WO2015012140A1

WO2015012140A1 - Content supply device, content supply method, program, terminal device, and content supply system

Info

Publication number: WO2015012140A1
Application number: PCT/JP2014/068678
Authority: WO
Inventors: 山岸　靖明
Original assignee: ソニー株式会社
Priority date: 2013-07-26
Filing date: 2014-07-14
Publication date: 2015-01-29

Abstract

The present disclosure relates to a content supply device that enables the realization of fast zapping during streaming. The present disclosure also relates to a content supply method, a program, a terminal device, and a content supply system. The content supply device of the present disclosure generates a zapping stream on the basis of content source data, generates zapping metadata for reception of the zapping stream, generates, on the basis of the content source data, an audiovisual stream, the segment length of which is longer than the segment length of the zapping stream, and generates audiovisual metadata for reception of the audiovisual stream. Then the zapping metadata, the audiovisual metadata, the zapping stream, and the audiovisual stream are multicast distributed over a network. The present disclosure is applicable to a streaming distribution system for content.

Description

Content supply apparatus, content supply method, program, terminal device, and content supply system

The present disclosure relates to a content supply device, a content supply method, a program, a terminal device, and a content supply system, and in particular, a content supply device, a content supply method, a program, a terminal device, and a content supply that enables rapid stream switching. About the system.

MPEG-DASH (Moving Picture Experts Group-Dynamic Adaptive Streaming over HTTP, hereinafter DASH, which uses HTTP unicast delivery similar to browsing of a Web site or the like as an internationally standardized video delivery protocol that can be used for video delivery via the Internet Is known (see, for example, Non-Patent Document 1).

Adaptive streaming technology is realized in DASH. That is, the content supply side of DASH prepares a plurality of streams whose image quality, angle of view size, etc. are changed according to the communication environment of the distribution path and the capability and state of the reception side as content of the same content. It is done. On the other hand, the receiving side is configured to select, receive, and reproduce an optimal stream that can be received by itself and that is suitable for its decoding capability, among a plurality of streams prepared by the supplying side.

As described above, in the DASH, metadata referred to as Media Presentation Description (MPD) is supplied from the supply side to the reception side so that the reception side can adaptively select and receive the stream.

The MPD describes the address (url information) of the web server that is the supply source of the chunked content segment stream (media data such as Audio / Video / Subtitle). The receiving side transmits an HTTP request to the web server as a content supply source based on the url information, and in response to the HTTP request, the web server receives and reproduces a segment stream to be unicast-distributed.

FIG. 1 shows an example of the configuration of a content supply system for distributing segment streams of content based on DASH.

The content supply system 10 includes a plurality of content supply devices 20 (20A, 20B, and 20C in this case) for supplying content, and a plurality of DASH clients 30 for receiving content. The content supply device 20 and the DASH client 30 are connected via the Internet 11. On the Internet 11, a CDN (Contents Delivery Network) 12 exists.

The content supply apparatus 20A distributes a plurality of segment streams having the same content as the channel A and different bit rates. The same applies to the content supply devices 20B and 20C. However, it is assumed that the content supply apparatuses 20A, 20B, and 20C are distributing contents having different contents. Hereinafter, the content supply devices 20A, 20B, and 20C are simply referred to as the content supply device 20 when it is not necessary to distinguish them individually.

The content supply device 20 includes a content management server 21, a DASH segment streamer 22, and a DASH MPD server 23.

The content management server 21 manages source data of content to be distributed to the DASH client 30, generates a plurality of streaming data having different bit rates from the source data of the content, and outputs the streaming data to the DASH segment streamer 22.

The DASH segment streamer 22 temporally divides (streams) each streaming data into segments to generate a segment stream. Also, the DASH segment streamer 22 holds the segment stream as a file, and as a WEB server, responds to a request (HTTP request) from the DASH client 30 to transmit the segment stream file via the CDN 12 to the DASH client 30 of the request source. Distribute HTTP Unicast to. Furthermore, the DASH segment streamer 22 notifies the DASH MPD server 23 of the address of the source of the file of the segment stream.

The DASH MPD server 23 generates an MPD in which an address representing the source of the segment stream file, etc., necessary for the DASH client 30 to acquire the segment stream file is described. Further, the DASH MPD server 23, as a WEB server, responds to a request (HTTP request) from the DASH client 30 and distributes the generated MPD to the DASH client 30 of the request source via the CDN 12 via HTTP unicast.

The DASH client 30 requests the MPD from the DASH MPD server 23 and receives the HTTP unicast distributed MPD accordingly. Furthermore, based on the received MPD, the DASH client 30 requests the DASH segment streamer 22 for the segment stream file, and receives and plays the HTTP unicast segment stream file accordingly.

The CDN 12 is provided with a cache server (not shown). The cache server caches files of MPDs and segment streams that are HTTP-unicast-distributed via CND 12. Then, instead of the DASH MPD server 23 or the DASH segment streamer 22 as a WEB server, the file of the MPD or segment stream being cached is delivered to the request source via HTTP unicast to the DASH client 30 that sent the HTTP request.

As described above, in the content supply system 10 using DASH, by preparing a plurality of channels (content supply devices 20A, 20B, 20C), a plurality of contents having different contents are simultaneously distributed to the receiving side. It is possible to do.

As described above, when it is possible to simultaneously supply a plurality of contents having different contents, the user of the DASH client 30 performs the zapping phase (switching and viewing channels one after another in a short time) as in the case of watching television broadcasting. After the state of searching for the content), it is assumed to shift to the viewing phase (the state of viewing the content without zapping).

Switching between channels in DASH is performed in units of segments or in units of subsegments into which segments are further subdivided. In the following, switching between channels in DASH will be described as being performed on a segment basis.

FIGS. 2 and 3 are capable of delivering three segment streams (Representations) having the same content and different bit rates in each channel (A, B, C) of the content supply system 10 using DASH. It shows that there is. The thick arrows in the figure show an example of switching transition when zapping between channels. The difference in the width of the band indicating the segment stream represents the magnitude of the bit rate.

At present, in DASH, the segment length (time length) of the segment stream can be arbitrarily determined for each channel. Therefore, the segment lengths of the segment streams delivered by each channel do not necessarily match. Also, the reproduction start time of the first segment of the segment stream distributed by each channel is not defined to be particularly coincident.

FIG. 2 shows an example in which the segment lengths do not match between the channels, and the reproduction start time of the first segment of the segment stream does not match.

