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

Abstract

To send or receive information to display over a picture of a broadcast program.SOLUTION: Information on the number of objects displayed in a screen at one time of pieces of display data or of objects is described in one mobile object list description document. The information on the display data / objects is made of the size and the position of the display data / objects on the screen and information of the display data or of where the display data is acquired. After that, the mobile object list description document and display data of the display data object to is to be referred to are made into a package and are sent intermittently as a general data stream with a time stamp showing the time of display of the package unit.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a transmitting device and a transmitting method for transmitting information to be overlaid on the video of a broadcast program, and a receiving device and a receiving method for receiving and displaying information to be overlaid on the video of a broadcast program. [Background technology]

[0002] Digital broadcasting services that use MPEG2-TS as the media transport method are being operated in countries around the world. In addition, a change from MPEG2-TS to the MMT (MPEG Media Transport) method is being considered for the next generation of digital broadcasting standards (see, for example, Patent Document 1). The MMT method is easy to use in combination with different transmission paths, and can be used commonly for multiple transmission paths for broadcasting and communication.

[0003] In digital broadcasting, a data broadcasting application can be transmitted over the airwaves, and various information linked to the broadcast program currently on air can be provided through the data broadcasting application. For example, a broadcasting system has been proposed that broadcasts annotation data to be displayed in the video frame along with the video data of the program (see, for example, Patent Document 2).

[0004] Also, a broadcasting system has been proposed that provides navigation information reflecting the contents of the video for each arbitrary section of a broadcast program. The navigation information represents hyperlinks to other content, buttons, text information, etc. For example, in a broadcasting program that provides a guide to world travel, multiple pieces of navigation information are provided that represent a menu of multiple buttons and supplementary explanations according to the country being introduced (for example, see Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-200054 A [Patent Document 2] Special Publication No. 2004-500770 [Patent Document 3] JP 2001-359090 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the technology disclosed in this specification is to provide an excellent transmitting device and transmitting method capable of transmitting information to be overlaid and displayed on the video of a broadcast program.

[0007] A further object of the technology disclosed in this specification is to provide an excellent receiving device and receiving method that are capable of receiving and displaying information that is overlaid on the image of a broadcast program. [Means for solving the problem]

[0008] The technology disclosed in this specification has been made in consideration of the above problems, and a first aspect of the technology is: A transmitting unit that transmits a broadcast signal including a video; a data transmission unit that transmits data for displaying an object that moves in synchronization with the movement of the video; A transmitting device comprising:

[0009] According to a second aspect of the technology disclosed in this specification, the data transmission unit of the transmitting device relating to the first aspect is configured to transmit the data including information regarding the position and size of the object on the screen and display data of the object.

[0010] According to a third aspect of the technology disclosed in this specification, the data transmission unit of the transmitting device relating to the first aspect is configured to intermittently transmit the data together with a timestamp indicating the display time of the data.

[0011] According to a fourth aspect of the technology disclosed in this specification, the data transmission unit of the transmission device relating to the first aspect is configured to intermittently transmit the data, including interpolation information for determining an interpolation position of the object until the next timing.

[0012] According to a fifth aspect of the technology disclosed in this specification, the data transmission unit of the transmission device relating to the fourth aspect is configured to transmit the interpolation information including at least one of velocity vector information or angular velocity information of the object.

[0013] According to a sixth aspect of the technology disclosed in this specification, the data transmission unit of the transmission device relating to the first aspect is configured to transmit the data including link destination information of the object.

[0014] According to a seventh aspect of the technology disclosed in this specification, the data transmission unit of the transmission device relating to the first aspect is configured to transmit a document file describing, in a predetermined format, the position and size of the object on the screen and a reference destination of the display data.

[0015] According to an eighth aspect of the technology disclosed in this specification, the data transmission unit of the transmitting device relating to the seventh aspect is configured to package the document file and a file of display data referenced by the document file, and transmit them in package units.

[0016] According to a ninth aspect of the technology disclosed in this specification, the data transmission unit of the transmitting device relating to the eighth aspect is configured to specify whether or not each display data to be included in the package needs to be retained and a retention period, and then transmit the data.

[0017] According to a tenth aspect of the technology disclosed in this specification, the data transmission unit of the transmitting device relating to the ninth aspect is configured to further transmit the document file that references a file of display data that was packaged and transmitted together with other document files.

[0018] In addition, a technique according to an eleventh aspect of the technique disclosed in this specification is A transmitting step of transmitting a broadcast signal including a video; a data transmission step of transmitting data for displaying an object that moves in synchronization with the movement of the video; It is a transmission method having the following structure.

[0019] In addition, a technology according to a twelfth aspect of the technology disclosed in this specification is A receiving unit for receiving a broadcast signal including a video signal; a data receiving unit for receiving data for displaying an object that moves in synchronization with the movement of the image; a control unit that executes a process for displaying the object on a broadcast video screen based on the received data; The receiving device is provided with:

[0020] According to a thirteenth aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the twelfth aspect receives the data including information regarding the position and size of the object on the screen and display data of the object, and the control unit is configured to display the display data of the object at the position and size on the screen specified by the data.

[0021] According to a 14th aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the 12th aspect is configured to intermittently receive the data together with a timestamp indicating the display time of the data, and the control unit is configured to control the display timing of the object based on the display time specified by the timestamp.

[0022] According to a fifteenth aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the fourteenth aspect is configured to intermittently receive the data including interpolation information for determining an interpolation position of the object until the next timing, and the control unit is configured to display the object at the interpolation position determined based on the interpolation information.

[0023] According to a sixteenth aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the twelfth aspect is configured to receive a document file that describes, in a predetermined format, the position and size of the object on the screen and a reference destination of the display data.

[0024] According to a 17th aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the 16th aspect is configured to receive in package units consisting of the document file and a file of display data referenced by the document file.

[0025] According to an 18th aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the 17th aspect receives the package in which the need to retain each display data and a retention period are specified, and the control unit is configured to retain the display data until the retention period has elapsed.

[0026] According to a 19th aspect of the technology disclosed in this specification, the data receiving unit of the receiving device relating to the 18th aspect further receives the document file that references a file of display data packaged and transmitted together with other document files, and the control unit is configured to display an object using the display data packaged and transmitted together with other document files, which is referenced by the document file.

[0027] In addition, a technology according to a twentieth aspect of the technology disclosed in this specification is A receiving step of receiving a broadcast signal including a video; a data receiving step of receiving data for displaying an object that moves in synchronization with the movement of the image; a control step of executing a process for displaying the object on a screen of a broadcast video based on the received data; The receiving method has the following features. Effect of the Invention

[0028] The technology disclosed in this specification makes it possible to provide an excellent transmission device and transmission method that can transmit display information of an object that is overlaid in accordance with the movement of the image in a broadcast program in time synchronization with the image.

[0029] Furthermore, according to the technology disclosed in this specification, it is possible to provide an excellent receiving device and receiving method that can receive object display information in time synchronization with a broadcast signal and overlay-display the object in accordance with the movement of the image.

[0030] It should be noted that the effects described in this specification are merely examples, and the effects of the present invention are not limited thereto. Furthermore, the present invention may have additional effects in addition to the effects described above.

[0031] Further objects, features and advantages of the technology disclosed in this specification will become apparent from the following detailed description based on the embodiments and the accompanying drawings. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a diagram showing a schematic configuration example of a digital broadcasting system 10. As shown in FIG. [Diagram 2] FIG. 2 is a diagram showing a protocol stack 200 in a digital broadcasting system 10 that uses the MMT method. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of the broadcast transmission system 11. As shown in FIG. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of a receiver 12 that receives a broadcast signal from a broadcast transmission system 11. [Diagram 5] FIG. 5 is a diagram showing an image of a broadcast signal 500 transmitted in accordance with the MMT method. [Figure 6] FIG. 6 is a diagram showing a mechanism for specifying each asset related to a broadcasting service from an MP table in a PA message. [Figure 7] FIG. 7 is a diagram showing an example syntax 700 of an MP table. [Figure 8] FIG. 8 is a diagram illustrating an example syntax 800 for an MPU timestamp descriptor. [Figure 9] FIG. 9 is a diagram for explaining a mechanism for acquiring files related to data broadcasting transmitted by MMT. [Figure 10] FIG. 10 is a diagram showing the configuration of the MPU and MFU of the general-purpose data. [Figure 11] FIG. 11 is a diagram showing an example syntax 1100 of the MFU of general-purpose data. [Figure 12] FIG. 12 is a diagram showing a display example of a broadcast screen on which a display object synchronized with the video of a broadcast program is displayed. [Figure 13] FIG. 13 is a diagram showing an example of the configuration of an MPU that transmits a general-purpose data stream in which a moving object list description document and display data are packaged. [Figure 14] FIG. 14 is a diagram showing a display example of the display object described by the moving object list description document shown in FIG. [Figure 15] FIG. 15 is a diagram showing an example of the configuration of an MPU that does not include display data and is composed only of an MFU for a moved object list description document. [Figure 16] FIG. 16 is a diagram showing an example syntax 1600 of additional information (mold_info) in an MFU that transmits a moved object list description document. [Figure 17] FIG. 17 is a diagram showing a syntax example 1700 of additional information (material_info) in an MFU that transmits material (display data). [Figure 18] FIG. 18 is a diagram showing an example syntax 1800 of a moving object list description document. [Figure 19] FIG. 19 is a diagram for explaining a mechanism for interpolating the display position of a display object based on the interpolation information. [Figure 20] FIG. 20 illustrates a scenario in which a moved object list description document is transmitted in a generic data stream. [Figure 21] FIG. 21 is a flowchart showing the processing steps performed when the receiver receives a general-purpose data stream. [Figure 22] FIG. 22 is a flowchart showing a processing procedure for a receiver to overlay and display a display object synchronized with a video based on a generic data stream. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, embodiments of the technology disclosed in this specification will be described in detail with reference to the drawings.

