TRANSMISSION APPARATUS, TRANSMISSION METHOD, REPRODUCTION
APPARATUS, REPRODUCTION METHOD AND RECEPTION APPARATUS
5 TECHNICAL FIELD
[0001]
The present technology relates to a transmission
apparatus, a transmission method, a reproduction
apparatus, a reproduction method, and a reception
10 apparatus, and more particularly, to a transmission
apparatus and the like transmitting a transmission stream
in which transmission packets are continuously arranged.
BACKGROUND ART
15 [0002]
In a case where a service stream is provided on an
IP packet, there are cases where a capsule layer is
provided as an interface between a physical layer
modulating a transmission channel and an IP packet layer
20 packetizing data (for example, see Patent Document 1).
In related art, as information contained in the capsule
layer, data having no constraint on time management or
file downloading are assumed to be suitable.
25 CITATION LIST
PATENT DOCUMENT
[0003]
Patent Document 1: Japanese Patent Application Laid-Open
No. 2012-015875
30
SUMMARY OF THE INVENTION
3
PROBLEMS TO BE SOLVED BY THE INVENTION
[0004]
In a case where a service that shares a service
using a broadcast wave and an IP transmission service is
provided, it may be considered to transmit 5 a real-time
service through a capsule layer in addition to a
conventional use for file downloading in which a service
packet of a broadcast wave is loaded into an IP packet,
and a capsule layer is introduced for transmitting the IP
10 packet using the broadcast wave. By the capsule layer
configured to have not a fixed length but a variable
length, a transmission target of an upper layer can be
efficiently transmitted. In the case of video or audio,
for example, encapsulation with a size of one access unit
15 or more is executed.
[0005]
At the time of trick reproduction such as fast
forward reproduction or fast reverse reproduction, a
capsule having a variable length is analyzed, a
20 multiplexed transport is analyzed, and compressed data is
decoded so as to arrive at a display process. In such a
case, in order to execute trick reproduction at a high
speed, it is necessary to analyze a variable-length
packet extending over multiple layers in a speedy manner.
25 [0006]
For example, as the capsule layer, a type length
value (TLV) will be considered. In such a case, based on
a TMCC inserted into a transmission frame, the start of
the TLV can be detected as an offset position from a
30 transmission slot. Thereafter, an analysis of an IP/UDP
and an IP/TCP is executed, and the payload of a transport
4
packet is analyzed, whereby the presence of a picture of
a random access point (RAP) to be displayed as trick play
can be acquired eventually.
[0007]
An object of the present technology 5 is to increase
the speed of trick reproduction.
SOLUTIONS TO PROBLEMS
[0008]
10 A concept of the present technology lies in
a transmission apparatus including:
a transmission unit that transmits a transmission
stream, in which first transmission packets that are
multilayer-configuration packets each having a
15 multiplexed transport packet in an upper layer are
continuously arranged,
wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
20 an access unit of a random access point starts and having
a header in which identification information is inserted
are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
25 specific first transmission packets and having a header
in which identification information is inserted are
arranged following the specific first transmission
packets.
[0009]
30 In the present technology, a transmission stream,
in which first transmission packets that are multilayer5
configuration packets each having a multiplexed transport
packet in an upper layer are continuously arranged is
transmitted. In the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which 5 a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
are arranged at a predetermined interval. In addition,
in the transmission stream, second transmission packets
10 each including access position information corresponding
to the previous and next specific first transmission
packets and having a header in which identification
information is inserted are arranged following the
specific first transmission packets.
15 [0010]
For example, the first transmission packet may be a
packet of a capsule layer acquired by encapsulating an IP
packet having a payload including the multiplexed
transport packet, and the second transmission packet may
20 be a packet of the capsule layer acquired by
encapsulating the access position information. In this
case, for example, the packet of the capsule layer may be
a TLV packet or a GSE packet.
[0011]
25 In addition, for example, the first transmission
packet may be an IP packet having a payload in which the
multiplexed transport packet is included, and the second
transmission packet may be an IP packet including the
access position information. Furthermore, for example,
30 the multiplexed transport packet may be an MMT packet, an
RTP packet, or a FLUTE packet.
6
[0012]
As above, in the present technology, in the
transmission stream, the specific first transmission
packets are arranged to be identifiable at a
predetermined interval, and the second 5 transmission
packets including the access position information are
arranged following the specific first transmission
packets. For this reason, on the reception side, in
trick reproduction such as fast forward reproduction or
10 fast reverse reproduction after the storage of this
transmission stream in a storage medium, data of the
access unit of a random access point that is necessary
for the trick reproduction can be efficiently acquired,
and the trick reproduction can be executed at a high
15 speed.
[0013]
In addition, another concept of the present
technology lies in
a reproduction apparatus including:
20 an acquisition unit that acquires a transmission
stream in which first transmission packets that are
multilayer-configuration packets each having a
multiplexed transport packet in an upper layer are
continuously arranged by accessing a storage medium
25 locally connected or a server connected through a
communication network;
a processing unit that acquires reproduction data
by processing the transmission stream acquired by the
acquisition unit; and
30 an access control unit that controls an access of
the acquisition unit to the storage medium or the server
7
based on identification information of the specific first
transmission packets and access position information
included in the second transmission packet that are
extracted from the acquired transmission stream,
wherein, in the transmission stream, 5 the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
10 are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
15 arranged following the specific first transmission
packets.
[0014]
In the present technology, a transmission stream is
acquired, by the acquisition unit, in which first
20 transmission packets that are multilayer-configuration
packets each having a multiplexed transport packet in an
upper layer are continuously arranged by accessing a
storage medium or a server connected. Furthermore,
reproduction data is acquired, by the processing unit, by
25 processing the transmission stream acquired by in the
acquisition unit.
[0015]
In this transmission stream, the specific first
transmission packets each including the multiplexed
30 transport packet including data in which a first byte of
an access unit of a random access point starts and having
8
a header in which identification information is inserted
are arranged at a predetermined interval. Furthermore,
in this transmission stream, second transmission packets
each including access position information corresponding
to the previous and next specific 5 first transmission
packets and having a header in which identification
information is inserted are arranged following the
specific first transmission packets.
[0016]
10 For example, it may be configured such that the
first transmission packet is a packet of a capsule layer
acquired by encapsulating an IP packet having a payload
including the multiplexed transport packet, and the
second transmission packet is a packet of the capsule
15 layer acquired by encapsulating the access position
information. In such a case, the packet of the capsule
layer may be a TLV packet or a GSE packet.
[0017]
In addition, for example, it may be configured such
20 that the first transmission packet is an IP packet having
a payload in which the multiplexed transport packet is
included, and the second transmission packet is an IP
packet including the access position information.
Furthermore, for example, the multiplexed transport
25 packet may be an MMT packet, an RTP packet, or a FLUTE
packet.
[0018]
An access of the acquisition unit to the storage
medium or the server is controlled by the access control
30 unit based on identification information of the specific
first transmission packets and access position
9
information included in the second transmission packet
that are extracted from the acquired transmission stream.
[0019]
For this reason, according to the present
technology, in trick reproduction such 5 as fast forward
reproduction or fast backward reproduction, data of the
access unit of a random access point that is necessary
for the trick reproduction can be efficiently acquired,
and the trick reproduction can be executed at a high
10 speed.
[0020]
In addition, a concept of the present technology
lies in
a reception apparatus including:
15 a reception unit that receives a transmission
stream, in which first transmission packets that are
multilayer-configuration packets each having a
multiplexed transport packet in an upper layer are
continuously arranged; and
20 a processing unit that acquires reception data by
processing the transmission stream acquired by the
reception unit,
wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
25 transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
are arranged at a predetermined interval, and, second
transmission packets each including access position
30 information corresponding to the previous and next
specific first transmission packets and having a header
10
in which identification information is inserted are
arranged following the specific first transmission
packets.
EFFECTS 5 OF THE INVENTION
[0021]
According to the present technology, an increase in
the speed of trick reproduction is achieved. Here,
effects described in this specification are merely
10 examples but are not for the purpose of limitation, and
an additional effect may be acquired.
BRIEF DESCRIPTION OF DRAWINGS
[0022]
15 Fig. 1 is a block diagram that illustrates an
example of the configuration of a display system
according to an embodiment.
Fig. 2 is a diagram that illustrates a transmission
protocol stack.
20 Fig. 3 is a diagram that illustrates an example of
the structure of TMCC information in a transmission frame.
Figs. 4(a) and 4(b) are diagrams that illustrate
major contents of an example of the structure of TMCC
information in a transmission frame.
25 Fig. 5 is a diagram that illustrates an example of
housing TLV packets in a data area of each slot of a
transmission frame.
Figs. 6(a) and 6(b) are diagrams that illustrate an
example in which the arrangement of TLV packets is not
30 synchronized with the start of each transmission frame
and an example in which the arrangement is synchronized
11
with the start of each transmission frame.
Fig. 7 is a schematic diagram that illustrates the
packet configuration of a transmission protocol stack.
Fig. 8 is a diagram that illustrates the
configuration of an MMT packet 5 in a tree form.
Fig. 9 is a diagram that illustrates the kinds of
MMT packets.
Fig. 10 is a diagram that illustrates an example of
the structure of an MMT payload header
10 (mmtp_payload_header()).
Fig. 11 is a diagram that illustrates an example of
the structure of an MMT payload header extension of a
case where time information included in an MMT payload
header (MPU payload header) is transmitted.
15 Fig. 12 is a diagram that illustrates an example of
the structure of a TLV packet (TLV packet()).
Fig. 13 is a diagram that illustrates an example of
a more detailed structure of a TLV packet.
Fig. 14 is a diagram that illustrates
20 identification information used for identifying whether a
packet, which is inserted into the header of a TLV packet,
is a packet to be handled with high priority.
Fig. 15 is a diagram that illustrates the packet
type of TLV packet.
25 Fig. 16 is a diagram that illustrates an example of
the structure of a signaling packet arranged in a payload
of a TLV packet.
Fig. 17 is a diagram that illustrates the content
of major information of the example of the structure of
30 the signaling packet.
Figs. 18(a) to 18(c) are diagrams that illustrate a
12
transmission stream (TLV packet stream) transmitted by a
broadcast station.
Figs. 19(a) to 19(b) are diagrams that
schematically illustrate the structures of various TLV
5 packets.
Fig. 20 is a diagram that illustrates an example of
a transmission system of a broadcast wave in a
broadcasting station.
Fig. 21 is a diagram that illustrates an example of
10 the structure of an internet protocol (IP) header.
Fig. 22 is a diagram that illustrates contents of
major information of the example of the structure of an
IP header.
Fig. 23 is a diagram that illustrates an example of
15 the structure of "Options" included inside an IP header.
Fig. 24 is a diagram that illustrates contents of
major information of the example of the structure of
"Options" included inside the IP header.
Fig. 25 is a diagram that illustrates priority
20 packet identification information defined in the
"Options" included inside the IP header.
Fig. 26 is a diagram that illustrates access
position information defined in the "Options" included
inside the IP header and identification information
25 thereof.
