FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“CONTENT SUPPLY DEVICE, CONTENT SUPPLY METHOD, PROGRAM,
TERMINAL DEVICE, AND CONTENT SUPPLY SYSTEM”
SONY CORPORATION, of 1-7-1, Konan, Minato-ku, Tokyo 108-0075, Japan
The following specification particularly describes the invention and the manner in
which it is to be performed.
2
Description
Title of Invention
CONTENT SUPPLY DEVICE, CONTENT SUPPLY METHOD, PROGRAM,
TERMINAL DEVICE, AND CONTENT 5 SUPPLY SYSTEM
Technical Field
[0001]
The present disclosure relates to a content supply device, a content supply
10 method, a program, a terminal device, and a content supply system, and more
particularly, to a content supply device, a content supply method, a program, a
terminal device, and a content supply system capable of performing zapping between
channels through which different content is delivered rapidly.
15 Background Art
[0002]
Moving Picture Experts Group-Dynamic Adaptive Streaming over HTTP
(hereinafter, referred to as "DASH") (MPEG-DASH) using the same HTTP as
browsing of a web site as an internationally standardized moving image delivery
20 protocol available for moving image delivery via the Internet has been known (for
example, see Non-Patent Literature 1).
[0003]
DASH implements adaptive streaming technology. In other words, a
content supply side is configured to prepare a plurality of streams in which content of
25 the same subject is included, and an image quality, an angle of view size, or the like
changes according to a communication environment of the Internet serving as a
delivery path or a capability or a state of a reception side. On the other hand, the
reception side can select an optimal stream among the plurality of streams prepared
by the supply side according to the communication environment of the Internet, the
30 decoding capability of the reception side, or the like and acquire and reproduce the
selected optimal stream.
3
[0004]
As described above, in the DASH, a metafile called a media presentation
description (MPD) is supplied from the supply side to the reception side so that the
reception side can adaptively select and acquire a stream.
5 [0005]
An address (url information) of a supply source of streaming data (media
data such as audio/video/subtitle) of content divided into chunks is described in the
MPD. The reception side can access a predetermined server serving as a content
supply source based on the url information, requests streaming data, and receives and
10 reproduce streaming data HTTP-unicast-delivered according to the request.
[0006]
FIG. 1 illustrates an example of a configuration of a content supply system
that delivers content in a streaming manner based on the DASH.
[0007]
15 A content supply system 10 includes a plurality of content supply devices 20
(in this case, 20A, 20B, and 20C) of a side at which content is supplied and a
plurality of DASH clients 30 of a side at which content is received. The DASH
clients 30 are connected to the content supply device 20 via a CDN 12 using the
Internet 11.
20 [0008]
The content supply device 20A delivers content of the same subject through
a plurality of streams as a channel A. The content supply device 20B delivers
content of the same subject different from content of the channel A through a
plurality of streams as a channel B. The same applies to the content supply device
25 20C. Hereinafter, when it is unnecessary to distinguish the content supply devices
20A, 20B, and 20C individually, the content supply device is referred to simply as a
content supply device 20.
[0009]
The content supply device 20 includes a content management server 21, a
30 DASH segment streamer 22, and a DASH MPD server 23.
[0010]
4
The content management server 21 manages content supplied to the DASH
clients 30, generates a plurality of pieces of streaming data having different bit rates
from content of the same subject, and outputs the generated streaming data to the
DASH segment streamer 22.
5 [0011]
The DASH segment streamer 22 temporally divides each piece of streaming
data into segments, holds each of the segments as a file, and notifies the DASH MPD
server 23 of an address of a supply source of the files. Further, the DASH segment
streamer 22 HTTP-unicast-delivers the file of the segmented streaming data in
10 response to a request (an HTTP request) from the DASH client 30, as a WEB server.
[0012]
The DASH MPD server 23 generates an MPD in which, for example, an
address indicating a supply source of files of (segments of) a plurality of pieces of
streaming data is described. The DASH MPD server 23 HTTP-unicast-delivers the
15 generated MPD according to the request (the HTTP request) from the DASH client
30 as the WEB server.
[0013]
The DASH client 30 requests the DASH MPD server 23 to transmit the
MPD, request the DASH segment streamer 22 to transmit the streaming data based
20 on the MPD HTTP-unicast-delivered according to the request, and receive and
reproduce the file HTTP-unicast-delivered according to the request.
[0014]
A cache server (not illustrated) is installed on the CDN 12. The cache
server caches the MPD or the file of the streaming data which is HTTP-unicast25
delivered through the CND 12, and HTTP-unicast-delivers the cached MPD or the
like to the DASH client 30 that has transmitted the HTTP request instead of the
DASH MPD server 23 serving as the WEB server or the DASH segment streamer 22.
Citation List
30 Non-Patent Literature
[0015]
5
Non-Patent Literature 1: Mitsuhiro Hirabayashi, “Achieving Uninterrupted
Video Streaming Using Existing Web Servers,” NIKKEI ELECTRONICS, March 19,
2012
Summary 5 of Invention
Technical Problem
[0016]
As described above, in DASH, an adaptive streaming technique using
HTTP-unicast delivery is implemented, and in the configuration of FIG. 1, a plurality
10 of channels (the content supply devices 20A, 20B, and 20C) are prepared, and thus a
plurality of pieces of content having different subjects can be simultaneously
delivered to the reception side.
[0017]
When it is possible to simultaneously supply a plurality of pieces of content
15 having different subjects as described above, the viewer is expected to be able to
perform so-called zapping (an operation of switching channels one after another
within a short period of time and searching for content to be viewed), similarly to
when viewing television broadcasts.
[0018]
20 In DASH, switching between channels is performed in units of segments or
in units of sub segments obtained by subdividing a segment. Hereinafter, a
description will continue under the assumption that, in DASH, switching between
channels is performed in units of segments.
[0019]
25 FIGS. 2 and 3 illustrate that three streams (representations) having different
bit rates serving as content of the same subject in channels A, B, and C of DASH are
prepared, and illustrate switching examples when zapping between channels is
performed.
[0020]
30 In DASH, since a segment length (a duration) is arbitrary, channels need not
necessarily have the same segment length. Further, channels need not necessarily
6
have the same reproduction start time of a segment at the head of content.
[0021]
FIG. 2 illustrates an example in which channels have neither the same
segment length nor the same reproduction start time of the segment at the head of
5 content.
[0022]
In this case, even if the user of the DASH client 30 gives an instruction to
perform switching (zapping) to a representation B2 of a channel B before T1 on a
DASH client time axis while viewing a representation A2 of a channel A, the
10 switching is delayed until T2 serving as a segment delimiter of the representation B2.
Further, even if the user gives an instruction to perform switching to a representation
C2 of a channel C before T3 while viewing the representation B2 of the channel B,
the switching is delayed until T4 serving as a segment delimiter of the representation
C2.
15 [0023]
FIG. 3 illustrates an example in which channels do not have the same
segment length, but the reproduction start times of the segments at the head of
content are matched in synchronization with an NTP time axis.
[0024]
20 In this case, even if the user of the DASH client 30 gives an instruction to
perform switching to the representation B2 of the channel B before T1 on the NTP
time axis while viewing the representation A2 of the channel A, the switching is
delayed until T2 serving as a segment delimiter of the representation B2. Further,
even if the user gives an instruction to perform switching to the representation C2 of
25 the channel C before T3 while viewing the representation B2 of the channel B, the
switching is delayed until T4 serving as a segment delimiter of the representation C2.
[0025]
As described above, in DASH, when a stream is switched between channels,
an extra delay occurs. Thus, in this case, it is difficult to perform rapid zapping
30 between channels.
[0026]
7
Further, although the occurrence of the above-described delay can be
suppressed by reducing the segment length of the segment of each channel to be
extremely small, in this case, coding efficiency deteriorates, a data amount of a
stream increases, and a wide communication band is necessary, and thus an excessive
load is put on the Internet 11, and service quality is likely 5 to deteriorate.
[0027]
The present disclosure was made in light of the foregoing, and it is desirable
to implement rapid zapping between channels in DASH.