[0034] A. System Configuration 1 shows a schematic configuration example of a digital broadcasting system 10. The illustrated digital broadcasting system 10 is made up of a broadcast transmission system 11 and a receiver 12.

[0035] The broadcast transmission system 11 applies the MMT method to the transmission of broadcast signals, and transmits each component constituting a broadcast service as an IP (Internet Protocol) packet. Specifically, the broadcast transmission system 11 loads the codes of the video and audio signals of the broadcast program, as well as the signals of the contents (such as a data broadcasting application) and subtitles related to the broadcast program, on the MMTP (MMT Protocol) payload to packetize them as MMTP packets, further packetize them as IP packets, and transmit them in the form of TLV (Type Length Value) packets on the broadcast transmission path. Here, the components related to the main body of the broadcast program, such as the video, audio, and subtitles, are synchronous (Timed) media. Moreover, the contents, that is, the data broadcasting application encoded in the HTML (Hyper Text Transfer Protocol) 5 format, are asynchronous (Non-Timed) media.

[0036] The broadcast transmission system 11 also performs signaling (notification) of MMT-SI, which is control information related to broadcast services that transmit synchronous and asynchronous media. MMT-SI includes messages, tables, and descriptors. Tables are transmitted as containers for messages. Some of the parameters indicated in messages and tables are written in the form of descriptors.

[0037] Meanwhile, the receiver 12 receives TLV packets sent from the broadcast transmission system 11 through the broadcast transmission path. The receiver 12 decodes the synchronous transmission media constituting the broadcast program, such as video, audio, and subtitles, from the received packets, and presents the images, audio, and subtitles. Furthermore, when the receiver 12 obtains each data file for data broadcasting from the received packets, it starts an application engine such as an HTML browser, and displays the data broadcasting linked to the broadcast program in a part or all of the area of ​​the screen that displays the video of the TV program.

[0038] The receiver 12 also receives MMT-SI, which is control information related to broadcast services. Based on the MMT-SI, the receiver 12 controls the reception of transmission media such as video, audio, subtitles, and data broadcasting, and controls the output (display, audio output) on the receiver 12.

[0039] FIG. 2 shows a protocol stack 200 in a digital broadcasting system 10 that uses the MMT method.

[0040] One broadcast service is made up of the following components: video 201, audio 202, subtitles 203, application 204, and content download 205. The video 201 is encoded 211 in HEVC (High Efficiency Video Coding) format, the audio 202 is encoded 212 in AAC (Advanced Audio Coding) format, and the subtitles 203 are subtitle encoded 213. The application 204 includes an EPG (Electric Program Guide), which is encoded 214 in, for example, HTML5 format.

[0041] On the MMT layer 220, the encoding components 211 and 212 of the video signal and audio signal of the broadcast program are treated as MFUs (Media Fragment Units) and MPUs (Media Processing Units), and are placed on the MMTP payload to be MMTP packetized. In addition, the encoding components 213 and 214 of the subtitle signal of the broadcast program and the application (data and content) related to the broadcast program are treated as MFUs and MPUs, and are placed on the MMTP payload to be MMTP packetized. In addition, the MMT-SI 221, which is control information (indicating the configuration of the broadcast program, etc.) related to the media transport method MMT, is also placed on the MMTP payload to be MMTP packetized. Details of the control information MMT-SI related to MMT will be described later. The MPU is the unit of processing, and the MFU is a smaller unit than the MPU. The data transmission method 215 of the content download 205 includes four types: the subtitle and text superimposition transmission method, the application transmission method, the event message transmission method, and the general-purpose data transmission method. Of these, the application transmission method is used for a data transmission service that is asynchronous with the broadcast program. In addition, the general-purpose data transmission method is a method for transmitting various types of data synchronously or asynchronously, and can be applied to streaming data used in players that present data other than video, audio, and subtitles, and data used in multimedia services.

[0042] In the UDP (User Datagram Protocol) / IP layer 530, the MMTP packets are IP packetized. In addition, the NTP (Network Time Protocol) packets 206, which contain information on the current time for synchronous media, are also IP packetized. Furthermore, these IP packets are TLV packetized in the TLV layer 240, and transmitted over the broadcast transmission path 250, which is the lowest physical layer. In addition, the TLV-SI 241, which relates to the TLV multiplexing format for multiplexing IP packets, is also TLV packetized, and transmitted over the broadcast transmission path 250. The transmission slot into which the TLV packets are multiplexed is identified by the TLV stream identification information (TLV_stream_id) from the TMCC (Transmission and Multiplexing Configuration Control) signal 251 of the transmission path.

[0043] Fig. 3 shows an example of the configuration of a broadcast transmission system 11 that transmits a broadcast signal having a protocol stack structure as shown in Fig. 2. The illustrated broadcast transmission system 11 includes a clock unit 301, a signal transmission unit 302, a video encoder 303, an audio encoder 304, a subtitle / text encoder 305, a signaling encoder 306, a file encoder 307, an electronic data processing system (EDPS) 308, a TLV signaling encoder 309, an IP service multiplexer (MUX) 310, a TLV multiplexer (MUX) 311, and a modulation and transmission unit 312.

[0044] The clock unit 301 generates time information synchronized with time information obtained from an NTP server (not shown), and sends an IP packet including this time information to the IP service multiplexer 310 .

[0045] The signal sending unit 302 is, for example, a recording and playback device such as a TV broadcasting studio or a VTR, and sends stream data such as video, audio, subtitles, and superimposed text, which are synchronous media, to a video encoder 303, an audio encoder 304, and a subtitle / superimposed text encoder 305. The signal sending unit 302 also sends a data broadcasting application, which is asynchronous media, and synchronous and asynchronous general-purpose data to a file encoder 307.

[0046] The electronic data processing system 308 is a scheduler and file source for the TV broadcasting station. The electronic data processing system 308 sends data broadcasting applications, which are asynchronous media, and synchronous and asynchronous general-purpose data to the file encoder 307. The electronic data processing system 308 also sends control information indicating the configuration of the broadcasting service to the signaling encoder 306. The electronic data processing system 308 also sends control information related to multiplexing of IP packets to the TLV signaling encoder 309.

[0047] The video encoder 303 HEVC-encodes the video signal sent from the signal sending unit 302, further packetizes the signal, and sends IP packets including MMT packets of the video signal to the IP service multiplexer 310. The audio encoder 304 AAC-encodes the audio signal sent from the signal sending unit 302, further packetizes the signal, and sends IP packets including MMT packets of the audio signal to the IP service multiplexer 310. The subtitle / text encoder 305 encodes the subtitle signal and text signal sent from the signal sending unit 302, and further generates an MPU for each presentation process, and sends IP packets including MMT packets of the subtitles to the IP service multiplexer 310.

[0048] When the broadcast transmission system 11 transmits multiple broadcast services, HEVC encoding of the video signal, AAC encoding of the audio signal, and encoding of the subtitles / superimposed characters are performed for each broadcast service, and the signals are sent to IP service multiplexers 310-1, ..., 310-N corresponding to each broadcast service #1 to #N.

[0049] The signaling encoder 306 generates control information (MMT-SI) indicating the configuration of the broadcast signal based on information sent from the electronic data processing system 308, and sends IP packets including MMT packets in which MMT-SI is placed in the payload section to the IP service multiplexer 310. The MMT-SI includes messages, tables, and descriptors (described above). The signaling encoder 306 generates MMT-SI for each broadcast service, as well as MMT-SI across broadcast services.

[0050] The file encoder 307 encodes the HTML5 format data broadcasting application sent from the signal sending unit 3102 or the electronic data processing system 308, or general-purpose data used in the data broadcasting application, and further packetizes it, and sends the IP packet including this MMT packet to the IP service multiplexer 310.

[0051] The broadcast transmission system 11 is equipped with a plurality of IP service multiplexers 310-1, ..., 310-N for each broadcast service (broadcast channel) #1 to #N to be transmitted. The IP service multiplexer 310 for each broadcast service channel multiplexes IP packets including video, audio, subtitles, (broadcast service unit) MMT-SI, data broadcast application, and general-purpose data transmitted from each encoder 303 to 307, and generates a broadcast signal for each broadcast service as well as a TLV packet including MMT-SI across broadcast services.

[0052] The TLV signaling encoder 309 generates a TLV packet in which the control information (TLV-SI) related to the multiplexing of the above IP packets is placed in the payload section based on the information sent from the electronic data processing system 308 .

[0053] The TLV multiplexer 311 multiplexes the TLV packets generated by each of the IP service multiplexers 310-1 to 310-N and the TLV signaling encoder 309, and generates a TLV stream identified by the TLV stream identification information.

[0054] The modulation / transmission unit 312 performs RF modulation processing on the TLV stream generated by the TLV multiplexer 311 and sends it out to a broadcast transmission path.

[0055] The operation of the broadcast transmission system 11 shown in FIG. 3 will now be described.

[0056] The video signal sent from the signal sending unit 302 is supplied to the video encoder 303. In the video encoder 303, the video signal is HEVC encoded and further packetized to generate IP packets including MMT packets of the HEVC encoded video signal. The IP packets are sent to the IP service multiplexer 310.