Figs. 27(a) to 27(b) are diagrams that illustrate a
transmission stream (IP packet stream) transmitted by a
distribution server.
Fig. 28 is a diagram that illustrates an example of
30 a reception system of a broadcast wave in a receiver.
Fig. 29 is a diagram that illustrates a display
13
delay at the time of execution of switching between
channels (at the time of executing a random access).
Fig. 30 is a flowchart that illustrates an example
of the process of a receiver of a case where a transition
is made from a normal reproduction 5 mode to a mode of
trick reproduction (fast forward reproduction or fast
reverse reproduction).
Fig. 31 is a flowchart that illustrates an example
of the process of an upper-layer analysis routine.
10 Fig. 32 is a flowchart that illustrates an example
of the process of a receiver of a case where a transition
is made from a normal reproduction mode to a mode of
trick reproduction (fast forward reproduction or fast
reverse reproduction).
15
MODE FOR CARRYING OUT THE INVENTION
[0023]
Hereinafter, embodiments of the invention
(hereinafter, referred to as "embodiments") will be
20 described. The description will be presented in the
following order.
1. Embodiment
2. Modified Example
[0024]
25 <1. Embodiment>
[Configuration Example of Display System]
Fig. 1 illustrates an example of the configuration
of a display system 10. In this display system 10, a
broadcasting station 110 and a distribution server 120
30 are arranged on the transmission side, and a receiver 200
is arranged on the reception side.
14
[0025]
The broadcasting station 110 loads a transmission
stream in which type length value (TLV) packets as
transmission packets are continuously arranged into a
broadcast wave and transmits the broadcast 5 wave to the
reception side through an RF transmission channel. The
TLV packet is a packet having a multilayer configuration
including a multiplexed transport packet in an upper
layer and media data such as video and audio and is an IP
10 packet including a multiplexed transport packet in a
payload or a packet of a capsule layer acquired by
encapsulating a transmission control signal (TLV-NIT or
AMT).
[0026]
15 Fig. 2 illustrates a transmission protocol stack.
At the bottom, a transmission channel modulation layer is
present. On this transmission channel modulation layer,
a transmission slot is present, and a TLV packet is
present in the transmission slot, and an IP packet is
20 present on the TLV packet. On this IP packet, a
multiplexed transport packet including media data of
video or audio and control system data is present through
a UDP packet or a TCP packet not illustrated in the
drawing.
25 [0027]
In one transmission frame, a maximum of 120
transmission slots are included according to a modulation
system. To each transmission slot, transmission and
multiplexing configuration control (TMCC) information is
30 added. This TMCC information is configured by
information relating to transmission control such as the
15
assignment of a transmission stream to each transmission
slot and a relation with a transmission system. As one
of such TMCC information, pointer information
representing the position of a TLV packet in the
transmission slot is included. By 5 referring to such
pointer information, the analysis can be correctly
started from the start of the TLV packet.
[0028]
An area used for the transmission of the TMCC
10 information is configured by 9422 bits per transmission
frame. In a case where switching of the transmission
system or the like is executed, the TMCC information goes
ahead of actual switching timing by two frames, and
information after the switching is transmitted. A
15 minimal update interval of the TMCC information, for
example, is one frame. Fig. 3 is a diagram that
illustrates an example (Syntax) of the structure of the
TMCC information in a transmission frame.
[0029]
20 In an advanced broadband satellite digital
broadcasting system, a maximum of 16 streams can be
transmitted by one satellite repeater. In "relative
stream/slot information", a relative stream number that
is one of 0 to 15 is assigned to each slot, and data of a
25 slot having the same relative stream number represents
one stream.
[0030]
In addition, in the "relative stream/transmission
stream ID information", a transmission stream ID is
30 assigned to each relative stream having a relative stream
number in the range of 0 to 15. For example, in a case
16
where the relative stream is an MPEG2-TS, the
transmission stream ID is assumed to be a "TS_ID". On
the other hand, in a case where the relative stream is a
TLV, the transmission stream ID is assumed to be a "TLV
stream ID". In addition, "relative 5 stream/stream type
information", as illustrated in Fig. 4(a), represents the
type of the stream of each relative stream number. As
illustrated in Fig. 4(b), for example, "0x01" represents
an MPEG2-TS, and "0x02" represents a TLV.
10 [0031]
In addition, "pointer/slot information" is
configured by a top pointer and a last pointer of each
slot and is mainly used for packet synchronization and
packet invalidation. Fig. 5 illustrates an example of
15 housing TLV packets in a data area of each slot. The top
pointer represents the position of the first byte of a
first packet among packets housed in each slot. The last
pointer represents "the position of the last byte of the
last packet + 1" among the packets housed in each slot.
20 [0032]
In a case where the top pointer is "0xFFFF", it
represents that the first byte of the first TLV packet in
the slot is not present. This represents that the first
TLV packet in the slot is continued from the previous
25 slot. In addition, in a case where the last pointer is
"0xFFFF", it represents that the last byte of the last
TLV packet in the slot is not present. This represents
that the last TLV packet in the slot is continued to the
next slot.
30 [0033]
Fig. 6(a) represents an example in which the
17
arrangement of TLV packets is not synchronized with the
start of each transmission frame. The start of each slot
is uniquely determined in a transmission frame. Each TLV
packet is present regardless of the slot. In a case
where TLV packets are continued over 5 a plurality of
transmission frames, there is a TLV packet divided into
two transmission frames.
[0034]
Fig. 6(b) represents an example in which the
10 arrangement of TLV packets is synchronized with the start
of each transmission frame. The start of each slot is
uniquely determined in a transmission frame. While each
TLV packet is not necessarily synchronized with a slot,
the start of a transmission frame is the start of a TLV
15 packet. In other words, the start of the first slot
(Slot 1) of each transmission frame is the start of a TLV
packet.
[0035]
In the case of Fig. 6(b), a null area is frequently
20 generated at the end of a transmission frame, and the
transmission efficiency is lower than that of the case of
Fig. 6(a). For the simplification of the drawings, in
the examples illustrated in the drawings, three slots are
represented to be present in each transmission frame.
25 Actually, as described above, a maximum of 120 slots are
included according to the modulation system.
[0036]
Fig. 7 is a schematic diagram that illustrates the
packet configuration of a transmission protocol stack. A
30 transmission slot is configured by a slot header and
transmission slot data. In the transmission slot data, a
18
TLV packet is included. The TLV packet is configured by
a header and data, and, as the data, an IP packet or a
transmission control signal is included. The
transmission control signal is "TLV-NIT" or "AMT". The
"TLV-NIT" is a modulation frequency 5 or information
associated with another program of a broadcast. The
"AMT" is an IP address relating to a broadcasting service.
[0037]
The IP packet is configured by an IP header and a
10 UDP packet or a TCP packet as data. Here, the UDP packet
is configured by a UDP header and data, and the TCP
packet is configured by a TCP header and data. As the
data of the UDP packet or the TCP packet, a multiplexed
transport packet is included. This multiplexed transport
15 packet is configured by a packet header, a payload header,
and transport data.
[0038]
As the transport data of the multiplexed transport
packet, a predetermined number of access units of a coded
20 stream of a transmission medium such as video or audio
are included. In the case of the video, one access unit
represents data of one picture. In the case of the audio,
one access unit represents an access unit of audio
acquired by lumping data of a predetermined number of
25 samples, for example, 1024 samples. In the coded stream,
coded data of an intra picture that becomes a random
access point is present. For a random access, the coded
data of the intra picture is decoded first.
[0039]
30 In this embodiment, the multiplexed transport
packet is assumed to be a transport packet having an MPEG
19
media transport (MMT) structure (see ISO/IEC CD 23008-1),
in other words, an MMT packet. Fig. 8 is a diagram that
illustrates the configuration of an MMT packet in a tree
form.
5 [0040]
The MMT packet is configured by an MMT packet
header, an MMT payload header, and an MMT payload. In
the MMT payload, a message, a media processing unit (MPU),
an FEC repair symbol, and the like are included, and such
10 signaling is executed according to a payload type
(payload_type) included in the MMT payload header.
[0041]
Here, the message configures information relating
to a transmission medium. In this message, various
15 message contents are inserted in a table form. The MPU
may be fragmented and subdivided into MMT fragment units
(MFU). In such a case, an MFU header is added to the
start of each MFU. In the MPU included in the MMT
payload, an MPU relating to media data such as video,
20 audio, and a subtitle and an MPU relating to metadata are
present. The MMT packet including each MPU is
identifiable by a packet ID (Packet_ID) present in the
MMT packet header.
[0042]
25 Fig. 9 illustrates the kinds of MMT packet. In the
example illustrated in the drawing, the MMT packets are
classified based on data or information inserted into the
payload. Here, transport message information is an MMT
packet in which a message (information relating to a
30 transmission medium) is included in the payload. A
transport metadata packet is an MMT packet in which
20
metadata is included in the payload. Here, the metadata,
for example, is data of each of boxes of "styp", "sidx",
"mmpu", "moov", and "moof" of an MMT file (MP4 file). A
transport media data packet is an MMT packet in which
media data such as video, audio, 5 and a subtitle is
included in the payload.
[0043]
In the MMT payload header, flag information
representing whether or not coded data of an intra
10 picture that becomes a random access point is present in
the MMT payload is arranged. Fig. 10 illustrates an
example (Syntax) of the structure of an MMT payload
header (mmtp_payload_header()).
[0044]
15 Although a detailed description will not be
presented, in this MMT payload header, a payload length
(payload_length), a payload type (payload_type), a
fragment type (fragment_type), a fragment count
(fragment_count), an aggregation information flag
20 (aggregation_info_flag), a RAP flag
(random_access_point_flag), a data offset (data_offset),
a data unit number (numDU), a data unit offset
(DU_offset), a payload sequence number
(payload_seq_number), a header extension field flag
25 (header_extension_field flag), and the like are included.
[0045]
In addition, when the header extension field flag
is "1", in this MMT payload header, an MMT payload header
extension (mmtp_payload_header_extension()) is further
30 included. Fig. 11 illustrates an example (Syntax) of the
syntax of the MMT payload header extension of such a case.
21
This example (Syntax) of the structure corresponds to a
case where time information (timing information) included
in the MMT payload header is transmitted.
[0046]
A 16-bit field of "payload_header_5 extension_type"
represents the type of MMT payload header extension. For
example, "0x01" represents that a display time stamp
(display time) of an NTP short time format is supplied.
"0x02" represents that a display time stamp and a
10 decoding time stamp (decoding time) of the NTP short time
format are supplied. "0x03" represents that a display
time stamp of 90 KHz precision is supplied. "0x04"
represents that a display time stamp and a decoding time
stamp of 90 KHz precision are supplied.
15 [0047]
A 16-bit field of "payload_header_extension_length"
represents the size of the MMT payload header extension.
A 32-bit field of "presentation_timestamp" represents the
value of the display time stamp (display time). A 32-bit
20 field of "decoding_timestamp" represents the value of the
decoding time stamp (decoding time).
