JP2022030209A - Metadata insertion device and program - Google Patents

Abstract

[Problem] To provide a metadata insertion device that can reduce delays in distribution of event data without reducing the segment length in data for video distribution. [Solution] The metadata insertion device includes a receiving unit and an event data insertion unit. The receiving unit receives video data encoded for HTTP streaming. The event data insertion unit inserts event metadata into any chunk of the received video data. The video data is composed of a plurality of segments. The chunk is a unit obtained by further dividing the segment. [Selected Figure] Figure 1

Description

The present invention relates to a metadata insertion device and a program.

In recent years, broadcasting stations have provided various Internet services for client devices such as televisions, personal computers (PCs), and smartphones (smartphones). In broadcasting services, broadcasting stations provide services such as breaking news in an emergency by using a trigger signal called an event message (EM). The event message is excellent in immediacy, and in general, the signal can be delivered to the viewer in about 3 seconds from the event message sending operation in the broadcasting station.

Non-Patent Document 1 describes CMAF (Common Media Application Format), which is a container format for media for video distribution via a communication network.

Non-Patent Document 2 describes use cases, requirements, and problems that utilize event metadata in online video distribution. For example, issues related to the use of triggers for inserting addressable advertisements and synchronization of video and subtitles are described.

Non-Patent Document 3 describes a method (in-band transmission) of inserting information by an emsg box (emsg) in a moving image content such as mp4. There are out-of-band transmission and in-band transmission as a method of distributing event metadata for online video distribution. In out-of-band transmission, event metadata is described in a manifest file such as MPEG-DASH (DASH) mpd and transmitted. Considering the immediacy of event metadata, in-band transmission has the advantage that it can be delivered together with the segment data being viewed rather than out-of-band transmission. When event metadata is transmitted by in-band transmission, the time (delay) required for event metadata distribution is almost the same as the time (delay) required for content distribution.

Non-Patent Document 4 describes a technique for realizing distribution of online moving images (for example, live distribution) with low delay. Non-Patent Document 4 describes low-delay delivery using CMAF's Ultra-Low-Latency (ULL). ULL is a technology that divides fragmented MP4 (fMP4) into smaller particles than segment files and intermittently distributes data to clients by Chunked Transfer Encoding defined by HTTP1.1. In this paper, the data obtained by dividing the segment into fine particles is used as chunks, and the data sent intermittently by Chunked Transfer Encoding is used as a frame.
When ULL is used, the delay in live distribution of online video can be suppressed to about 3 seconds.

"ISO / IEC 23000-19: 2020 Information technology --Multimedia application format (MPEG-A) --Part 19: Common media application format (CMAF) for segmented media.", International Organization for Standardization, March 2020. "Requirements for Media Timed Events W3C Interest Group Note 25 June 2020", updated June 25, 2020, [online], [downloaded July 25, 2020], Internet <URL: https://www.w3.org / TR / 2020 / NOTE-media-timed-events-20200625 /> "" ISO / IEC 23009-1: 2019 Information technology --Dynamic adaptive streaming over HTTP (DASH) --Part 1: Media presentation description and segment formats ", International Organization for Standardization, August 2019. Will Law, "WHITE PAPER: Ultra-Low-Latency Streaming Using Chunked-Encoded and Chunked-Transferred CMAF", Akamai, [Downloaded July 25, 2020], Internet <URL: https://www.akamai.com/ us / en / multimedia / documents / white-paper / low-latency-streaming-cmaf-whitepaper.pdf ＞

In video distribution via a communication network such as the Internet, it is insufficient to study a method of transmitting event data with low delay, and it often takes longer than distribution of event data in a broadcasting service. If the broadcasting station can improve the immediacy of event data distribution in online video distribution to the same level as in broadcasting, it can also increase the flexibility of services by a system that links broadcasting and communication (broadcasting communication cooperation system). Since event data can be inserted in segment units in the current online video distribution, it is possible to reduce the distribution delay by, for example, reducing the segment length of the content, but if this is the case, for distribution, etc. Another problem arises that the load on the server unit increases significantly.

The present invention has been made in consideration of the above circumstances, and is a metadata insertion device capable of reducing the delay in the distribution of event data without reducing the segment length in the data for video distribution. It is intended to provide a program.

Further, it is a further object of the present invention to make it possible to deliver event data only in a situation that meets a specific condition.

[1] In order to solve the above problems, the metadata insertion device according to one aspect of the present invention has an arbitrary chunk of a receiving unit that receives video data encoded for HTTP streaming and the received video data. It is said that the video data is composed of a plurality of segments, and the chunk is a unit obtained by further dividing the segment. It is a thing.

[2] Further, in one aspect of the present invention, in the above-mentioned metadata insertion device, the video data received by the receiving unit is data in an ultra-low delay format in a common media application format.