[0057] Similar processing is also performed on the audio signal and the subtitle and superimpose signals sent from the signal sending unit 302. That is, IP packets including MMT packets of the AAC encoded audio signal generated by the audio encoder 304 are sent to the IP service multiplexer 310, and IP packets including MMT packets of the subtitle encoded signal generated by the subtitle / superimpose encoder 305 are sent to the IP service multiplexer 310.

[0058] The signaling encoder 306 also generates control information (MMT-SI) indicating the configuration of the broadcast signal based on information sent from the electronic data processing system 308, and generates IP packets including MMT packets in which the MMT-SI is placed in the payload section. These IP packets are sent to the IP service multiplexer 310.

[0059] Furthermore, the data broadcasting application sent from the signal sending unit 302 or the electronic data processing system 308 and general-purpose data used in the data broadcasting application are supplied to a file encoder 307. In the file encoder 307, the data broadcasting application and general-purpose data in HTML5 format are encoded and further packetized to generate IP packets including the MMT packets. These IP packets are sent to an IP service multiplexer 310.

[0060] In each IP service multiplexer 310-1, ..., 310-N, IP packets including video, audio, subtitles, MMT-SI (for each broadcasting service and across services), data broadcasting applications (HTML5 documents), and general-purpose data sent from each encoder 303 to 307 are multiplexed to generate TLV packets that make up one channel.

[0061] In the TLV signaling encoder 309, based on the information sent from the electronic data processing system 308, a TLV packet is generated in which the control information (TLV-SI) related to the multiplexing of the above IP packets is placed in the payload section.

[0062] In the TLV multiplexer 311, the TLV packets generated by each of the IP service multiplexers 310-1 to 310-N and the TLV signaling encoder 309 are multiplexed to generate a TLV stream. In the modulation and transmission unit 312, an RF modulation process is performed on the TLV stream generated by the TLV multiplexer 311, and the RF modulated signal is sent to a broadcast transmission path.

[0063] 4 shows an example of the configuration of a receiver 12 that receives a broadcast signal from the broadcast transmission system 11. The illustrated receiver 12 includes a tuner / demodulation unit 401, an MMT demultiplexer (DEMUX) 402, a clock recovery unit 403, a video decoder 404, an audio decoder 405, a superimposed text decoder 406, a subtitle decoder 407, a multimedia (MM) cache 408, an SI cache 409, a broadcast system control unit 410, an application (App) engine 411, a communication interface (IF) 412, a scaler 414, and synthesis units 415-418.

[0064] The tuner / demodulator 401 selects and receives a broadcast signal, performs demodulation processing, and obtains a TLV stream. The MMT demultiplexer 402 performs demultiplexing processing and depacketization processing on this TLV stream. The demultiplexer 402 includes a packet filter 402-1 and an SI filter 402-2.

[0065] The packet filter 402-1 filters IP packets based on the TLV stream identification information and IP address, and further filters MMTP packets from the IP packets based on the information in the MMTP header, and distributes synchronous transmission media such as video, audio, superimposed text, and subtitles to the video decoder 404, audio decoder 405, superimposed text decoder 406, and subtitle decoder 407, respectively. The packet filter 402-1 also distributes each coding component of multimedia (data broadcasting application) and general-purpose data to the multimedia (MM) cache 408. The packet filter 402-1 also distributes MMTP packets carrying signaling information to the SI filter 402-2. The SI filter 402-2 then filters the signaling information SI and caches it in the SI cache 410.

[0066] The clock recovery unit 403 generates time information synchronized with the current time information contained in the NTP packets filtered by the packet filter 402-1 in the MMT demultiplexer 402, based on the current time information contained in the NTP packets filtered by the packet filter 402-1 in the MMT demultiplexer 402, and outputs this time information to the video decoder 404, audio decoder 405, subtitle decoder 406, and subtitle decoder 407 for decoding each synchronous transmission media.

[0067] The video decoder 404 decodes the encoded video signal obtained by the MMT demultiplexer 402 to obtain a baseband video signal. The audio decoder 405 decodes the encoded audio signal obtained by the MMT demultiplexer 402 to obtain a baseband audio signal. The subtitle decoder 406 and the subtitle decoder 407 decode the encoded subtitle signals obtained by the MMT demultiplexer 402 to obtain display signals for subtitles and subtitles, respectively.

[0068] The broadcasting system control unit 410 controls the broadcasting service reception operation of the entire receiver 12 based on the MMT-SI cached in the SI cache 409. For example, the broadcasting system control unit 410 analyzes the application execution control information (MH-AIT) included in the MMT-SI, and when it finds a data broadcasting application that has been instructed to be started, it instructs the application engine 411 to perform the data broadcasting presentation process.

[0069] The application engine 411 is, for example, an HTML browser, and processes data broadcasting applications (such as HTML5 documents) cached in the multimedia cache 408 to generate display signals and audio signals for data broadcasting. The application engine 411 can also obtain data files required for displaying data broadcasting (such as media data used to display data broadcasting and linked applications) from the IP network via the communication interface 412.

[0070] In this embodiment, it is assumed that generic data used in a data broadcasting application is streamed. The application engine 411 acquires the streamed generic data and reflects it in the display of the application.

[0071] The scaler 414 scales the video signal (broadcast video) decoded by the video decoder 404 in accordance with the screen size of the receiver 12 .

[0072] The synthesis unit 415 synthesizes the audio signal decoded by the audio decoder 405 and the audio signal for data broadcasting reproduced by the application engine 411 to generate an audio signal for output.

[0073] The synthesis unit 416 synthesizes the superimposed text decoded by the superimposed text decoder 4206 and the subtitles decoded by the subtitle decoder 407. The synthesis unit 417 also synthesizes the broadcast video scaled by the scaler 414 and the display signal of the data broadcast generated by the application engine 411. The synthesis unit 418 at the subsequent stage further synthesizes the broadcast video on which the display of the data broadcast is superimposed and the superimposed text and subtitles output from the synthesis unit 416 to generate a video signal for output.

[0074] The operation of the receiver 12 shown in FIG. 4 will now be described.

[0075] The tuner / demodulator 401 receives a broadcast signal and performs demodulation processing to obtain a TLV stream. The MMT demultiplexer 402 performs demultiplexing and packetization processing on this TLV stream, extracting NTP time information, video, audio, superimposed text and subtitles, data broadcasting application, and each coded signal of general-purpose data, as well as signaling information, and distributes them to the video decoder 404, audio decoder 405, superimposed text decoder 406, subtitle decoder 407, multimedia (MM) cache 408, and SI filter 402-1, respectively.

[0076] Also, the NTP packets extracted by the demultiplexer 402 are distributed to a clock recovery unit 403. Based on the time information carried in the NTP packet, the clock recovery unit 403 generates time information synchronized with this time information. In other words, the clock recovery unit 403 generates time information that matches the time information generated by the clock unit 401 on the broadcast transmission system 11 side. The generated time information is output to a video decoder 404, an audio decoder 405, a text decoder 406, and a subtitle decoder 407 for decoding each synchronous transmission media.

[0077] The encoded video signal extracted by the MMT demultiplexer 402 is sent to a video decoder 404 where it is decoded to obtain a baseband video signal. The encoded subtitle signal extracted by the demultiplexer 402 is sent to a subtitle decoder 406 where it is decoded to obtain a subtitle display signal. The encoded subtitle signal extracted by the demultiplexer 402 is sent to a subtitle decoder 407 where it is decoded to obtain a subtitle display signal.

[0078] The broadcasting system control unit 410 controls the overall reception processing operation of the receiver 12, including processing of the data broadcasting application, based on the MMT-SI received via the SI filter 402-2 and the SI cache 409.

[0079] The application engine 411 processes the data broadcasting application (such as HTML5 document) cached in the multimedia cache 408, and generates the display signal and audio signal of the data broadcasting. In this embodiment, it is assumed that generic data used in the data broadcasting application is streamed. The application engine 411 reflects the acquired generic data in the display of the application.

[0080] The scaler 414 performs scaling processing on the video signal (broadcast video) decoded by the video decoder 404. The synthesizer 416 synthesizes the superimposed text decoded by the superimposed text decoder 406 and the subtitles decoded by the subtitle decoder 407. The synthesizer 417 then synthesizes the broadcast video scaled by the scaler 414 with the display signal of the data broadcast generated by the application engine 411. The synthesizer 418 at the subsequent stage further synthesizes the broadcast video on which the data broadcast display is superimposed with the superimposed text and subtitles output from the synthesizer 416 to generate a video signal for output.

[0081] Furthermore, the synthesis unit 415 synthesizes the audio signal decoded by the audio decoder 405 and the audio signal for data broadcasting reproduced by the application engine 411 to generate an audio signal for output.

[0082] B. Broadcast Signal Configuration FIG. 5 shows an image of a broadcast signal 500 transmitted from the broadcast transmission system 11 to the receiver 12 via a broadcast transmission path in accordance with the MMT method.

[0083] A broadcast signal is composed of synchronous media related to the main broadcast program such as video, audio, and subtitles, and asynchronous media such as data broadcasting applications. With the MMT method, it is easy to use these synchronous and asynchronous media in combination with different transmission paths. In the example shown in Fig. 5, MMT transmission paths 501 to 506 are used for broadcast signal 500, one for each type of data, such as video, audio, subtitles, data broadcasting applications, general-purpose data, and control information related to broadcasting services (MMT-SI).

