U.S. patent application number 16/037369 was filed with the patent office on 2019-01-10 for methods and apparatuses for encoding and decoding video using multiple reference pictures.
The applicant listed for this patent is Sun Patent Trust. Invention is credited to Chong Soon LIM, Sue Mon Thet NAING, Takahiro NISHI, Hisao SASAI, Youji SHIBAHARA, Toshiyasu SUGIO, Viktor WAHADANIAH.
Application Number | 20190014344 16/037369 |
Document ID | / |
Family ID | 46507083 |
Filed Date | 2019-01-10 |
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United States Patent
Application |
20190014344 |
Kind Code |
A1 |
LIM; Chong Soon ; et
al. |
January 10, 2019 |
METHODS AND APPARATUSES FOR ENCODING AND DECODING VIDEO USING
MULTIPLE REFERENCE PICTURES
Abstract
A method of encoding video using a plurality of reference
pictures is provided. The method includes: writing one of a
parameter or a flag into one or more reference pictures of the
plurality of reference pictures, creating a first list of reference
pictures comprising the plurality of reference pictures sorted
based on the parameter or flag, and encoding a current picture of
the video using at least the first list of reference pictures. A
method of decoding video using a plurality of reference pictures is
also provided. The method includes parsing one of a parameter or
flag from one or more reference pictures of the plurality of
reference pictures, creating a first list of reference pictures
comprising the plurality of reference pictures sorted based on the
parameter or flag, and decoding a current picture of the video
using at least the first list of reference pictures. In addition,
there are provided corresponding apparatuses for encoding and
decoding video.
Inventors: |
LIM; Chong Soon; (Singapore,
SG) ; WAHADANIAH; Viktor; (Singapore, SG) ;
NAING; Sue Mon Thet; (San Jose, CA) ; NISHI;
Takahiro; (Nara, JP) ; SHIBAHARA; Youji;
(Tokyo, JP) ; SASAI; Hisao; (Osaka, JP) ;
SUGIO; Toshiyasu; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sun Patent Trust |
New York |
NY |
US |
|
|
Family ID: |
46507083 |
Appl. No.: |
16/037369 |
Filed: |
July 17, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13978633 |
Jul 8, 2013 |
10027957 |
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PCT/JP2012/000144 |
Jan 12, 2012 |
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16037369 |
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61431885 |
Jan 12, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N 19/58 20141101;
H04N 19/46 20141101; H04N 19/573 20141101 |
International
Class: |
H04N 19/58 20060101
H04N019/58; H04N 19/46 20060101 H04N019/46; H04N 19/573 20060101
H04N019/573 |
Claims
1. A decoding method, comprising: for each of a plurality of
reference pictures to which a current picture refers, parsing a
parameter related to a picture quality of the reference picture;
creating a first list of reference pictures including the plurality
of reference pictures sorted based on the parameter; and decoding
the current picture using one or more of the plurality of reference
pictures in the first list based on an order in which the plurality
of reference pictures are sorted in the first list.
2. A decoding apparatus, comprising: circuitry; and memory, wherein
the circuitry performs the following using the memory: for each of
a plurality of reference pictures to which a current picture
refers, parsing a parameter related to a picture quality of the
reference picture; creating a first list of reference pictures
including the plurality of reference pictures sorted based on the
parameter; and decoding the current picture using one or more of
the plurality of reference pictures in the first list based on an
order in which the plurality of reference pictures are sorted in
the first list.
Description
TECHNICAL FIELD
[0001] The present invention relates to methods of encoding and
decoding video using multiple reference pictures, and apparatuses
thereof, and more particularly, for inter picture prediction.
BACKGROUND ART
[0002] State-of-the-art video coding schemes, such as MPEG-4
AVC/H.264, and the upcoming HEVC (High-Efficiency Video Coding),
support inter-picture prediction utilizing motion-compensated
prediction from more than one reference pictures. These schemes
also support a special type of bi-direction inter-picture
prediction where both directions are pointing to the same direction
in time. FIG. 1 shows an example of such forward bi-predictive
inter-picture prediction. In the case where there are more than one
reference picture, two lists of reference pictures are created for
bi-predictive inter-picture prediction and the reference pictures
that are closer to the current picture (i.e., temporal distance)
are sorted to the top of the lists by a predefined process.
[0003] It is against this background that the present invention has
been developed.
CITATION LIST
Non Patent Literature
[0004] [NPL 1] [0005] ISO/IEC 14496-10, "MPEG-4 Part 10 Advanced
Video Coding"
SUMMARY OF INVENTION
Technical Problem
[0006] A problem with the prior art is that reference
frames/pictures closest to the current picture are always sorted to
the top of the lists. However, the closest reference frames to the
current picture may not always be the best reference frames to be
used for forward bi-predictive inter-picture prediction.