In the case of FIG. 2, when the user of the DASH client 30 instructs switching (zapping) to Channel B's Representation B2 by T1 on the DASH client time axis while watching the Channel A's Representation A2, the actual switching timing is Representation B2 Delayed to T2, which is the segment break. After that, when the user instructs to switch to Channel C's Representation C 2 by T 3 while watching Channel B's Representation B 2, the actual switching timing is also delayed to T 4 which is the segment of Representation C 2.

FIG. 3 shows an example of the case where the reproduction start time of the segment at the beginning of the segment stream is coincident with each other in synchronization with the NTP time axis, but the segment lengths are not coincident between the channels.

In the case of FIG. 3, when the user of the DASH client 30 instructs the switching to Channel B's Representation B2 by T1 of the NTP time axis while watching the Channel A's Representation A2, the actual switching timing is the segmentation of the Representation B2 segment. It is delayed to a certain T2. Thereafter, when switching to Channel C's Representation C 2 is instructed by T 3 while watching Channel B's Representation B 2, the actual switching timing is delayed to T 4 which is the segment of Representation C 2.

As shown in FIG. 2 and FIG. 3, when switching segment streams between channels of the content supply system 10 utilizing DASH, extra delays may occur to the indication. As described above, when actual switching is delayed with respect to the switching instruction, quick zapping can not be performed. Therefore, some measures are necessary.

The present disclosure has been made in view of such a situation, and enables rapid zapping to be realized.

A content supply apparatus according to a first aspect of the present disclosure is a content supply apparatus that supplies, in the same channel, a plurality of streams having the same content and different bit rates according to an adaptive streaming technique. A first stream generation unit that generates a zapping stream based on data, a first metadata generation unit that generates zapping metadata for receiving the zapping stream, and a source data of the content A second stream generation unit that generates a viewing stream longer in minimum unit length when switching the stream than the zapping stream; and generating viewing metadata for receiving the viewing stream A second metadata generation unit; Comprising ring meta data, the viewing metadata, the zapping stream, and a multicast distribution unit the viewing stream for multicasting over a network.

The multicast distribution unit may perform FLUTE multicast distribution of the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via (e) MBMS.

The zapping metadata and the viewing metadata may be a combination of USD, MPD and SDP, or a combination of OMA-ESG, USD, MPD and SDP.

The first stream generation unit can generate a stream having a sufficiently short minimum unit length when switching streams based on source data of the content, and the first metadata generation unit Information representing that a stream corresponding to the zapping metadata can be used for zapping applications can be described in the zapping metadata.

In the first stream generation unit, the division of the minimum unit when switching the stream is in NTP synchronization based on the source data of the content, and the length of the minimum unit is unified with other channels The zapping stream can be generated, and the first metadata generation unit is information indicating that the stream corresponding to the zapping metadata can be used for the zapping stream, and the division of the minimum unit is NTP synchronization. The zapping metadata can describe at least one of information indicating that the user is doing, or information indicating that the length of the minimum unit is the same as that of another channel.

In the second stream generation unit, the division of the minimum unit when switching the stream is in NTP synchronization, and the length of the minimum unit is the zapping stream generated by the first stream generation unit The first stream data generation unit may generate the view stream for viewing that is an integral multiple of the minimum unit, and the first metadata generation unit may further generate the second stream generation unit for the zapping stream corresponding to the zapping metadata. Information representing that switching that does not cause an extra delay in one direction asymmetrically in only one direction can be described in the metadata for zapping from the stream for viewing generated by the second metadata The data generation unit is configured to use the first stream generation unit to generate the viewing stream corresponding to the viewing metadata. To the zapping stream to be made, it is possible to describe information indicating that it is possible to switch which does not cause asymmetrically extra delay in only one direction in the metadata for the viewing.

The content supply apparatus according to the first aspect of the present disclosure may further include a unicast distribution unit that unicasts the zapping metadata and the viewing metadata via a network.

A content supply method according to a first aspect of the present disclosure is a content supply method of a content supply apparatus for supplying, in the same channel, a plurality of streams having the same content and different bit rates according to an adaptive streaming technique. The content providing apparatus generates a zapping stream based on the source data of the content, and viewing a longer minimum unit length when switching the stream than the zapping stream based on the source data of the content A stream generation step of generating a stream for the stream, metadata for zapping for receiving the stream for the zapping, and a metadata generation process for generating metadata for viewing for the reception of the stream for viewing Tsu including a flop, the zapping metadata, the viewing metadata, the zapping stream, and a multicast distribution step of multicasting over a network the viewing stream for.

A program according to a first aspect of the present disclosure, based on source data of the content, provides a computer that supplies a plurality of streams having the same content and different bit rates in the same channel according to the adaptive streaming technology. A first stream generation unit that generates a zapping stream, a first metadata generation unit that generates zapping metadata for receiving the zapping stream, and the zapping based on source data of the content A second stream generation unit configured to generate a viewing stream longer in minimum unit length when switching the stream than a stream; and a second meta generating a viewing metadata for receiving the viewing stream A data generation unit, the zapping metadata, Serial view metadata, the zapping stream, and the to function for viewing the stream as a multicast distribution unit for multicasting over a network.

In the first aspect of the present disclosure, a zapping stream is generated based on source data of content, and zapping metadata for receiving the zapping stream is generated. Also, a viewing stream having a longer minimum unit length when switching the stream than the zapping stream is generated based on source data of the content, and viewing metadata for receiving the viewing stream is It is generated. Further, the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream are distributed by multicast via a network.

A terminal device according to a second aspect of the present disclosure, according to adaptive streaming technology, supplies the stream supplied from a content supply device that supplies, in the same channel, a plurality of streams having the same content and different bit rates according to adaptive streaming technology. In the terminal device for receiving, the content supply device generates a first stream generation unit that generates a zapping stream based on source data of the content, and zapping metadata for receiving the zapping stream. A first metadata generation unit; and a second stream generation unit for generating a viewing stream longer in minimum unit length when switching the stream than the zapping stream based on source data of the content; To receive the viewing stream A second metadata generation unit for generating viewing metadata; a multicast distribution unit for multicasting the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via a network; While acquiring the zapping metadata, receiving and reproducing the zapping stream based on the acquired zapping metadata, acquiring the viewing metadata, and acquiring the acquired viewing metadata The stream for viewing is received and reproduced based on the above.

In the second aspect of the present disclosure, zapping metadata is acquired, the zapping stream is received and reproduced based on the acquired zapping metadata, and the viewing metadata is acquired. The viewing stream is received and reproduced based on the acquired viewing metadata.