10 Solution to Problem
[0028]
According to a first aspect of the present disclosure, there is provided a
content supply device that supplies a plurality of pieces of streaming data that
include content of a same subject and differ in attribute through a same channel,
15 according to an adaptive streaming technique, the content supply device including: a
zapping segment stream generating unit configured to generate a zapping segment
stream by delimiting zapping streaming data among the plurality of pieces of
streaming data into minimum units when reception of the streaming data is switched,
according to a common timing with another channel; a unicast delivery unit
20 configured to unicast-deliver the zapping segment stream; a multicast delivery unit
configured to multicast-deliver the zapping segment stream; and a metafile
generating unit configured to generate a metafile for a reception side to receive the
zapping segment stream that is unicast-delivered and multicast-delivered.
[0029]
25 The zapping segment stream generating unit can generate the zapping
segment stream by delimiting the zapping streaming data into the minimum units,
according to a common timing with the other channel belonging to a same group.
[0030]
The unicast delivery unit can HTTP-unicast-deliver the zapping segment
30 stream. The multicast delivery unit can FLUTE-multicast-deliver a zapping
FLUTE stream based on the zapping segment stream.
8
[0031]
The content supply device according to the first aspect of the present
disclosure can further include: an RTP stream generating unit configured to generate
a zapping RTP stream based on the zapping streaming data among the plurality of
pieces of streaming data. The metafile generating unit can generate 5 a metafile for
the reception side to receive the zapping segment stream that is HTTP-unicastdelivered,
the zapping FLUTE stream that is FLUTE-multicast-delivered, and the
zapping RTP stream that is RTP-multicast-delivered. The multicast delivery unit
can also RTP-multicast-deliver the zapping RTP stream.
10 [0032]
The zapping segment stream generating unit can generate the zapping
segment stream by aligning heads of the minimum units with the other channel
belonging to the same group in synchronization with an NTP time axis and
delimiting the zapping streaming data into the minimum units using a common
15 duration with the other channel belonging to the same group.
[0033]
The zapping segment stream generating unit can generate the zapping
segment stream by delimiting the zapping streaming data into the minimum units
using a duration shorter than the minimum unit of viewing streaming data.
20 [0034]
The metafile generating unit can generate an extended MPD as the metafile.
[0035]
The content supply device according to the first aspect of the present
disclosure can further include: a collecting unit configured to collect the metadata
25 and supply the metadata to the reception side.
[0036]
The metafile generating unit can generate the MPD in which an
MPD/@NTPSynchronized attribute and an MPD/SegmentAlignedGroupID attribute
are introduced, as the metafile. The collecting unit can collect the metadata for the
30 zapping based on the MPD/@NTPSynchronized attribute and the
MPD/SegmentAlignedGroupID attribute.
9
[0037]
The metafile generating unit can generate the MPD in which an
MPD/@forZapping attribute is introduced, as the metafile. The collecting unit can
collect the metadata for the zapping based on the MPD/@forZapping attribute.
5 [0038]
The metafile generating unit can describe at least one of a duration and a
maximum duration of the minimum unit of the streaming data in the metadata, as the
metafile. The collecting unit can collect the metadata for the zapping based on the
at least one of the duration and the maximum duration of the minimum unit of the
10 streaming data.
[0039]
According to the first aspect of the present disclosure, there is provided a
content supply method of a content supply device that supplies a plurality of pieces
of streaming data that include content of a same subject and differ in attribute
15 through a same channel, according to an adaptive streaming technique, the content
supply method including: a zapping segment stream generating step of generating, by
the content supply device, a zapping segment stream by delimiting zapping
streaming data among the plurality of pieces of streaming data into minimum units
when reception of the streaming data is switched, according to a common timing
20 with another channel; a unicast delivery step of unicast-delivering, by the content
supply device, the zapping segment stream; a multicast delivery step of multicastdelivering,
by the content supply device, the zapping segment stream; and a metafile
generating step of generating, by the content supply device, a metafile for a reception
side to receive the zapping segment stream that is unicast-delivered and multicast25
delivered.
[0040]
According to the first aspect of the present disclosure, there is provided a
program causing a computer that supplies a plurality of pieces of streaming data that
include content of a same subject and differ in attribute through a same channel,
30 according to an adaptive streaming technique to function as: a zapping segment
stream generating unit configured to generate a zapping segment stream by
10
delimiting zapping streaming data among the plurality of pieces of streaming data
into minimum units when reception of the streaming data is switched, according to a
common timing with another channel; a unicast delivery unit configured to unicastdeliver
the zapping segment stream; a multicast delivery unit configured to multicastdeliver
the zapping segment stream; and a metafile generating 5 unit configured to
generate a metafile for a reception side to receive the zapping segment stream that is
unicast-delivered and multicast-delivered.
[0041]
In the first aspect of the present disclosure, a zapping segment stream is
10 generated by delimiting zapping streaming data among a plurality of pieces of
streaming data into minimum units when reception of the streaming data is switched,
according to a common timing with another channel, the zapping segment stream is
unicast-delivered, and the zapping segment stream is multicast-delivered. Further, a
metafile for a reception side to receive the zapping segment stream that is unicast15
delivered and multicast-delivered is generated.
[0042]
According to a second aspect of the present disclosure, there is provided a
terminal device that receives streaming data supplied from a content supply device
that supplies a plurality of pieces of streaming data that include content of a same
20 subject and differ in attribute through a same channel, according to an adaptive
streaming technique. The content supply device includes a zapping segment stream
generating unit configured to generate a zapping segment stream by delimiting
zapping streaming data among the plurality of pieces of streaming data into
minimum units when reception of the streaming data is switched, according to a
25 common timing with another channel, a unicast delivery unit configured to unicastdeliver
the zapping segment stream, a multicast delivery unit configured to multicastdeliver
the zapping segment stream, and a metafile generating unit configured to
generate a metafile for a reception side to receive the zapping segment stream that is
unicast-delivered and multicast-delivered. The terminal device acquires the
30 metafile, and switches reception of the zapping segment stream that is unicastdelivered
and multicast-delivered through different channels, based on the acquired
11
metafile.
[0043]
In the second aspect of the present disclosure, the metafile is acquired, and
reception of the zapping segment stream that is unicast-delivered and multicastdelivered
through different channels is switched based on the 5 acquired metafile.
[0044]
According to a third aspect of the present disclosure, there is provided a
content supply system including: a content supply device configured to supply a
plurality of pieces of streaming data that include content of a same subject and differ
10 in attribute through a same channel, according to an adaptive streaming technique;
and a terminal device configured to receive the streaming data. The content supply
device includes a zapping segment stream generating unit configured to generate a
zapping segment stream by delimiting zapping streaming data among the plurality of
pieces of streaming data into minimum units when reception of the streaming data is
15 switched, according to a common timing with another channel, a unicast delivery
unit configured to unicast-deliver the zapping segment stream, a multicast delivery
unit configured to multicast-deliver the zapping segment stream, and a metafile
generating unit configured to generate a metafile for a reception side to receive the
zapping segment stream that is unicast-delivered and multicast-delivered. The
20 terminal device acquires the metafile, and switches reception of the zapping segment
stream that is unicast-delivered and multicast-delivered through different channels,
based on the acquired metafile.
[0045]
In the third aspect of the present disclosure, a content supply device
25 generates a zapping segment stream by delimiting zapping streaming data among a
plurality of pieces of streaming data into minimum units when reception of the
streaming data is switched, according to a common timing with another channel,
unicast-delivers the zapping segment stream, and multicast-delivers the zapping
segment stream. The content supply device generates a metafile for a reception side
30 to receive the zapping segment stream that is unicast-delivered and multicastdelivered.
A terminal device acquires the metafile, and switches reception of the
12
zapping segment stream that is unicast-delivered and multicast-delivered through
different channels, based on the acquired metafile.
Advantageous Effects of Invention
5 [0046]
According to the first to third aspects of the present disclosure, it is possible
to implement rapid zapping between channels in DASH.
Brief Description of Drawings
10 [0047]
[FIG. 1] FIG. 1 is a block diagram illustrating an example of a configuration of a
content supply system of the related art.
[FIG. 2] FIG. 2 is a diagram for describing a delay occurring due to switching
between channels.
15 [FIG. 3] FIG. 3 is a diagram for describing a delay occurring due to switching
between channels.
[FIG. 4] FIG. 4 is a diagram for describing an overview of the present disclosure.