Solution to Problem
[0007] According to embodiment(s) of the present invention, methods
of encoding/decoding video are provided to solve or at least
mitigate the problem associated with the prior art described
hereinbefore. For example, the methods allow the inter picture
prediction using two reference lists where one of the lists is
ordered based on a flag or a parameter such as the quality of the
reference pictures/frames.
[0008] By way of example, according to embodiment(s) of the present
invention, when forward bi-predictive inter-picture prediction is
used, two reference lists are created where one of the reference
lists is ordered based on the quality of the reference pictures or
frames while the other reference list is ordered based on the
nearest temporal distance to the current picture or frame.
[0009] The effect of embodiment(s) of the present invention is in
the form of improvement in coding efficiency as, for example, two
different reference pictures lists are provided to improve the
picture quality with minimal or negligible increase in overhead
information.
[0010] In accordance to a first broad aspect of the present
invention, there is provided a method of encoding video using a
plurality of reference pictures, the method comprising: [0011]
writing one of a parameter or a flag into one or more reference
pictures of the plurality of reference pictures; [0012] creating a
first list of reference pictures comprising the plurality of
reference pictures sorted based on the parameter or flag; and
[0013] encoding a current picture of the video using at least the
first list of reference pictures.
[0014] The step of encoding a current picture may comprise
performing motion estimation and motion prediction for the current
picture using at least the first list of reference pictures.
[0015] The step of writing may comprise writing the parameter or
flag into a header of the reference picture.
[0016] In the case where the step of writing comprises writing a
flag into said one or more reference pictures, the method may
further comprise: [0017] determining if the flag is of a predefined
value; [0018] wherein, if the flag is of the predefined value,
[0019] creating the first list of reference pictures sorted based
on a quality of the reference pictures, and [0020] wherein, if the
flag is not of the predefined value, [0021] creating the first list
of reference pictures sorted based on an inter-picture prediction
dependency of the reference pictures.
[0022] In the case where the step of writing comprises writing a
flag into said one or more reference pictures, the method may
further comprise: [0023] determining if the reference picture
comprises the flag having a predefined value, for each of the
plurality of reference picture; [0024] wherein, if the flag of the
reference picture is of a predefined value; [0025] labeling the
reference picture as a first type of reference picture; [0026]
wherein, if the flag of the reference picture is not of a
predefined value, [0027] labeling the reference picture as a second
type of reference picture; [0028] creating the first list of
reference pictures sorted by ordering the reference picture labeled
as the first type higher in the first list than the reference
picture labeled as the second type.
[0029] The step of labeling the reference picture as a first type
of reference picture may comprise: [0030] labeling the reference
picture as a long-term reference picture; [0031] setting a
long-term index value to a predefined value; [0032] locating a
previously reconstructed long term reference picture in a memory
having said long-term index value; and [0033] replacing said long
term reference picture with said labeled picture if said long term
reference picture is located in said memory.
[0034] Preferably, the reference picture labeled as the first type
is ordered at the top of the first list.
[0035] The method may further comprise creating a second list of
reference pictures and a third list of reference pictures, each of
the second and third lists sorted based on a temporal distance to
the current picture.
[0036] The method may further comprise determining if the second
list matches the third list, [0037] wherein, if the second list
matches the third list, [0038] creating the first list of reference
pictures sorted based on the parameter or flag, and encoding the
current picture of the video using at least the first list of
reference pictures; and [0039] wherein, if the second list does not
match the third list, [0040] encoding the current picture of the
video using the second list and the third list.
[0041] In accordance to a second broad aspect of the present
invention, there is provided a method of decoding video using a
plurality of reference pictures, the method comprising: [0042]
parsing one of a parameter or flag from one or more reference
pictures of the plurality of reference pictures; [0043] creating a
first list of reference pictures comprising the plurality of
reference pictures sorted based on the parameter or flag; and
[0044] decoding a current picture of the video using at least the
first list of reference pictures.
[0045] The step of decoding a current picture may comprise
performing motion prediction for the current picture using at least
the first list of reference pictures.
[0046] The step of parsing may comprise parsing the parameter or
flag from a header of the reference picture.
[0047] In the case where the step of parsing comprises parsing the
flag from said one or more reference pictures, the method may
further comprise: [0048] determining if the flag is of a predefined
value; [0049] wherein, if the flag is of the predefined value,
[0050] creating the first list of reference pictures sorted based
on a quality of the reference pictures, and [0051] wherein, if the
flag is not of the predefined value, [0052] creating the first list
of reference pictures sorted based on an inter-picture prediction
dependency of the reference pictures.