[0048]
In this embodiment, in the broadcasting station 110,
in the TLV packet, identification information used for
25 identifying whether or not the packet is a packet handled
with high priority is inserted, and identification
information used for identifying whether or not the
packet is a packet including access position information
is inserted. In this sense, the broadcasting station 110
30 configures an information inserting unit that inserts
identification information. Fig. 12 illustrates an
22
example (Syntax) of the structure of a TLV packet (TLV
packet()). This TLV packet is configured by a TLV header
(TLV_header) of 32 bits and a TLV payload (TLV_payload)
having a variable length.
5 [0049]
Fig. 13 illustrates an example (Syntax) of a more
detailed structure of the TLV packet (TLV packet()). A
32-bit TLV header (TLV_header) is configured by a two-bit
field of "01", a one-bit field of "non_priority_bit1", a
10 one-bit field of "non_priority_bit2", a one-bit field of
"non_priority_bit3", a three-bit field of
"reserved_future_use", an eight-bit field of
"packet_type", and a 16-bit field of "length".
[0050]
15 As the one-bit field of "non_priority_bit1", flag
information representing whether or not the packet is a
priority TLV type1 packet is newly defined. As
illustrated in Fig. 14, "1" represents that the packet is
a non-priority TLV packet, in other words, the packet
20 does not include data in which the first byte (1st byte)
of the access unit of a random access point starts. On
the other hand, "0" represents that the packet is a
priority TLV type1 packet, in other words, the packet
includes data in which the first byte (1st byte) of the
25 access unit of a random access point starts.
[0051]
As the one-bit field of "non_priority_bit2", flag
information representing whether or not the packet is a
priority TLV type2 packet is newly defined. As
30 illustrated in Fig. 14, "1" represents that the packet is
a non-priority TLV packet, in other words, the packet
23
includes neither the timing information nor a start
portion of attribute information at the time of
displaying a random access point. On the other hand, "0"
represents that the packet is a priority TLV type2 packet,
in other words, the packet includes timing 5 information or
a start portion of attribute information at the time of
displaying a random access point.
[0052]
As the one-bit field of "non_priority_bit3", flag
10 information representing whether or not the packet is a
priority TLV type3 packet is newly defined. As
illustrated in Fig. 14, "1" represents that the packet is
a non-priority TLV packet, in other words, the packet
does not include a byte offset value toward a priority
15 TLV packet. On the other hand, "0" represents that the
packet is a priority TLV type3 packet, in other words,
the packet includes a byte offset value toward a priority
TLV packet.
[0053]
20 In addition, a TLV packet set as a priority TLV
packet does not have only a TLV packet including a
transport media packet that is an MMT packet including
media data such as video and audio as the target. A TLV
packet including the transport message information or the
25 MMT packet of the transport metadata packet is also set
as a priority TLV packet as is necessary.
[0054]
Referring back to Fig. 13, the eight-bit field of
"packet_type" represents the packet type of the TLV
30 packet (see Fig. 15). "0x01" represents that the packet
includes an IPv4 packet. "0x02" represents that the
24
packet includes an IPv6 packet. "0x03" represents that
the packet includes a header-compressed IP packet.
"0xFE" represents that the packet includes a transmission
control signal. "0xFF" represents that the packet is a
null packet. The 16-bit field of "length" 5 represents the
size of a variable-length TLV payload (TLV_payload)
following the TLV header (TLV_header).
[0055]
A TLV packet that is set such that
10 "non_priority_bit1 = 0", "non_priority_bit2 = 1", and
"non_priority_bit3 = 1" is a packet acquired by
encapsulating an IP packet including a transport media
packet (see Fig. 9) in the payload, and "packet_type" is
"0x01", "0x02", or "0x03". Also in a TLV packet of which
15 "packet_type" is "0x01", "0x02", or "0x03", in a case
where data in which the first byte of the access unit of
a random access point starts is not included therein, the
bits are set such that "non_priority_bit1 = 1",
"non_priority_bit2 = 1", and "non_priority_bit3 = 1".
20 [0056]
A TLV packet set such that "non_priority_bit1 = 1",
"non_priority_bit2 = 0", and "non_priority_bit3 = 1" is a
packet acquired by encapsulating an IP packet including
transport message information or a transport metadata
25 packet (see Fig. 9) in the payload, and "packet_type" is
"0x01", "0x02", or "0x03".
[0057]
A TLV packet set such that "non_priority_bit1 = 1",
"non_priority_bit2 = 1", and "non_priority_bit3 = 0" is a
30 packet acquired by encapsulating access position
information that is a transmission control signal, and
25
"packet_type" is "0xFE". In such a case, in the payload
of the TLV packet, a signaling packet (signaling_packet)
is arranged. Fig. 16 illustrates an example (Syntax) of
the structure of the signaling packet, and Fig. 17
illustrates the content (Semantics) of 5 major information
of the example of the structure. Such a structure, for
example, is a structure that matches the transmission
control signal TLV_NIT.
[0058]
10 A 16-bit field of "Pointer_previous TLV_priority
packet" represents a byte offset value toward a previous
priority packet (the reverse side). In addition, a 16-
bit field of "Pointer_next TLV_priority packet"
represents a byte offset value toward a next priority
15 packet (the forward side).
[0059]
Here, the priority packet is a TLV packet set such
that "non_priority_bit1 = 0" or a TLV packet set such
that "non_priority_bit2 = 0". In a case where a TLV
20 packet set such that "non_priority_bit1 = 0" is
independently present, the byte offset value is a byte
offset value toward this TLV packet. On the other hand,
in a case where a TLV packet set such that
"non_priority_bit2 = 0" and a TLV packet set such that
25 "non_priority_bit1 = 0" are continuously present in this
order, the byte offset value is a byte offset value
toward the TLV packet set such that "non_priority_bit2 =
0".
[0060]
30 In a transmission stream (TLV packet stream)
transmitted by the broadcasting station 110, as
26
illustrated in Fig. 18(a), TLV packets (PCT PRO 1) each
including an MMT packet that includes data in which the
first byte of the access unit of a random access point
starts are arranged at a predetermined interval. Fig.
19(a) schematically illustrates the structure 5 of such a
TLV packet (PCT PRO 1).
[0061]
In this TLV packet (PCT PRO 1), "non_priority_bit1"
is set to "0", and each of "non_priority_bit2" and
10 "non_priority_bit3" is set to "1". In addition, in this
TLV packet (PCT PRO 1) is a packet acquired by
encapsulating an IP packet including a transport media
packet (see Fig. 9) in the payload, and "packet_type" is
"0x01", "0x02", or "0x03".
15 [0062]
In addition, as illustrated in Fig. 18(a),
immediately before the TLV packet (PCT PRO 1), there are
cases where a TLV packet (PCT PRO 2) is present.
Although not illustrated in the drawing, in this TLV
20 packet (PCT PRO 2), "non_priority_bit2" is set to "0",
and each of "non_priority_bit1" and "non_priority_bit3"
is set to "1". In addition, this TLV packet (PCT PRO 2)
is a packet acquired by encapsulating an IP packet
including transport message information or a transport
25 metadata packet (see Fig. 9) in the payload, and
"packet_type" is "0x01", "0x02", or "0x03".
[0063]
In addition, as illustrated in Fig. 18(a),
immediately after the TLV packet (PCT PRO 1), a TLV
30 packet (PCT PRO 3) is present. Fig. 19(b) schematically
illustrates the structure of this TLV packet (PCT PRO 3).
27
In this TLV packet (PCT PRO 3), "non_priority_bit3" is
set to "0", and each of "non_priority_bit1" and
"non_priority_bit2" is set to "1". In addition, this TLV
packet (PCT PRO 3) is a packet acquired by encapsulating
the access position information that 5 is a transmission
control signal, and "packet_type" is "0xFE".
[0064]
In the payload of this TLV packet (PCT PRO 3), a
signaling packet (signaling packet) (see Fig. 16)
10 including fields of "Pointer_previous TLV_priority
packet" and "Pointer_next TLV_priority packet" is
included. As described above, "Pointer_previous
TLV_priority packet" represents a byte offset value
toward the previous priority packet (the reverse side),
15 and "Pointer_next TLV_priority packet" represents a byte
offset value toward the next priority packet (the forward
side).
[0065]
In addition, while the TLV packet is a packet
20 acquired by encapsulating an IP packet including a
transport media packet (see Fig. 9) in the payload,
apparently, there are cases where the TLV packet does not
include data in which the first byte of the access unit
of a random access point starts. In Fig. 18(a), this TLV
25 packet is illustrated simply as "PCT". Fig. 19(c)
schematically illustrates the structure of this TLV
packet (PCT).
[0066]
In this TLV packet (PCT), all the
30 "non_priority_bit1", "non_priority_bit2", and
"non_priority_bit3" are set to "1". In addition, this
28
TLV packet (PCT) is a packet acquired by encapsulating an
IP packet including a transport metadata packet (see Fig.
9) in the payload, and "packet_type", similar to the TLV
packet (PCT PRO 1) is "0x01", "0x02", or "0x03".
5 [0067]
In this way, in the transmission stream transmitted
by the broadcasting station 110, TLV packets (PCT PRO 1)
are arranged to be identifiable at a predetermined
interval, and the TLV packet (PCT PRO 3) including access
10 position information is arranged following each TLV
packet (PCT PRO 1). For this reason, on the reception
side, in the trick reproduction such as fast forward
reproduction or fast reverse reproduction after the
storage of this transmission stream in a storage medium,
15 data of the access unit of a random access point that is
necessary for the trick reproduction can be efficiently
acquired, and the trick reproduction can be executed at a
high speed.
[0068]
20 Fig. 18(b) illustrates an overview of fast forward
reproduction corresponding to the transmission stream
illustrated in Fig. 18(a). In this case, based on a user
instruction for fast forward reproduction, first, from a
TLV packet stream sequentially extracted from a storage
25 medium, for example, a first TLV packet (PCT PRO 2) of a
packet group of the TLV packet (PCT PRO 2), a TLV packet
(PCT PRO 1), and a TLV packet (PCT PRO 3) of a period T1
is found out based on the identification information.
For this TLV packet (PCT PRO 2), a header analysis is
30 sequentially executed up to an upper layer, and
information necessary for decoding the media data and the
29
like are acquired.
[0069]
Next, the TLV packet (PCT PRO 1) is extracted from
the storage medium, a header analysis is sequentially
executed up to an upper layer, and the 5 media coded data
is decoded, whereby media data (data of video and audio)
including data of the first byte of the access unit of
the random access point is acquired. Next, the TLV
packet (PCT PRO 3) is extracted from the storage medium,
10 and access position information (a byte offset value
toward a previous priority packet and a byte offset value
toward a next priority packet) is acquired.
[0070]
Thereafter, until data of access units
15 corresponding to a required number is acquired, TLV
packets (PCT) are sequentially extracted from the storage
medium, a header analysis is sequentially executed up to
an upper layer, and media coded data is decoded. Here,
the access units corresponding to a required number may
20 be configured by only access units of I pictures of
random access points, or access units of a B picture or a
P picture following them may be further included. While
the number of the access units is determined by a
reproduction application, it relates to the speed of fast
25 forward reproduction.