[0084] In each MMT transmission path, the encoded media data is converted to MPU format, packetized as MMTP packets, and transmitted in IP packets. Each MMT transmission path corresponds to one IP data flow. An IP data flow here is a set of IP packets in which the values ​​of the five fields in the IP header and UDP header - source IP address, destination IP address, protocol type in the IP header, source port number, and destination port number - are all the same.

[0085] A broadcasting service is a package consisting of multiple components, such as video, audio, subtitles, and data broadcasting applications (however, one broadcasting service corresponds to one channel, i.e., one broadcast program). In the MMT transmission method, components are defined as "assets." Each asset is identified by its own asset identification information (asset_id). The asset identification information uniquely corresponds to the component tag that identifies the component (a video asset corresponds to the video component, an audio asset corresponds to the audio component, a subtitle asset corresponds to the subtitle component, and a data file asset for a data broadcasting application corresponds to the data file component).

[0086] Each asset is composed of a set (logical group) of one or more MPUs that share the same asset identification information. An MPU is a format that serves as a transmission unit in the MMT method, and is composed of one or more MFUs. MPUs are transmitted on an ES (Elementary Stream) dedicated to each asset, i.e., an MMT transmission path. Each MPU is identified by the asset identification information and the sequence number of the MPU on the corresponding transmission path.

[0087] In the example shown in Fig. 5, MMTP packets of encoded video signals consisting of MPU logical groups with common asset identification information for video signals are transmitted on transmission path 501. Similarly, MMT packets of encoded audio signals consisting of MPU logical groups with common asset identification information for audio signals are transmitted on transmission path 502, MMTP packets of encoded subtitle signals consisting of MPU groups with common asset identification information for subtitle signals are transmitted on transmission path 503, and MMTP packets of encoding applications consisting of MPU logical groups with common asset identification information for data broadcasting applications are transmitted on transmission paths 504-1 and 504-2. Also, on transmission path 505, MMTP packets of encoded general-purpose data signals consisting of MPU groups with common asset identification information are transmitted.

[0088] In some cases, multiple assets of the same type are transmitted within one package (broadcasting service). In the example shown in Fig. 5, assets of two data broadcasting applications are assigned different asset identification numbers and transmitted via dedicated ESs, i.e., MMT transmission paths 504-1 and 504-2. For example, one MMT transmission path 504-1 transmits assets of a program-linked data broadcasting application that is linked to a broadcast program, and the other MMT transmission path 504-2 transmits assets of a program-unlinked data broadcasting application that is not linked to a broadcast program (e.g., weather forecasts and news). It is also possible that assets of data broadcasting applications are provided independently from two or more delivery segments.

[0089] Moreover, the MMT method can share multiple transmission paths for broadcasting and communication. For example, asynchronous media such as data broadcasting (HTML5 documents, etc.) can be transmitted together with synchronous media of the same broadcasting service using transmission paths 504-1 and 504-2 of broadcast signal 500 as shown in Fig. 5, and can also be transmitted via a communication transmission path (not shown) such as an IP network.

[0090] In a broadcasting system using MMT, the transmission path 505 is used to transmit various data by a general-purpose data transmission method. The general-purpose data transmission can be used for streaming data for a data broadcasting application in HTML5 format.

[0091] The transmission path 506 is used for transmitting MMT-SI, which is signaling in the MMT system, that is, control information indicating the configuration of MMT packages and information related to broadcast services. In the transmission path 506, MMT messages including MMT-SI are packetized as MMTP packets and repeatedly transmitted by the carousel method. Note that the transmission path for TLV-SI is omitted in FIG. 5.

[0092] MMT-SI includes messages, tables, and descriptors. Messages transmitted over the transmission path 506 include a PA message 510, an M2 section message 520, and a data transmission message 530.

[0093] The PA message 510 is control information indicating the configuration of a broadcast program, and is a container for storing an MP (MMT Package) table 511 that describes information constituting a package, such as a list of assets and their locations.

[0094] The MP (MMT Package) table 511 is a table indicating basic reception control information for each broadcast service, and specifically, provides information constituting a package, such as a list of assets and asset location information. The MP table 511 also includes MPT descriptors such as application service descriptors. The application service descriptor indicates entry information of a data broadcasting application (for example, data transmission messages and entry information of each M2 section message that transmits an MH-AIT and an EMT). The MPU table 511 also includes an MPU timestamp descriptor that provides the presentation time of the MPU.

[0095] PA message 510 is an entry point for a broadcasting service, and fixed packet identification information (e.g., 0x0000) is assigned to the MMTP packet that transmits PA message 510. Therefore, on the receiver side, the fixed packet identification information can be directly specified on the MMT transmission path 506 to acquire PA message 510. Then, by referring to MP table 511 transmitted in PA message 510, each asset (video, audio, subtitles, data broadcasting application, general-purpose data) that constitutes a package (broadcast program) and other signaling messages can be indirectly specified.

[0096] Although omitted in FIG. 5, the tables stored in the PA message 510 include a PL (Package List) table (PLT) and an LC (Layout Configuration) table (LCT) in addition to the MP table. The PLT indicates a list of IP data flows and packet IDs that transmit the PA message of the MMT package provided as a broadcasting service, as well as IP data flows that transmit IP services. The LCT is used to associate layout information for presentation with layout numbers. The PA message is a container that can store up to three tables: the MP table, the PL table, and the LC table.

[0097] The M2 section message 520 is a message that transmits the section extension format of MPEG-2 Systems, and is a container that stores one signaling table in the section format. Tables such as an MH-AIT (Application Information Table) 521 and an EMT (Event Message Table) 522 are stored in the M2 section message 520.

[0098] MH-AIT521 is a table that specifies dynamic control information related to applications and additional information required for execution. Specifically, in an application information loop, MH-AIT521 indicates the processing method of each application controlled by the table in application_control_code, and places various application information descriptors that describe application information. Here, application_control_code indicates the processing method of an application, such as autostart (automatic start of application), present (application is in executable state), kill (application is terminated), and prefetch (acquisition and retention (pre-caching) of an application). In addition, a transmission protocol descriptor, which is one of the application information descriptors, specifies the transmission method of the application and location information corresponding to the transmission method (in the case of applications of HTTP / HTTPS and MMT asynchronous transmission, location information is commonly specified in URL (Uniform Resource Locator) format).

[0099] EMT522 is a signaling table used in the event message transmission method, and stores information (event message descriptors) about event messages (synchronous and asynchronous messages from a broadcasting station to applications on a receiver). The event message transmission method provides a means for a broadcasting station to send message information to a data broadcasting application running on a receiver, either immediately or at a specified time.

[0100] The data transmission message 530 is a message for transmitting control information related to the transmission of a data broadcasting application. The data transmission message 530 is a container that can simultaneously store up to three tables: a Data Directory Management Table (DDMT) 531, a Data Asset Management Table (DAMT) 532, and a Data Content Configuration Table (DCCT) 533. The Data Directory Management Table and the Data Asset Management Table are essential for the data broadcasting service, but the Data Content Management Table is optional.

[0101] Here, the data directory management table 531 is a table for managing data broadcasting applications on a directory basis (in other words, the production unit of a data broadcasting application). This table describes the directory structure of items contained in one package (directories and subdirectories and files contained in the directories), so that the file configuration of the application can be separated from the configuration for file transmission. This table shows the correspondence between the path names of each node, such as directories and files, and the node tags that identify each node in a data transmission message.

[0102] The data asset management table 532 is a table for managing data broadcasting applications on an asset basis, and describes the MPU configuration in the asset and the version information for each MPU. Specifically, the table shows the download identification information of each component, and the correspondence between the node tag that identifies the node (file or directory) included in each MPU that transmits the component in the data transmission message and the item identification information that identifies the node on the MMT transmission path.

[0103] Moreover, the data content management table 533 is a table for managing data broadcasting applications for each presentation unit (PU). This table shows presentation unit identification information for identifying a data broadcasting application for each presentation unit, and node tags for identifying nodes (files or directories) included in each presentation unit in a data transmission message. This table can also include linked presentation unit identification information for identifying presentation units linked to presentation units, and information regarding cache control for each presentation unit, and can be used for flexible and effective cache control of file data for data broadcasting applications on the receiver side.

[0104] In the data broadcasting application transmission method by MMT, by utilizing the above three types of signaling tables 531-533 transmitted in the data transmission message, it is possible to express the data structure of the usage unit such as application unit or presentation unit, independent of the transmission data structure of the file unit and the directory structure in the content (data broadcasting application) production. The configuration of each signaling table 531-533 is specified in ARIB STD B-60.

[0105] The packet identification information of messages and tables transmitted as MMT-SI may be fixed or indirectly specified from other tables. Among them, the PA message is the entry point of the broadcasting service, and is assigned fixed packet identification information (e.g., 0x0000). The MP table transmitted in the PA message indicates the asset identification information and location information of each asset (video, audio, subtitles, data broadcasting application, etc.) that constitutes the package (broadcast program). Therefore, the receiver side can directly specify the above fixed packet identification information on the MMT transmission path to obtain the PA message. Then, as shown in Figure 6, each asset (video, audio, subtitles, data broadcasting application, etc.) related to the broadcasting service and other signaling messages can be indirectly specified by referring to the MP table transmitted in the PA message. Note that the MP table places the MH-data encoding method descriptor in order to identify the data encoding method for each asset other than video and audio.

[0106] 7 shows an example of the syntax of an MP table 700. The meaning of each parameter of the MP table will be explained below.