A content supply system according to a third aspect of the present disclosure receives a stream according to an adaptive streaming technique and supplies a plurality of streams having the same content and different bit rates in the same channel, and the stream In a content supply system including a terminal device, a first stream generation unit for generating a zapping stream based on source data of the content, and the zapping for receiving the zapping stream. A first metadata generation unit for generating metadata, and a second for generating a viewing stream having a minimum unit length when switching the stream rather than the zapping stream based on the source data of the content With a stream generator A second metadata generation unit that generates viewing metadata for receiving the viewing stream, the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream as a network And a multicast distribution unit that performs multicast distribution via the network. Then, the terminal device acquires the zapping metadata, receives and reproduces the zapping stream based on the acquired zapping metadata, acquires the viewing metadata, and acquires the viewing Receiving and reproducing the viewing stream based on the meta data;

In the third aspect of the present disclosure, the content supply device generates a zapping stream based on source data of the content, and zapping metadata for receiving the zapping stream is generated. Also, a viewing stream having a longer minimum unit length when switching the stream than the zapping stream is generated based on source data of the content, and viewing metadata for receiving the viewing stream is It is generated. Further, the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream are distributed by multicast via a network. Also, the zapping metadata is acquired by the terminal device, and the zapping stream is received and reproduced based on the acquired zapping metadata, and the viewing metadata is acquired and acquired. The viewing stream is received and reproduced based on the viewing metadata.

According to the first to third aspects of the present disclosure, rapid zapping can be realized.

It is a block diagram which shows an example of a structure of the conventional content supply system. It is a figure explaining the delay which arises in switching between channels. It is a figure explaining the delay which arises in switching between channels. It is a figure explaining the relation of the segment stream for zapping distributed from each channel of the contents supply system to which this indication is applied, respectively. It is a figure explaining the relationship between the segment stream for zapping delivered by each channel of the content supply system to which this indication is applied, and the segment stream for viewing and listening. It is a block diagram showing an example of composition of a contents supply system to which this indication is applied. It is a figure which shows the flow of the data of a zapping phase. It is a figure which shows the flow of the data of a viewing-and-listening phase. (e) It is a figure which shows arrangement | positioning of Service Announcement & Metadata in MBMS. It is a figure which shows the data model of USD. It is a figure which shows the 1st example of a description of USD. It is a figure which shows the outline | summary of the 1st example of description of USD. It is a figure which shows the 2nd example of a description of USD. It is a figure which shows the outline | summary of the 2nd example of a description of USD. It is a figure which shows the 3rd example of a description of USD. It is a figure which shows the outline | summary of the 3rd description example of USD. It is a figure which shows the data model of OMA-ESG. It is a figure which shows the 1st example of a description of OMA-ESG. It is a figure which shows the outline | summary of the 1st example of a description of OMA-ESG. It is a figure which shows the 2nd example of a description of OMA-ESG. It is a figure which shows the outline | summary of the 2nd example of a description of OMA-ESG. It is a figure which shows the 3rd example of a description of OMA-ESG. It is a figure which shows the 3rd example of a description of OMA-ESG. It is a figure which shows the outline | summary of the 3rd description example of OMA-ESG. It is a flow chart explaining processing of a contents supply device. It is a flowchart explaining a series of processings of a contents supply system. It is a block diagram showing an example of composition of a computer.

Hereinafter, the best mode for carrying out the present disclosure (hereinafter, referred to as an embodiment) will be described, but before that, an outline of the present disclosure will be described.

FIG. 4 shows segment streams for the zapping phase (hereinafter referred to as zapping segment streams) distributed in each channel of the content supply system according to the embodiment of the present disclosure and the segment lengths thereof. The thick arrows in the figure show an example of switching transition when zapping between channels. The difference in the width of the band indicating the zapping segment stream indicates the magnitude of the bit rate.

In the example of the figure, it is shown that three zapping segment streams (Representations) having different bit rates are prepared for the channels A, B, and C, respectively. Although not shown in FIG. 4, the channels A, B, and C have the same content as the zapping segment stream, and the segment stream for the viewing phase (the segment length is longer than the zapping segment stream) Hereinafter, a plurality of viewing segment streams are also prepared. The viewing segment stream will be described later with reference to FIG.

In the content supply system to which the present disclosure is applied, the segment division of the zapping segment stream is synchronized with the NTP time axis, and the segment length of the zapping segment stream of each channel belonging to the same group is unified into a common time length. It has been decided. Furthermore, the start point (MPD / @ availabilityStartTime + Period / @ start) of the media playback time of the leading segment of the zapping segment stream is determined to coincide on the NTP time axis.

By defining in this way, switching of zapping segment streams among channels belonging to the same group, that is, zapping can be performed without causing an extra delay.

Specifically, when the viewer instructs to switch Channel B to Representation B 2 by T 1 of the DASH client time axis while watching the Representation A 2 of channel A, as in the example of the transition indicated by the thick arrow in FIG. The actual switching is performed at T1 which is a segment of Representation A2 and which is also a segment of Representation B2.

Also, when switching to Channel C's Representation C 2 is instructed by T 2 while watching Channel B's Representation B 2, actual switching is performed at T 2 which is a segment of Representation B 2 and is also a segment of Representation C 2.

Furthermore, when switching to Channel A's Representation A2 is instructed by T3 while watching Channel C's Representation C2, actual switching is performed at T3, which is a segment of Representation C2 and is also a segment of Representation A2.

Next, FIG. 5 shows the relationship between zapping segment streams and viewing segment streams prepared in each channel of the content supply system to which the present disclosure is applied. The difference in width between the zapping segment stream and the viewing segment stream indicates the magnitude of the bit rate.

Although in FIG. 4 each channel prepares three zapping segment streams, in FIG. 5 two zapping segment streams are shown for each channel (only channel A is shown in FIG. 5). And 5 segment streams for viewing are prepared. However, although the number of zapping segment streams and viewing segment streams prepared by each channel is arbitrary, it is desirable to prepare one or more zapping segment streams and two or more viewing segment streams.

As shown in FIG. 5, the segments of the zapping segment stream and the viewing segment stream of each channel are synchronized to the NTP time axis. Also, the segment length of the viewing segment stream is an integral multiple (3 times in the case of FIG. 5) of the segment length of the zapping segment stream of the same channel.

This makes it possible to perform switching without causing extra delay asymmetrically in only one direction from the viewing segment stream of the same channel to the zapping segment stream. Although switching from the zapping segment stream of the same channel to the viewing segment stream is possible, an extra delay may occur in that case.