[FIG. 5] FIG. 5 is a block diagram illustrating an exemplary configuration of a
content supply system to which the present disclosure is applied.
20 [FIG. 6] FIG. 6 is a diagram illustrating the flow of data at the time of zapping.
[FIG. 7] FIG. 7 is a diagram illustrating the flow of data at the time of viewing.
[FIG. 8] FIG. 8 is a diagram illustrating an arrangement of a USD in an MBMS.
[FIG. 9] FIG. 9 is a diagram illustrating an arrangement of a USD in an MBMS.
[FIG. 10] FIG. 10 is a diagram illustrating an example in which an MPD is described
25 in an XML format.
[FIG. 11] FIG. 11 is a diagram illustrating an example in which an extended MPD is
described in an XML format.
[FIG. 12] FIG. 12 is a flowchart for describing a process of a content supply device.
[FIG. 13] FIG. 13 is a diagram illustrating a difference between a zapping segment
30 length and a viewing segment length.
[FIG. 14] FIG. 14 is a flowchart for describing a series of processes of a content
13
supply system.
[FIG. 15] FIG. 15 is a flowchart for describing a series of processes of a content
supply system.
[FIG. 16] FIG. 16 is a flowchart for describing a series of processes of a content
5 supply system.
[FIG. 17] FIG. 17 is a block diagram illustrating an exemplary configuration of a
computer.
Description of Embodiments
10
[0048]
Hereinafter, preferred modes (hereinafter referred to as embodiments) for
carrying out the present disclosure will be described in detail. Before that, an
overview of the present disclosure will be described with reference to FIG. 4.
15 [0049]
FIG. 4 illustrates a switching example in which zapping is performed among
a plurality of channels prepared in a content supply system according to an
embodiment of the present disclosure.
[0050]
20 FIG. 4 illustrates that different content is delivered in the channels A, B, and
C, and three streams (representations) having different bit rates are prepared in each
channel.
[0051]
In the content supply system to which the present disclosure is applied, a
25 segment delimiter of content is synchronized with an NTP time axis, and segment
lengths of respective channels belonging to a predetermined group are set to one
common duration. Further, starting points
(MPD/@availabilityStartTime+Period/@start) of media reproduction times at the
heads of segments are set to be matched on the NTP time axis.
30 [0052]
As the above setting is performed, when the viewer using the content supply
14
system gives an instruction to perform switching to the representation B2 of the
channel B before T1 on the DASH client time axis while viewing the representation
A2 of the channel A, the switching is performed at T1 serving as both the segment
delimiter of the representation A2 and the segment delimiter of the representation B2
as 5 illustrated in FIG. 4.
[0053]
Further, when the viewer gives an instruction to perform switching to the
representation C2 of the channel C before T2 while viewing the representation B2 of
the channel B, the switching is performed at T2 serving as both the segment delimiter
10 of the representation B2 and the segment delimiter of the representation C2.
Moreover, when the viewer gives an instruction to perform switching to the
representation A2 of the channel A before T3 while viewing the representation C2 of
the channel C, the switching is performed at T3 serving as both the segment delimiter
of the representation C2 and the segment delimiter of the representation A2.
15 [0054]
In the content supply system, one or more pieces of zapping streaming data
serving as content of the same subject and two or more pieces of viewing streaming
data having a higher bit rate than the zapping streaming data are prepared in each
channel. Further, in channels belonging to the same group, the segment lengths of
20 the zapping streaming data are set to the same length, and the reproduction start
times of the segments at the heads of content are set to be matched in
synchronization with an NTP time.
[0055]
Further, in the content supply system, the zapping streaming data, the
25 viewing streaming data, and the MPD used to receive the zapping streaming data and
the viewing streaming data are supplied through not only HTTP-unicast delivery but
also multicast delivery performed via a broadcasting network in which
communication quality is guaranteed. Specifically, the MPD is supplied through
HTTP-unicast delivery, UPD-multicast delivery, and FLUTE-multicast delivery.
30 The zapping streaming data and the viewing streaming data are supplied through the
HTTP-unicast delivery, the FLUTE-multicast delivery, and the RTP-multicast
15
delivery.
[0056]
Further, when zapping is performed, the reception side receives and
reproduces the multicast-delivered zapping streaming data using the MPD that is
multicast-delivered whenever possible. When this is difficult, 5 the reception side
receives and reproduces the multicast-delivered zapping streaming data using the
HTTP-unicast-delivered MPD. When this is also difficult, the reception side
receives and reproduces the HTTP-unicast-delivered zapping streaming data using
the HTTP-unicast-delivered MPD.
10 [0057]
As a result, it is possible to suppress the occurrence of an extra delay when
zapping is performed between channels belonging to the same group. Further, it is
possible to suppress a situation in which an excessive load is put on the Internet and
service quality also deteriorates.
15 [0058]
[Exemplary configuration of content supply system]
FIG. 5 illustrates an exemplary configuration of a content supply system
according to an embodiment of the present disclosure.
[0059]
20 The content supply system 50 includes a plurality of content supply devices
60X corresponding to a channel X (X=A, B, ), an MPD acquisition portal 70, and a
plurality of terminal devices 80. The terminal device 80 is connected to the content
supply device 60 via a network 51.
[0060]
25 Here, the network 51 includes various broadcasting networks using
terrestrial broadcasting waves, satellite broadcasting waves, a mobile broadcasting
(e)MBMS, or the like in addition to a two-way communication network represented
by the Internet and a CDN using the Internet.
[0061]
30 An NTP server 52 that provides system time information according to a
UTC time format is disposed on (the Internet included in) the network 51. The
16
content supply devices 60 and the terminal devices 80 are assumed to operate in a
state in which system time is synchronized with the NTP time axis according to the
system time information provided from the NTP server 52.
[0062]
The content supply device 60A corresponding to the channel 5 A includes a
channel server 61, a zapping segmenter 62, a zapping MPD generator 63, a viewing
segmenter 64, a viewing MPD generator 65, an RTP streamer 66, a FLUTE streamer
67, a WEB server 68, and a multicast server 69.
[0063]
10 The channel server 61 to the multicast server 69 installed in the content
supply device 60A may be integratedly arranged or may be distributedly arranged via
the Internet or the like.
[0064]
FIGS. 6 and 7 illustrate the flow of various kinds of data between the
15 channel server 61 to the multicast server 69. FIG. 6 illustrates the flow of various
kinds of data at the time of zapping, and FIG. 7 illustrates the flow of various kinds
of data at the time of viewing.
[0065]
The channel server 61 manages source data of content delivered from the
20 channel A, and generates one or more pieces of zapping streaming data and two or
more pieces of viewing streaming data that differ in bit rate from the source data of
the same subject. The channel server 61 outputs the zapping streaming data to the
zapping segmenter 62 and the RTP streamer 66, and outputs the viewing streaming
data to the viewing segmenter 64 and the RTP streamer 66.
25 [0066]
The zapping segmenter 62 generates a zapping segment stream such as a
fragmented MP4 by temporally delimiting the zapping streaming data into periods
and further dividing a period into segments, and outputs the generated zapping
segment stream to the FLUTE streamer 67 and the WEB server 68. The zapping
30 segment stream has the same segment length as the zapping segment streams of other
channels belonging to the same group, and is set to one duration shorter than a
17
segment length of a viewing segment stream which will be described later. The
zapping segmenter 62 operates in synchronization with the NTP time axis, and thus
the segment delimiter is synchronized with the NTP time axis as well.
[0067]
The zapping segmenter 62 notifies the zapping 5 MPD generator 63 of
metadata (for example, a URL of the WEB server 68 serving as a supply source of a
file storing the zapping segment stream) of the generated zapping segment stream.
[0068]
The zapping MPD generator 63 generates an MPD (hereinafter referred to
10 as a zapping MPD) extended for zapping necessary when the terminal device 80
receives the zapping segment stream or a zapping RTP stream (which will be
described later), and outputs the zapping MPD to the FLUTE streamer 67 and the
WEB server 68.
[0069]
15 The viewing segmenter 64 generates a viewing segment stream by
temporally delimiting the viewing streaming data into periods and further dividing
the periods into segments, and outputs the generated viewing segment stream to the
FLUTE streamer 67 and the WEB server 68. The viewing segmenter 64 notifies the
viewing MPD generator 65 of metadata (for example, a URL of the WEB server 68
20 serving as a supply source of a file storing the viewing segment stream) of the
generated viewing segment stream.