[0071]
Next, based on the access position information (the
byte offset value toward the next priority packet)
acquired from the TLV packet (PCT PRO 3), a first TLV
30 packet (PCT PRO 1) of a packet group of the TLV packet
(PCT PRO 1) and a TLV packet (PCT PRO 3) of a period T2
30
is extracted from the storage medium. Then, for this TLV
packet (PCT PRO 1), a header analysis is executed up to
an upper layer, and the media coded data is decoded,
whereby media data (data of video and audio) including
data of the first byte of the access 5 unit of a random
access point is acquired.
[0072]
Next, the TLV packet (PCT PRO 3) is extracted from
the storage medium, and access position information (a
10 byte offset value toward a previous priority packet and a
byte offset value toward a next priority packet) is
acquired. Thereafter, until data of access units
corresponding to a required number is acquired, TLV
packets (PCT) are sequentially extracted from the storage
15 medium, a header analysis is sequentially executed up to
an upper layer, and media coded data is decoded.
[0073]
Next, based on the access position information (the
byte offset value toward the next priority packet)
20 acquired from the TLV packet (PCT PRO 3), a first TLV
packet (PCT PRO 2) of a packet group of the TLV packet
(PCT PRO 2), a TLV packet (PCT PRO 1), and a TLV packet
(PCT PRO 3) of a period T3 is extracted from the storage
medium. Thereafter, the process is similarly repeated,
25 whereby the fast forward reproduction is executed.
[0074]
Fig. 18(c) illustrates an overview of fast reverse
reproduction corresponding to the transmission stream
illustrated in Fig. 18(a). In this case, based on a user
30 instruction for fast reverse reproduction, first, from a
TLV packet stream sequentially extracted from a storage
31
medium, for example, a first TLV packet (PCT PRO 2) of a
packet group of the TLV packet (PCT PRO 2), a TLV packet
(PCT PRO 1), and a TLV packet (PCT PRO 3) of a period T3
is found out based on the identification information.
For this TLV packet (PCT PRO 2), a 5 header analysis is
sequentially executed up to an upper layer, and
information necessary for decoding the media data and the
like are acquired.
[0075]
10 Next, the TLV packet (PCT PRO 1) is extracted from
the storage medium, a header analysis is sequentially
executed up to an upper layer, and the media coded data
is decoded, whereby media data (data of video and audio)
including data of the first byte of the access unit of
15 the random access point is acquired. Next, the TLV
packet (PCT PRO 3) is extracted from the storage medium,
and access position information (a byte offset value
toward a previous priority packet and a byte offset value
toward a next priority packet) is acquired. Thereafter,
20 until data of access units corresponding to a required
number is acquired, TLV packets (PCT) are sequentially
extracted from the storage medium, a header analysis is
sequentially executed up to an upper layer, and media
coded data is decoded.
25 [0076]
Next, based on the access position information (the
byte offset value toward the previous priority packet)
acquired from the TLV packet (PCT PRO 3), a first TLV
packet (PCT PRO 1) of a packet group of the TLV packet
30 (PCT PRO 1) and a TLV packet (PCT PRO 3) of a period T2
is extracted from the storage medium. Then, for this TLV
32
packet (PCT PRO 1), a header analysis is executed up to
an upper layer, and the media coded data is decoded,
whereby media data (data of video and audio) including
data of the first byte of the access unit of a random
access 5 point is acquired.
[0077]
Next, the TLV packet (PCT PRO 3) is extracted from
the storage medium, and access position information (a
byte offset value toward a previous priority packet and a
10 byte offset value toward a next priority packet) is
acquired. Thereafter, until data of access units
corresponding to a required number is acquired, TLV
packets (PCT) are sequentially extracted from the storage
medium, a header analysis is sequentially executed up to
15 an upper layer, and media coded data is decoded.
[0078]
Next, based on the access position information (the
byte offset value toward the previous priority packet)
acquired from the TLV packet (PCT PRO 3), a first TLV
20 packet (PCT PRO 2) of a packet group of the TLV packet
(PCT PRO 2), a TLV packet (PCT PRO 1), and a TLV packet
(PCT PRO 3) of a period T1 is extracted from the storage
medium. Thereafter, the process is similarly repeated,
whereby the fast reverse reproduction is executed. In
25 addition, in this reverse reproduction, while data of a
predetermined number of access units in a forward
direction is acquired in each period, data of the access
units is aligned and used in a reverse direction at the
time of display.
30 [0079]
Fig. 20 is a diagram that illustrates an example of
33
a transmission system 111 of a broadcast wave in the
broadcasting station 110. This transmission system 111
includes: an encoder unit 112; a multiplexer unit 113; a
framing unit 114; and a modulator/emission unit 115. The
encoder unit 112 codes media data such 5 as video, audio,
and the like, thereby acquiring coded data. For example,
for video data, coding such as MPEG4-AVC, high efficiency
video coding (HEVC), or the like is executed.
[0080]
10 In addition, the encoder unit 112 packetizes coded
data of video, audio, or the like, thereby generating a
multiplexed transport packet for each medium. As
described above, in this embodiment, the multiplexed
transport packet, for example, is assumed to be an MMT
15 packet. In addition, in an MMT packet that is actually
transmitted, as described above, in addition to a
transport media packet including media data such as video
and audio in the payload, transport message information
and a transport metadata packet are also present (see Fig.
20 9).
[0081]
Furthermore, the encoder unit 112 packetizes the
multiplexed transport packet into a UDP or a TCP and adds
an IP header thereto, thereby generating an IP packet
25 including the multiplexed transport packet. The encoder
unit 112 transmits each IP packet to the multiplexer unit
113. The multiplexer unit 113 multiplexes such IP
packets.
[0082]
30 In addition, the multiplexer unit 113 determines
whether or not data of the first byte of an access unit
34
(intra picture) configuring a random access point is
included based on the IP packet including the coded data
of video, audio, and the like. Alternatively, when an IP
packet including the coded data of video, audio, and the
like is supplied from the encoder unit 5 112, as denoted by
a broken line, the multiplexer unit 113 is simultaneously
supplied also with information of an access unit (intra
picture) configuring a random access point.
[0083]
10 Furthermore, the multiplexer unit 113 supplies a
multiplexed stream of IP packets to the framing unit 114.
At this time, as denoted by a broken line, the
multiplexer unit 113 also supplies information on whether
or not the data of the first byte of the access unit
15 (intra picture) configuring the random access point is
included to the framing unit 114 in correspondence with
the supply of the IP packet including the coded data of
video, audio, and the like.
[0084]
20 The framing unit 114 generates a TLV packet
acquired by encapsulating the multiplexed IP packet. In
addition, the framing unit 114 generates a TLV packet
acquired by encapsulating transmission control signals
(TLV-NIT and AMT). At the time of executing the
25 encapsulating process, the framing unit 114 sets priority
packet identification information included in the TLV
header, in other words, setting of the one-bit field of
"non_priority_bit1", the one-bit field of
"non_priority_bit2", and the one-bit field of
30 "non_priority_bit3" is executed (Figs. 13 and 14).
[0085]
35
The framing unit 114 sets the one-bit field of
"non_priority_bit1" to "0" when the data in which the
first byte of the access unit of the random access point
starts is included in the TLV packet so as to present a
priority TLV type1 packet. In addition, 5 the framing unit
114 sets the one-bit field of "non_priority_bit2" to "0"
when the timing information or the start portion of the
attribute information at the time of displaying the
random access point is included so as to represent a
10 priority TLV type2 packet. Furthermore, the framing unit
114 sets the one-bit field of "non_priority_bit3" to "0"
when a byte offset value toward the priority TLV packet
is included so as to represent a priority TLV type3
packet.
15 [0086]
In addition, the framing unit 114 executes a
framing process in which each TLV packet is stored in a
slot of the transmission frame. The framing unit 114
supplies the generated transmission frame to the
20 modulator/emission unit 115. The modulator/emission unit
115 executes an RF modulation process for the
transmission frame so as to generate a broadcast wave and
transmits the broadcast wave to the reception side
through an RF transmission channel.
25 [0087]
Referring back to Fig. 1, the distribution server
120, for example, distributes a transmission stream in
which IP packets as transmission packets each including
an MMT packet as handled by the broadcasting station 110
30 described above are continuously arranged to the
reception side through a communication network 300
36
through multicast. Alternatively, the distribution
server 120, based on a reproduction command transmitted
from the reception side, transmits a transmission stream,
in which predetermined IP packets as transmission packets
each including an MMT packet are continuously 5 arranged,
in accordance with the reproduction mode to the reception
side through the communication network 300 as an ondemand
video service. In the reproduction mode, in
addition to a normal reproduction mode, trick
10 reproduction such as fast forward reproduction and fast
reverse reproduction is included.
[0088]
In this embodiment, in the IP packet as the
transmission packet stored in the distribution server 120,
15 the identification information used for identifying
whether or not the packet is a packet handled with high
priority is inserted, and identification information used
for identifying whether or not the packet is a packet
including the access position information is inserted.
20 Fig. 21 illustrates an example (Syntax) of the structure
of an internet protocol (IP) header. Fig. 22 illustrates
contents (Semantics) of major information of the example
of the structure.
[0089]
25 A four-bit field of "Version" represents the
version of the IP header. A four-bit field of "IHL = Hdr
Len" represents the length of the IP header in units of
32 bits. In a case where there is no option, the length
of the IP header is 20 bytes. An eight-bit field of
30 "TOS/DSCP/ECN" is a service type field. A 16-bit field
of "Total Length" represents the total length of the IP
37
packet in the number of bytes.
[0090]
A first bit of a three-bit field of "Flags" is
unused. A second bit designates whether or not
fragmentation is permitted. In addition, 5 in the case of
fragmentation, a third bit represents whether or not the
fragment is in the middle or at the end of the original
IP packet. A 13-bit field of "Fragment Offset", in a
case where an IP packet is fragmented, represents the
10 position indicating the sequence of the fragment.
[0091]
An eight-bit field of "Time To Live" represents a
maximal period during which the IP packet can live on the
Internet. The purpose thereof is to prevent an IP packet
15 having a destination that is not found from continuing to
be circulated on the network. An eight-bit field of
"Protocol" is an identifier used for identifying a highorder
protocol. For example, "1" represents "ICMP", "2"
represents "IGMP", "3" represents "TCP", "17" represents
20 "UDP", "41" represents "IPv6", and "89" represents "OSPF".
[0092]
A 16-bit field of "Header Checksum" is a CRC used
for checking the IP header. A 32-bit field of "Source
Address" represents the IP address of a transmission
25 source. A 32-bit field of "Destination Address"
represents the IP service of a destination.
[0093]
Fig. 23 illustrates an example (Syntax) of the
structure of "Options". Fig. 24 illustrates contents
30 (Semantics) of major information of the example of the
structure. A one-bit field of "type_copy" represents
38
that copy is executed within a first fragment when
"type_copy" has a value "1". When "type_copy" has a
value "0", it represents that copy is executed over all
the fragments. "type_class" represents the type of
application target. A five-bit field 5 of "type_number"
represents a type number. For example, "01111" will be
newly defined as a type number that represents media
access priority information. In addition, for example,
"01110" will be newly defined as a type number that
10 represents a media access offset position. An eight-bit
field of "length" represents a size after that in number
of bytes.
