data structure of the data transmission message. No. 1 placed at the beginning of the message. The “message_id” of 2 is a 16-bit area indicating an ID (Identifier) of a data transmission message, and “0x8002” is set in the present embodiment. The next No. The “version” of 3 is an 8-bit area indicating the version number of the data transmission message. The next No. “Length” of 4 is a 32-bit area indicating the number of bytes of the data transmission message after the area.

The next No. “Num_of_tables” of 5 is an 8-bit area indicating the number of tables stored in the data transmission message. Next No. No. 6 “for (i = 0; i <N; i ++) {” is hereinafter “}”. It is shown that up to 10 is repeated N times, that is, for the number of stored tables (num_of_tables). The next No. “Table_id” of 7 is an 8-bit area indicating the ID of the table stored in the data transmission message. The value of this area is the same as the value of "table_id" arranged at the head of each table.

The next No. The "table_version" of 8 is the No. 1 immediately before. It is an 8-bit area indicating the version number of the table indicated by the table ID of 7. The value in this area is the same as the "version" value in the table. The next No. “Table_length” of 9 is the number immediately before. It is a 16-bit area indicating the length of the table indicated by the table ID of 7. The value in this area is the same as the "length" value in the table. Next No. "}" In 10 is No. Corresponds to 6 "{".

Next No. No. 11 "for (i = 0; i <N; i ++) {" is hereinafter "}". It is shown that up to 13 is repeated N times, that is, for the number of stored tables (num_of_tables). Next No. 12 "table ()" indicates that one table is stored.

FIG. 9 is a table showing the data structure of the data directory management table. In the table, No. Is a column indicating the serial number of the row in the table. The data structure is a column indicating the data structure of the data directory management table. The number of bits is a column indicating the number of bits of the data structure. The bit string notation is a column indicating the data format of the data structure of the number of bits.
Uimsbf in bit string notation is an abbreviation for unsigned integer most significant bit first, and means an unsigned integer and the most significant bit is the first. In addition, char in bit string notation means a character.

In FIG. 9, No. "Data_Directory_Management_Table () {" of No. 1 is hereinafter referred to as No. Up to 33 "}" indicates that it is the data structure of the data directory management table. No. 1 located at the top of the table. The “table_id” of 2 is an 8-bit area indicating the ID of the data directory management table. In this embodiment, "0x87" is used as the ID of the data directory management table. The next No. The “version” of 3 is an 8-bit area indicating the version number of the data directory management table. The next No. “Length” of 4 is a 16-bit area indicating the number of bytes of the data directory management table after the area.

The next No. The “list_scene” of No. 5 is No. It is a 32-bit area that specifies a data structure up to 32. When the value of "list_scene" is "1", it indicates that the correspondence between the path name of the file and the information regarding the arrangement in the transmission line is stored in the external file. When the value of "list_scene" is "2", it indicates that the correspondence is described directly in this table. Next No. 6 "if (list_scene == 1) {" is No. When the value of "list_scene" of 5 is "1", No. Indicates that the data structures up to 11 "}" are arranged. No. The "list_length" arranged in 7 is an 8-bit area indicating the length of reference information (for example, URL) to the file that stores the correspondence between the path name of the file and the information related to the arrangement in the transmission line. is there.

Next No. No. 8 “for (i = 0; i <list_length; i ++) {” indicates No. Up to 10 "}", that is, No. It is shown that the data structure of 9 is repeated by "list_length". No. The “list_value” of 9 is an 8-bit area that is arranged by the amount of “list_length” and indicates reference information to the file that stores the correspondence between the path name of the file and the information regarding the arrangement in the transmission line.

Next No. 12 "if (list_scene == 2) {" is No. When the value of "list_scene" of 5 is "2", No. Indicates that the data structures up to 32 "}" are arranged. The next No. 13 "num_of_files" is an 8-bit area indicating the number of files constituting the content, that is, the number of files in which information is stored in the data directory management table. Next No. 14 "for (j = 0; j <M; j ++) {" is No. It is shown that the data structures up to "}" of 30 are repeatedly arranged by the value of "num_of_files".

No. to be placed next Fifteen "Transport_location_info ()" is an area of transmission arrangement information that specifies an IP data flow, a package, etc., among information regarding arrangement in a transmission line. Details of the transmission arrangement information will be described later. Hereinafter, No. The files shown up to 25 are arranged in the transmission line specified by this transmission arrangement information. No. to be placed next The “location_type” of 16 is an 8-bit area indicating the type of transmission line. Next No. 17 "if (location_type == 0x00 || 0x01 || 0x02) {" is the immediately preceding No. When the value of "location_type" of 16 is "0x00", "0x01" or "0x02", No. It shows that 18 data structures are arranged. No. The “item_ID” of 18 is a 32-bit area indicating the value of the item ID that identifies the file distributed from the broadcasting equipment 11 in the package.