[0070]
The viewing MPD generator 65 generates an MPD (hereinafter referred to
as a viewing MPD) necessary when the terminal device 80 receives the viewing
25 segment stream or a viewing RTP stream (which will be described later), and outputs
the generated viewing MPD to the FLUTE streamer 67 and the WEB server 68.
[0071]
The zapping MPD generated in the zapping MPD generator 63 and the
viewing MPD generated in the viewing MPD generator 65 correspond to content of
30 the same subject, and are explicitly associated with each other, for example, through
a URL of an acquisition destination. Specifically, for example, when the URL of
18
the acquisition destination of the zapping MPD is
http://a.com/channel_1.forZapping.mpd, the URL of the acquisition destination of
the viewing MPD is regarded to be http://a.com/channel_1.mpd or the like.
[0072]
The RTP streamer 66 generates a zapping RTP stream 5 and a viewing RTP
stream by storing the zapping streaming data and the viewing streaming data input
from the channel server 61 in RTP packets, and outputs the zapping RTP stream and
the viewing RTP stream to the multicast server 69. The RTP streamer 66 notifies
the zapping MPD generator 63 of the metadata of the zapping RTP stream, and
10 notifies the viewing MPD generator 65 of the metadata of the viewing RTP stream.
[0073]
The FLUTE streamer 67 generates a zapping FLUTE stream and a viewing
FLUTE stream by storing the zapping segment stream input from the zapping
segmenter 62 and the viewing segment stream input from the viewing segmenter 64
15 in FLUTE packets, and outputs the zapping FLUTE stream and the viewing FLUTE
stream to the multicast server 69. The FLUTE streamer 67 outputs the zapping
MPD input from the zapping MPD generator 63 and the viewing MPD input from
the viewing MPD generator 65 to the multicast server 69.
[0074]
20 The WEB server 68 HTTP-unicast-delivers the zapping MPD or the viewing
MPD to the request source according to a request (an HTTP request) from the MPD
acquisition portal 70 or the terminal device 80. The WEB server 68 HTTP-unicastdelivers
the zapping segment stream or the viewing segment stream to the request
source according to the request (the HTTP request) from the terminal device 80.
25 [0075]
The multicast server 69 FLUTE-multicast-delivers and UDP-multicastdelivers
the zapping MPD and the viewing MPD. The multicast server 69 FLUTEmulticast-
delivers the zapping FLUTE stream and the viewing FLUTE stream. The
multicast server 69 RTP-multicast-delivers the zapping RTP stream and the viewing
30 RTP stream.
[0076]
19
The content supply device 60B corresponding to the channel B has a similar
configuration to the content supply device 60A, and thus a description thereof is
omitted.
[0077]
The MPD acquisition portal 70 crawls the content supply 5 devices 60 of the
respective channels according to the query API requesting the zapping MPD from the
terminal device 80, collects the zapping MPDs, and transmits the zapping MPDs to
the terminal device 80. When no zapping MPD is generated by the content supply
devices 60 of the respective channels, the viewing MPD satisfying a predetermined
10 condition (which will be described later) is collected and transmitted to the terminal
device 80. The MPD acquisition portal 70 crawls the content supply devices 60 of
the respective channels according to the query API requesting the viewing MPD
from the terminal device 80, collects the viewing MPDs, and transmits the viewing
MPDs to the terminal device 80.
15 [0078]
When the zapping is performed, the terminal device 80 acquires the
multicast-delivered zapping MPD whenever possible, and receives and reproduces
the multicast-delivered zapping stream (the FLUTE stream or the RTP stream) based
on the acquired zapping MPD whenever possible. When this is difficult, the
20 terminal device 80 acquires the HTTP-unicast-delivered MPD, and receives and
reproduces the multicast-delivered zapping stream. When this is also difficult, the
terminal device 80 receives and reproduces the HTTP-unicast-delivered zapping
streaming data using the HTTP-unicast-delivered MPD.
[0079]
25 Further, when the terminal device 80 knows the address of the acquisition
destination of the zapping MPD or the viewing MPD, the terminal device 80 can
acquire the zapping MPD or the viewing MPD directly without using the MPD
acquisition portal 70.
[0080]
30 The terminal device 80 refers to the zapping MPD or the viewing MPD
when receiving the zapping or viewing segment stream or the RTP stream. Further,
20
the terminal device 80 refers to announcement information in which a portal channel
of the multicast server 69 performing the FLUTE-multicast delivery is described
when receiving the zapping MPD, the viewing MPD, or the zapping or viewing
FLUTE stream which is FLUTE-multicast-delivered.
5 [0081]
The announcement information is known through an interaction channel or
a broadcast/multicast channel, for example, by a user service description (USD) in
the MBMS when the FLUTE-multicast delivery is performed through the mobile
broadcasting (e)MBMS included in the network 51. FIG. 8 illustrates an
10 arrangement of the USD in the MBMS.
[0082]
Further, when the FLUTE-multicast delivery is performed through the
terrestrial broadcasting waves or the satellite broadcasting included in the network 51,
the announcement information is known through the interaction channel or the
15 broadcast/multicast channel, for example, an electronic service guide (ESG) of DVBH
(IPDC). FIG. 9 illustrates an arrangement of the ESG in the DVB-H (IPDC).
[0083]
Alternatively, the MPD acquisition portal 70 may be configured to manage
the announcement information and notify the request source of the announcement
20 information according to a request from the terminal device 80.
[0084]
[Extension of MPD]
Next, the MPD in the DASH and an extension thereof will be described.
[0085]
25 In the MPD, information related to content (Media) is divided into units of
periods. In each period, a plurality of representations including information related
to streaming data of the same subject that differs in image quality or an angle of view
size and differs in a stream attribute such as a bit rate are prepared. The
representation stores information related to a segment obtained by further temporally
30 dividing a period.
[0086]
21
FIG. 10 illustrates an example in which a structure below the representation
is described in an XML format.
[0087]
In FIG. 10, "http://example.com/counter-10mn_avc_dash.mp4" described in
MPD/Period/AdaptationSet/Representation/BaseURL indicates 5 the address of the
supply source of the file into which a plurality of segments are collectively converted.
[0088]
MPD/Period/AdaptationSet/Representation/SegmentList/SegmentURL/@m
ediaRange indicates a byte range of the segmented streaming data in the file.
10 [0089]
For example, MPD/Period/AdaptationSet/Representation/SegmentList/
SegmentURL/@mediaRange="795-83596" indicates that the byte range of a 795th
byte to an 83596th byte in the file is first segmented streaming data.
[0090]
15 Thus, when the terminal device 40 acquires first segmented streaming data,
it is desirable to designate the mediaRange "795-83596" to a range header together
with a url "http://example.com/counter-10mn_avc_dash.mp4" of the file and issue an
HTTP request. At this time, the HTTP request is as follows:
GET /counter-10mn_avc_dash.mp4 HTTP/1.1
20 Host: example.com
Range: bytes=795-83596
[0091]
FIG. 11 illustrates an example in which a structure below the MPD extended
as the zapping MPD is described in an XML format.
25 [0092]
In other words, in the extended MPD, an MPD/@NTPSynchronized (a
boolean type, and a value is true/false) attribute and an
MPD/@SegmentAlignedGroupID (group identifier) attribute are newly introduced
below the MPD.
30 [0093]
True or false indicating whether or not the segment delimiter of the segment
22
stream for the MPD is in synchronization with the NTP time axis is described in the
MPD/@NTPSynchronized attribute. In this case, when the zapping segmenter 62
operates in synchronization with the NTP time axis, the segment delimiters are
matched on the NTP time axis. Thus, the value of the synchronous
MPD/@NTPSynchronized 5 attribute is true.
[0094]
An identifier of a group to which channels in which the segment delimiters
of the segment stream are matched belong is described in the
MPD/@SegmentAlignedGroupID attribute.
10 [0095]
Thus, the MPD acquisition portal 70 preferably collects the MPD (the
zapping MPD) in which the MPD/@NTPSynchronized attribute is true, and the
MPD/@SegmentAlignedGroupID attribute is the same group identifier according to
the following query API requesting the zapping MPD from the terminal device 80:
15 Http://the MPDPortal.com/getMPDforZapping
Between the channels corresponding to the collected zapping MPD, the
segment delimiters are matched in synchronization with the NTP time axis, and thus
rapid zapping is possible.