[0094]
For example, as illustrated in Fig. 25, by setting
15 "type_number = '01111'" and "length = 2", for example,
information used for identifying whether or not a first
byte of the access unit of a random access point is
included and the like are defined. In "information" of
two bytes at that time, "0x0001" represents that the
20 first byte (1st byte) of the access unit of the random
access point is included. On the other hand, "0x0002"
represents that the timing information or the start
portion of the attribute information at the time of
displaying a random access point is included. In
25 addition, "0x0000" represents that the other information
is included.
[0095]
As illustrated in Fig. 26, by setting "type_number
= '01110'" and "length = 4", for example, information for
30 supplying a random access point or a packet position for
special reproduction is defined. In "information" of
39
four bytes at that time, following "Media Access offset
position forward (16 bits)", "Media Access offset
position backward (16 bits)" is transmitted.
[0096]
Here, "Media Access offset 5 position backward
(16bits)", similar to the 16-bit field of
"Pointer_previous TLV_priority packet" included in the
signaling packet (signaling) (see Fig. 16) described
above, represents a byte offset value toward a previous
10 priority packet (the reverse side). In addition, "Media
Access offset position forward (16 bits)", similar to the
16-bit field of "Pointer_next TLV_priority packet"
included in the signaling packet described above,
represents a byte offset value toward a next priority
15 packet (the forward side).
[0097]
In the transmission stream (IP packet stream)
transmitted by the distribution server, as illustrated in
Fig. 27(a), IP packets (PCT PRO 1) each including a
20 transport media packet (see Fig. 9) that includes data,
in which a first byte of the access unit of the random
access point starts, are arranged at a predetermined
interval. In this IP packet (PCT PRO 1), by setting
"type_number = '01111'" and "length = 2", "information"
25 of the two bytes is set to "0x0001".
[0098]
In addition, as illustrated in Fig. 27(a),
immediately before the IP packet (PCT PRO 1), there are
cases where the IP packet (PCT PRO 2) is present. This
30 IP packet (PCT PRO 2) is an IP packet including transport
message information or a transport metadata packet (see
40
Fig. 9). This IP packet (PCT PRO 2) is set such that
"type_number = '01111'" and "length = 2", and
"information" of the two bytes is "0x0002".
[0099]
As illustrated in Fig. 27(a), immediately 5 after the
IP packet (PCT PRO 1), an IP packet (PCT PRO 3) is
present. This IP packet (PCT PRO 3) is an IP packet that
includes access position information. In this IP packet
(PCT PRO 3), "type_number = '01110'", and "length = 4",
10 and "Media Access offset position forward (16bits)" and
"Media Access offset position backward (16bits)" are
arranged in "information" of four bytes.
[0100]
In addition, while the IP packet is a packet
15 including a transport media packet (see Fig. 9) in the
payload, apparently, there are cases where the IP packet
does not include data in which the first byte of the
access unit of a random access point starts. In Fig.
27(a), this IP packet is illustrated simply as "PCT".
20 [0101]
In this way, in the transmission stream transmitted
by the distribution server 120, IP packets (PCT PRO 1)
are arranged to be identifiable at a predetermined
interval, and the IP packet (PCT PRO 3) including access
25 position information is arranged following each IP packet
(PCT PRO 1). For this reason, on the reception side, for
example, in the trick reproduction such as fast forward
reproduction or fast reverse reproduction after the
storage of this transmission stream in a storage medium,
30 data of the access unit of a random access point that is
necessary for the trick reproduction can be efficiently
41
acquired, and the trick reproduction can be executed at a
high speed.
[0102]
Fig. 27(b) illustrates an overview of fast forward
reproduction corresponding to the transmission 5 stream
illustrated in Fig. 27(a). In addition, Fig. 27(c)
illustrates an overview of fast reverse reproduction
corresponding to the transmission stream illustrated in
Fig. 27(a). While detailed description thereof will not
10 be presented, the reproduction is similar to the overview
of the reproduction of the case of the TLV packet stream
illustrated in Figs. 18(b) and 18(c).
[0103]
Referring back to Fig. 1, the receiver 200:
15 includes a tuner 201; a demultiplexer 202, a decoder 203;
a display 204; a gateway/network router 205; a central
processing unit (CPU) 206; and a user operation unit 207.
[0104]
The CPU 206 controls the operation of each unit of
20 the receiver 200. A user can execute various inputs by
using the user operation unit 207. This user operation
unit 207 is a remote control unit, a touch panel unit
that executes an instruction input through an
approach/touch, a mouse, a keyboard, a gesture input unit
25 that detects an instruction input by using a camera, an
audio input unit that gives an instruction by using audio,
or the like. The user can execute an instruction input
such as fast forward reproduction or fast reverse
reproduction by using the user operation unit 207.
30 [0105]
The tuner 201 and the gateway/network router 205
42
configure an acquisition unit or a reception unit. The
tuner 201 receives a broadcast wave transmitted through
the RF transmission channel from the transmission side,
acquires a transmission frame by executing RF
demodulation, executing a deframing 5 process and
decapsulation, and outputs an IP packet. In addition,
the tuner 201 supplies transmission control signals (TLVNIT
and AMT) acquired by decapsulation of the TLV packet
to a CPU (control unit) 206 not illustrated in the
10 diagram. In these control signals, the access position
information used at the time of executing trick
reproduction such as fast forward reproduction or fast
reverse reproduction is also included.
[0106]
15 In addition, a storage medium 210 located outside
the receiver 200, for example, an HDD is connected to the
tuner 201, and the transmission stream acquired by the
tuner 201 can be recorded and reproduced. At the time of
reproduction, the tuner 201 transmits a reproduction
20 command to the storage medium 210, receives a
transmission stream reproduced from the storage medium
210, executes decapsulation thereof, and outputs an IP
packet. In such a case, in accordance with a
reproduction mode represented in the reproduction command,
25 the trick reproduction such as the fast forward
reproduction or the fast reverse reproduction can be
executed in additional to normal reproduction.
[0107]
The tuner 201 supplies the output IP packet to the
30 demultiplexer 202. At this time, the tuner 201 also
supplies the priority packet identification information
43
extracted from the header of the TLV packet to the
demultiplexer 202 in correspondence with the supply of
each IP packet. The demultiplexer 202 executes an
extraction process for each type (video, audio, metadata,
a message, or the like) of data included 5 in the payload
for the IP packets supplied from the tuner 201. The
demultiplexer 202 supplies the extracted IP packet of
each type to the corresponding decoder 203 together with
the priority packet identification information.
10 [0108]
The decoder 203 executes a de-packetizing process
and a decoding process as is necessary for the IP packets
for each type. The decoder 203 supplies a message and
metadata to a control unit not illustrated in the diagram.
15 In addition, the decoder 203 supplies video data to the
display 204 as a display unit and supplies audio data to
an audio output unit not illustrated in the diagram, for
example, a speaker.
[0109]
20 Fig. 28 illustrates an example of a
reception/reproduction system 211 of the receiver 200.
This reception/reproduction system 211 includes: a
tuner/demodulator unit 212; a deframing unit 213; a
demultiplexer unit 214; a decoder unit 215; and a media
25 interface 216. The tuner/demodulator unit 212 receives a
broadcast wave through the RF transmission channel and
executes an RF demodulation process thereof, thereby
acquiring a transmission frame in which a TLV packet is
included in the transmission slot. The tuner/demodulator
30 unit 212 supplies the transmission frame to the deframing
unit 213.
44
[0110]
The deframing unit 213 extracts a TLV packet
included in each slot from the transmission frame. In
addition, the deframing unit 213 executes a decapsulation
process for each extracted TLV packet, 5 thereby acquiring
an IP packet and transmission control signals (TLV-NIT
and AMT).
[0111]
The deframing unit 213 supplies the acquired
10 transmission control signals to the CPU 206. In addition,
the deframing unit 213 supplies the acquired IP packet to
the demultiplexer 214. At this time, the deframing unit
213, as denoted by a broken line, also supplies the
priority packet identification information included in
15 the TLV header to the demultiplexer unit 214 in
correspondence with the supply of each IP packet. This
priority packet identification information, as described
above, is information of the one-bit field of
"non_priority_bit1" and the one-bit field of
20 "non_priority_bit2" (see Fig. 13).
[0112]
The demultiplexer unit 214 executes the process of
extracting the IP packets supplied from the deframing
unit 213 for each type of data included in the payload.
25 The demultiplexer unit 214 supplies the extracted IP
packet of each type to the corresponding decoder unit 215.
At this time, the demultiplexer unit 214, as denoted by a
broken line, also supplies the priority packet
identification information to the decoder unit 215 in
30 correspondence with the supply of each IP packet.
[0113]
45
The decoder unit 215 executes a de-packetizing
process and a decoding process as is necessary for the IP
packets for each type. The decoder unit 215 supplies a
message and metadata to a control unit not illustrated in
the drawing. In addition, the decoder 5 unit 215 supplies
video data to a display unit not illustrated in the
drawing and supplies audio data to an audio output unit
not illustrated in the drawing.
[0114]
10 The media interface 216, under the control of the
CPU 206, executes recording of the transmission stream
(TLV packet stream) for the storage medium 210 and
reproduction of the transmission stream (TLV packet
stream) supplied from the storage medium 210. The media
15 interface 216 transmits the transmission stream (TLV
packet stream) acquired by the deframing unit 213 to the
storage medium 210 so as to be stored (recorded) therein
at the time of recording.
[0115]
20 The media interface 216 accesses the storage medium
210, extracts a stored transmission stream (TLV packet
stream), and transmits the transmission stream to the
deframing unit 213 at the time of reproduction. The
deframing unit 213 executes a decapsulation process for
25 each TLV packet of the extracted transmission stream (TLV
packet stream), thereby acquiring an IP packet and
transmission control signals (TLV-NIT and AMT).
[0116]
The time of the reproduction, the deframing unit
30 213 supplies the transmission control signals (TLV-NIT
and AMT) acquired through the decapsulation process to
46
the CPU 206. In these control signals, the access
position information ("Pointer_previous TLV_priority
packet", "Pointer_next TLV_priority packet") included in
the TLV packet (PCT PRO 3) are also included. In
addition, the deframing unit 213 5 also supplies the
identification information ("non_priority_bit1",
"non_priority_bit2", and "non_priority_bit3") of the TLV
packet acquired through the decapsulation process to the
CPU 206. In addition, at the time of the reproduction,
10 the decoder 215 supplies decoding information to the CPU
206.
[0117]
The CPU 206 controls accesses to the storage medium
210 from the media interface 216 based on various kinds
15 of information supplied as described above. In this way,
the media interface 216, in trick reproduction such as
the fast forward reproduction and the fast reverse
reproduction, can efficiently extract a TLV packet
including data of the access unit that is necessary for
20 the trick reproduction from the storage medium 210.