[0107] table_id is an 8-bit fixed value (0x20) that identifies the table as an MP table. version is an 8-bit integer value that indicates the version number of the MP table. For example, if even some of the parameters (descriptors) that make up the MP table are updated, version is incremented by +1. length is a 32-bit parameter that indicates the size of the MP table in bytes, counted from immediately after this field. Additionally, MPT_mode indicates the behavior when this MP table is divided into subsets.

[0108] MMT_package_id_length indicates the size in bytes of the text information of the package identification information (MMT_package_id). In the following package identification information loop, MMT_package_id is indicated in bytes (MMT_package_id_byte). The package identification information is the identification information for the entire package, consisting of all signals (video, audio, subtitles) transmitted by the broadcast signal (IP data flow) as well as assets such as file data. This identification information is text information, and the upper 16 bits have the same value as the service identification information used to identify the service.

[0109] MPT_descriptor_length indicates the size of the MP table descriptor area in bytes. In the MP table descriptor loop, the contents of the MP table descriptor are described in bytes (MPT_descriptors_byte). The MPT descriptor describes basic information related to the reception control of the entire corresponding broadcasting service (package).

[0110] number_of_assets is an 8-bit parameter indicating the number of assets (signals, files) that make up a broadcasting service (package). There are as many asset information loops as there are number_of_asset. Within one asset information loop, the following parameters are placed as information about each asset: asset identification information (asset_id), general location information (MMT_general_location_info), and asset descriptor (asset_descriptor). The information placed within the asset information loop is explained below.

[0111] The identifier_type indicates the ID scheme of the MMTP packet flow. If the ID scheme indicates asset identification information (asset_id), set it to 0x00. The asset_id_scheme indicates the format of the asset identification information. The asset__id_length indicates the size of the text information of the asset identification information in bytes. In the following asset identification information loop, the asset identification information is indicated in bytes (asset_id_byte).

[0112] "asset_type" indicates the type of asset (video, audio, superimposed text / subtitles, application, etc.) as a 32-bit string. "asset_clock_relation_flag" is a flag indicating whether the asset has a clock information field. When the flag is 1, the clock information identification field (asset_clock_relation_id) and the timescale flag field (asset_timescale_flag) are present, and when the flag is 0, these fields are not present. "location_count" indicates the number of location information items for the asset, and in the subsequent location information loop that is repeated the same number of times as location_count, MMT_general_location_info, which is the location information for the corresponding asset, is indicated.

[0113] "asset_type" is a 32-bit string that indicates the type of asset (video, audio, superimposed text / subtitles, application, etc.). The types of assets represented by asset_type (character) are shown in Table 1 below.

[0114] [Table 1]

[0115] asset_clock_relation_flag is a flag indicating the presence or absence of the clock information field of the asset. When the flag is 1, the clock information identification field (asset_clock_relation_id) and the timescale flag field (asset_timescale_flag) are present, and when the flag is 0, these fields are not present. location_count indicates the number of location information of the asset, and in the subsequent location information loop repeated the number of times corresponding to location_count, MMT_general_location_info, which is the location information of the corresponding asset, is indicated. The location information of the asset is described in the form of packet identification information (packet_id: PID) on the MMT transmission path from which the asset is acquired. Therefore, by looking up the asset identification information on the MP table, the corresponding packet identification information on the MMT transmission path (IP data flow) can be extracted (see Figure 6).

[0116] asset_descriptor_length indicates the size of the text information of the asset descriptor (asset_descriptor) in bytes. In the asset descriptor loop indicated by reference number 701, the contents of the descriptor for each asset are indicated in bytes (asset_descriptors_byte). Examples of asset descriptors placed in the asset information loop (second loop of the MP table) include the "MH-data encoding method descriptor" used to identify the data encoding method, the "MPU timestamp descriptor" that provides the presentation time of the MPU, the "MPU extended timestamp descriptor" that provides the decoding time of the access unit in the MPU, the "asset group descriptor" that provides the group relationship of assets and the priority within the group, the "MPU presentation area designation descriptor" that provides the presentation position of the MPU, and the "dependency descriptor" that provides the asset ID of assets that have dependencies.

[0117] 8 shows an example syntax 800 of the MPU timestamp descriptor placed in the asset information loop of the MP table. The MPU timestamp descriptor indicates the presentation time of the first access unit in presentation order in the MPU. The meaning of each parameter of the MPU timestamp descriptor is explained below.

[0118] The descriptor_tag indicates an 8-bit fixed value that identifies the relevant descriptor 800. The descriptor_length is an 8-bit area in which the byte length of the data of the relevant descriptor that follows this field is written.

[0119] The mpu_sequence_number indicates the sequence number of the MPU that describes the timestamp in the descriptor. The mpu_presentation_time indicates the presentation time of the MPU indicated by the sequence number above in 64-bit NTP timestamp format.

[0120] In MH-AIT, the location information of each application is described in URL format, in other words, a path name consisting of a combination of a directory node name and a file name. On the other hand, the path name of an asset can be converted into identification information (packet identification information) on the MMT transmission path using the data directory management table and data asset management table transmitted in the data transmission message. With reference to Figure 9, we will briefly explain the mechanism for obtaining files related to data broadcasting transmitted via MMT.

[0121] The receiver can detect the application to be started (e.g., an application for which autostart is specified in the application control code) by referring to the application information loop in the MH-AIT transmitted in the M2 section message. The receiver can also obtain the location information of the application, i.e., the path name, from the transmission protocol descriptor placed in the MH-AIT. In the case of an application transmitted by broadcasting, the node tag of the file corresponding to the specified path name can be obtained from the data directory management table in the data transmission message, as shown by reference numeral 901.

[0122] Next, as shown by reference numeral 902, the component tag, download identification information, MPU sequence number, and item identification information of the data asset for which the item having the node tag obtained in the data directory management table is to be transmitted can be obtained from the data asset management table also in the data transmission message.

[0123] Furthermore, by obtaining location information of an asset having the component tag obtained in the data asset management table from the MP table, as shown by reference numeral 903, it is possible to identify the data asset to which the corresponding file is actually transmitted, as shown by reference numeral 904.

[0124] Then, within the identified data asset, the unit of repeated transmission of the file corresponding to the carousel can be uniquely identified by the download identification information obtained from the data asset management table and the download identification information written in the header field of the MMTP packet that transmits the item. As shown by reference numeral 905, among the repeatedly transmitted items, an item having the MPU sequence number and item identification information obtained from the data asset management table can be specified as the desired file.

[0125] C. Transmission of generic data streams The general-purpose data transmission method is a method for transmitting various types of data synchronously or asynchronously, and can be applied to streaming data used in players that present data other than video, audio, and subtitles, and data used in multimedia services. General-purpose data transmission can be used to transmit various types of data used in HTML5 format data broadcasting applications as streams. There is synchronous general-purpose data transmitted by a synchronous MPU, and asynchronous general-purpose data transmitted by an asynchronous MPU. The presentation time is indicated in the MPU of synchronous general-purpose data by the MPU timestamp descriptor (mentioned above).

[0126] In general-purpose data transmission processing, the MPU is the processing unit. The MPU contains data to be used at a certain timing, and is the unit that can perform processing such as presentation on an MPU basis. Figure 10 shows the configuration of the MPU and MFU for general-purpose data.

[0127] A generic data MPU does not contain MPU metadata or movie fragment metadata, and consists of one or more MFUs. Each MFU consists of a generic data header section and a data section. Data of any size can be stored in the data section of each MFU. For example, one file can be sent in one MFU.

[0128] 11 shows a syntax example 1100 of the MFU of generic data. The meaning of each parameter of the MFU of generic data will be explained below.

[0129] The component_tag is a label for identifying the component stream, and is written with the 16-bit value of the component tag that uniquely corresponds to the asset identification information of the generic data stream given by the MH-stream identification descriptor in the MP table.

[0130] The data_type_length indicates the length of the following data type description (data_type_byte) in bytes. The data_type_byte indicated by reference number 1101 is an area for storing the MIME (Multipurpose Internet Mail Extension) type of the data transmitted by the MFU.

[0131] The additional_info_length indicates the length of the following additional information description in bytes. The additional_info_byte indicated by reference number 1102 is an area for storing additional information related to the data transmitted by the MFU.

[0132] The data_length indicates the length of the data bytes of the subsequent generic data in bytes. The data_byte indicated by reference number 1103 is an area for storing generic data.

[0133] The component tag, data type, and additional information correspond to the generic data header section. The data_byte corresponds to the data section.

[0134] In this specification, as a use case of generic data, we propose a technology to transmit data for constantly changing display objects as a generic data stream to a data broadcasting application in HTML5 format. In the following, as one embodiment of the technology disclosed in this specification, we will explain in detail a technology to transmit control information for display objects as a generic data stream to a data broadcasting application that overlays display objects on the video of a broadcast program.

[0135] For example, if you want to display a display object that is synchronized with the video of a broadcast program, you can transmit the control information for the display object, which changes from moment to moment, in a synchronous general-purpose data stream that is time-synchronized with the video.Then, based on the control information received as the general-purpose data stream, the data broadcasting application can overlay the display object on the video in accordance with the movement of the video.

[0136] Fig. 12 shows an example of a broadcast screen displaying display objects synchronized with the video of a broadcast program. The figure shows a broadcast screen of a soccer game, in which "balloon"-shaped display objects showing information about the participating players (e.g., player names, positions, number of goals, etc.) are overlaid and displayed in accordance with the movements of each player.