Then, in the content supply system to which the present disclosure is applied, the zapping segment stream, the viewing segment stream, and the metadata such as the MPD for receiving them are defined by the mobile telephone communication network (3 GPP (3rd Generation Partnership Project) It is assumed that FLUTE multicast delivery is performed via a broadcast multicast channel of (e) MBMS (evolved Multimedia Broadcast Multicast Service). However, metadata such as MPD can be distributed via HTTP (e) MBMS interaction channel via HTTP unicast.

Hereinafter, the zapping segment stream and the viewing segment stream distributed by FLUTE multicast are also referred to as a zapping FLUTE stream or a viewing FLUTE stream, respectively.

On the receiving side, first, metadata for zapping is acquired, and based on the metadata, it becomes a zapping phase for receiving and reproducing a FLUTE stream for zapping. Then, metadata for viewing is also acquired during the zapping phase, and it operates to prepare for transition to the viewing phase for receiving and playing the FLUTE stream for viewing.

[Configuration example of content supply system]
FIG. 6 shows a configuration example of a content supply system according to an embodiment of the present disclosure.

This content supply system 50 is composed of a plurality of content supply devices 60X corresponding to channel X (X = A, B,...) And a large number of terminal devices 80. The content supply device 60X and the terminal device 80 are connected via the network 51.

Here, the network 51 includes a two-way communication network represented by the Internet, and various broadcast networks, but in the present embodiment, it is particularly assumed that (e) MBMS is defined in 3GPP. .

In the network 51, there is an NTP server 52 that provides system time information according to the UTC time format. It is assumed that each content supply device 60 and each terminal device 80 operate by synchronizing their own system time with the NTP time axis according to the system time information provided from the NTP server 52 respectively.

The (e) MBMS of the network 51 has an interaction channel for two-way communication and a broadcast / multicast channel for one-way communication.

(E) The MBMS interaction channel is used for HTTP unicast delivery of metadata such as MPD required to receive zapping segment streams and viewing segment streams. (e) The broadcast multicast channel of MBMS is used for FLUTE multicast distribution of metadata such as zapping segment streams and viewing segment streams, and MPD.

The content supply apparatus 60A corresponding to the channel A includes a channel server 61, a zapping segmenter 62, a zapping metadata generator 63, a viewing segmenter 64, a viewing metadata generator 65, a FLUTE streamer 66, a web server 67, and a multicast server. It has 68.

The channel servers 61 to the multicast server 68 included in the content supply apparatus 60A may be integrated and disposed, or may be distributed and disposed via the Internet or the like.

7 and 8 show the flow of various data between the channel server 61 and the multicast server 68. FIG. 7 is of the zapping face, and FIG. 8 is of the viewing phase.

The channel server 61 manages source data of contents distributed from the channel A, and from the source data of the same contents, one or more zapping streaming data different in bit rate and two or more viewing streaming data Generate Further, the channel server 61 outputs the zapping streaming data to the zapping segmenter 62, and outputs the viewing streaming data to the viewing segmenter 64.

The zapping segmenter 62 divides zapping streaming data into periods in time, and further divides the zapping streaming data into segments, thereby generating a zapping segment stream such as fragmented MP 4 and outputs the zapping segment stream to the FLUTE streamer 66. The segment length of the zapping segment stream is common to the zapping segment streams of other channels belonging to the same group, and is unified to a time length shorter than the segment length of the viewing segment stream described later. Since the zapping segmenter 62 operates in synchronization with the NTP time axis, the segments of the zapping segment stream are also synchronized with the NTP time axis.

Note that instead of generating the zapping segment stream described above in the zapping segmenter 62, a segment stream having a sufficiently short segment length (for example, a playback time of 2 seconds or less) may be generated. This segment stream can be used for zapping applications as it reduces the delay that can occur during switching.

Furthermore, the zapping segmenter 62 notifies the zapping metadata generator 63 of the data range of each segment in the generated zapping segment stream file.

The zapping metadata generator 63 generates metadata such as MPD (hereinafter referred to as zapping metadata) necessary for the terminal device 80 to receive the zapping segment stream, and sends it to the FLUTE streamer 66 and the WEB server 67. Output.

Zapping metadata can be a combination of USD (User Service Description), MPD (Media Presentation Description), and SDP (Service Description Protocol), or OMA-ESG (Open Mobile Alliance-Electronic Service Guide), USD, MPD, and SDP. It consists of a combination of

The viewing segmenter 64 generates a viewing segment stream such as fragmented MP 4 from the viewing streaming data and outputs the segment stream to the FLUTE streamer 66. Furthermore, the viewing segmenter 64 notifies the viewing metadata generator 65 of the data range of each segment in the file of the generated viewing segment stream.

The viewing metadata generator 65 generates metadata such as MPD (hereinafter referred to as viewing metadata) necessary for the terminal device 80 to receive the viewing segment stream, and sends it to the FLUTE streamer 66 and the WEB server 67. Output.

The viewing metadata is composed of a combination of USD, MPD, and SDP, or a combination of OMA-ESG, USD, MPD, and SDP, as with zapping metadata.

The FLUTE streamer 66 generates a zapping FLUTE stream by storing the zapping segment stream input from the zapping segmenter 62 in a FLUTE packet and outputs the zapping segment to the multicast server 68. Further, the FLUTE streamer 66 generates a viewing FLUTE stream by storing the viewing segment stream input from the viewing segmenter 64 in the FLUTE packet, and outputs the viewing FLUTE stream to the multicast server 68. In addition, the FLUTE streamer 66 outputs the zapping metadata input from the zapping metadata generator 63 and the viewing metadata input from the viewing metadata generator 65 to the multicast server 68.

In response to the request (HTTP request) from the terminal device 80, the WEB server 67 distributes the zapping metadata or the viewing metadata to the request source via the network 51 by HTTP unicast.

The multicast server 68 distributes FLUTE multicast of zapping metadata and viewing metadata via the network 51. Also, the multicast server 68 distributes FLUTE multicasts for the zapping FLUTE stream and the viewing FLUTE stream via the network 51.

The content supply device 60B corresponding to the channel B is configured in the same manner as the content supply device 60A, so the description thereof is omitted.

[Known portal channel for FLUTE multicast distribution]
As the portal channel of FLUTE multicast delivery to the terminal device 80, (e) USD of MBMS is used, or OMA-ESG and USD are used in combination.

First, a method of using USD of (e) MBMS for well-known portal channel of FLUTE multicast delivery to the terminal device 80 will be described.