[0118]
Referring back to Fig. 1, the gateway/network
router unit 205 receives a transmission stream of a
service distributed through multicast from the
25 distribution server 120 through the communication network
300 and outputs an IP packet similar to the output of the
tuner 201 described above. In addition, in the header of
this IP packet, the identification information used for
identifying whether or not the packet is a packet to be
30 handled with high priority is inserted, and the
identification information used for identifying whether
47
or not the packet is a packet including the access
position information is inserted (see Figs. 23 to 26).
[0119]
In addition, a storage medium 220 located outside
the receiver 200, for example, an HDD is 5 connected to the
gateway/network router unit 205 through a local network,
and the transmission stream received by the
gateway/network router unit 205 can be recorded and
reproduced. At the time of reproduction, the
10 gateway/network router unit 205 transmits a reproduction
command to the storage medium 220, receives a
transmission stream (IP packet stream) reproduced from
the storage medium 220, and outputs an IP packet
configuring the transmission frame. In such a case, in
15 accordance with a reproduction mode directed by the
reproduction command, the trick reproduction such as the
fast forward reproduction or the fast reverse
reproduction can be executed in additional to normal
reproduction.
20 [0120]
At the time of the reproduction, the identification
information used for identifying whether or not the
packet is a packet to be handled with high priority, the
identification information used for identifying whether
25 or not the packet is a packet including the access
position information, and the access position information
("Media Access offset position forward" and "Media Access
offset position backward"), which are inserted in the IP
packet, are supplied to the CPU 206. In addition, at
30 this time of the reproduction, decoding information is
supplied from the decoder 215 to the CPU 206.
48
[0121]
The CPU 206, similar to the process executed at the
time of reproduction of the transmission stream (TLV
packet stream) of the broadcasting system described above,
controls accesses to the storage medium 5 220 based on
supplied various kinds of information. In this way, in
trick reproduction such as the fast forward reproduction
or the fast reverse reproduction, an IP packet including
data of the access unit that is necessary for the trick
10 reproduction can be efficiently extracted from the
storage medium 220.
[0122]
Alternatively, the gateway/network router unit 205
transmits a reproduction command to the distribution
15 server 120, receives a transmission stream of an ondemand
video service from the distribution server 120
through the communication network 300, and outputs an IP
packet similar to that of the case of the multicast
distribution described above. In such a case, the
20 transmission stream transmitted from the distribution
server 120 corresponds to the reproduction mode
represented in the reproduction command. In the
reproduction mode, in addition to a normal reproduction
mode, trick reproduction such as fast forward
25 reproduction and fast reverse reproduction is included.
[0123]
The CPU 206 can execute access control for the
distribution server 120 through the gateway/network
router unit 205 similar to the access control for the
30 storage medium 220 described above. In this way, in
trick reproduction such as the fast forward reproduction
49
or the fast reverse reproduction, an IP packet including
data of the access unit that is necessary for the trick
reproduction can be efficiently extracted from the
distribution server 120.
5 [0124]
The gateway/network router unit 205 supplies the
output IP packet to the demultiplexer 202. The
demultiplexer 202 executes an extraction process for each
type (video, audio, metadata, a message, or the like) of
10 data included in the payload for the IP packets supplied
from the gateway/network router unit 205. The
demultiplexer 202 supplies the extracted IP packet of
each type to the corresponding decoder 203.
[0125]
15 The decoder 203 executes a de-packetizing process
and a decoding process as is necessary for the IP packets
for each type. The decoder 203 supplies a message and
metadata to the CPU (control unit) 206. In addition, the
decoder 203 supplies video data to the display 204 as a
20 display unit and supplies audio data to an audio output
unit not illustrated in the diagram, for example, a
speaker.
[0126]
The operation of the display system 10 illustrated
25 in Fig. 1 will be briefly described. First, a case will
be described in which the tuner 201 of the receiver 200
receives a broadcast wave from the broadcasting station
110 and executes the process. In such a case, a
broadcast wave carrying a transmission stream in which
30 TLV packets as transmission packets are continuously
arranged is transmitted from the broadcasting station 110
50
to the reception side through the RF transmission channel.
This broadcast wave is received by the tuner 201 of the
receiver 200.
[0127]
The tuner 201 acquires a transmission 5 frame by
executing the RF demodulation process for the received
broadcast wave, executes the deframing process and
decapsulation, and outputs an IP packet. Here, the
transmission control signals (TLV-NIT and AMT) acquired
10 by decapsulation of the TLV packet are supplied to the
CPU 206.
[0128]
The IP packet output from the tuner 201 is supplied
to the demultiplexer 202. At this time, priority packet
15 identification information extracted from the header of
the TLV packet is also supplied from the tuner 201 to the
demultiplexer 202 in correspondence with the supply of
each IP packet. The demultiplexer 202 executes an
extraction process for each type (video, audio, metadata,
20 a message, or the like) of data included in the payload
for the IP packets sequentially supplied from the tuner
201.
[0129]
The IP packets of each type extracted by the
25 demultiplexer 202 are supplied to the corresponding
decoder 203 together with the priority packet
identification information. The decoder 203 executes a
de-packetizing process and a decoding process as is
necessary for the IP packets for each type. Here, video
30 data acquired by the decoder 203 is supplied to the
display 204 as a display unit, and an image is displayed.
51
In addition, audio data acquired by the decoder 203 is
supplied to an audio output unit not illustrated in the
diagram, for example, a speaker, and audio is output.
Furthermore, a message and metadata acquired by the
decoder 203 are supplied 5 to the CPU 206.
[0130]
Here, an operation executed in a case where channel
switching (random access) of broadcasting occurs
according to a user operation will be described. In this
10 case, in the receiver 200, the target for a display
process is started from a first random access point (RAP)
of a transmission stream after the channel switching. As
this random access point, the start of the access unit
configured only by non-predictive components (an I
15 picture and an IDR picture) or a start point of message
information relating thereto is the target.
[0131]
Fig. 29 illustrates an example of a case where
switching is made from channel A (CH-A) to channel B (CH20
B) at a service switching time point SSP. In this case,
when the display is restarted, at least a delay t1 from
the time point SSP to a time point RAP occurs. In
addition, in a case where a predictive differential
picture (a P picture or a B picture) referring to a
25 picture positioned before an I picture in the display
order is present after the time point RAP, a delay t2
caused thereby occurs as well.
[0132]
According to this embodiment, based on the priority
30 packet identification information included in the header
of the TLV packet, an analysis process of the header of
52
each packet in the transmission stream up to a first
random access point (RAP) is omitted appropriately, and a
delay until decoding/displaying of a picture of the first
random access point decreases, whereby a response time
until initial display 5 is shortened.
[0133]
Next, an operation will be described which is
executed in a case where a reproduction command is
transmitted to the storage medium 210 according to a user
10 operation, and trick reproduction such as fast forward
reproduction or fast reverse reproduction is executed.
In such a case, accesses to the storage medium 210 are
controlled by the CPU 206, and, for example, a TLV packet
including the access unit of the random access point
15 (RAP) is selectively extracted, and a transmission stream
including the TLV packet is returned to the tuner 201 as
a reproduction transmission stream.
[0134]
The tuner 201 executes decapsulation of the TLV
20 packet included in the transmission stream supplied from
the storage medium 210 and outputs an IP packet. Here,
transmission control signals (TLV-NIT and AMT) acquired
through the decapsulation of the TLV packet are supplied
to the CPU 206.
25 [0135]
The IP packet output from the tuner 201 is supplied
to the demultiplexer 202. The demultiplexer 202 executes
the extraction process for each type (video or audio) of
data included in the payload for the IP packets
30 sequentially supplied from the tuner 201. The IP packets
of each type extracted by the demultiplexer 202 are
53
supplied to the corresponding decoder 203 together with
the priority packet identification information.
[0136]
The decoder 203 executes the de-packetizing process
and the decoding process for the IP packets 5 for each type.
Here, video data acquired by the decoder 203 is supplied
to the display 204 as a display unit, and accordingly, an
image of the trick reproduction is displayed. In
addition, audio data acquired by the decoder 203 is
10 supplied to an audio output unit not illustrated in the
diagram, for example, a speaker, and accordingly, audio
corresponding to the display image is output.
[0137]
Fig. 30 illustrates an example of the process of
15 the receiver 200 of a case where a transition is made
from a normal reproduction mode to a mode of trick
reproduction (fast forward reproduction or fast reverse
reproduction) in accordance with a user operation. The
receiver 200 starts the process in Step ST1 in accordance
20 with the transition to the trick reproduction mode and
thereafter causes the process to proceed to the process
of Step ST2. In this Step ST2, the receiver 200 accesses
a storage position of a next TLV packet in the storage
medium 210 and acquires the TLV packet.
25 [0138]
Next, in Step ST3, the receiver 200 analyzes the
header of the acquired TLV packet and recognizes the
settings of "non_priority_bit1", "non_priority_bit2", and
"non_priority_bit3". Then, in Step ST4, the receiver 200
30 determines whether or not "non_priority_bit2" is set to
"0". When "non_priority_bit2" is set to "0", the
54
receiver 200 causes the process to proceed to Step ST50
and executes the process of an upper-layer analysis
routine and, in parallel, returns the process to Step ST2
and executes the process of acquiring a next TLV packet
from the storage 5 medium 210.
[0139]
In a case where "non_priority_bit2" is not set to
"0" in Step ST4, the receiver 200 determines whether or
not "non_priority_bit1" is set to "0" in Step ST5. When
10 "non_priority_bit1" is set to "0", the receiver 200
causes the process to proceed to Step ST50 and executes
the upper-layer analysis routine and, in parallel,
returns the process to Step ST2 and executes the process
of acquiring a next TLV packet from the storage medium
15 210.
[0140]
When "non_priority_bit1" is not set to "0" in Step
ST5, the receiver 200 determines whether or not
"non_priority_bit3" is set to "0" in Step ST6. When
20 "non_priority_bit3" is set to "0", the receiver 200, in
Step ST7, acquires the access position information from
the TLV packet and, thereafter, in Step ST8, determines
whether or not the decoding process for the target access
unit has been completed. This determination is executed
25 based on decoding status information of the target access
unit supplied from the decoder 203. As the target access
units, a case where only access units of I pictures of
the random access point are included or a case where
access units of I pictures and a predetermined number of
30 access units of B pictures and P pictures after that are
included may be considered.
55
[0141]
In a case where "non_priority_bit3" is not set to
"0" in Step ST6, the receiver 200 determines whether or
not the decoding process for the target access unit has
been completed in Step ST8. This 5 determination is
executed based on the decoding status information of the
target access unit supplied from the decoder 203. As the
target access units, a case where only access units of I
pictures of the random access point are included or a
10 case where access units of I pictures and a predetermined
number of access units of B pictures and P pictures after
that are included may be considered.
[0142]
When the decoding process for the target access
15 unit has been completed, the receiver 200, in Step ST9,
accesses the storage position of a jumped TLV packet in
the storage medium 210 based on the access position
information acquired in Step ST7 described above,
acquires the TLV packet and, thereafter, returns the
20 process to Step ST3. On the other hand, when the
decoding process for the target access unit has not been
completed, the receiver 200 causes the process to proceed
to Step ST50 and executes the upper-layer analysis
routine and, in parallel, returns the process to Step ST2
25 and executes the process of acquiring a next TLV packet
from the storage medium 210.