[0096]
20 Although not illustrated, in the zapping MPD, within the group to which the
channels of the content supply devices 60 belong, the starting points
(MPD/@availabilityStartTime+Period/@start) of the media reproduction times at the
heads of the segments are matched on the NTP time axis.
[0097]
25 At least one of a segmentBase/@duration attribute storing a value indicating
the segment length and an MPD/@maxSegmentDuration attribute storing a value
indicating the maximum segment length is mandatorily described in the zapping
MPD and the viewing MPD.
[0098]
30 When one of them is described, the non-extended viewing MPD, that is, the
viewing MPD in which the MPD/@NTPSynchronized attribute and the
23
MPD/@SegmentAlignedGroupID attribute are not introduced, can be collected as a
zapping MPD. Specifically, for example, when the terminal device 80 requests the
MPD acquisition portal 70 to transmit the MPD through the following query API, a
viewing MPD of a segment length (an expected segment length) satisfying a
predetermined condition can be collected. In the following 5 example, the segment
length of 2 seconds or less is used as the expected segment length.
Http://MPDPortal.com/getMPD?expectedSegmentSizeLimit="PT2S"
[0099]
Between channels corresponding to the collected viewing MPD
10 corresponding to the expected segment length, since the segment length is a
relatively short period of time (2 seconds in the above example), the rapid zapping is
possible.
[0100]
Instead of introducing the MPD/@NTPSynchronized attribute and the
15 MPD/@SegmentAlignedGroupID attribute, the MPD/forZapping (a boolean type,
and a value is true/false) attribute indicating whether or not the MPD is the zapping
MPD may be introduced.
[0101]
A ServiceLocation element is newly introduced in the MPD so that seamless
20 switching between the HTTP-unicast-delivered segment stream and the RTPmulticast-
delivered RTP stream can be performed. Further, an rtspRange attribute
indicating an interval of a stream segment that is multicast-transmitted and
broadcast-transmitted according to an RTP and corresponds to a byte range of a
segment that is HTTP-unicast-transmitted is introduced.
25 [0102]
The rtspRange attribute specifies an interval of an RTP stream that is RTPmulticast-
delivered and serves as a switching target of a segment stream that is
HTTP-unicast-delivered and arranged in a SegmentURL element. The rtspRange
attribute stores a character string of a format (a UTC format) of a range parameter
30 identifying an RTP stream interval defined in a real time streaming protocol (RTSP)
used for control of RTP streaming specified in a request for comment (RFC) 2326.
24
The format of information stored in the rtspRange attribute is not limited to the UTC
format.
[0103]
A ServiceLocationAttributeUrl attribute in which a url of a
ServiceLocationAttribute file storing the ServiceLocation element 5 as a root element
is arranged in a BaseURL of the MPD.
[0104]
The ServiceLocation element includes a tuning parameter
(DeliverySystemAttributes) and an IP multicast address (IPMulticastAddress).
10 [0105]
For example, when a multicast bearer or a broadcast bearer of a mobile
network such as the MBMS is used, a format identifier (ID_MBMS in the case of the
MBMS) of a data structure of a tuning parameter employed in multicast transmission
or broadcast transmission by the MBMS or the like is described in
15 DeliverySystemIdentifier of DeliverySystemAttributes.
[0106]
Further, for example, when a broadcast bearer of the existing television
broadcasting network such as the DVB terrestrial network is used, a format identifier
(ID_DVB_T in the case of the DVB terrestrial network) of a data structure of a
20 tuning parameter employed in broadcast transmission of the DVB terrestrial network
is described.
[0107]
A data structure (a parameter) corresponding to a delivery form identified by
DeliverySystemIdentifier is described in DeliverySystemDescriptor of
25 DeliverySystemAttributes.
[0108]
[Operation of content supply system 50]
Next, an operation of the content supply system 50 will be described.
[0109]
30 FIG. 12 is a flowchart for describing a process performed by each content
supply device 60 in order to deliver content. The following description will
25
proceed with an example of the content supply device 60A that delivers content as
the channel A.
[0110]
In step S1, the content supply device 60A synchronizes its system time with
the NTP time axis according to the system time information provided 5 from the NTP
server 52. As a result, the zapping segmenter 62 and the like configuring the
content supply device 60A operates in synchronization with the NTP time axis.
[0111]
In step S2, the channel server 61 generates the zapping streaming data and
10 the viewing streaming data that differ in bit rate from source data of content to be
delivered as the channel A. The channel server 61 outputs the zapping streaming
data to the zapping segmenter 62 and the RTP streamer 66, and outputs the viewing
streaming data to the viewing segmenter 64 and the RTP streamer 66.
[0112]
15 The process of steps S3 to S8 and the process of steps S13 to S18 are
performed in parallel, but for convenience of description, the process of steps S3 to
S8 will be first described.
[0113]
In step S3, the RTP streamer 66 generates the zapping RTP stream by
20 storing the zapping streaming data input from the channel server 61 in the RTP
packet, and outputs the zapping RTP stream to the multicast server 69. The RTP
streamer 66 notifies the zapping MPD generator 63 of the metadata of the zapping
RTP stream.
[0114]
25 The zapping segmenter 62 generates the zapping segment stream such as the
fragmented MP4 by temporally delimiting the zapping streaming data input from the
channel server 61 into periods and further dividing the period into segments, and
outputs the zapping segment stream to the FLUTE streamer 67 and the WEB server
68. The zapping segmenter 62 notifies the zapping MPD generator 63 of the
30 metadata of the generated zapping segment stream.
[0115]
26
The FLUTE streamer 67 generates the zapping FLUTE stream by storing
the zapping segment stream input from the zapping segmenter 62 in the FLUTE
packet, and outputs the zapping FLUTE stream to the multicast server 69.
[0116]
In step S4, the zapping MPD generator 63 generates 5 the zapping MPD
necessary when the terminal device 80 receives the zapping segment stream or the
zapping RTP stream, and outputs the zapping MPD to the FLUTE streamer 67 and
the WEB server 68.
[0117]
10 In step S5, the FLUTE streamer 67 outputs the zapping MPD input from the
zapping MPD generator 63 to the multicast server 69. The multicast server 69
FLUTE-multicast-delivers and UDP-multicast-delivers the zapping MPD.
[0118]
In step S6, when there is the request (the HTTP request) from the MPD
15 acquisition portal 70 or the terminal device 80, the WEB server 68 HTTP-unicastdelivers
the zapping MPD to the request source in response to the request.
[0119]
In step S7, the multicast server 69 FLUTE-multicast-delivers the zapping
FLUTE stream, and RTP-multicast-delivers the zapping RTP stream.
20 [0120]
In step S8, when there is the request (the HTTP request) from the terminal
device 80, the WEB server 68 HTTP-unicast-delivers the zapping segment stream to
the request source in response to the request.
[0121]
25 In parallel to the process of steps S3 to S8, in step S13, the RTP streamer 66
generates the viewing RTP stream by storing the viewing streaming data input from
the channel server 61 in the RTP packet, and outputs the viewing RTP stream to the
multicast server 69. The RTP streamer 66 notifies the viewing MPD generator 65
of the metadata of the viewing RTP stream.
30 [0122]
The viewing segmenter 64 generates the viewing segment stream such as a
27
fragmented MP4 by temporally delimiting the viewing streaming data input from the
channel server 61 into periods and further dividing the period into segments, and
outputs the viewing segment stream to the FLUTE streamer 67 and the WEB server
68. The viewing segmenter 64 notifies the viewing MPD generator 65 of the
metadata of the generated viewing 5 segment stream.
[0123]
The FLUTE streamer 67 generates the 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 69.
10 [0124]
In step S14, the viewing MPD generator 65 generates the viewing MPD
necessary when the terminal device 80 receives the viewing segment stream or the
viewing RTP stream, and outputs the viewing MPD to the FLUTE streamer 67 and
the WEB server 68.
15 [0125]
In step S15, the FLUTE streamer 67 outputs the viewing MPD input from
the viewing MPD generator 65 to the multicast server 69. The multicast server 69
FLUTE-multicast-delivers and UDP-multicast-delivers the viewing MPD.