Next No. 19 "} else {" is the previous No. When the value of "location_type" of 16 is neither "0x00", "0x01", nor "0x02", No. It indicates that the data structure of No. 20 is arranged up to "}" of 21. No. The “transport_file_ID” of 20 is a 32-bit area indicating the value of the file ID that identifies the file distributed by the distribution facility 12 by IP multicast in the data flow by the IP multicast.

The next No. 22 “file_direction_length” is an 8-bit area indicating the length of the path name of the file. The next "for (k = 0; k <file_direction_length; k ++) {" is No. Up to 25 "}", that is, No. It is shown that 24 data structures are arranged by "file_direction_byte". No. The 24 "file_direction_byte" is an 8-bit area that is arranged by the amount of "file_direction_length" and indicates the path name of the file. No. to be placed next The 26 "descriptor_loop_length" is a 16-bit area indicating the number of descriptors to be arranged thereafter.
Next No. 27 "for (l = 0; l <N; l ++) {" is No. Up to 29 "}", that is, No. It is shown that the data structure of 28 is repeated by "descriptor_loop_length". No. 28. “Descriptor ()” is an area for arranging an arbitrary descriptor (descriptor).

FIG. 10 is a table showing a data structure of transmission arrangement information. In the table, No. Is a column indicating the serial number of the row in the table. The data structure is a column indicating the data structure of the transmission arrangement information. The number of bits is a column indicating the number of bits of the data structure. The bit string notation is a column indicating the data format of the data structure of the number of bits. Uimsbf in bit string notation is an abbreviation for unsigned integer most significant bit first, and means an unsigned integer and the most significant bit is the first. In addition, char in bit string notation means a character.

No. "Transport_location_info () {" of No. 1 is No. Up to 34 "}" indicates that the data structure of the transmission arrangement information. No. to be placed next The “location_type” of 2 is an 8-bit area indicating the type of transmission line. Next No. "If (location_type == 0x00) {" of 3 is No. When the value of "location_type" of 2 is "0x00", No. Indicates that the data structures up to "}" of 5 are arranged. When the value of "location_type" is "0x00", it is the MMTP packet transmitted in the IP data flow in which this transmission arrangement information is transmitted that the file is transmitted. No. The “packet_id” arranged in 4 is a 16-bit area indicating the packet ID of the MMTP packet.

Next No. 6 "if (location_type == 0x01) {" is No. When the value of "location_type" of 2 is "0x01", No. Indicates that the data structures up to 11 "}" are arranged. When the value of "location_type" is "0x01", the file is transmitted to the MMTP packet transmitted by the IP data flow by the IP multicast of IPv4. The next No. “Ipv4_src_addr” in 7 is a 32-bit area indicating the source address of the IP data flow. The next No. “Ipv4_dst_addr” of No. 8 is a 32-bit area indicating the multicast address (destination address) of the IP data flow. The next No. “Dst_port” of 9 is a 16-bit area indicating a destination port number of the IP data flow. The next No. The “packet_id” of 10 is the packet ID of the MMTP packet.

Next No. 12 "if (location_type == 0x02) {" is No. When the value of "location_type" of 2 is "0x02", No. Indicates that the data structures up to 17 "}" are arranged. When the value of "location_type" is "0x02", the file is transmitted to the MMTP packet transmitted by the IP data flow by the IP multicast of IPv6. The next No. “Ipv6_src_addr” of 13 is a 128-bit area indicating the source address of the IP data flow. The next No. “Ipv6_dst_addr” of 14 is a 128-bit area indicating a multicast address (destination address) of the IP data flow. The next No. “Dst_port” of 15 is a 16-bit area indicating a destination port number of the IP data flow. The next No. The “packet_id” of 16 is the packet ID of the MMTP packet.

Next No. 18 "if (location_type == 0x03) {" is No. When the value of "location_type" of 2 is "0x03", No. Indicates that the data structures up to 22 "}" are arranged. When the value of "location_type" is "0x03", the file is transmitted by the IP data flow by IP multicast of IPv4. The next No. “Ipv4_src_addr” in 19 is a 32-bit area indicating the source address of the IP data flow. The next No. “Ipv4_dst_addr” of 20 is a 32-bit area indicating the multicast address (destination address) of the IP data flow. The next No. “Dst_port” of 21 is a 16-bit area indicating a destination port number of the IP data flow.

Next No. 23 "if (location_type == 0x04) {" is No. When the value of "location_type" of 2 is "0x04", No. Indicates that the data structures up to "}" of 27 are arranged. When the value of "location_type" is "0x04", it is the IP data flow by IP multicast of IPv6 that the file is transmitted. The next No. “Ipv6_src_addr” of 24 is a 128-bit area indicating the source address of the IP data flow. The next No. “Ipv6_dst_addr” of 25 is a 128-bit area indicating a multicast address (destination address) of the IP data flow. The next No. “Dst_port” of 26 is a 16-bit area indicating a destination port number of the IP data flow.