[0143]
A flowchart represented in Fig. 31 illustrates an
example of the process of the upper-layer analysis
30 routine in Step 50 described above. The receiver 200
starts the process in Step ST10. Thereafter, the
56
receiver 200 analyzes the IP header in Step 11 and
analyzes the UDP header or the TCP header in Step ST12.
In addition, the receiver 200 analyzes the MMT payload
header in Step ST13.
5 [0144]
Then, the receiver 200, in Step ST14, determines
whether or not "random_access_point_flag" represents the
RAP. When the RAP is represented, the receiver 200
executes a decoding process in Step ST15. When media
10 data such as video is decoded, the receiver 200 executes
a presentation process such as image display and audio
output in Step ST16 and thereafter, ends the process in
Step ST17. In addition, the decoder 203 notifies the CPU
206 of the processing status of the target access unit.
15 Accordingly, the determination of Step ST8 in the
flowchart represented in Fig. 30 described above can be
executed. In addition, the decoder unit 215 sets meta
data information included in the TLV packet in which
"non_priority_bit2" is set to "0" as is necessary.
20 [0145]
In addition, when "random_access_point_flag" does
not represent the RAP in Step ST14, the receiver 200
determines whether to execute a decoding process in Step
ST18. For example, when the decoding process for the
25 target access unit has been completed, decoding is
determined to be executed. In addition, for the MMT
packet in which meta information is included, decoding is
determined to be executed. When decoding is determined
not to be executed in Step ST18, the receiver 200
30 immediately ends the process in Step ST17. For example,
media data included in the MMT packet immediately after
57
the start of the trick reproduction mode until a first
random access point is found, and the like correspond to
a case where decoding is determined not to be executed.
[0146]
Next, a case will be described 5 in which the
gateway/network router 205 of the receiver 200 receives a
transmission stream of a service transmitted from the
distribution server 120 through the communication network
300 and executes the process. In such a case, an IP
10 packet included in the received transmission stream is
output from the gateway/network router 205. In addition,
in the header of this IP packet, the priority packet
identification information and the identification
information used for determining whether or not the
15 access position information is included are included.
[0147]
The IP packet output from the gateway/network
router 205 is supplied to the demultiplexer 202. The
demultiplexer 202 executes an extraction process for each
20 type (video, audio, metadata, a message, or the like) of
data included in the payload for the IP packets that are
sequentially supplied from the tuner 201.
[0148]
The IP packets of each type extracted by the
25 demultiplexer 202 are supplied to the corresponding
decoder 203 together with the priority packet
identification information. The decoder 203 executes the
de-packetizing process and a decoding process as is
necessary for the IP packet for each type. The video
30 data acquired by the decoder 203 is supplied to the
display 204 as a display unit, whereby an image is
58
displayed. In addition, the audio data acquired by the
decoder 203 is supplied to an audio output unit not
illustrated in the diagram, for example, a speaker,
whereby audio is output. Furthermore, a message and
metadata acquired by the decoder 203 are 5 supplied to the
CPU 206.
[0149]
Here, the operation of a case where service
switching (random access) of multicast distribution
10 occurs according to a user operation will be described.
In such a case, in the receiver 200, a target for the
display process is from the first random access point
(RAP) of the transmission stream after the service
switching. As targets for this random access point,
15 there are the start of an access unit configured only by
non-predictive components (an I picture and an IDR
picture) and the start point of message information
relating thereto.
[0150]
20 In this case, while detailed description will not
be presented, similar to the case of the switching of the
broadcasting channel described above, based on the
priority packet identification information included in
the header of the IP packet, the analysis process for the
25 header of each packet in the transmission stream up to
the first random access point (RAP) is appropriately
omitted (see Fig. 25). Accordingly, a delay until
decoding/display of a picture of the first random access
point decreases, whereby a response time until initial
30 display is shortened.
[0151]
59
Next, an operation will be described which is
executed in a case where a reproduction command is
transmitted to the storage medium 220 according to a user
operation, and trick reproduction such as fast forward
reproduction or fast reverse reproduction 5 is executed.
In such a case, accesses to the storage medium 220 are
controlled, and, for example, an IP packet including the
access unit of the random access point (RAP) is
selectively extracted, and a transmission stream
10 including the IP packet is returned to the
gateway/network router 205 as a reproduction transmission
stream.
[0152]
From the gateway/network router 205, the IP packet
15 included in the transmission stream supplied from the
storage medium 220 is output. The demultiplexer 202
executes the extraction process for each type (video or
audio) of data included in the payload for the IP packets
sequentially supplied from the gateway/network router 205.
20 The IP packets of each type extracted by the
demultiplexer 202 are supplied to the corresponding
decoder 203.
[0153]
The decoder 203 executes the de-packetizing process
25 and the decoding process for the IP packets for each type.
Here, video data acquired by the decoder 203 is supplied
to the display 204 as a display unit, and accordingly, an
image of the trick reproduction is displayed. In
addition, audio data acquired by the decoder 203 is
30 supplied to an audio output unit not illustrated in the
diagram, for example, a speaker, and accordingly, audio
60
corresponding to the display image is output.
[0154]
Fig. 32 illustrates an example of the process of
the receiver 200 of a case where a transition is made
from a normal reproduction mode 5 to a mode of trick
reproduction (fast forward reproduction or fast reverse
reproduction) in accordance with a user operation. The
receiver 200 starts the process in Step ST31 in
accordance with the transition to the trick reproduction
10 mode and thereafter, causes the process to proceed to the
process of Step ST32. In this Step ST32, the receiver
200 accesses a storage position of a next IP packet in
the storage medium 220 and acquires the IP packet.
[0155]
15 Next, in Step ST33, the receiver 200 analyzes the
header of the acquired IP packet and recognizes the
settings of options and the like. Then, in Step ST34,
the receiver 200 determines whether or not "Type_number =
0x1F" and "MPI = 0x1". Here, "MPI" is an abbreviation of
20 "Media Priority Information". When "Type_number = 0x1F"
and "MPI = 0x1", the receiver 200 causes the process to
proceed to Step ST60 and executes the process of an
upper-layer analysis routine and, in parallel, returns
the process to Step ST12 and executes the process of
25 acquiring a next IP packet from the storage medium 210.
[0156]
On the other hand, in a case where "Type_number =
0x1F" and "MPI = 0x1" are not satisfied in Step ST34, the
receiver 200 determines whether or not "Type_number =
30 0x1F" and "MPI = 0x2" in Step ST35. When "Type_number =
0x1F" and "MPI = 0x2", the receiver 200 causes the
61
process to proceed to Step ST60 and executes the upperlayer
analysis routine and, in parallel, returns the
process to Step ST12 and executes the process of
acquiring a next IP packet from the storage medium 210.
5 [0157]
When "Type_number = 0x1F" and "MPI = 0x2" are not
satisfied in Step ST35, the receiver 200 determines
whether or not "Type_number = 0x1E" in Step ST36. When
it is set that "Type_number = 0x1E", the receiver 200
10 acquires the access position information from the IP
packet in Step ST37 and thereafter, in Step ST38,
determines whether or not the decoding of the target
access unit has ended. This determination is executed
based on the decoding status information of the target
15 access unit supplied from the decoder 203. As the target
access units, a case where only access units of I
pictures of the random access point are included or a
case where access units of I pictures and a predetermined
number of access units of B pictures and P pictures after
20 that are included may be considered.
[0158]
When "Type_number = 0x1E" is not set in Step ST36,
the receiver 200 determines whether or not the decoding
of the target access unit has ended in Step ST38. As the
25 target access units, a case where only access units of I
pictures of the random access point are included or a
case where access units of I pictures and a predetermined
number of access units of B pictures and P pictures after
that are included may be considered.
30 [0159]
When the decoding process for the target access
62
unit has been completed, the receiver 200, in Step ST39,
accesses the storage position of a jumped IP packet in
the storage medium 220 based on the access position
information acquired in Step ST37 described above,
acquires the IP packet and, thereafter, 5 returns the
process to Step ST33. On the other hand, when the
decoding process for the target access unit has not been
completed, the receiver 200 causes the process to proceed
to Step ST60 and executes the upper-layer analysis
10 routine and, in parallel, returns the process to Step
ST32 and executes the process of acquiring a next IP
packet from the storage medium 210.
[0160]
While the example of the process of the upper-layer
15 analysis routine of Step ST60 described above will not be
described in detail, it is similar to the upper-layer
analysis routine of Step ST50 of the flowchart
represented in Fig. 30. However, in the upper-layer
analysis routine of Step ST60, since the packet of the
20 lowermost layer is the IP packet, in the upper-layer
analysis routine illustrated in Fig. 31, Step ST11 is
excluded.
[0161]
Next, an operation will be described which is
25 executed in a case where a reproduction command is
transmitted to the distribution server 120 according to a
user operation, and a transmission stream is received,
and trick reproduction such as fast forward reproduction
or fast reverse reproduction is executed. In such a case,
30 accesses to the distribution server 120 are controlled,
and, based on the priority packet identification
63
information included in the header of the IP packet and
the access position information, for example, an IP
packet including the access unit of the random access
point (RAP) is selectively extracted, and a transmission
stream including the IP packet 5 is returned to the
gateway/network router 205.
[0162]
From the gateway/network router 205, the IP packet
included in the transmission stream supplied from the
10 distribution server 120 is output. The demultiplexer 202
executes the extraction process for each type (video or
audio) of data included in the payload for the IP packets
sequentially supplied from the gateway/network router 205.
The IP packets of each type extracted by the
15 demultiplexer 202 are supplied to the corresponding
decoder 203 together with the priority packet
identification information.
[0163]
The decoder 203 executes the de-packetizing process
20 and the decoding process for the IP packets for each type.
Here, video data acquired by the decoder 203 is supplied
to the display 204 as a display unit, and accordingly, an
image of the trick reproduction is displayed. In
addition, audio data acquired by the decoder 203 is
25 supplied to an audio output unit not illustrated in the
diagram, for example, a speaker, and accordingly, audio
corresponding to the display image is output.
[0164]
As described above, in the display system 10
30 illustrated in Fig. 1, in the transmission stream,
transmission packets (TLV packets or IP packets)
64
including data of the first byte of the access unit of
the random access point are arranged to be identifiable
at a predetermined interval, and transmission packets
(TLV packets or IP packets) including the access position
information are arranged following 5 this transmission
packets.
[0165]
Accordingly, on the reception side, for example, in
trick reproduction such as fast forward reproduction or
10 fast reverse reproduction after the storage of this
transmission stream in the storage medium 210 or 220,
control of accesses to the storage medium 210 or 220 is
executed based on the identification information or the
access position information, and data of an access unit
15 of the random access point that is necessary for the
trick reproduction or a predetermined number of access
units following the access unit can be efficiently
acquired, whereby an increase in the speed of the trick
reproduction can be achieved.