[0126]
20 In step S16, when there is the request (the HTTP request) from the MPD
acquisition portal 70 or the terminal device 80, the WEB server 68 HTTP-unicastdelivers
the viewing MPD to the request source in response to the request.
[0127]
In step S17, the multicast server 69 FLUTE-multicast-delivers the viewing
25 FLUTE stream, and RTP-multicast-delivers the viewing RTP stream.
[0128]
In step S18, when there is the request (the HTTP request) from the terminal
device 80, the WEB server 68 HTTP-unicast-delivers the viewing segment stream to
the request source in response to the request. The process performed by each
30 content supply device 60 is thus finished.
[0129]
28
FIG. 13 illustrates the segment delimiter of the zapping segment stream
generated by the process of step S3 of FIG. 12 and the viewing segment stream
generated by the process of step S13.
[0130]
As illustrated in FIG. 13, in the content supply device 60A 5 corresponding to
the channel A, one or more (two in FIG. 13) zapping segment streams and two or
more (five in FIG. 13) viewing streams are generated, and the segment delimiters
thereof are synchronized with the NTP time axis.
[0131]
10 The segment delimiter of the zapping stream matches the segment delimiter
(not illustrated) of the zapping stream of another channel belonging to the same
group.
[0132]
Next, a series of processes of the content supply system 50 until the terminal
15 device 80 transitions to a viewing phase through a zapping phase of content will be
described with reference to FIGS. 14 and 15 (hereinafter referred to as a series of
processes).
[0133]
FIG. 14 is a flowchart corresponding to a case in which the terminal device
20 80 can receive the zapping MPD that is multicast-delivered and receive and
reproduce the zapping FLUTE stream or the RTP stream that is multicast-delivered.
A method of receiving the viewing MPD and the viewing stream is arbitrary, but
since the HTTP-unicast-delivered viewing stream commonly has high image quality
(a high bit rate), the viewing stream that is HTTP-unicast-delivered is received
25 whenever possible.
[0134]
In step S21, the terminal device 80 synchronizes its system time with the
NTP time axis according to the system time information provided from the NTP
server 52. In step S22, the terminal device 80 receives the zapping MPD that is
30 FLUTE-multicast-delivered as the process of step S5 of FIG. 12. Further, instead of
receiving the zapping MPD, a request for the zapping MPD may be transmitted to the
29
MPD acquisition portal 70. The terminal device 80 that has received the zapping
MPD enters the zapping phase.
[0135]
In step S23, the terminal device 80 receives and reproduces the zapping
FLUTE stream that is FLUTE-multicast-delivered or the zapping 5 RTP stream that is
RTP-multicast-delivered as the process of step S7 of FIG. 12 based on the zapping
MPD.
[0136]
During the zapping phase, the terminal device 80 can perform the rapid
10 zapping between channels belonging to the same group by appropriately repeating
the process of step S23.
[0137]
The terminal device 80 acquires the viewing MPD during the zapping phase.
Specifically, in step S24, the terminal device 80 requests the WEB server 68 to
15 transmit the viewing MPD, and receives the viewing MPD that is HTTP-unicastdelivered
as the process of step S16 of FIG. 12.
[0138]
The terminal device 80 that has received the viewing MPD can transition
from the zapping phase to the viewing phase. In step S25, the terminal device 80
20 requests the WEB server 68 to transmit the viewing segment stream based on the
viewing MPD. In response to the request, the WEB server 68 HTTP-unicastdelivers
the requested viewing segment stream as step S18 of FIG. 12, and in step
S26, the terminal device 80 receives and reproduces the HTTP-unicast-delivered
viewing segment stream.
25 [0139]
Thereafter, the terminal device 80 can return from the viewing phase to the
zapping phase and then transition to the viewing phase again. The description of
the series of processes is now finished. According to the series of process described
above, it is possible to rapidly perform zapping between channels belonging to the
30 same group without the occurrence of an extra delay.
[0140]
30
Next, FIG. 15 is a flowchart corresponding to a case in which the terminal
device 80 can acquire the HTTP-unicast-delivered zapping MPD and receive and
reproduce the zapping FLUTE stream or the RTP stream that is multicast-delivered.
A method of receiving the viewing MPD and the viewing stream is arbitrary,
similarly to the example of FIG. 14, but since the HTTP-unicast-5 delivered viewing
stream commonly has high image quality (a high bit rate), the viewing stream that is
HTTP-unicast-delivered is received whenever possible.
[0141]
In step S41, the terminal device 80 synchronizes its system time with the
10 NTP time axis according to the system time information provided from the NTP
server 52. In step S42, the terminal device 80 requests the MPD acquisition portal
70 to transmit the zapping MPD. In response to the request, in step S51, the MPD
acquisition portal 70 is connected to the WEB server 68 of each content supply
device 60, and requests the WEB server 68 of each content supply device 60 to
15 transmit the zapping MPD (the MPD in which the MPD/@NTPSynchronized
attribute is true, and the MPD/@SegmentAlignedGroupID attribute is the same
group identifier). In response to the request, the WEB server 68 HTTP-unicastdelivers
the zapping MPD to the MPD acquisition portal 70 as the process of step S6
of FIG. 12.
20 [0142]
In step S52, the MPD acquisition portal 70 collects the HTTP-unicastdelivered
zapping MPD, and transmits the collected zapping MPD to the terminal
device 80 of the request source. The MPD acquisition portal 70 may collect the
UDP-multicast-delivered zapping MPD. Further, the terminal device 80 may
25 collect the zapping MPD from the WEB server 68 of each content supply device 60
directly without using the MPD acquisition portal 70. The terminal device 80 that
has received the zapping MPD enters the zapping phase.
[0143]
In step S43, the terminal device 80 receives and reproduces the zapping
30 FLUTE stream that is FLUTE-multicast-delivered or the zapping RTP stream that is
RTP-multicast-delivered as the process of step S7 of FIG. 12 based on the zapping
31
MPD.
[0144]
During the zapping phase, the terminal device 80 can perform the rapid
zapping between channels belonging to the same group by appropriately repeating
the process 5 of step S43.
[0145]
The terminal device 80 acquires the viewing MPD during the zapping phase.
Specifically, in step S44, the terminal device 80 requests the WEB server 68 to
transmit the viewing MPD, and receives the viewing MPD that is HTTP-unicast10
delivered as the process of step S16 of FIG. 12 in response to the request.
[0146]
The terminal device 80 that has received the viewing MPD can transition
from the zapping phase to the viewing phase. In step S45, the terminal device 80
requests the WEB server 68 to transmit the viewing segment stream based on the
15 viewing MPD. In response to the request, the WEB server 68 HTTP-unicastdelivers
the requested viewing segment stream as step S18 of FIG. 12, and in step
S46, the terminal device 80 receives and reproduces the HTTP-unicast-delivered
viewing segment stream.
[0147]
20 Thereafter, the terminal device 80 can return from the viewing phase to the
zapping phase and then transition to the viewing phase again. The description of
the series of processes is now finished. According to a series of process described
above, it is possible to rapidly perform zapping between channels belonging to the
same group without the occurrence of an extra delay.
25 [0148]
Next, FIG. 16 is a flowchart corresponding to a case in which the terminal
device 80 can acquire the HTTP-unicast-delivered zapping MPD and receive and
reproduce the HTTP-unicast-delivered zapping segment stream rather than the
zapping FLUTE stream or the RTP stream that is multicast-delivered. A method of
30 receiving the viewing MPD and the viewing stream is arbitrary, similarly to the
example of FIG. 14, but since the HTTP-unicast-delivered viewing stream commonly
32
has high image quality (a high bit rate), the viewing stream that is HTTP-unicastdelivered
is received whenever possible.
[0149]
In step S71, the terminal device 80 synchronizes its system time with the
NTP time axis according to the system time information provided 5 from the NTP
server 52. In step S72, the terminal device 80 requests the MPD acquisition portal
70 to transmit the zapping MPD. In response to the request, in step S81, the MPD
acquisition portal 70 is connected to the WEB server 68 of each content supply
device 60, and requests the WEB server 68 of each content supply device 60 to
10 transmit the zapping MPD. In response to the request, the WEB server 68 HTTPunicast-
delivers the zapping MPD to the MPD acquisition portal 70 as the process of
step S6 of FIG. 12.