[3] Further, in one aspect of the present invention, in the above-mentioned metadata insertion device, the segment is composed of a plurality of the chunks, and the first chunk in the segment is control data such as type, sidx, and moof. And mdat which is moving image data, and chunks other than the beginning in the segment include moof which is control data and mdat which is moving image data, and the event data insertion part is an arbitrary chunk. , Emsg, which is the metadata for the event, is inserted immediately before the moof.

[4] Further, one aspect of the present invention further includes a content output unit for transmitting the video data output by the event data insertion unit to a distribution device in the content delivery network in the metadata insertion device. do.

[5] Further, one aspect of the present invention is a content distribution unit that distributes the video data output by the event data insertion unit as a response corresponding to a request from the client device in the metadata insertion device. Further equipped.

[6] Further, in one aspect of the present invention, in the metadata insertion device, the event data insertion unit inserts the event metadata only in any chunk in a specific content based on the set information. It is to be inserted.

[7] Further, in one aspect of the present invention, in the metadata insertion device of the above [5], the event data insertion unit has the video data into which the event metadata has been inserted and the event metadata. Outputs the video data in which the event is not inserted, and the content distribution unit distributes the video data in which the event metadata is inserted to the client device of a specific user based on the set information. The video data in which the event metadata is not inserted is delivered to the client device of another user based on the set information.

[8] Further, the metadata insertion device according to one aspect of the present invention has a receiving unit that receives video data encoded for HTTP streaming, and event data that inserts event metadata into the received video data. The event data insertion unit includes an insertion unit and a content distribution unit that distributes the video data output by the event data insertion unit as a response corresponding to a request from the client device, and the event data insertion unit is the event metadata. The video data in which the data is inserted and the video data in which the event metadata is not inserted are output, and the content distribution unit outputs the event to the client device of a specific user based on the set information. The video data in which the event metadata is inserted is delivered, and the video data in which the event metadata is not inserted is delivered to the client device of another user based on the set information. ..

[9] Further, one aspect of the present invention is a program for making a computer function as the metadata insertion device according to any one of the above [1] to [8].

According to the present invention, the metadata insertion device can insert event metadata into video data, and can reduce the transmission of event metadata. The delay in the transmission of event metadata is, for example, about 3 seconds, which is equivalent to the transmission of events in broadcasting.

Further, in broadcasting, since event data is collectively distributed to all users, it is difficult to send event data to individual users, but in the present invention, a specific client device is used depending on the situation. It is also possible to send event data only to.

It is a block diagram which shows the schematic functional structure of the metadata insertion apparatus according to 1st Embodiment of this invention. It is a block diagram which shows the functional structure of the whole system including the metadata insertion apparatus by the same embodiment. It is a schematic diagram which shows the example of the structure of the data which the receiving part receives from an encoder device by the same embodiment. It is a schematic diagram which shows the example of the structure of the data output by the event data insertion part by the same embodiment. It is a schematic diagram which shows the example of the specific delivery method of the content output by the metadata insertion apparatus by the same embodiment. It is a schematic diagram which shows another example of the specific delivery method of the content output by the metadata insertion apparatus by the same embodiment. It is a block diagram which shows the schematic functional structure of the metadata insertion apparatus by 2nd Embodiment. It is a schematic diagram which shows the data structure example in the case where the insertion condition storage part by the same embodiment stores information indicating whether or not event metadata should be inserted for each content. It is a schematic diagram which shows the data structure example in the case where the insertion condition storage part by the same embodiment stores the information which shows whether or not the event metadata should be inserted for each user. It is a schematic diagram which shows the data structure example in the case where the insertion condition storage part by the same embodiment stores the information which shows whether or not the event metadata should be inserted for each attribute of a user. It is a block diagram which shows the internal structure example of the metadata insertion apparatus by 1st Embodiment or 2nd Embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the video data is data including video and audio. Video data is also called content data or content.

FIG. 1 is a block diagram showing a schematic functional configuration of a metadata insertion device according to the present embodiment. As shown in the figure, the metadata insertion device 1 includes a reception unit 11, an analysis unit 12, an event data insertion unit 13, a content output unit 14, and a content distribution unit 15. Each of these functional units can be realized by, for example, a computer and a program. In addition, each functional unit has a storage means, if necessary. The storage means is, for example, a variable on the program or a memory allocated by executing the program. Further, if necessary, a non-volatile storage means such as a magnetic hard disk device or a solid state drive (SSD) may be used. Further, at least a part of the functions of each functional unit may be realized as a dedicated electronic circuit instead of a program. The functions of each part are as described below.

The receiving unit 11 receives the video data and passes it to the analysis unit 12. The video data is Chunked Transfer Encoding. That is, in the present embodiment, the video data received by the receiving unit 11 is the ULL output (Chunked Transfer Encoding output) of CMAF (Common Media Application Format). As described above, ULL is data in a format in which fragmented MP4 (fMP4) can be divided into frame units and transmitted. The receiving unit 11 passes the received video data to the analysis unit 12. The receiving unit 11 is not limited to the Chunked Transfer Encoding output, and may receive video data encoded by another method. In the configuration of the system 100 (see FIG. 2) described later, the receiving unit 11 receives the above-mentioned video data from the encoder device 3.