[0137] 12 is merely one example of display object overlay display on a broadcast program screen. Similar display object overlay display can be applied to broadcast programs that broadcast various sports other than soccer, such as baseball, basketball, golf, track and field, judo, and car racing. Of course, similar display object overlay display can be applied to broadcast programs of various genres other than sports, such as dramas and music programs.

[0138] As a method of expressing information about display objects synchronized with video, for example, a Moving Object List Description (MOLD) document described below can be used. The Moving Object List Description document has a document structure that describes a list of information about display objects for the number of objects to be displayed on the screen at the same time. The Moving Object List Description document may describe, as information for each display object, the position and size of the display object on the screen, and the display data itself or information on where to obtain the display data (such as the data reference number or URL to be referenced).

[0139] The transmitting side (broadcasting station) packages the moving object list description document and the display data (image files) of the display objects referenced from it, and transmits them intermittently for broadcast as a general-purpose data stream together with a timestamp indicating the display time of each package.Then, the receiver side extracts information for drawing each display object from the moving object list description document, and is able to overlay the display objects synchronized with the video on the broadcast program screen based on the display time specified by the timestamp.

[0140] The timestamp information indicating the display time of each package can be indicated by the MPU timestamp descriptor that provides the presentation time of the MPU. The MPU timestamp descriptor is one of the asset descriptors 701 arranged in the second loop of the MP table. An example of the syntax of the MPU timestamp descriptor is shown in Fig. 8. The sequence number of the MPU that transmits the moving object list description document is specified by mpu_sequence_number, and the display time is specified by mpu_presentation_time.

[0141] In addition, as information about display objects, the moving object list description document also describes interpolation information for determining the interpolation position of each display object until the next timing. The interpolation information includes information for determining the interpolation position for each time into which the time until the next timing is divided. It is not realistic to transmit a general-purpose data stream for each video frame because of the large amount of information. By transmitting the general-purpose data stream intermittently and displaying the display object at the interpolation position determined based on the interpolation information described in the moving object list description document on the receiver side, the display object can be moved smoothly until the next timing. In the display example of the broadcast program shown in Figure 12, the display object can be overlaid by interpolation so as to smoothly follow the soccer player who is always moving around on the pitch.

[0142] For example, by describing the velocity vector information of a display object as the interpolation information, it becomes possible to linearly interpolate the interpolation position of the display object. Furthermore, by including angular velocity information, it becomes possible to curve-interpolate the interpolation position of the display object. The velocity vector and angular velocity can be found by analyzing the movement of the corresponding player.

[0143] Moreover, the URL information of a hyperlink may be described in the moved object list description document as information about the display object. When a viewer of the video operates a display object, the receiver can obtain and display information from the link destination specified based on the URL specified for the display object.

[0144] In addition, the display data of a display object commonly referenced by a plurality of moving object list description documents may be packaged with the first moving object list description document as a representative and transmitted, and may be commonly referenced by the moving object list description documents transmitted thereafter, instead of being packaged with the moving object list description document and transmitted every time. By transmitting generic data consisting of only the moving object list description document that references external display data, the amount of information transmitted can be reduced (i.e., the transmission bandwidth can be saved). If the display data is packaged with the moving object list description document and transmitted when it is updated, the effect of bandwidth saving can be enhanced. However, it is preferable to transmit generic data packaged with the display data at regular intervals so that the display object can be displayed even on a receiver that has tuned in during a program.

[0145] Furthermore, the above-mentioned general-purpose data stream may be transmitted intermittently at a constant cycle, or the transmission cycle may be variably controlled. For example, the transmission cycle of the general-purpose data stream may be controlled according to the movement of the display object. For example, if the movement of the display object is fast, the data may be transmitted at one-second intervals, making it easier to obtain a more accurate interpolation position of the display object. Conversely, if the movement of the display object is slow, the data may be transmitted at five-second intervals to reduce the amount of information transmitted (i.e., to save the transmission bandwidth).

[0146] FIG. 13 shows a schematic diagram of a moving object list description document that describes information about display objects for the number of objects, and a generic data stream structure that packages the display data referenced by the document.

[0147] This generic data stream is transmitted as a synchronous MPU. As already explained with reference to Fig. 10, in the processing of generic data transmission, the MPU is the processing unit, and the MPU is composed of multiple MFUs. When transmitting information about display objects as generic data, a moving object list description document and a package of display data referenced by the document are transmitted as a processing unit by one MPU.

[0148] In FIG. 13, reference numeral 1300 denotes an MPU that transmits one package, and stores a moved object list description document in the first MFU indicated by reference numeral 1310, and stores display data (image files) of each display object referenced from this moved object list description document in subsequent MFUs 1320-1, ..., 1320-N.

[0149] The moved object list description document stored in the data section of the first MFU 1310 consists of a list of information on display objects for the number of objects displayed on the screen, N. As shown in Fig. 14, when four display objects #1 to #4 are displayed on the screen simultaneously, N=4, and the moved object list description document lists information on the four display objects.

[0150] In the moving object list description document, the information block indicated by reference number 1311 contains, as information about display object #1, tag information (Tag) for identifying the display object, the position (Position) and size (Size) at which the display object is displayed on the screen, velocity vector information (Vector) and angular velocity information (θ) as interpolation information, and display data information (MediaData) of the display object. As described above, the information about the display object may further contain URL information of a hyperlink (omitted in FIG. 13). Although omitted for the sake of simplicity of the drawing, it should be understood that the other information blocks also describe similar information about the corresponding display objects.

[0151] The information on the display data of a display object (MediaData) can be expressed by the acquisition destination information of the display data (such as the data reference number or URL to be referenced). In the example shown in Fig. 13, it is assumed that the display data (image file) of the display object is also packaged with the moving object list description document, and the acquisition destination information such as a URL specifies the location information of the MFU that stores the corresponding image file, which is transmitted within the same MPU. Alternatively, the display data itself, i.e., the binary data, can be described in the information block of the moving object list description document.

[0152] Also, reference numeral 1330 denotes an MP table, which specifies asset identification information and location information for each asset (video, audio, subtitles, data broadcasting application, etc.) that constitutes a broadcast signal. An MPU timestamp descriptor 1331 arranged for an asset of a generic data stream in the second loop of this MP table specifies the presentation time of the MPU 1300. That is, the MPU timestamp descriptor 1331 specifies the sequence number of the MPU 1300 that transmits the moving object list description document by mpu_sequence_number, and specifies the presentation time by mpu_presentation_time.

[0153] FIG. 13 shows an example of the configuration of an MPU that packages and transmits a moved object list description document and display data referenced from the document, and the display data (image file) of each display object is transmitted in a subsequent MFU in the same MPU. As a variation of this, as shown in FIG. 15, an MPU that does not include display data and is composed only of an MFU for a moved object list description document is also assumed. Such a moved object list description document references display data transmitted in an MFU included in a preceding MPU. By packaging and transmitting display data commonly referenced by multiple moved object list description documents in only one moved object list description document, the amount of information transmitted can be reduced (i.e., transmission bandwidth can be saved). By introducing a mechanism for specifying the retention period of display data (described later), when the receiver receives an MPU that packages the display data, the display data is cached until the specified retention period, so that the display data can be referenced from a moved object list description document transmitted later until the retention period. When updating the display data, the updated display data and the packaged moved object list description document can be transmitted again. However, in order to enable a receiver that has tuned in midway through a program to display the display object, it is preferable to transmit the MPU in which the display data is packaged at regular intervals.

[0154] In addition, when realizing a similar function in a broadcasting system using the MPEG TS method instead of the MMT method, similar information can be transmitted in a Packetized Elementary Stream (PES) packet and the display time can be indicated by a Presentation TimeStamp (PTS).

[0155] 11 illustrates an example syntax 1100 for the generic data MFU. The use of each parameter of the MFU as applied to the transmission of a moving object list description document and the display data referenced therein is further described below.

[0156] The data_type_byte indicated by reference number 1101 specifies the type of data to be transmitted by the MFU in question, using a character string with a data length specified by data_type_length. The MFU in the MPU shown in Fig. 13 transmits either a Moved Object List Description document (MOLD) or an image file of display data. The data types specified by the character string in data_type_byte are shown in Table 2 below. In the case of a Moved Object List Description document, "mld" can be specified; in the case of JPEG format display data, "jpg" can be specified; and in the case of PNG format display data, "png" can be specified.

[0157] [Table 2]

[0158] In addition, in the additional information area (additional_info_byte) indicated by reference number 1102, additional information according to the data stored in the data section is described. That is, in the case of an MFU that transmits a moved object list description document, additional information for the moved object list description document is described. In addition, in the case of an MFU that transmits other than the above, that is, materials of display objects such as display data, additional information related to the materials is described in the additional information area.

[0159] The data section (data_byte) indicated by reference number 1103 stores the general-purpose data itself transmitted by the MFU. If the preceding parameter data_type_byte specifies "mld", i.e., a moving object list description document, the data section stores a moving object list description document file. If data_type_byte specifies "jpg" or "png", the data section stores a display data file in JPEG or PNG format.

[0160] 16 shows a syntax example 1600 of additional information (mold_info) in an MFU that transmits a moved object list description document. The meaning of each parameter of the additional information (mold_info) will be explained below.