The USD is stored and delivered in (e) MBMS Service Announcement & Metadata.

FIG. 9 shows the arrangement of (e) Service Announcement & Metadata in MBMS. Service Announcement & Metadata 91 is allocated to an (e) MBMS interaction channel and a broadcast / multicast channel. Thus, the USD is HTTP unicast distributed on the interaction channel and FLUTE multicast distributed on the broadcast / multicast channel. However, delivery of the USD may be either HTTP unicast delivery on the interaction channel or FLUTE multicast delivery on the broadcast / multicast channel.

In (e) MBMS, the zapping FLUTE stream and the viewing FLUTE stream are stored in the Donload 3GPP file format, Binary data, Still images, Text, etc. 92 of the broadcast / multicast channel and distributed by FLUTE multicast.

FIG. 10 is a data model of the USD stored in the Service Announcement & Metadata 91, and this embodiment relates particularly to the User Service Bundle Description 101, the User Service Description 102, the Delivery Method 103, the Session Description 104, and the media Presentation Description 105.

FIG. 11 shows a first description example of the USD. This first example of description is applied when the corresponding FLUTE stream is available for zapping (the segment length is sufficiently short).

Specifically, the class name "urn: streamType: forZapping" is defined and introduced in serviceClass as a flag attribute indicating that the FLUTE stream can be used for zapping. When this is described, the FLUTE stream described by this userServiceDescription metadata indicates that the segment length is sufficiently small that it can be used for zapping applications.

FIG. 12 shows an outline of a first description example of the USD in FIG. bundleDescription / userServiceDescription / @ r7: serviceClass = "urn: streamType: forZapping" indicates that the corresponding FLUTE stream can be used for zapping. In userServiceDescription / deliveryMethod / @ sessionDescriptionURI, the URL of the SDP acquisition destination is described. The SDP describes the IP address and port of the corresponding FLUTE stream. In userServiceDescription / mediaPresentationDescription / @ mpdURI, the URL of the MPD acquisition destination is described. The arrangement of each segment in the corresponding FLUTE stream is described in the AdaptationSet / Representation of this MPD.

FIG. 13 shows a second description example of USD. This second description example is applied to the case where a plurality of corresponding FLUTE streams are each a zapping FLUTE stream and can be switched without causing an extra delay to each other (the relationship shown in FIG. 4). Be done.

Specifically, in addition to the first description example, NTPSynchronized and SegmentAligned are introduced immediately below bundleDescription. In bundleDescription / @ NTPSynchronized, the zapping segmenter 62 (of the content supply device 60) of each channel belonging to the same group operates in NTP synchronization, that is, the segment of the FLUTE stream segment of each channel is synchronized with the NTP time axis. Indicates that bundleDescription / @ SegmentAligned represents that the segment lengths of the FLUTE stream segments of the respective channels are unified.

FIG. 14 shows an outline of a second description example of the USD in FIG. The bundleDescription in which NTPSynchronized and SegmentAligned are introduced immediately below is used to group userServiceDescription groups that respectively describe two zapping streams.

If bundleDescription / @ NTPSynchronized (boolean type) is true, it indicates that the segment of each FLUTE stream described in the userServiceDescription group is in NTP synchronization. Furthermore, if bundleDescription / @ SegmentAligned '(boolean type) is true, it indicates that the segment lengths of the segments of each FLUTE stream described in the userServiceDescription group are unified. In the case of the second description example, it is shown that the segment of the FLUTE stream indicated by circle 1 and the segment of the FLUTE stream indicated by circle 2 in the figure are in NTP synchronization and that the segment lengths match.

FIG. 15 shows a third description example of USD. In this third description example, the corresponding zapping FLUTE streams can be switched without causing an extra delay to each other (the relationship shown in FIG. 4), and further, zapping from the corresponding viewing streams For the FLUTE stream for streams, it is applied in the case where it is the relation (the relation shown in FIG. 5) which can be switched without causing extra delay asymmetrically in only one direction.

Specifically, in addition to the second description example, unsymmetricallyAlignedGroupFrom and unsymmetricallyAlignedGroupTo are introduced into serviceDescription. unsymmetricallyAlignedGroupFrom represents a relationship (group) that can be switched without causing an extra delay in one direction asymmetrically in only one direction and its switching source, and unsymmetricallyAlignedGroupTo represents the relationship (group) and its switching destination.

FIG. 16 shows an outline of a third description example of the USD in FIG. In the third description example, the portion indicated by circle 1 and the portion indicated by circle 2 indicate that they are switchable FLUTE streams for zapping that can be switched without causing an extra delay. In addition, for the zapping FLUTE indicated by the circle 1, it is possible to switch from the viewing stream for the circle 1 'only in one direction asymmetrically without causing an extra delay. Furthermore, for the zapping FLUTE indicated by the circle 2, it is possible to switch from the viewing stream of the circle 2 'only in one direction asymmetrically without causing an extra delay.

Next, (e) A method of using the OMA-ESG of MBMS and USD together will be described for the portal channel of FLUTE multicast delivery to the terminal device 80.

The OMA-ESG and the USD are stored and delivered in (e) MBMS Service Announcement & Metadata 91. That is, OMA-ESG and USD are distributed by HTTP unicast on the (e) MBMS interaction channel, and are distributed by FLUTE multicast on the broadcast / multicast channel. However, delivery of OMA-ESG and USD may be either HTTP unicast delivery on an interaction channel or FLUTE multicast delivery on a broadcast / multicast channel.

FIG. 17 is a data model of OMA-ESG stored in Service Announcement & Metadata 91, and in the present embodiment, Service 111 and Access 112 are particularly concerned.

FIG. 18 shows a first description example of OMA-ESG, FIG. 18A is a description example of Service, and FIG. 18B is a description example of Access referring to Service of FIG. This first example of description applies when the corresponding FLUTE stream is available for zapping applications.

Specifically, a value “11” meaning Service / ServiceType “ZappingStream” is defined and introduced as a flag attribute indicating that the FLUTE stream can be used for zapping applications. When this is described, the FLUTE stream described by this Service metadata indicates that the segment length is sufficiently small and can be used for zapping.