The analysis unit 12 analyzes the video data received by the reception unit 11. Specifically, the analysis unit 12 analyzes the data structure of fMP4 and determines a place where emsg (also referred to as emsg box), which will be described later, should be inserted. Further, the analysis unit 12 determines whether the video data (data of fMP4) received by the reception unit 11 is the data that is still being created or the data of the completed MP4. The data being created means that mdat, which will be described later, is being created.

The event data insertion unit 13 inserts event metadata into the above video data at a predetermined timing. The event data insertion unit 13 determines, for example, the timing for inserting event metadata based on a signal from the outside. The event data insertion unit 13 may also determine the timing for inserting the event metadata based on, for example, the operation of the operator of the metadata insertion device 1. The content of the event metadata (content of the message) to be inserted is also determined based on, for example, an external signal or an operation of the operator. The event data insertion unit 13 passes the video data after the process of inserting the event metadata to the content output unit 14 and the content distribution unit 15.

The event metadata may be scheduled to be inserted in advance, or may correspond to a sudden event (for example, an Earthquake Early Warning or a breaking news of other events). May be good. Further, the content (message) of the event metadata may be associated with the video data (content) to be delivered, or may be independent of the video data. The event metadata may be, for example, data for presenting information (image, sound, etc.) on the client device 6 side. The event metadata is, for example, data for directing the content to be delivered (for example, directing a decisive moment in a sports broadcast (soccer goal scene, etc.) by a special effect on the client device 6 side). May be good. The event metadata may be, for example, data sent to a peripheral device (not shown, including an IoT device) on the client device 6 side, or may control the operation of the peripheral device. Further, the event metadata may include location information (URL, etc.) for accessing a specific information resource.

The position where the event data insertion unit 13 inserts the event metadata will be described later with reference to FIG. The event metadata may be, for example, data called emsg or other data.

The content output unit 14 outputs the video data received from the event data insertion unit 13 to an external device. In the configuration of the system 100 (see FIG. 2) described later, the content output unit 14 passes the video data to the distribution device 4 or the like in the content delivery network 5.

The content distribution unit 15 distributes the video data received from the event data insertion unit 13 in response to a request from the client device 6. The content distribution unit 15 passes video data to the client device 6 in frame units, for example. Event metadata may be inserted into the video data distributed by the content distribution unit 15 by the event data insertion unit 13.

FIG. 2 is a block diagram showing a functional configuration of the entire system including the metadata insertion device 1 of the present embodiment. As shown in the figure, the system 100 includes a metadata insertion device 1, a video supply device 2, an encoder device 3, a distribution device 4, a content delivery network 5, and a client device 6.

The metadata insertion device 1 is a device described with reference to FIG. The metadata insertion device 1 receives the encoded video data from the encoder device 3. The metadata insertion device 1 inserts the event metadata emsg into the video data at an arbitrary timing. The metadata insertion device 1 outputs video data in which event metadata has been inserted. The metadata insertion device 1 distributes video data in which event metadata has been inserted to the client device 6 via the content delivery network 5 or directly to the client device 6.

The video supply device 2 supplies video. The video supply device 2 passes the video to the encoder device 3. The video here may be a pre-recorded video or a live video.

The encoder device 3 performs a predetermined encoding process based on the video passed from the video supply device 2 and outputs it. The encoder device 3 passes the video data in the ULL format of the CMAF to the metadata insertion device 1.

The distribution device 4 is a device having a function of distributing content. The distribution device 4 is provided in the content delivery network 5. The distribution device 4 distributes the content passed from the metadata insertion device 1 to the client device 6 in response to a request from the client device 6.

The content delivery network 5, also called a CDN, is a network particularly provided for distributing content (video content, etc.) to the client device 6. The content delivery network 5 may be configured to include a large number of distribution devices 4. The client device 6 can access an appropriate distribution device 4 in the content delivery network 5 in order to receive the distribution of the content. The content delivery network 5 may include a coordinating mechanism that optimizes the total traffic between the distribution device 4 and the client device 6.

The client device 6 is a device having a function of receiving content via a communication network and presenting the content to a user from a screen, a speaker, or the like. The client device 6 is realized by using, for example, a smart phone (smartphone), a television receiver (so-called "television"), a tablet-type terminal device, a personal computer (PC), or the like. The client device 6 receives the above content by using a wired or wireless communication means. The client device 6 can receive the content from the distribution device 4 in the content delivery network 5, or can receive the content directly from the metadata insertion device 1. The client device 6 has a function (player function) of reproducing the content and presenting it to the user as video or audio.