[0150]
In step S82, the MPD acquisition portal 70 collects the HTTP-unicast15
delivered zapping MPD, and transmits the collected zapping MPD to the terminal
device 80 of the request source. The MPD acquisition portal 70 may collect the
UDP-multicast-delivered zapping MPD. Further, the terminal device 80 may
collect the zapping MPD from the WEB server 68 of each content supply device 60
directly without using the MPD acquisition portal 70. The terminal device 80 that
20 has received the zapping MPD enters the zapping phase.
[0151]
In step S73, the terminal device 80 requests the WEB server 68 to transmit
the zapping segment stream based on the zapping MPD. In response to the request,
the WEB server 68 HTTP-unicast-delivers the zapping segment stream to the
25 terminal device 80 as the process of step S8 of FIG. 12.
[0152]
In step S74, the terminal device 80 receives and reproduces the HTTPunicast-
delivered zapping segment stream.
[0153]
30 During the zapping phase, the terminal device 80 can perform the rapid
zapping between channels belonging to the same group by appropriately repeating
33
the process of steps S73 and S74.
[0154]
The terminal device 80 acquires the viewing MPD during the zapping phase.
Specifically, in step S75, the terminal device 80 requests the WEB server 68 to
transmit the viewing MPD, and receives the viewing MPD 5 that is HTTP-unicastdelivered
as the process of step S16 of FIG. 12 in response to the request.
[0155]
The terminal device 80 that has received the viewing MPD can transition
from the zapping phase to the viewing phase. In step S76, the terminal device 80
10 requests the WEB server 68 to transmit the viewing segment stream based on the
viewing MPD. In response to the request, the WEB server 68 HTTP-unicastdelivers
the requested viewing segment stream as step S18 of FIG. 12, and in step
S77, the terminal device 80 receives and reproduces the HTTP-unicast-delivered
viewing segment stream.
15 [0156]
Thereafter, the terminal device 80 can return from the viewing phase to the
zapping phase and then transition to the viewing phase again. The description of
the series of processes is now finished. According to the series of processes
described above, it is possible to rapidly perform zapping between channels
20 belonging to the same group without the occurrence of an extra delay.
[0157]
In the above description, switching between channels in DASH is performed
in units of segments, but switching between channels may be performed in units of
sub segments obtained by subdividing the segments. In this case, preferably, an
25 MPD/@SubSegmentDuration attribute storing a value indicating a sub segment
length is mandatorily described in the zapping MPD and the viewing MPD, and
“segment” in the above description is replaced with “sub segment.”
[0158]
By the way, each of the content supply device 60 and the terminal device 80
30 that execute a series of processes described above can be configured with hardware
or can be implemented by executing software through a computer. Examples of the
34
computer include a computer embedded in dedicated hardware and a general-purpose
personal computer capable of installing various kinds of programs and executing
various kinds of functions.
[0159]
FIG. 17 is a block diagram illustrating an exemplary hardware 5 configuration
of the computer.
[0160]
In a computer 100, a central processing unit (CPU) 101, a read only memory
(ROM) 102, and a random access memory (RAM) 103 are connected with one
10 another via a bus 104.
[0161]
An input/output interface 105 is connected to the bus 104. An input unit
106, an output unit 107, a storage unit 108, a communication unit 109, and a drive
110 are connected to the input/output interface 105.
15 [0162]
The input unit 106 includes a keyboard, a mouse, a microphone, and the like.
The output unit 107 includes a display, a speaker, and the like. The storage unit 108
includes a hard disk, a non-volatile memory, and the like. The communication unit
109 includes a network interface. The drive 110 drives a removable medium 111
20 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor
memory.
[0163]
In the computer 100 having the above-described configuration, for example,
a series of processes described above are performed by loading a program stored in
25 the storage unit 108 onto the RAM 103 through the input/output interface 105 and
the bus 104 and executing the loaded program through the CPU 101.
[0164]
For example, the program executed by the computer 100 (the CPU 101)
may be recorded in the removable medium 111 serving as a package medium or the
30 like and provided. The program may be provided via a wired or wireless
transmission medium such as a local area network, the Internet, or digital satellite
35
broadcasting.
[0165]
In the computer 100, the removable medium 111 may be mounted on the
drive 110, and the program may be installed in the storage unit 108 through the
input/output interface 105. The program may be received by 5 the communication
unit 109 via a wired or wireless transmission medium and installed in the storage unit
108. Moreover, the program may be installed in the ROM 102 or the storage unit
108 in advance.
[0166]
10 Further, the program executed by the computer 100 may be a program in
which a process is chronologically performed according to the sequence described in
the present specification or may be a program in which a process is performed in
parallel or at a necessary timing, for example, when calling is performed.
[0167]
15 An embodiment of the present disclosure is not limited to the above
embodiments, and various changes can be made within the scope not departing from
the gist of the present disclosure.
[0168]
Additionally, the present technology may also be configured as below.
20 (1)
A content supply device that supplies a plurality of pieces of streaming data
that include content of a same subject and differ in attribute through a same channel,
according to an adaptive streaming technique, the content supply device including:
a zapping segment stream generating unit configured to generate a zapping
25 segment stream by delimiting zapping streaming data among the plurality of pieces
of streaming data into minimum units when reception of the streaming data is
switched, according to a common timing with another channel;
a unicast delivery unit configured to unicast-deliver the zapping segment
stream;
30 a multicast delivery unit configured to multicast-deliver the zapping
segment stream; and
36
a metafile generating unit configured to generate a metafile for a reception
side to receive the zapping segment stream that is unicast-delivered and multicastdelivered.
(2)
The content supply device 5 according to (1),
wherein the zapping segment stream generating unit generates the zapping
segment stream by delimiting the zapping streaming data into the minimum units,
according to a common timing with the other channel belonging to a same group.
(3)
10 The content supply device according to (1) or (2),
wherein the unicast delivery unit HTTP-unicast-delivers the zapping
segment stream, and
wherein the multicast delivery unit FLUTE-multicast-delivers a zapping
FLUTE stream based on the zapping segment stream.
15 (4)
The content supply device according to any of (1) to (3), further including:
an RTP stream generating unit configured to generate a zapping RTP stream
based on the zapping streaming data among the plurality of pieces of streaming data,
wherein the metafile generating unit generates a metafile for the reception
20 side to receive the zapping segment stream that is HTTP-unicast-delivered, the
zapping FLUTE stream that is FLUTE-multicast-delivered, and the zapping RTP
stream that is RTP-multicast-delivered, and
wherein the multicast delivery unit also RTP-multicast-delivers the zapping
RTP stream.
25 (5)
The content supply device according to any of (1) to (4),
wherein the zapping segment stream generating unit generates the zapping
segment stream by aligning heads of the minimum units with the other channel
belonging to the same group in synchronization with an NTP time axis and
30 delimiting the zapping streaming data into the minimum units using a common
duration with the other channel belonging to the same group.
37
(6)
The content supply device according to any of (1) to (5),
wherein the zapping segment stream generating unit generates the zapping
segment stream by delimiting the zapping streaming data into the minimum units
using a duration shorter than the minimum unit of viewing 5 streaming data.
(7)
The content supply device according to any of (1) to (6),
wherein the metafile generating unit generates an extended MPD as the
metafile.
10 (8)
The content supply device according to any of (1) to (7), further including:
a collecting unit configured to collect the metadata and supply the metadata
to the reception side.
(9)
15 The content supply device according to (8),
wherein the metafile generating unit generates the MPD in which an
MPD/@NTPSynchronized attribute and an MPD/SegmentAlignedGroupID attribute
are introduced, as the metafile, and
wherein the collecting unit collects the metadata for the zapping based on
20 the MPD/@NTPSynchronized attribute and the MPD/SegmentAlignedGroupID
attribute.
(10)
The content supply device according to (8),
wherein the metafile generating unit generates the MPD in which an
25 MPD/@forZapping attribute is introduced, as the metafile, and
wherein the collecting unit collects the metadata for the zapping based on
the MPD/@forZapping attribute.