20 [0166]
<2. Modified Example>
In the embodiment described above, an example has
been illustrated in which a TLV packet is used as a
packet of the capsule layer in the broadcasting. However,
25 the packet of the capsule layer is not limited to the TLV
packet. For example, the packet of the capsule layer may
be a generic stream encapsulation (GSE) packet or a
packet achieving a role of the same kind as that of such
a packet. In addition, similarly, the multiplexed
30 transport packet is not limited to the MMT packet. For
example, the multiplexed transport packet may be a real65
time transport protocol (RTP) packet, a file delivery
over unidirectional transport protocol (FLUTE) packet, or
the like.
[0167]
In addition, in the embodiment described 5 above, in
the broadcasting system, an example has been illustrated
in which data exchange between the tuner 201 and the
storage medium 210 is executed by using the TLV packet.
However, such exchange may be executed by using the IP
10 packet. Alternatively, a configuration enabling
designation of one thereof may be considered. Also in a
case where data is exchanged by using the IP packet as
above, since the priority packet identification
information, additional information of the access
15 position information, the access position information,
and the like are included in the IP packet, for example,
an increase in the speed of the trick reproduction can be
achieved.
[0168]
20 Furthermore, in the embodiment described above, the
receiver 200 has been illustrated to include an output
unit (presentation unit), in other words, an output unit
such as a display or a speaker. However, the output unit
of the receiver 200 and the like may be configured to be
25 separately provided. The receiver of such a case has a
setup box configuration.
[0169]
In addition, the present technology may employ a
configuration as below.
30 (1) A transmission apparatus including:
a transmission unit that transmits a transmission
66
stream, in which first transmission packets that are
multilayer-configuration packets each having a
multiplexed transport packet in an upper layer are
continuously arranged,
wherein, in the transmission stream, 5 the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
10 are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
15 arranged following the specific first transmission
packets.
(2) The transmission apparatus according to (1),
wherein the first transmission packet is a packet
of a capsule layer acquired by encapsulating an IP packet
20 having a payload including the multiplexed transport
packet, and
the second transmission packet is a packet of the
capsule layer acquired by encapsulating the access
position information.
25 (3) The transmission apparatus according to (2),
wherein the packet of the capsule layer is a TLV packet
or a GSE packet.
(4) The transmission apparatus according to (1),
wherein the first transmission packet is an IP
30 packet having a payload in which the multiplexed
transport packet is included, and
67
the second transmission packet is an IP packet
including the access position information.
(5) The transmission apparatus according to any of
(1) to (4), wherein the multiplexed transport packet is
an MMT packet, an RTP packet, 5 or a FLUTE packet.
(6) A transmission method including:
transmitting a transmission stream, in which first
transmission packets that are multilayer-configuration
packets each having a multiplexed transport packet in an
10 upper layer are continuously arranged,
wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
15 a header in which identification information is inserted
are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
20 in which identification information is inserted are
arranged following the specific first transmission
packets.
(7) A reproduction apparatus including:
an acquisition unit that acquires a transmission
25 stream in which first transmission packets that are
multilayer-configuration packets each having a
multiplexed transport packet in an upper layer are
continuously arranged by accessing a storage medium
locally connected or a server connected through a
30 communication network;
a processing unit that acquires reproduction data
68
by processing the transmission stream acquired by the
acquisition unit; and
an access control unit that controls an access of
the acquisition unit to the storage medium or the server
based on identification information of 5 the specific first
transmission packets and access position information
included in the second transmission packet that are
extracted from the acquired transmission stream,
wherein, in the transmission stream, the specific
10 first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
are arranged at a predetermined interval, and, second
15 transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
arranged following the specific first transmission
20 packets.
(8) The reproduction apparatus according to (7),
further including:
a reception unit that receives the transmission
stream through a predetermined transmission channel and
25 stores the received transmission stream in the storage
medium,
wherein the predetermined transmission channel is
an RF transmission channel or a communication network
transmission channel.
30 (9) The reproduction apparatus according to (7) or
(8),
69
wherein the first transmission packet is a packet
of a capsule layer acquired by encapsulating an IP packet
having a payload including the multiplexed transport
packet, and
the second transmission packet 5 is a packet of the
capsule layer acquired by encapsulating the access
position information.
(10) The reproduction apparatus according to (9),
wherein the packet of the capsule layer is a TLV packet
10 or a GSE packet.
(11) The reproduction apparatus according to (7),
wherein the first transmission packet is an IP
packet having a payload in which the multiplexed
transport packet is included, and
15 the second transmission packet is an IP packet
including the access position information.
(12) The reproduction apparatus according to any of
(7) to (9), wherein the multiplexed transport packet is
an MMT packet, an RTP packet, or a FLUTE packet.
20 (13) A reproduction method including:
acquiring a transmission stream in which first
transmission packets that are multilayer-configuration
packets each having a multiplexed transport packet in an
upper layer are continuously arranged by accessing a
25 storage medium locally connected or a server connected
through a communication network;
acquiring reproduction data by processing the
transmission stream acquired by in the acquiring of a
transmission stream; and
30 controlling an access of the acquisition unit to
the storage medium or the server based on identification
70
information of the specific first transmission packets
and access position information included in the second
transmission packet that are extracted from the acquired
transmission stream,
wherein, in the transmission stream, 5 the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
10 are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
15 arranged following the specific first transmission
packets.
(14) A reception apparatus including:
a reception unit that receives a transmission
stream, in which first transmission packets that are
20 multilayer-configuration packets each having a
multiplexed transport packet in an upper layer are
continuously arranged; and
a processing unit that acquires reception data by
processing the transmission stream acquired by the
25 reception unit,
wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
30 a header in which identification information is inserted
are arranged at a predetermined interval, and, second
71
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
arranged following the specific 5 first transmission
packets.
[0170]
The main feature of the present technology is to
increase the speed of trick reproduction such as fast
10 forward reproduction and fast reverse reproduction by
inserting the identification information used for
identifying a packet to be handled with high priority,
the information used for identifying whether or not the
access position information used for the trick
15 reproduction is included, and the access position
information in a packet (transmission packet) of a
capsule layer acquired by encapsulating an IP packet in
which a multiplexed transport packet is included in the
payload (see Figs. 1, 13, and 18).
20
REFERENCE SIGNS LIST
[0171]
10 Display system
110 Broadcasting station
25 111 Transmission system
112 Encoder unit
113 Multiplexer unit
114 Framing unit
115 Modulator/emission unit
30 120 Distribution server
200 Receiver
72
201 Tuner
202 Demultiplexer
203 Decoder
204 Display
205 Gateway/5 network router
206 CPU
207 User operation unit
210 Storage medium
211 Reception/reproduction system
10 212 Tuner/Demodulator
213 Deframing unit
214 Demultiplexer unit
215 Decoder unit
216 Media interface
15 220 Storage medium
73
CLAIMS
1. A transmission apparatus comprising:
a transmission unit that transmits a transmission
stream, in which first transmission 5 packets that are
multilayer-configuration packets each having a
multiplexed transport packet in an upper layer are
continuously arranged,
wherein, in the transmission stream, the specific
10 first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
are arranged at a predetermined interval, and, second
15 transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
arranged following the specific first transmission
20 packets.
2. The transmission apparatus according to claim 1,
wherein the first transmission packet is a packet
of a capsule layer acquired by encapsulating an IP packet
25 having a payload including the multiplexed transport
packet, and
the second transmission packet is a packet of the
capsule layer acquired by encapsulating the access
position information.
30
3. The transmission apparatus according to claim 2,
74
wherein the packet of the capsule layer is a TLV packet
or a GSE packet.
4. The transmission apparatus according to claim 1,
wherein the first transmission 5 packet is an IP
packet having a payload in which the multiplexed
transport packet is included, and
the second transmission packet is an IP packet
including the access position information.
10
5. The transmission apparatus according to claim 1,
wherein the multiplexed transport packet is an MMT packet,
an RTP packet, or a FLUTE packet.
15 6. A transmission method comprising:
transmitting a transmission stream, in which first
transmission packets that are multilayer-configuration
packets each having a multiplexed transport packet in an
upper layer are continuously arranged,
20 wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
25 are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
30 arranged following the specific first transmission
packets.
75
7. A reproduction apparatus comprising:
an acquisition unit that acquires a transmission
stream in which first transmission packets that are
multilayer-configuration packets 5 each having a
multiplexed transport packet in an upper layer are
continuously arranged by accessing a storage medium
locally connected or a server connected through a
communication network;
10 a processing unit that acquires reproduction data
by processing the transmission stream acquired by the
acquisition unit; and
an access control unit that controls an access of
the acquisition unit to the storage medium or the server
15 based on identification information of the specific first
transmission packets and access position information
included in the second transmission packet that are
extracted from the acquired transmission stream,
wherein, in the transmission stream, the specific
20 first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
are arranged at a predetermined interval, and, second
25 transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
arranged following the specific first transmission
30 packets.
76
8. The reproduction apparatus according to claim 7,
further comprising:
a reception unit that receives the transmission
stream through a predetermined transmission channel and
stores the received transmission stream 5 in the storage
medium,
wherein the predetermined transmission channel is
an RF transmission channel or a communication network
transmission channel.
10
9. The reproduction apparatus according to claim 7,
wherein the first transmission packet is a packet
of a capsule layer acquired by encapsulating an IP packet
having a payload including the multiplexed transport
15 packet, and
the second transmission packet is a packet of the
capsule layer acquired by encapsulating the access
position information.
20 10. The reproduction apparatus according to claim 9,
wherein the packet of the capsule layer is a TLV packet
or a GSE packet.
11. The reproduction apparatus according to claim 7,
25 wherein the first transmission packet is an IP
packet having a payload in which the multiplexed
transport packet is included, and
the second transmission packet is an IP packet
including the access position information.
30
12. The reproduction apparatus according to claim 7,
77
wherein the multiplexed transport packet is an MMT packet,
an RTP packet, or a FLUTE packet.
13. A reproduction method comprising:
acquiring a transmission stream 5 in which first
transmission packets that are multilayer-configuration
packets each having a multiplexed transport packet in an
upper layer are continuously arranged by accessing a
storage medium locally connected or a server connected
10 through a communication network;
acquiring reproduction data by processing the
transmission stream acquired by in the acquiring of a
transmission stream; and
controlling an access of the acquisition unit to
15 the storage medium or the server based on identification
information of the specific first transmission packets
and access position information included in the second
transmission packet that are extracted from the acquired
transmission stream,
20 wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
a header in which identification information is inserted
25 are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
in which identification information is inserted are
30 arranged following the specific first transmission
packets.
78
14. A reception apparatus comprising:
a reception unit that receives a transmission
stream, in which first transmission packets that are
multilayer-configuration packets 5 each having a
multiplexed transport packet in an upper layer are
continuously arranged; and
a processing unit that acquires reception data by
processing the transmission stream acquired by the
10 reception unit,
wherein, in the transmission stream, the specific
first transmission packets each including the multiplexed
transport packet including data in which a first byte of
an access unit of a random access point starts and having
15 a header in which identification information is inserted
are arranged at a predetermined interval, and, second
transmission packets each including access position
information corresponding to the previous and next
specific first transmission packets and having a header
20 in which identification information is inserted are
arranged following the specific first transmission
packets.