FIG. 3 is a schematic diagram showing an example of the configuration of data received by the receiving unit 11 from the encoder device 3. The figure shows the structure of data for one segment. Video content usually consists of a large number of segments. The data obtained by dividing the segment into fine particles is the chunk, and the data sent intermittently by the Chunked Transfer Encoding is the frame.

In the illustrated example, one segment consists of four chunks. One chunk consists of four frames. That is, in the figure, the first to fourth frames belong to the first chunk, the fifth to eighth frames belong to the second chunk, the ninth to twelfth frames belong to the third chunk, and the thirteenth to sixteenth frames. The frame belongs to the 4th chunk. The transmission of physical data is done on a segment-by-segment basis.

Further, each chunk is composed of control data and mdat having the substance of the image. The control data of the first chunk are type, sidex, and moof. The control data possessed by each of the second chunk to the fourth chunk is moof. These control data are defined by the standard. In the illustrated example, the first frame in each chunk contains control data and mdat. Frames other than the beginning in each chunk contain mdat.

FIG. 4 is a schematic diagram showing an example of the configuration of data output by the event data insertion unit 13. The figure shows the structure of data for one segment. Video content usually consists of a large number of segments. The data shown in FIG. 4 is obtained by inserting metadata representing an event into the data shown in FIG. In other words, the event data insertion unit 13 can insert emsg as metadata into the data received by the reception unit 11.

Similar to the case shown in FIG. 3, in the data shown in FIG. 4, one segment consists of four chunks. Also, one chunk consists of four frames. In the data shown in FIG. 4, it is possible to insert emsg, which is control data representing an event, immediately before the moof of each chunk. That is, the event data insertion unit 13 inserts emsg immediately before the moof in the appropriate chunk of the appropriate segment when there is an event to be transmitted to the client device 6 side. It should be noted that emsg may not exist in chunks in which there is no event to be inserted. In other words, emsg in each chunk can have a length of 0 bits or more.

That is, in the data shown in FIG. 4, each chunk is composed of control data and mdat having an actual image. The control data that the first chunk can have are type, sidex, emsg, and moof. The control data that can be possessed by each of the second chunk to the fourth chunk are emsg and moof. The control data and mdat in each chunk are appropriately assigned to frames according to their length.

As described above, the transmission of event information in this embodiment is in-band transmission. That is, the event information is not put in the manifest file and transmitted, but the event information is put in the content file itself and transmitted. Further, in the prior art, the metadata emsg for the event can be inserted only in the head portion of the segment, whereas in the present embodiment, the event data insertion unit 13 is inserted in the head portion of any chunk in the segment. Metadata emsg can be inserted. That is, in the present embodiment, there are more opportunities to insert event data as compared with the conventional technique. That is, by using the metadata insertion device 1, it becomes possible to insert event metadata with finer particle size in time, and it becomes possible to reduce the delay in delivery.

FIG. 5 is a schematic diagram showing an example of a specific distribution method of the content output by the metadata insertion device 1. In this example, the content output by the metadata insertion device 1 is delivered from the content delivery network 5 to the client device 6. In the case of the distribution method shown in FIG. 5, the content output unit 14 of the metadata insertion device 1 sequentially outputs content data (video data) to the content delivery network 5. As an example, the content output unit 14 pushes content data as an HTTP proxy. The distribution device 4 exists in the content delivery network 5. A plurality of distribution devices 4 may exist in the content delivery network 5. The content data output by the content output unit 14 is held in the distribution device 4. The client device 6 transmits a content data request to any of the distribution devices 4 in the content delivery network 5 based on the user's operation or the like. The distribution device 4 receives the request and transmits the content data corresponding to the request to the client device 6 as a response. This content data is the content data output by the metadata insertion device 1. This content data may include event metadata inserted by the event data insertion unit 13 of the metadata insertion device 1.

FIG. 6 is a schematic diagram showing another example of a specific distribution method of the content output by the metadata insertion device 1. In this example, the metadata insertion device 1 directly delivers the content data to the client device 6 without going through the content delivery network 5. In the case of the distribution method shown in FIG. 6, the client device 6 transmits a content data request to the metadata insertion device 1 based on a user operation or the like. The content distribution unit 15 of the metadata insertion device 1 receives a request from the client device 6 and transmits the content data corresponding to the request to the client device 6 as a response. This content data may include event metadata inserted by the event data insertion unit 13.

That is, in the present embodiment, as shown in FIG. 5, the metadata insertion device 1 can be provided between the encoder device 3 and the content delivery network 5. The system for passing content data from the encoder device 3 to the content delivery network 5 without going through the metadata insertion device 1 is a conventional system. That is, in the present embodiment, the metadata insertion device 1 can be provided in the middle of the conventional system. Further, in the present embodiment, as shown in FIG. 6, a metadata insertion device 1 can be provided between the encoder device 3 and the client device 6. In this case, the content distribution unit 15 of the metadata insertion device 1 performs distribution processing to the client device 6.