FIG. 19 shows an outline of a first description example of the OMA-ESG of FIG. Access refers to Service and 3GPP: MBMS: bundleServiceDescrittion / userServiceDescription. <ServiceType> 11 </ ServiceType> of the referenced Service indicates that the corresponding FLUTE stream is available for zapping. In deliveryMethod / @ sessionDescription URI of the referenced bundleServiceDescrittion / userServiceDescription, the URL of the SDP acquisition destination is described. The SDP describes the IP address and port of the corresponding FLUTE stream. In mediaPresentationDescription / @ mpdURI of the referenced bundleServiceDescrittion / userServiceDescription, the URL of the MPD acquisition destination is described. The arrangement of each segment in the corresponding FLUTE stream is described in the AdaptationSet / Representation of this MPD.

FIG. 20 shows a second description example of OMA-ESG. FIG. 6A is an example of Service description corresponding to a FLapping stream for zapping indicated by a circle 1, and FIG. 7B is an example of Access described with reference to the Service of FIG. Further, FIG. C is a description example of Service corresponding to the FLUTE stream for zapping shown by a circle 2, and FIG. D is an description example of Access referring to Service of FIG.

This second example is applied to the case where a plurality of corresponding FLUTE streams are zapping FLUTE streams and can be switched without causing an extra delay to each other (the relationship shown in FIG. 4). Ru.

Specifically, in addition to the first description example, NTP Synchronized and SegmentAlignedGroupID are introduced to Access. Access / NTP Synchronized belongs to the same group, ie zapping segmenter 62 of each channel (content supply device 60) of the same SegmentAlignedGroupID operates in NTP synchronization, ie the segment of FLUTE stream segment of each channel is NTP time Indicates that it is synchronized with the axis. Access / SegmentAlignedGroupID represents an ID of a group in which segment lengths of FLUTE stream segments are unified.

FIG. 21 shows an outline of a second description example of the OMA-ESG of FIG. Access in which NTPSynchronized and SegmentAlignedGroupID are introduced is used to group Service / Access groups that describe zapping streams.

If Access / NTP Synchronized (boolean type) is true, it indicates that the segment of the corresponding FLUTE stream is in NTP synchronization. If the Access / SegmentAlignedGroupIDs are the same, it indicates that the segment lengths of the FLUTE stream segments match. In the case of the second description example, the FLUTE stream indicated by circle 1 and the FLUTE stream indicated by circle 2 have their segment delimitation synchronized with each other and both belong to group ID = ID-1 Therefore, it indicates that the segment lengths match.

22 and 23 show a third description example of OMA-ESG. A of FIG. 22 is a description example of Service corresponding to the FLUTE stream for zapping shown by circle 1, and B of FIG. 22 is a description example of Access referring to Service of A of FIG. 22C is a description example of Service corresponding to the viewing FLUTE stream indicated by a circle 1 ', and D in FIG. 22 is an access description example referring to Service of C in FIG. 23A is a description example of Service corresponding to the FLUTE stream for zapping indicated by a circle 2, and B in FIG. 23 is an description example of Access referring to Service of A in FIG. 23. Also, C in FIG. 23 is a description example of Service corresponding to a viewing FLUTE stream indicated by a circle 2 ', and D in FIG. 23 is an access description example referring to Service of C in FIG.

This third description example is a relation (the relation shown in FIG. 4) in which the zapping FLUTE streams indicated by the circle 1 and the circle 2 can be switched without causing an extra delay to each other. From the viewing FLUTE stream indicated by the circle 1 ′ to the zapping FLUTE stream indicated by the circle 1 and from the viewing FLUTE stream indicated by the circle 2 ′ to the zapping FLUTE stream indicated by the circle 2 It applies in the case where it is a relation (the relation shown in FIG. 5) which can be switched only in one direction asymmetrically without causing an extra delay.

Specifically, in addition to the second description example, unsymmetricallyAlignedGroupFrom and unsymmetricallyAlignedGroupTo are introduced into Access. unsymmetricallyAlignedGroupFrom represents a relationship (group) that can be switched without causing an extra delay in one direction asymmetrically in only one direction and its switching source, and unsymmetricallyAlignedGroupTo represents the relationship (group) and its switching destination.

FIG. 24 shows an outline of a third description example of the OMA-ESG of FIG. 22 and FIG. In the third description example, it is indicated that circle 1 and circle 2 are zapping FLUTE streams that can be switched without causing an extra delay to each other. In addition, with respect to the FLUTE stream for zapping shown by circle 1, it can be switched asymmetrically in one direction only from the viewing FLUTE stream shown by circle 1 'without causing an extra delay. Furthermore, with respect to the FLUTE stream for zapping shown by circle 2, it can be switched asymmetrically in one direction only from the viewing FLUTE stream shown by circle 2 'without causing an extra delay.

[Operation of content supply system 50]
The operation of the content supply system 50 will be described.

FIG. 25 is a flow chart for explaining the processing performed by each content supply device 60 for distributing content streams by FLUTE multicast.

In step S1, the content supply device 60 synchronizes its own system time with the NTP time axis in accordance with the system time information provided by the NTP server 52. As a result, the zapping segmenter 62, the viewing segmenter 64, and the like constituting the content supply device 60 operate in synchronization with the NTP time axis.

In step S2, the channel server 61 generates zapping streaming data and viewing streaming data having different bit rates from the source data of the content. Further, the channel server 61 outputs the zapping streaming data to the zapping segmenter 62, and outputs the viewing streaming data to the viewing segmenter 64.

In step S 3, the zapping segmenter 62 generates a zapping segment stream such as fragmented MP 4 from the zapping streaming data and outputs the zapping segment stream to the FLUTE streamer 66. Further, the zapping segmenter 62 notifies the zapping metadata generator 63 of the URL of the supply source of the generated zapping segment stream and the like. In parallel to this, the viewing segmenter 64 generates a viewing segment stream such as fragmented MP 4 from the viewing streaming data and outputs the segment stream to the FLUTE streamer 66. Also, the viewing segmenter 64 notifies the viewing metadata generator 65 of the URL and the like of the supply source of the generated viewing segment stream.

In step S4, the FLUTE streamer 66 generates the zapping FLUTE stream by storing the zapping segment stream in the FLUTE packet and outputs the zapping FLUTE stream to the multicast server 68. Also, the FLUTE streamer 66 generates a viewing FLUTE stream by storing the viewing segment stream in a FLUTE packet and outputs the streaming FLUTE stream to the multicast server 68.

In step S5, the zapping metadata generator 63 generates zapping metadata and outputs the zapping metadata to the FLUTE streamer 66 and the WEB server 67. At the same time, the viewing metadata generator 65 generates viewing metadata and outputs it to the FLUTE streamer 66 and the WEB server 67.