Next No. 28 "if (location_type == 0x05) {" is No. When the value of "location_type" of 2 is "0x05", No. Indicates that the data structures up to 33 "}" are arranged. When the value of "location_type" is "0x05", the file is transmitted by unicast. The next No. “URL_length” of 29 is an 8-bit area indicating the length of the URL of the file. Next No. 30 "for (i = 0; i <N; i ++) {" is No. Up to 32 "}", that is, No. It shows that the data structure of 31 is arranged by "URL_length". No. The “URL_byte” of 31 is an 8-bit area that is arranged by the amount of “URL_length” and indicates a URL.

FIG. 11 is a table showing the data structure of the data asset management table. In the table, No. Is a column indicating the serial number of the row in the table. The data structure is a column indicating the data structure of the data asset management table. The number of bits is a column indicating the number of bits of the data structure. The bit string notation is a column indicating the data format of the data structure of the number of bits. Uimsbf in bit string notation is an abbreviation for unsigned integer most significant bit first, and means an unsigned integer and the most significant bit is the first. In addition, char in bit string notation means a character.

In FIG. 11, No. 1 "Data_Asset_Management_Table () {" is hereinafter referred to as No. Up to 27 "}" indicates that it is the data structure of the data asset management table. No. 1 located at the top of the table. The “table_id” of 2 is an 8-bit area indicating the ID of the data asset management table. In this embodiment, "0x88" is used as the ID of the data asset management table. The next No. The “version” of 3 is an 8-bit area indicating the version number of the data asset management table. The next No. “Length” of 4 is a 16-bit area indicating the number of bytes of the data directory management table after the area.

The next No. “Asset_ID_scene” in 5 is a 32-bit area indicating the scheme (description format) of the asset ID (asset_ID). The next No. “Asset_ID_length” of No. 6 is an 8-bit area indicating the length (number of bytes) of the asset ID. Next No. 7 "for (i = 0; i <asset_ID_length; i ++) {" is No. Up to 9 "}", that is, No. The data structure of No. 8 was changed to No. It is shown to repeat for 6 "asset_ID_length". The next No. The “asset_ID_byte” of 8 is an 8-bit area indicating the asset ID, which is arranged by the amount of “asset_ID_length”. This asset ID indicates which data asset the data asset management table stores information about.

The next No. No. 10 "num_of_item" is No. It is an 8-bit area indicating the number of items stored in the data asset of the asset ID of 8. Next No. 11 "for (j = 0; j <M; j ++) {" is No. The data structures up to 14 are described in No. It is shown to repeat for 10 "num_of_item" minutes. The next No. The “item_ID” of 12 is a 32-bit area indicating the item ID.
This item ID is No. It is the item ID of the file stored in the data asset of the asset ID of 8. The next No. 13 "item_version" is the previous No. It is an 8-bit area indicating the version number of the file indicated by 12 “item_ID”.

Next No. "For (j = 0; j <M; j ++) {" of 15 is No. The data structures up to 22 are described in No. It is shown to repeat for 10 "num_of_item" minutes. The next No. The “item_ID” of 16 is a 32-bit area indicating the item ID. Immediately after No. The data of the data structure up to 21 is the data related to the file indicated by this item ID. The next No. “Item_checksum” of 17 is a 32-bit area indicating a checksum of a file. For this checksum, for example, Cyclic Redundancy Check (CRC) is used.

The next No. 18 "item_location_length" is the immediately preceding No. It is a 32-bit area indicating the length (number of bytes) of the path name of the file indicated by 16 “item_ID”. Next No. 19 "for (k = 0; k <item_location_length; k ++) {" is No. Up to 21, that is, No. The data structure of 20 is No. It is shown that it is repeated for 18 "item_location_length". The next No. 20 "item_location_bite" is an 8-bit area indicating a path name by being repeatedly arranged by "item_location_longth".

No. to be placed next The “descriptor_loop_length” of 23 is a 16-bit area indicating the number of descriptors to be placed immediately after. Next No. 24 "for (l = 0; l <N; l ++) {" indicates the immediately preceding No. 23 "descriptor_loop_length", No. Up to 26 "}", that is, No. It shows that 25 data structures are arranged repeatedly. The next No. 25 "descriptor ()" indicates that the descriptor is placed.

In the present embodiment, the IP data flow is transmitted by the MMT multiplexing method, but the IP data flow is not limited to this. For example, it may be transmitted on an IP network, or may be transmitted by another bitstream transmitted by a broadcast wave. Further, the TLV stream may be transmitted by a medium other than a broadcast wave such as a cable television.