In general Chunked Transfer Encoding, 0 bytes (0 bytes) of data are finally transmitted to indicate that the video data to be transmitted intermittently has been transmitted. Therefore, when data processing of video transmission or distribution as an HTTP session, session management may be performed using 0-byte data as a file break. On the other hand, depending on the function of the video distribution unit, it is possible to process the data received by Chunked Transfer Encoding as a sequential file. When processing as a file, the distribution unit cannot determine whether the video data (mdat) to be distributed to the client is completed. Therefore, the event data insertion unit 13 inserts information indicating whether the MP4 data of the received content is still being created (mdat is being created) or the MP4 data is completed (mdat is completed). May be good. Specifically, the event data insertion unit 13 may insert box data (for example, odes) which is an identifier as a break of the moving image when the moving image data (mdat) is completed. The content distribution unit 15 needs to determine whether the data that responds to the video request from the client device 6 is being created or has already been completed. The content distribution unit 15 determines the presence or absence of the above-mentioned odes inserted by the event data insertion unit 13 for the determination. When the content requested from the client device 6 is completed (there are odes), the content distribution unit 15 distributes the content as a response. When the content requested from the client device 6 is being created (there is no odes), the content distribution unit 15 operates to distribute the content after the content is completed while maintaining the session of the request. ..

The configuration of the first embodiment is summarized as follows. The receiving unit 11 receives the video data encoded for HTTP streaming. The event data insertion unit 13 inserts event metadata into an arbitrary chunk of the received video data. Here, the video data is composed of a plurality of segments. Further, the chunk is a unit obtained by further dividing the segment (see FIG. 4).

The video data received by the receiving unit 11 may be data in the form of ultra-low delay (CMAF ULL) in the common media application format. Further, the segment may be composed of a plurality of the chunks. At this time, the first chunk in the segment includes the control data style, sidx, and moof, and the moving image data mdat, and the chunks other than the first chunk in the segment include the control data moof. Includes mdat, which is moving image data. Then, the event data insertion unit 13 inserts the event metadata emsg immediately before the moof of an arbitrary chunk (depending on the schedule for inserting the event, the timing at which a sudden event occurs, and the like). You can do it.

The metadata insertion device 1 may include a content output unit 14 that transmits the video data output by the event data insertion unit 13 to the distribution device 4 in the content delivery network 5. Further, the metadata insertion device 1 may include a content distribution unit 15 that distributes the video data output by the event data insertion unit 13 as a response corresponding to a request from the client device 6.

According to the first embodiment described above, for example, by providing the metadata insertion device 1 between the encoder device 3 and the content delivery network 5 of the existing system, the event metadata is transmitted with low delay. You will be able to. That is, there is no need to repair the hardware of the existing equipment. Specifically, the metadata insertion device 1 can insert event metadata in chunk units instead of segment units. As a result, it is possible to reduce the delay in the transmission of event metadata. As an example, the length of time corresponding to one segment can be 8 seconds, the length of time corresponding to one chunk can be 2 seconds, and the length of time corresponding to one frame can be 500 milliseconds. In the case of this example, in the prior art, there was a place where the event metadata was inserted only once per segment, that is, once every 8 seconds. On the other hand, in the embodiment described above, there is a place where event metadata is inserted once every two seconds. In addition to these 2 seconds, even considering various time overheads, it is possible to deliver event metadata to the client device with a delay of about 3 seconds at the maximum. That is, in the embodiment described above, the event metadata can be delivered with a shorter delay time as compared with the conventional technique. Even when the length of one chunk is other than the two seconds exemplified here, it is possible to deliver the event metadata with a shorter delay time as compared with the prior art, depending on the length.

As described above, according to the present embodiment, it is possible to quickly deliver the event metadata to the client device 6 at the same speed as the EM of broadcasting even in the online video distribution. Further, by using this embodiment, an alternative means of broadcasting EM can be realized by the Internet. That is, for example, it is possible to transmit video and audio by broadcasting and transmit only event metadata on the Internet.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The matters already described in the previous embodiment may be omitted below. Here, the matters peculiar to the present embodiment will be mainly described.

FIG. 7 is a block diagram showing a schematic functional configuration of the metadata insertion device according to the second embodiment. As shown in the figure, the metadata insertion device 8 of the present embodiment includes a reception unit 11, an analysis unit 12, an event data insertion unit 13, a content output unit 14, a content distribution unit 15, and an insertion condition storage unit 17. Consists of including. Of these, the receiving unit 11, the analysis unit 12, the event data inserting unit 13, the content output unit 14, and the content distribution unit 15 have the same functions as those of the first embodiment. The feature of this embodiment is that the metadata insertion device 8 has an insertion condition storage unit 17. The content distribution unit 15 can insert event metadata into the video data based on the insertion conditions stored in the insertion condition storage unit 17. Further, the content distribution unit 15 can distribute the content data in which the event metadata is inserted to the client device 6 that meets the predetermined conditions based on the conditions of the insertion condition storage unit 17. Further, the content distribution unit 15 can distribute the content data in which the event metadata is not inserted into the other client device 6.