In step S6, the FLUTE streamer 66 outputs the zapping metadata and the viewing metadata to the multicast server 68. The multicast server 68 distributes FLUTE multicast of zapping metadata and viewing metadata via the network 51.

In step S7, when there is a request (HTTP request) from the terminal device 80, the web server 67 distributes the zapping metadata or the viewing metadata to the request source via the network 51 in response to the request. .

In step S 8, the multicast server 68 distributes FLUTE multicasts for the zapping FLUTE stream and the viewing FLUTE stream via the network 51. Above, the process which each content supply apparatus 60 performs is complete | finished.

Next, a series of processes (hereinafter, referred to as a series of processes) of the content supply system 50 until the terminal device 80 transitions to the viewing phase through the zapping phase will be described.

FIG. 26 is a flowchart illustrating a series of processes of the content supply system 50.

In step S11, the terminal device 80 synchronizes its own system time with the NTP time axis in accordance with the system time information provided by the NTP server 52. In step S12, the terminal device 80 receives zapping metadata distributed by FLUTE multicast as the process of step S6 in FIG. Note that, instead of receiving the zapping metadata distributed by FLUTE multicast, the HTTP request may be transmitted to the WEB server 67 to distribute the zapping metadata by HTTP unicast, and may be received. The terminal device 80 that has received the zapping metadata is in the zapping phase.

In step S13, the terminal device 80 receives and reproduces the zapping FLUTE stream distributed by FLUTE multicast as the process of step S8 in FIG. 25 based on the zapping metadata.

During the zapping phase, the terminal device 80 can switch between the zapping LUTE streams being distributed by FLUTE multicast without causing an extra delay by appropriately repeating the process of step S13.

The terminal device 80 obtains viewing metadata during the zapping phase. Specifically, in step S14, the terminal device 80 receives the viewing metadata distributed by FLUTE multicast as the process of step S6 in FIG. It should be noted that the HTTP request may be transmitted to the WEB server 67 to cause the HTTP metadata to be distributed for viewing metadata, and the content may be received via HTTP unicast instead of receiving the viewing metadata for FLUTE multicast distribution. .

The terminal device 80 that has received the viewing metadata can transition from the zapping phase to the viewing phase.

In step S15, the terminal device 80 receives and reproduces the zapping FLUTE stream distributed by FLUTE multicast as the process of step S8 in FIG. 25 based on the viewing metadata.

After this, it is also possible to return from the viewing phase to the zapping phase, that is, to switch from the viewing FLUTE stream to the zapping FLUTE stream. At this time, if the viewing FLUTE stream before switching and the zapping FLUTE stream after switching have the relationship shown in FIG. 5, it is possible to switch without causing an extra delay.

This is the end of the description of the series of processes of the content supply system 50. According to the series of processes described above, zapping can be performed promptly.

In the above description, stream switching is performed in units of segments, but may be performed in units of subsegments in which segments are further subdivided. In that case, "segment" in the above description may be read as "sub-segment".

By the way, the content supply device 60 and the terminal device 80 that execute the series of processes described above can be realized by a computer executing software, in addition to hardware configuration. The computer includes, for example, a general-purpose personal computer capable of executing various functions by installing a computer incorporated in dedicated hardware and various programs.

FIG. 27 is a block diagram showing an example of the hardware configuration of the computer described above.

In the computer 200, a central processing unit (CPU) 201, a read only memory (ROM) 202, and a random access memory (RAM) 203 are mutually connected by a bus 204.

Further, an input / output interface 205 is connected to the bus 204. An input unit 206, an output unit 207, a storage unit 208, a communication unit 209, and a drive 210 are connected to the input / output interface 205.

The input unit 206 includes a keyboard, a mouse, a microphone and the like. The output unit 207 includes a display, a speaker, and the like. The storage unit 208 includes a hard disk, a non-volatile memory, and the like. The communication unit 209 is configured of a network interface or the like. The drive 210 drives removable media 211 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

In the computer 200 configured as described above, for example, the CPU 201 loads the program stored in the storage unit 208 into the RAM 203 via the input / output interface 205 and the bus 204 and executes the program. A series of processing is performed.

The program executed by the computer 200 (CPU 201) can be provided by being recorded on, for example, a removable medium 211 as a package medium or the like. Also, the program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

In the computer 200, the program can be installed in the storage unit 208 via the input / output interface 205 by attaching the removable media 211 to the drive 210. The program can be received by the communication unit 209 via a wired or wireless transmission medium and installed in the storage unit 208. In addition, the program can be installed in advance in the ROM 202 or the storage unit 208.

Note that the program executed by the computer 200 may be a program that performs processing in chronological order according to the order described in the present specification, or necessary timing such as when calling is performed in parallel or in parallel. The program may be a program to be processed in

Embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

The present disclosure can also be configured as follows.
(1)
According to an adaptive streaming technique, in a content supply apparatus that supplies, in the same channel, a plurality of streams having the same content and different bit rates,
A first stream generation unit that generates a zapping stream based on source data of the content;
A first metadata generation unit that generates zapping metadata for receiving the zapping stream;
A second stream generation unit configured to generate a viewing stream longer in minimum unit length when switching the stream than the zapping stream based on source data of the content;
A second metadata generation unit configured to generate viewing metadata for receiving the viewing stream;
A content supply apparatus comprising: a multicast distribution unit that multicasts the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via a network.
(2)
The content distribution apparatus according to (1), wherein the multicast distribution unit distributes the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via (e) MBMS through the FLUTE multicast. .
(3)
The zapping metadata and the viewing metadata are a combination of USD, MPD, and SDP, or a combination of OMA-ESG, USD, MPD, and SDP. The content supply according to (1) or (2). apparatus.
(4)
The first stream generation unit generates a stream having a sufficiently short minimum unit length when switching the stream, based on source data of the content,
The first metadata generation unit describes, in the zapping metadata, information indicating that a stream corresponding to the zapping metadata can be used for zapping applications. Content supply device.
(5)
In the first stream generation unit, the division of the minimum unit when switching the stream is in NTP synchronization based on the source data of the content, and the length of the minimum unit is unified with other channels Generate a stream for zapping,
The first metadata generation unit is information indicating that a stream corresponding to the zapping metadata can be used for the zapping stream, information indicating that the division of the minimum unit is NTP synchronized, or the information The at least one of the information indicating that the minimum unit length is in common with other channels is described in the zapping metadata. The content supply device according to any one of (1) to (3) .
(6)
In the second stream generation unit, the division of the minimum unit when switching the stream is in NTP synchronization, and the length of the minimum unit is the zapping stream generated by the first stream generation unit Generating a stream for viewing that is an integral multiple of the minimum unit,
Further, the first metadata generation unit is asymmetrically in one direction only from the viewing stream generated by the second stream generation unit with respect to the zapping stream corresponding to the zapping metadata. Information is described in the zapping metadata indicating that switching is possible without causing extra delays.
The second metadata generation unit is redundant in one direction only in one direction with respect to the zapping stream generated by the first stream generation unit from the viewing stream corresponding to the viewing metadata. The content providing device according to (5), wherein information representing that switching without causing delay is possible is described in the viewing metadata.
(7)
The content supply device according to any one of (1) to (6), further comprising: a unicast distribution unit configured to unicast the zapping metadata and the viewing metadata via a network.