[0161] The material_location is a 2-bit field that indicates the acquisition destination information of the display data referenced from the moved object list description document (i.e., stored in the data section). The meanings of the values ​​of material_location are shown in Table 3 below. When the display data is transmitted by the same MPU as the moved object list description document (see Figure 13), material_location is specified as 00. When the display data was transmitted by the previous MPU, material_location is specified as 01. When the display data is referenced on the Internet, material_location is specified as 10. When material_location is specified as 01 or 10, the display data is not packaged in the same MPU as the moved object list description document (see Figure 15), so the transmission bandwidth is saved. As will be described later, the MFU that transmits the display data can specify the retention period. Therefore, if the display data that has already been transmitted is within the retention period, material_location can be specified as 01.

[0162] [Table 3]

[0163] The estimaled_next_MPU_time indicates the estimated transmission time of the next MPU (transmitting the moving object list description document). The receiver interpolates the display position of the display object taking into account the estimated transmission time of the next MPU (see Figure 13).

[0164] 17 shows a syntax example 1700 of additional information (material_info) in an MFU that transmits material (display data) referenced from a moving object list description document. The meaning of each parameter of the additional information (material_info) will be explained below.

[0165] The material_name_length indicates the length of the subsequent material name description (material_name_byte) in bytes. The material_name_byte is an area that stores the material reference name used when referencing the material transmitted in the data part of the MFU from the movement object list description document.

[0166] The persistent_flag is a data retention flag that specifies whether the receiver should retain the display data (JPEG or PNG image file) stored in the data section (data_byte) of the MFU even after the processing of the MPU is completed. If the persistent_flag is set to 1, the expiration date for the display data stored in the data section of the MFU is described in the expire_date field.

[0167] The data retention flag and data retention period can be specified for each MFU, i.e., for each display data, in the general-purpose data header.

[0168] On the receiver side, display data with persistent_flag set to 1 in the general data header will continue to be retained (cached) for the retention period specified by expire_date, even after the processing by the MPU has finished. The retained display data can also be referenced (i.e., reused) from a Moved Object List Description document transmitted by a subsequent MPU. In short, the subsequent MPU no longer needs to package the display data referenced from the Moved Object List Description document and transmit it from the same MPU, thus saving transmission bandwidth.

[0169] Fig. 18 shows a syntax example 1800 of a moved object list description document. When "mld" is specified in the parameter data_type_byte in the general data header section of the MFU, a moved object list description document as shown in the figure is stored in the data section. In the figure, parameters with @ at the beginning are attribute information, and parameters without @ indicate elements. The meaning of each parameter is explained below.

[0170] "mold" indicates that the data is a moving object list description document. The information of moving objects "mo" is placed in the document for the number of objects to be displayed on the screen at the same time.

[0171] Each moving object mo is identified by an object tag. The moTag field contains the object tag as an attribute value.

[0172] The information for each moving object mo includes the object's position information (position), the object's size information (size), the object's motion vector information (mv), information about the object's display data (media), and link destination information (link) when operating the object.

[0173] The object position information (position) includes the horizontal coordinate x and vertical coordinate y of the object's display position on the screen (the upper left corner in the case of a rectangular area) as attribute values, each of which indicates a pixel position as an integer value.

[0174] The size information (size) of an object indicates the size of the object to be displayed on the screen, and includes the width x and height y of a rectangular area as attribute values, each of which is indicated by a pixel value (integer value).

[0175] The motion vector information (mv) of an object includes a velocity vector consisting of the horizontal velocity x and vertical velocity y of the object, and angular velocity information θ (when the object's movement is a curved motion represented by an arc) as attribute values, and integer values ​​indicating each are described. On the receiver side, the motion vector information (mv) can be used to find the interpolated position of the object until the timing of the next MPU (i.e., the next moving object list description document) (as described above).

[0176] The information about the display data (media) indicates the type of display data for the object (JPEG or PNG) and the information about the source of the display data for the object. The source of the display data is broadly classified as either within the same MPU, the previous MPU, or on the Internet, and is specified by the parameter material_location in the additional information (mold_info) of the general-purpose data header (described above). The information about the source of the display data specifies the source of the data at the location specified by material_location in URL format, and it is assumed that the destination specified by the URL contains an image file in the format specified by the type of display data. Note that if 0 is specified as the information about the source of the display data, the binary data of the display data may be stored in the type area of ​​the display data.

[0177] The link information (link) when operating an object specifies the link information of the object in URL format. When a video viewer operates a displayed object, information can be obtained and displayed from the link specified by the link information (link).

[0178] FIG. 19 illustrates a mechanism for interpolating the display position of a display object based on the interpolation information specified in a moving object list description document. Reference numeral 1901 indicates the display position (X1, Y1) of a display object specified in a moving object list description document transmitted at a certain timing T1. Reference numeral 1902 indicates the display position (X2, Y2) of the same display object specified in a moving object list description document transmitted at the next timing T2. Reference numerals 1911 to 1914 indicate the interpolation positions for each time period obtained by subdividing the time interval of the timing. In the moving object list description document transmitted at the timing T1, a velocity vector (x, y) and an angular velocity θ are specified as the interpolation information of this display object. Based on the velocity vector (x, y), it is possible to linearly interpolate the interpolation positions 1911, ... for each subdividing time period, and further, it is possible to perform curved interpolation of the interpolation positions 1911, ... based on the angular velocity θ.

[0179] An application engine 411 that executes an application for overlaying display objects on video sequentially acquires moving object list description documents transmitted in a general-purpose data stream, and performs interpolation based on the interpolation information, thereby enabling the display objects to move smoothly in accordance with the movement of the video.

[0180] Fig. 20 illustrates an example scenario in which a moved object list description document is transmitted in a generic data stream. In the figure, a broadcast signal transmitted from a broadcaster (broadcast station) is illustrated, with the horizontal axis representing the time axis. The broadcast signal includes a video asset 2010, an audio asset 2020, a data (application) asset 2030, and a generic data asset 2040 as components that make up a broadcast program. The broadcast signal may further include other assets, but these are omitted for simplicity of the drawing.

[0181] The broadcast signal also includes a control signal 2050 that transmits control information (MMT-SI), such as a signaling table such as an MP table, and a signaling message that serves as a container for the signaling table.

[0182] In the figure, the data asset 2030 transmits a data broadcasting application that overlays display objects on the video of a broadcast program, and the general-purpose data asset 2040 is assumed to transmit control information for the display objects, i.e., a moving object list description document, intermittently as a general-purpose data stream. The display time of each MPU transmitted by the general-purpose data asset 2040 is specified by the MPU timestamp descriptor in the MP table (as described above).

[0183] Reference number 2041 indicates an MPU that packages a moved object list description document and the display data (image file) of the display object referenced from the moved object list description document. The moved object list description document is stored in the data section of the first MFU, and the second and subsequent MFUs store one piece of display data referenced from the moved object list description document (see FIG. 13).

[0184] Also, reference number 2042 indicates an MPU that does not package display data. This MPU transmits only one MFU that stores a moved object list description document. This moved object list description document refers to display data that has already been transmitted by the preceding MPU 2041 (see FIG. 15). However, the referenced display data is assumed to be specified as data retention by persistent_flag in the general data header section of the MFU, and the data retention period specified by expire_date has not yet elapsed. Similarly, the MPU indicated by reference number 2043 transmits only the MFU of the moved object list description document. By packaging display data commonly referenced by multiple moved object list description documents into only one moved object list description document and transmitting it, the amount of information to be transmitted can be reduced (i.e., the transmission bandwidth can be saved).

[0185] Reference numeral 2044 denotes an MPU that packages a moved object list description document and the display data of the display object referenced from the moved object list description document. As with the MPU indicated by reference numeral 2041, the moved object list description document is stored in the data section of the first MFU, and the second and subsequent MFUs store each piece of display data referenced from the moved object list description document (same as above).

[0186] When the display data is updated, the MPU2044 including the updated display data and the packaged moved object list description document is transmitted again. Alternatively, in order to enable a receiver that has tuned in during a program to display the display object, the MPU2044 packaged with the display data is transmitted after a certain time has elapsed since the transmission of the MPU2041.

[0187] The MPU timestamp descriptor in the MP table indicated by reference number 2051 specifies the display time T10 of the display object according to the moving object list description document transmitted by the MPU indicated by reference number 2041. Similarly, the MPU timestamp descriptor in the MP table indicated by reference number 2052 specifies the display time T20 of the MPU indicated by reference number 2042, the MPU timestamp descriptor in the MP table indicated by reference number 2053 specifies the display time T30 of the MPU indicated by reference number 2043, and the MPU timestamp descriptor in the MP table indicated by reference number 2054 specifies the display time of the MPU indicated by reference number 2044.

[0188] On the receiver side, when MPU2041 transmitted via broadcast waves is received, the receiver analyzes the moving object list description document transmitted in the first MFU, and retains the display data transmitted in the second and subsequent MFUs for the retention period specified in the header.

[0189] Then, when the display time T10 specified by the MPU timestamp descriptor in the MP table 2051 arrives, the receiver overlays each display object on the broadcast program image, as shown by reference numeral 2061, in accordance with the contents of the moving object list description document received by the MPU 2041.

[0190] In addition, until the arrival of the next display time T20 specified for the MPU 2042, the receiver determines an interpolation position at time T11, which is a subdivision of the time interval, based on the interpolation information (velocity vector, angular velocity) specified for each display object in the moving object list description document, and updates the display of each display object, as shown by reference numeral 2062.

[0191] Thereafter, when the display time T20 specified by the MPU timestamp descriptor in the MP table 2052 arrives, the receiver overlays each display object on the broadcast program image by referring to the display data transmitted by the preceding MPU 2041, as shown by reference numeral 2063, in accordance with the contents of the moving object list description document received by the MPU 2042.