The insertion condition storage unit 17 should output the content data in which the event metadata is inserted in any situation, and outputs the content data in which the event metadata is not inserted in any situation. Memorize information that indicates whether it should be. Specifically, the insertion condition storage unit 17 may store information indicating whether or not event metadata should be inserted for each content as the first pattern. Further, as the second pattern, the insertion condition storage unit 17 may store information indicating whether or not event metadata should be inserted for each user of the client device 6. Further, as the third pattern, the insertion condition storage unit 17 may store information indicating whether or not event metadata should be inserted for each user attribute of the client device 6. Next, the information stored in the insertion condition storage unit 17 will be described for each of these patterns.

FIG. 8 corresponds to the first pattern. FIG. 8 is a schematic diagram showing a data configuration example when the insertion condition storage unit 17 stores information indicating whether or not event metadata should be inserted for each content. As shown in the figure, the insertion condition storage unit 17 stores the table. This table has a content ID and an item indicating whether or not event information is inserted (true / false). That is, the insertion condition storage unit 17 stores information indicating whether the event information should be inserted (T, true) or the event information should not be inserted (F, false) for each content ID. .. By referring to the information of the insertion condition storage unit 17, the event data insertion unit 13 inserts the event metadata only when necessary according to the content ID of the target content. That is, when the event information insertion value corresponding to the content ID is "T", the event data insertion unit 13 inserts the event metadata into the content. Then, when the value of the event information insertion is "F", the event metadata is not inserted into the content.

In the case of the first pattern described above, the content data output by the event data insertion unit 13 is from the content output unit 14 (the form shown in FIG. 5) or from the content distribution unit 15 (the form shown in FIG. 6). ) Can be output in either form.

FIG. 9 corresponds to the second pattern. FIG. 9 is a schematic diagram showing a data configuration example when the insertion condition storage unit 17 stores information indicating whether or not event metadata should be inserted for each user of the client device 6. Is. As shown in the figure, the insertion condition storage unit 17 stores the table. This table has a user ID and an item indicating whether or not event information is inserted (true / false). That is, the insertion condition storage unit 17 stores information indicating whether the event information should be inserted (T, true) or the event information should not be inserted (F, false) for each user ID. .. In this case, the event data insertion unit 13 creates both the content data in which the event metadata is inserted and the content data in which the event metadata is not inserted, and passes the content data to the content distribution unit 15. The content distribution unit 15 refers to the insertion condition storage unit 17, determines the condition corresponding to the user ID, and transfers the content data with or without the insertion of the event metadata to the client device 6. To deliver. Specifically, when the value of the event information insertion of the user ID associated with the client device 6 that is the request source of the content data is "T", the content distribution unit 15 is the content data in which the event metadata is inserted. Is delivered to the client device 6. When the event information insertion value of the user ID associated with the client device 6 that is the request source of the content data is "F", the content distribution unit 15 inputs the content data into which the event metadata is not inserted to the client. Deliver to device 6.

In the case of the second pattern described above, since it is necessary to control whether or not the event metadata is inserted for each user ID, the content is distributed from the content output unit 14 via the content delivery network 5 (FIG. The form shown in 5) is not performed. In the case of the second pattern, the processing is performed in the form of distributing the content from the content distribution unit 15 (the form shown in FIG. 6).

FIG. 10 corresponds to the third pattern. FIG. 10 shows a data configuration example when the insertion condition storage unit 17 stores information indicating whether or not event metadata should be inserted for each user attribute of the client device 6. It is a schematic diagram. As shown in the figure, the insertion condition storage unit 17 stores the table. This table has user attributes and items indicating whether or not event information is inserted (true / false). That is, the insertion condition storage unit 17 stores information indicating whether the event information should be inserted (T, true) or the event information should not be inserted (F, false) for each user attribute. .. In this case, the event data insertion unit 13 creates both the content data in which the event metadata is inserted and the content data in which the event metadata is not inserted, and passes the content data to the content distribution unit 15. The content distribution unit 15 refers to the insertion condition storage unit 17, determines the condition according to the attribute of the requesting user, and inserts or does not insert the event metadata into the content data. Deliver to client device 6. Specifically, when the event information insertion value corresponding to the user attribute associated with the client device 6 that is the request source of the content data is "T", the content distribution unit 15 inserts the event metadata. The content data is distributed to the client device 6. When the value of the event information insertion corresponding to the user attribute associated with the client device 6 that is the request source of the content data is "F", the content distribution unit 15 inputs the content data in which the event metadata is not inserted. , Distribute to the client device 6.

In the example shown in FIG. 10, when the user attribute of the client device 6 is "resident in Tokyo" or "resident in Saitama prefecture", the content distribution unit 15 inserts the content data into which the event metadata is inserted. Deliver to the client device 6. When the attribute of the user of the client device 6 is "resident in Kanagawa prefecture", the content distribution unit 15 distributes the content data into which the event metadata is not inserted to the client device 6.