50 content supply system, 51 network, 52 NTP server, 60 content supply device, 61 channel server, 62 segmenter for zapping, 63 metadata generator for zapping, 64 segmenter for viewing, 65 metadata generator for viewing, 66 FLUTE streamer, 67 Web server, 68 multicast server, 80 terminals, 100 computers, 101 CPU

Claims

According to an adaptive streaming technique, in a content supply apparatus that supplies, in the same channel, a plurality of streams having the same content and different bit rates,
A first stream generation unit that generates a zapping stream based on source data of the content;
A first metadata generation unit that generates zapping metadata for receiving the zapping stream;
A second stream generation unit configured to generate a viewing stream longer in minimum unit length when switching the stream than the zapping stream based on source data of the content;
A second metadata generation unit configured to generate viewing metadata for receiving the viewing stream;
A content supply apparatus comprising: a multicast distribution unit that multicasts the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via a network.
The content supply device according to claim 1, wherein the multicast distribution unit distributes the metadata for zapping, the metadata for viewing, the stream for zapping, and the streaming for viewing via FLUTE multicast via (e) MBMS.
The content supply device according to claim 2, wherein the zapping metadata and the viewing metadata are a combination of USD, MPD, and SDP, or a combination of OMA-ESG, USD, MPD, and SDP.
The first stream generation unit generates a stream having a sufficiently short minimum unit length when switching the stream, based on source data of the content,
The content supply device according to claim 2, wherein the first metadata generation unit describes, in the zapping metadata, information indicating that a stream corresponding to the zapping metadata can be used for zapping applications.
In the first stream generation unit, the division of the minimum unit when switching the stream is in NTP synchronization based on the source data of the content, and the length of the minimum unit is unified with other channels Generate a stream for zapping,
The first metadata generation unit is information indicating that a stream corresponding to the zapping metadata can be used for the zapping stream, information indicating that the division of the minimum unit is NTP synchronized, or the information The content supply device according to claim 2, wherein at least one of the information indicating that the length of the smallest unit is the same as that of another channel is described in the zapping metadata.
In the second stream generation unit, the division of the minimum unit when switching the stream is in NTP synchronization, and the length of the minimum unit is the zapping stream generated by the first stream generation unit Generating a stream for viewing that is an integral multiple of the minimum unit,
Further, the first metadata generation unit is asymmetrically in one direction only from the viewing stream generated by the second stream generation unit with respect to the zapping stream corresponding to the zapping metadata. Information is described in the zapping metadata indicating that switching is possible without causing extra delays.
The second metadata generation unit is redundant in one direction only in one direction with respect to the zapping stream generated by the first stream generation unit from the viewing stream corresponding to the viewing metadata. The content supply device according to claim 5, wherein information representing that switching without delay is possible is described in the viewing metadata.
The content supply device according to claim 2, further comprising: a unicast distribution unit configured to perform unicast distribution of the zapping metadata and the viewing metadata via a network.
According to an adaptive streaming technique, in a content supply method of a content supply apparatus for supplying, in the same channel, a plurality of streams having the same content and different bit rates,
According to the content supply device
A stream for generating a zapping stream based on source data of the content and generating a viewing stream having a longer minimum unit length when switching the stream than the zapping stream based on the source data of the content A generation step,
A metadata generation step of generating zapping metadata for receiving the zapping stream and generating viewing metadata for receiving the viewing stream;
A content delivery method comprising: multicast distribution of the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via a network.
According to adaptive streaming technology, a computer that supplies a plurality of streams having the same content but different bit rates in the same channel,
A first stream generation unit that generates a zapping stream based on source data of the content;
A first metadata generation unit that generates zapping metadata for receiving the zapping stream;
A second stream generation unit configured to generate a viewing stream longer in minimum unit length when switching the stream than the zapping stream based on source data of the content;
A second metadata generation unit configured to generate viewing metadata for receiving the viewing stream;
A program that functions as a multicast distribution unit that multicasts the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via a network.
According to an adaptive streaming technique, a terminal apparatus receiving the stream supplied from a content supply apparatus that supplies a plurality of streams having the same content and different bit rates in the same channel,
The content supply device is
A first stream generation unit that generates a zapping stream based on source data of the content;
A first metadata generation unit that generates zapping metadata for receiving the zapping stream;
A second stream generation unit configured to generate a viewing stream longer in minimum unit length when switching the stream than the zapping stream based on source data of the content;
A second metadata generation unit configured to generate viewing metadata for receiving the viewing stream;
A multicast distribution unit that multicasts the zapping metadata, the viewing metadata, the zapping stream, and the viewing stream via a network;
The zapping metadata is acquired, and the zapping stream is received and reproduced based on the acquired zapping metadata, and the viewing metadata is acquired, and the viewing metadata is acquired based on the acquired metadata. A terminal device that receives and plays a stream for viewing.
A content supply system comprising: a content supply apparatus for supplying a plurality of streams having the same content and different bit rates in the same channel according to an adaptive streaming technology, and a terminal apparatus for receiving the streams;
The content supply device is
A first stream generation unit that generates a zapping stream based on source data of the content;
A first metadata generation unit that generates zapping metadata for receiving the zapping stream;
A second stream generation unit configured to generate a viewing stream longer in minimum unit length when switching the stream than the zapping stream based on source data of the content;
A second metadata generation unit configured to generate viewing metadata for receiving the viewing stream;
The zapping metadata, the viewing metadata, the zapping stream, and a multicast distribution unit that multicasts the viewing stream via a network.
The terminal device is
The zapping metadata is acquired, and the zapping stream is received and reproduced based on the acquired zapping metadata, and the viewing metadata is acquired, and the viewing metadata is acquired based on the acquired metadata. Content supply system that receives and plays viewing streams.