[0192] 21 is a flowchart showing the procedure for a receiver to receive a generic data stream. The procedure corresponds to the process for acquiring generic data received and decoded by the HTML browser (application engine 411).

[0193] When the receiver receives an MP table in a PA message, which is the entry point of a broadcast service, it checks whether an MPU timestamp descriptor of a general-purpose data asset exists (step S2101).

[0194] If an MPU timestamp descriptor is present in the general-purpose data asset (Yes in step S2101), the receiver stores the information of the MPU timestamp descriptor, that is, the MPU sequence number and its presentation time (step S2102).

[0195] Furthermore, when the receiver receives an MPU of a general-purpose data asset (Yes in step S2103), the receiver stores the general-purpose data MPU together with information of an MPU timestamp descriptor that specifies the MPU sequence number (step S2104).

[0196] Here, the receiver refers to material_location in the general-purpose data header section of the first MFU of the MPU (i.e., the MFU that transmits the Movement Object List Description Document). If material_location=10, that is, the display data acquisition destination is specified to be on the Internet (Yes in step S2105), the receiver acquires the display data (image file) of each display object based on the display data acquisition destination URL specified in the Movement Object List Description Document stored in the data section of that MFU (step S2106).

[0197] 22 is a flowchart showing a process for a receiver to overlay display objects synchronized with video based on a generic data stream. The process corresponds to a process for updating the display of a display object based on the latest generic data in an HTML browser (application engine 411).

[0198] Each time the display timing of a video frame arrives (Yes in step S2201), the receiver checks whether or not the timing matches the MPU presentation time specified in the stored MPU timestamp descriptor (step S2202).

[0199] Then, if the current display timing is the MPU presentation time specified by the stored MPU timestamp descriptor (Yes in step S2202), the receiver refers to the material data based on the description of the moved object list description document transmitted in the first MFU of the corresponding MPU, and overlays the display object on the video frame (step S2203).

[0200] The receiver also deletes display data that was packaged in an MPU received before the MPU of this presentation time, except for display data whose data retention flag (persistent_flag) is set to 1 (step S2204).

[0201] Furthermore, the receiver checks whether all of the display data being held is within its retention period (step S2205), and if there is any display data whose retention period has expired, it deletes it (step S2206).

[0202] Furthermore, if the current display timing is not the MPU presentation time specified by the stored MPU timestamp descriptor (No in step S2202), the receiver performs an interpolation calculation for the interpolated position at the current time for each display object listed in the moving object list description document of the MPU being processed based on the element information of the motion vector (mv) (i.e., velocity vector information and angular velocity information), and updates the display of the object (step S2207). [Industrial Applicability]

[0203] The technology disclosed in this specification has been described in detail above with reference to specific embodiments. However, it is obvious that a person skilled in the art can modify or substitute the embodiments without departing from the gist of the technology disclosed in this specification.

[0204] In this specification, the embodiment in which the technology disclosed in this specification is applied to a broadcasting system that adopts the MMT method for media transmission has been mainly described, but the gist of the technology disclosed in this specification is not limited to this. The technology disclosed in this specification can be similarly applied to various types of broadcasting systems equipped with a mechanism for streaming data used in data broadcasting applications. For example, to realize a similar function in an MPEG TS broadcasting system, it is sufficient to transmit similar information in a PES packet and indicate the display time with a PTS.

[0205] In short, the technology disclosed in this specification has been described in the form of examples, and the contents of the specification should not be interpreted in a limiting manner. In order to judge the gist of the technology disclosed in this specification, the claims should be taken into consideration.

[0206] The technology disclosed in this specification can also be configured as follows. (1) a transmitter for transmitting a broadcast signal including video; a data transmission unit that transmits data for displaying an object that moves in synchronization with the movement of the video; A transmitting device comprising: (2) the data transmission unit transmits the data including information regarding a position and a size of the object on the screen and display data of the object; A transmitting device as described in (1) above. (3) the data transmission unit intermittently transmits the data together with a time stamp indicating a display time of the data; A transmitting device according to any one of (1) or (2) above. (4) The data transmission unit intermittently transmits the data including interpolation information for determining an interpolation position of the object until the next timing. A transmitting device according to any one of (1) to (3) above. (5) The data transmission unit transmits the interpolation information including at least one of velocity vector information and angular velocity information of the object. The transmitting device according to (4) above. (6) The data transmission unit transmits the data including link destination information of the object. A transmitting device according to any one of (1) to (5) above. (7) the data transmission unit transmits a document file in which the position and size of the object on the screen and a reference destination of the display data are described in a predetermined format. A transmitting device as described in (1) above. (8) The data transmission unit packages the document file and a file of display data referenced by the document file, and transmits the package. The transmitting device according to (7) above. (9) The data transmission unit transmits the package by specifying whether or not each piece of display data to be included in the package needs to be retained and a retention period. The transmitting device according to (8) above. (10) The data transmission unit further transmits the document file that references a file of display data that has been packaged together with other document files and transmitted. The transmitting device according to (9) above. (11) a transmitting step of transmitting a broadcast signal including a video; a data transmission step of transmitting data for displaying an object that moves in synchronization with the movement of the video; A transmission method comprising: (12) a receiving unit for receiving a broadcast signal including a video; a data receiving unit for receiving data for displaying an object that moves in synchronization with the movement of the image; a control unit that executes a process for displaying the object on a broadcast video screen based on the received data; A receiving device comprising: (13) The data receiving unit receives the data including information regarding a position and a size of the object on the screen and display data of the object; the control unit causes the display data of the object to be displayed at a position and size on the screen designated by the data. The receiving device according to (12) above. (14) The data receiving unit intermittently receives the data together with a time stamp indicating a display time of the data; the control unit controls a display timing of the object based on a display time designated by the time stamp. A receiving device according to any one of (12) and (13) above. (15) The data receiving unit intermittently receives the data including interpolation information for determining an interpolation position of the object until a next timing, The control unit displays the object at an interpolation position determined based on the interpolation information. The receiving device according to (14) above. (16) The data receiving unit receives a document file describing the position and size of the object on the screen and a reference destination of the display data in a predetermined format. The receiving device according to (12) above. (17) The data receiving unit receives the document file and a display data file referenced by the document file in a package unit. The receiving device according to (16) above. (18) The data receiving unit receives the package in which the necessity of holding each piece of display data and a holding period are specified, The control unit holds the display data until the holding period has elapsed. The receiving device according to (17) above. (19) The data receiving unit further receives the document file that references a file of display data that is packaged together with other document files and transmitted; the control unit displays an object using display data that is packaged and transmitted together with other document files referenced by the document file; The receiving device according to (18) above. (20) a receiving step of receiving a broadcast signal including a video; a data receiving step of receiving data for displaying an object that moves in synchronization with the movement of the image; a control step of executing a process for displaying the object on a screen of a broadcast video based on the received data; A receiving method comprising: [Explanation of symbols]

[0207] 10... digital broadcasting system, 11... broadcast transmission system, 12... receiver 301: Clock section, 302: Signal sending section 303: Video Encoder, 304: Audio Encoder 305…Subtitle / Transcription Encoder 306: Signaling Encoder, 307: File Encoder 308...Electronic data processing systems; 309…TLV signaling encoder 310…IP service multiplexer 311: TLV multiplexer, 312: Modulation and transmission section 401: Tuner demodulation unit, 402: MMT demultiplexer 403: clock recovery unit, 404: video decoder 405...Audio decoder 406... Superimposed Text Decoder, 407... Subtitle Decoder 408...Multimedia cache, 409...SI cache 410: broadcasting system control unit, 411: application engine 412... communication interface, 414... scaler 415~418…Synthetic section

Claims

1. a transmitting step of transmitting a broadcast signal including an IP packetized video signal; a data transmission step of transmitting a document file described in a predetermined format for displaying the superimposed display data; having In the data transmission step, the document file is transmitted together with position information of the superimposed display data and interpolation information including information on an interpolation position of the superimposed display data at least one time until a timing at which the document file is next transmitted. Transmission method.

2. a transmitting unit for transmitting a broadcast signal including an IP packetized video signal; a data transmission unit that transmits a document file described in a predetermined format for displaying the superimposed display data; Equipped with the data transmission unit transmits the document file including position information of the superimposed display data and interpolation information including information on an interpolation position of the superimposed display data at least one time until a timing at which the document file is next transmitted. Transmitting device.

3. A receiving step of receiving a broadcast signal including an IP packetized video signal; a data receiving step of receiving a document file described in a predetermined format for displaying the superimposed display data; a control step of executing a process for displaying the superimposed display data on a screen based on the video signal, based on the received document file; having the document file includes position information of the superimposed display data and interpolation information including information on an interpolation position of the superimposed display data at least one time until the next timing of transmitting the document file; In the control step, the superimposed display data is displayed at an interpolated position determined based on the position information and the interpolation information. Receiving method.

4. A receiving unit that receives a broadcast signal including an IP packetized video signal; a data receiving unit for receiving a document file described in a predetermined format for displaying the superimposed display data; a control unit that executes a process for displaying the superimposed display data on a screen based on the video signal, based on the received document file; Equipped with the document file includes position information of the superimposed display data and interpolation information including information on an interpolation position of the superimposed display data at least one time until the next timing of transmitting the document file; the control unit causes the superimposed display data to be displayed at an interpolated position determined based on the position information and the interpolation information. Receiving device.

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