In the case of the above third pattern, since it is necessary to control whether or not the event metadata is inserted for each user attribute, the content is distributed from the content output unit 14 via the content delivery network 5 ( The form shown in FIG. 5) is not performed. In the case of the third pattern, the processing is performed in the form of distributing the content from the content distribution unit 15 (the form shown in FIG. 6).

The user attributes are not limited to the pre-registered attributes. For example, the content distribution unit 15 may determine the attributes of the user of the client device 6 based on the status of the request from the client device 6. For example, the content distribution unit 15 may read the location of the user of the client device 6 requesting the content from the communication content and determine it. Further, for example, the content distribution unit 15 may determine the attribute of the user of the client device 6 as the "continuous viewing user" when the request from the specific client device 6 continues for a predetermined time or longer. Further, for example, when the request for the specific content from the specific client device 6 continues for a predetermined time or more, the content distribution unit 15 determines the attribute of the user of the client device 6 as the continuous viewing user of the content. May be good. It is also possible to control the user having the attributes as illustrated here to send the event metadata for recommending a specific product or service.

There may be a plurality of types of event metadata. Further, the insertion condition storage unit 17 may store information as shown in FIGS. 8, 9, and 10 for each type of event metadata. Further, the event data insertion unit 13 may determine whether or not to insert the event metadata separately for each type of event metadata. Further, the content distribution unit 15 separately distributes the content in which the event metadata is inserted to each client device 6 for each type of event metadata, or the event metadata is not inserted. You may control whether the content is delivered.

The features of the second embodiment are summarized as follows. The event data insertion unit 13 inserts the event metadata only in an arbitrary chunk in a specific content based on the set information. Here, the set information is information set to be stored in the above-mentioned insertion condition storage unit 17 (see FIG. 8).

Further, the event data insertion unit 13 may output the video data in which the event metadata is inserted and the video data in which the event metadata is not inserted. The content distribution unit 15 distributes the video data in which the event metadata is inserted into the client device 6 of the specific user based on the set information, and the client of the other user based on the set information. The video data in which the event metadata is not inserted may be delivered to the device 6. Here, the set information is information set to be stored in the above-mentioned insertion condition storage unit 17 (see FIGS. 9 and 10).

As described above, in the second embodiment, the event metadata is further inserted only in a specific content, or the event metadata is inserted only in a specific user or a user having a specific user attribute. be able to. For example, event metadata for recommending related content of the content being delivered can be transmitted only to a specific single or plurality of client devices 6. Further, for example, event metadata for transmitting earthquake breaking news and other disaster breaking news can be transmitted only to the client device 6 existing in a specific area. Further, for example, it is possible to prevent the event metadata from being transmitted to a specific one or more client devices 6.

According to either the first embodiment or the second embodiment described above, the metadata insertion device can insert event metadata in chunk units instead of segment units. This makes it possible to reduce the delay in the transmission of event metadata to the client device.

FIG. 11 is a block diagram showing an example of a part of the internal configuration of the metadata insertion device 1 (or 8) in the first embodiment and the second embodiment. The metadata insertion device 1 (or 8) can be realized using a computer. As shown in the figure, the computer includes a central processing unit 901, a RAM 902, an input / output port 903, input / output devices 904 and 905, and a bus 906. The computer itself can be realized using existing technology. The central processing unit 901 executes an instruction included in a program read from RAM 902 or the like. The central processing unit 901 writes data to RAM 902, reads data from RAM 902, and performs arithmetic operations and logical operations according to each instruction. The RAM 902 stores data and programs. Each element contained in the RAM 902 has an address and can be accessed using the address. RAM is an abbreviation for "random access memory". The input / output port 903 is a port for the central processing unit 901 to exchange data with an external input / output device or the like. The input / output devices 904 and 905 are input / output devices. The input / output devices 904 and 905 exchange data with the central processing unit 901 via the input / output ports 903. Bus 906 is a common communication path used inside a computer. For example, the central processing unit 901 reads and writes data in the RAM 902 via the bus 906. Further, for example, the central processing unit 901 accesses the input / output port via the bus 906.

It should be noted that at least a part of the functions of the metadata insertion device 1 (or 8) of the above-described embodiment can be realized by a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. The "computer-readable recording medium" is a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, a DVD-ROM, or a USB memory, or a storage device such as a hard disk built in a computer system. That means. Furthermore, a "computer-readable recording medium" is a device that temporarily and dynamically holds a program, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In that case, it may include a program that holds a program for a certain period of time, such as a volatile memory inside a computer system that is a server or a client. Further, the above-mentioned program may be for realizing a part of the above-mentioned functions, and may be further realized for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although a plurality of embodiments have been described above, the present invention can be further implemented in the following modifications. In addition, a plurality of modified examples may be combined and carried out as long as they can be combined.