(11)
The content supply device according to (8),
30 wherein the metafile generating unit describes at least one of a duration and
a maximum duration of the minimum unit of the streaming data in the metadata, as
38
the metafile, and
wherein the collecting unit collects the metadata for the zapping based on
the at least one of the duration and the maximum duration of the minimum unit of the
streaming data.
5
Reference Signs List
[0169]
50 content supply system
51 network
10 52 NTP server
60 content supply device
61 channel server
62 zapping segmenter
63 zapping MPD generator
15 64 viewing segmenter
65 viewing MPD generator
66 RTP streamer
67 FLUTE streamer
68 WEB server
20 69 multicast server
70 MPD acquisition portal
80 terminal device
100 computer
101 CPU
25
39
CLAIMS
Claim 1
A content supply device that supplies a plurality of pieces of streaming data
that include content of a same subject and differ in attribute through a same channel,
according to an adaptive streaming technique, the content supply 5 device comprising:
a zapping segment stream generating unit configured to generate a zapping
segment stream by delimiting zapping streaming data among the plurality of pieces
of streaming data into minimum units when reception of the streaming data is
switched, according to a common timing with another channel;
10 a unicast delivery unit configured to unicast-deliver the zapping segment
stream;
a multicast delivery unit configured to multicast-deliver the zapping
segment stream; and
a metafile generating unit configured to generate a metafile for a reception
15 side to receive the zapping segment stream that is unicast-delivered and multicastdelivered.
Claim 2
The content supply device according to claim 1,
20 wherein the zapping segment stream generating unit generates the zapping
segment stream by delimiting the zapping streaming data into the minimum units,
according to a common timing with the other channel belonging to a same group.
Claim 3
25 The content supply device according to claim 2,
wherein the unicast delivery unit HTTP-unicast-delivers the zapping
segment stream, and
wherein the multicast delivery unit FLUTE-multicast-delivers a zapping
FLUTE stream based on the zapping segment stream.
30
Claim 4
40
The content supply device according to claim 2, further comprising:
an RTP stream generating unit configured to generate a zapping RTP stream
based on the zapping streaming data among the plurality of pieces of streaming data,
wherein the metafile generating unit generates a metafile for the reception
side to receive the zapping segment stream that is HTTP-5 unicast-delivered, the
zapping FLUTE stream that is FLUTE-multicast-delivered, and the zapping RTP
stream that is RTP-multicast-delivered, and
wherein the multicast delivery unit also RTP-multicast-delivers the zapping
RTP stream.
10
Claim 5
The content supply device according to claim 2,
wherein the zapping segment stream generating unit generates the zapping
segment stream by aligning heads of the minimum units with the other channel
15 belonging to the same group in synchronization with an NTP time axis and
delimiting the zapping streaming data into the minimum units using a common
duration with the other channel belonging to the same group.
Claim 6
20 The content supply device according to claim 2,
wherein the zapping segment stream generating unit generates the zapping
segment stream by delimiting the zapping streaming data into the minimum units
using a duration shorter than the minimum unit of viewing streaming data.
25 Claim 7
The content supply device according to claim 2,
wherein the metafile generating unit generates an extended MPD as the
metafile.
30 Claim 8
The content supply device according to claim 2, further comprising:
41
a collecting unit configured to collect the metadata and supply the metadata
to the reception side.
Claim 9
The content supply device according 5 to claim 8,
wherein the metafile generating unit generates the MPD in which an
MPD/@NTPSynchronized attribute and an MPD/SegmentAlignedGroupID attribute
are introduced, as the metafile, and
wherein the collecting unit collects the metadata for the zapping based on
10 the MPD/@NTPSynchronized attribute and the MPD/SegmentAlignedGroupID
attribute.
Claim 10
The content supply device according to claim 8,
15 wherein the metafile generating unit generates the MPD in which an
MPD/@forZapping attribute is introduced, as the metafile, and
wherein the collecting unit collects the metadata for the zapping based on
the MPD/@forZapping attribute.
20 Claim 11
The content supply device according to claim 8,
wherein the metafile generating unit describes at least one of a duration and
a maximum duration of the minimum unit of the streaming data in the metadata, as
the metafile, and
25 wherein the collecting unit collects the metadata for the zapping based on
the at least one of the duration and the maximum duration of the minimum unit of the
streaming data.
Claim 12
30 A content supply method of a content supply device that supplies a plurality
of pieces of streaming data that include content of a same subject and differ in
42
attribute through a same channel, according to an adaptive streaming technique, the
content supply method comprising:
a zapping segment stream generating step of generating, by the content
supply device, a zapping segment stream by delimiting zapping streaming data
among the plurality of pieces of streaming data into minimum 5 units when reception
of the streaming data is switched, according to a common timing with another
channel;
a unicast delivery step of unicast-delivering, by the content supply device,
the zapping segment stream;
10 a multicast delivery step of multicast-delivering, by the content supply
device, the zapping segment stream; and
a metafile generating step of generating, by the content supply device, a
metafile for a reception side to receive the zapping segment stream that is unicastdelivered
and multicast-delivered.
15
Claim 13
A program causing a computer that supplies a plurality of pieces of
streaming data that include content of a same subject and differ in attribute through a
same channel, according to an adaptive streaming technique to function as:
20 a zapping segment stream generating unit configured to generate a zapping
segment stream by delimiting zapping streaming data among the plurality of pieces
of streaming data into minimum units when reception of the streaming data is
switched, according to a common timing with another channel;
a unicast delivery unit configured to unicast-deliver the zapping segment
25 stream;
a multicast delivery unit configured to multicast-deliver the zapping
segment stream; and
a metafile generating unit configured to generate a metafile for a reception
side to receive the zapping segment stream that is unicast-delivered and multicast30
delivered.
43
Claim 14
A terminal device that receives streaming data supplied from a content
supply device that supplies a plurality of pieces of streaming data that include
content of a same subject and differ in attribute through a same channel, according to
an adaptive 5 streaming technique,
wherein the content supply device includes
a zapping segment stream generating unit configured to generate a zapping
segment stream by delimiting zapping streaming data among the plurality of pieces
of streaming data into minimum units when reception of the streaming data is
10 switched, according to a common timing with another channel,
a unicast delivery unit configured to unicast-deliver the zapping segment
stream,
a multicast delivery unit configured to multicast-deliver the zapping
segment stream, and
15 a metafile generating unit configured to generate a metafile for a reception
side to receive the zapping segment stream that is unicast-delivered and multicastdelivered,
and
wherein the terminal device acquires the metafile, and switches reception of
the zapping segment stream that is unicast-delivered and multicast-delivered through
20 different channels, based on the acquired metafile.
Claim 15
A content supply system comprising:
a content supply device configured to supply a plurality of pieces of
25 streaming data that include content of a same subject and differ in attribute through a
same channel, according to an adaptive streaming technique; and
a terminal device configured to receive the streaming data,
wherein the content supply device includes
a zapping segment stream generating unit configured to generate a
30 zapping segment stream by delimiting zapping streaming data among the plurality of
pieces of streaming data into minimum units when reception of the streaming data is
44
switched, according to a common timing with another channel,
a unicast delivery unit configured to unicast-deliver the zapping
segment stream,
a multicast delivery unit configured to multicast-deliver the
zapping 5 segment stream, and
a metafile generating unit configured to generate a metafile for a
reception side to receive the zapping segment stream that is unicast-delivered and
multicast-delivered, and
wherein the terminal device acquires the metafile, and switches reception of
10 the zapping segment stream that is unicast-delivered and multicast-delivered through
different channels, based on the acquired metafile.
45
ABSTRACT
“CONTENT SUPPLY DEVICE, CONTENT SUPPLY METHOD, PROGRAM,
TERMINAL DEVICE, AND CONTENT SUPPLY SYSTEM”
The present disclosure relates to a content supply device, content supply method,
program, terminal device, and content supply system, whereby it is possible to
implement rapid zapping among channels in DASH. This content supply device:
generates a segment stream for zapping by segmenting streaming data for zapping
among a plurality of instances of streaming data into the smallest units when
receiving of the streaming data is switched, according to a timing which is
standardized with other channels; unicast distributes the segment stream for zapping;
multicast distributes the segment stream for zapping; and generates a metafile for a
receiving side to receive the segment stream for zapping which is unicast and
multicast distributed. It would be possible to apply the present disclosure to a system
which distributes content by streaming.