In this way, the data transmission device 104 acquires the files constituting the contents and repeatedly transmits the MMTP packet containing the files.
In addition, the receiving device 12 includes a broadcast receiving unit 201 that receives an MMTP packet that stores a file that constitutes the content, and a file restoring unit 211 that restores a file from the received MMTP packet.
Thereby, in the MMT method transmission, all the files can be received no matter when the data reception is started.

Further, the data transmission device 104 stores the MMTP payload generation unit 142 that stores the file in the MMTP payload, the payload storage unit 143 that stores the MMTP payload, and the MMTP payload stored in the payload storage unit 143 in the MMTP packet. It is provided with a transmission unit 146 that repeats transmission.
This eliminates the need to generate MMTP payloads with the same content each time they are repeatedly sent.

Further, the broadcasting equipment 11 (data transmission system) includes a data transmission device 104, a control message generation device 101 that transmits an MMTP packet storing a table that stores a path name of each file constituting the content, and a data transmission device 104. And a multiplexing device 105 that multiplexes the MMTP packet sent by the control message generation device 101.
As a result, the combination of the rate between the asset that transmits the file and the table that stores the path name of the file can be freely changed.

Further, a program for realizing the functions of the broadcasting equipment 11, the receiving device 12, the control message generating device 101, and the data transmitting device 104 in FIG. 1 is recorded on a computer-readable recording medium, and the recording medium is used. These devices may be realized by loading the recorded program into a computer system and executing it. The term "computer system" as used herein includes hardware such as an OS and peripheral devices.

In addition, the "computer system" includes a homepage providing environment (or display environment) if a WWW system is used.
Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system. Further, a "computer-readable recording medium" is a communication line for transmitting a program via a network such as the Internet or a communication line such as a telephone line, and dynamically holds the program for a short period of time. In that case, it also includes the one that holds the program for a certain period of time, such as the volatile memory inside the computer system that becomes the server or client. Further, the above-mentioned program may be a program for realizing a part of the above-mentioned functions, and may be a program for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within a range not deviating from the gist of the present invention are also included.

10 ... Content transmission system, 11 ... Broadcasting equipment, 12 ... Receiver device, 13 ... Output device, 101 ... Control message generator, 102 ... Video transmission device, 103 ... Voice transmission device, 104 ... Data transmission device, 105 ... Multiplexing device , 106 ... distribution device, 111 ... directory management table generation unit, 112 ... asset management table generation unit, 113 ... data transmission message generation unit, 141 ... file acquisition unit, 142 ... MMTP payload generation unit, 143 ... payload storage unit 144. ... MMTP packet generation unit, 145 ... data asset transmission unit, 146 ... transmission unit, 201 ... broadcast reception unit, 202 ... separation unit, 203 ... designation acquisition unit, 204 ... reception control unit, 205 ... control message processing unit, 206 ... Video decoding unit, 207 ... Audio decoding unit, 208 ... Data rendering unit, 209 ... Video synthesis unit, 210 ... Audio synthesis unit, 211 ... File restoration unit

Claims (4)

A data transmission device that acquires files that make up the content and repeatedly sends out MMTP packets that store the files that make up the content.
A control message generator that sends out an MMTP packet that stores a table that stores a path name and item ID for each of the files that make up the content.
It includes a multiplexing device that multiplexes the MMTP packet sent by the data sending device and the MMTP packet sent by the control message generating device.
The packet ID of the MMTP packet that stores the files that make up the content is different from the packet ID of the MMTP packet that stores the table.
The table is a data transmission system characterized by being a data asset management table. The data transmission device
A file acquisition unit that acquires the files that make up the content, and
An MMTP payload generation unit that stores the file acquired by the file acquisition unit in the MMTP payload, and
A payload storage unit that stores the MMTP payload and
The data transmission system according to claim 1, further comprising a transmission unit that repeatedly stores and transmits the MMTP payload stored in the payload storage unit in an MMTP packet. A receiver that receives MMTP packets that are repeatedly sent and stores files that make up the content, and MMTP packets that store a table that stores the path name and item ID of each of the files that make up the content.
With reference to the table, a file restoration unit that restores a file with a desired path name from the MMTP packet received by the receiving unit is provided.
The packet ID of the MMTP packet that stores the files that make up the content is different from the packet ID of the MMTP packet that stores the table.
The receiving device is characterized in that the table is a data asset management table. Computer,
A receiver that receives MMTP packets that are repeatedly sent and stores files that make up the content, and MMTP packets that store the table that stores the path name and item ID of each of the files that make up the content.
A program for functioning as a file restoration unit that restores a file with a desired path name from an MMTP packet received by the reception unit with reference to the table.
The packet ID of the MMTP packet that stores the files that make up the content is different from the packet ID of the MMTP packet that stores the table.
The table is a program characterized by being a data asset management table.

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