[First modification]
In each of the above embodiments, the metadata insertion devices 1 and 8 are provided with both a content output unit 14 and a content distribution unit 15. In this first modification, the metadata insertion devices 1 and 8 do not necessarily have to include the content output unit 14 and the content distribution unit 15. The metadata insertion devices 1 and 8 having neither the content output unit 14 nor the content distribution unit 15 can generate video data in which event metadata is inserted. The metadata insertion device 1 or 8 provided with only the content output unit 14 can pass the video data in which the event metadata is inserted to the distribution device 4. The metadata insertion devices 1 and 8 provided with only the content distribution unit 15 can distribute the video data in which the event metadata is inserted to the client device 6 without going through the content delivery network.

[Second modification]
In the second embodiment described above, the event data insertion unit 13 inserts event metadata into any chunk in the segment. In this second modification, the event data insertion unit 13 does not necessarily have to insert the event metadata into any chunk. That is, in this second modification, the event data insertion unit 13 may insert event metadata only in the first chunk in the segment. Also in this case, the metadata insertion device 8 may output the content in which the event metadata is inserted only in the specific content, or may output the specific (single or single or) content based on the condition information stored in the insertion condition storage unit 17. Deliver content with event metadata inserted to user-only client devices (multiple), or deliver event metadata-inserted content to user-only client devices with specific attributes. It is possible to do.

In this second modification, the receiving unit 11 receives the video data encoded for HTTP streaming. The event data insertion unit 13 inserts event metadata into the received video data. The content distribution unit 15 distributes the video data output by the event data insertion unit 13 as a response corresponding to the request from the client device 6. Then, the event data insertion unit 13 outputs the video data in which the event metadata is inserted and the video data in which the event metadata is not inserted. The content distribution unit 15 distributes the video data in which the event metadata is inserted to the client device 6 of a specific user based on the set information (FIGS. 9, 10, etc.), and distributes the video data to the set information. The video data in which the event metadata is not inserted is delivered to the client device 6 of another user based on the above.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs and the like within a range that does not deviate from the gist of the present invention.

The present invention can be used, for example, in a business of producing and distributing content. It can also be used in the business of manufacturing and selling equipment for that purpose. However, the scope of use of the present invention is not limited to those exemplified here.

1 Metadata insertion device 2 Video supply device 3 Encoder device 4 Distribution device 5 Content delivery network 6 Client device 8 Metadata insertion device 11 Receiver 12 Analysis unit 13 Event data insertion unit 14 Content output unit 15 Content distribution unit 17 Insertion condition storage Part 100 System 901 Central processing unit 902 RAM
903 I / O ports 904,905 I / O devices 906 buses

Claims (9)

A receiver that receives video data encoded for HTTP streaming,
An event data insertion unit that inserts event metadata into an arbitrary chunk of the received video data,
Equipped with
The video data is composed of a plurality of segments and is composed of a plurality of segments.
The chunk is a unit obtained by further dividing the segment.
Metadata insertion device. The video data received by the receiving unit is data in the ultra-low delay format of the common media application format.
The metadata insertion device according to claim 1. The segment is composed of a plurality of the chunks.
The first chunk in the segment includes control data such as type, sidex, and moof, and moving image data, mdat.
Chunks other than the beginning in the segment include control data moof and moving image data mdat.
The event data insertion unit inserts the event metadata emsg immediately before the moof of any chunk.
The metadata insertion device according to claim 1 or 2. A content output unit that transmits the video data output by the event data insertion unit to a distribution device in the content delivery network.
The metadata insertion device according to any one of claims 1 to 3, further comprising. A content distribution unit that distributes the video data output by the event data insertion unit as a response corresponding to a request from a client device.
The metadata insertion device according to any one of claims 1 to 4, further comprising. The event data insertion unit inserts the event metadata only in any chunk in a specific content based on the set information.
The metadata insertion device according to any one of claims 1 to 5. The event data insertion unit outputs the video data in which the event metadata is inserted and the video data in which the event metadata is not inserted.
The content distribution unit distributes the video data in which the event metadata is inserted to the client device of a specific user based on the set information, and the client device of another user based on the set information. Distributes the video data in which the event metadata is not inserted.
The metadata insertion device according to claim 5. A receiver that receives video data encoded for HTTP streaming,
An event data insertion unit that inserts event metadata into the received video data,
A content distribution unit that distributes the video data output by the event data insertion unit as a response corresponding to a request from a client device, and a content distribution unit.
Equipped with
The event data insertion unit outputs the video data in which the event metadata is inserted and the video data in which the event metadata is not inserted.
The content distribution unit distributes the video data in which the event metadata is inserted to the client device of a specific user based on the set information, and the client device of another user based on the set information. Distributes the video data in which the event metadata is not inserted.
Metadata insertion device. Computer,
The metadata insertion apparatus according to any one of claims 1 to 8.
A program to function as.

Images