[0053] In the case where the step of parsing comprises parsing the
flag from said one or more reference pictures, the method may
further comprise: [0054] determining if the reference picture
comprises the flag having a predefined value, for each of the
plurality of reference picture; [0055] wherein, if the flag of the
reference picture is of a predefined value; [0056] labeling the
reference picture as a first type of reference picture; [0057]
wherein, if the flag of the reference picture is not of a
predefined value, [0058] labeling the reference picture as a second
type of reference picture; [0059] creating the first list of
reference pictures sorted by ordering the reference picture labeled
as the first type higher in the first list than the reference
picture labeled as the second type.
[0060] The step of labeling the reference picture as a first type
of reference picture may comprise: [0061] labeling the reference
picture as a long-term reference picture; [0062] setting a
long-term index value to a predefined value; [0063] locating a
previously reconstructed long term reference picture in a memory
having said long-term index value; and [0064] replacing said long
term reference picture with said labeled picture if said long term
reference picture is located in said memory.
[0065] Preferably, the reference picture labeled as the first type
is ordered at the top of the first list.
[0066] The method may further comprise creating a second list of
reference pictures and a third list of reference pictures, each of
the second and third lists sorted based on a temporal distance to
the current picture.
[0067] The method may further comprise determining if the second
list matches the third list, [0068] wherein, if the second list
matches the third list, [0069] creating the first list of reference
pictures sorted based on the parameter or flag, and encoding the
current picture of the video using at least the first list of
reference pictures; and [0070] wherein, if the second list does not
match the third list, [0071] encoding the current picture of the
video using the second list and the third list.
[0072] In accordance to a third broad aspect of the present
invention, there is provided an apparatus for encoding video using
a plurality of reference pictures, the apparatus comprising: [0073]
a writing unit configured to write one of a parameter or flag into
one or more reference pictures of the plurality of reference
pictures; [0074] a first list creation unit configured to create a
first list of reference pictures comprising the plurality of
reference pictures sorted based on the parameter or flag; and
[0075] an encoding section configured to encode a current picture
of the video using at least the first list of reference
pictures.
[0076] The encoding section may comprise a motion estimation unit
configured to perform motion estimation for the current picture
using at least the first list of reference pictures and a motion
prediction unit configured to perform motion prediction for the
current picture using at least the first list of reference
pictures.
[0077] The writing unit may be configured to write the parameter or
flag into a header of the reference picture.
[0078] In the case where the writing unit is configured to write
the flag into said one or more reference pictures, the apparatus
may further comprise: [0079] a determining unit configured to
determine if the flag is of a predefined value; [0080] wherein, if
the flag is of the predefined value, [0081] the first list creation
unit is operable to create the first list of reference pictures
sorted based on the quality of the reference pictures, and [0082]
wherein, if the flag is not of the predefined value, [0083] the
first list creation unit is operable to create the first list of
reference pictures sorted based on an inter-picture prediction
dependency of the reference pictures.
[0084] In the case where the writing unit is configured to write
the flag into said one or more reference pictures, the apparatus
may further comprise: [0085] a determining unit configured to
determine if the reference picture comprises the flag having a
predefined value, for each of the plurality of reference picture;
and [0086] a labeling unit configured to label the reference
picture, [0087] wherein, if the flag of the reference picture is of
a predefined value; [0088] the labeling unit is operable to label
the reference picture as a first type of reference picture; [0089]
wherein, if the flag of the reference picture is not of a
predefined value, [0090] the labeling unit is operable to label the
reference picture as a second type of reference picture; and [0091]
wherein the first list creation unit is operable to create the
first list of reference pictures sorted by ordering the reference
picture labeled as the first type higher in the first list than the
reference picture labeled as the second type.
[0092] The labeling of the reference picture as a first type of
reference picture may comprise: [0093] labeling the reference
picture as a long-term reference picture; [0094] setting a
long-term index value to a predefined value; [0095] locating a
previously reconstructed long term reference picture in a memory
having said long-term index value; and [0096] replacing said long
term reference picture with said labeled picture if said long term
reference picture is located in said memory.
[0097] Preferably, the reference picture labeled as the first type
is ordered at the top of the first list.
[0098] The apparatus may further comprise a second list creation
unit configured to create a second list of reference pictures and a
third list creation unit configured to create a third list of
reference pictures, each of the second and third lists being sorted
based on a temporal distance to the current picture.
[0099] The apparatus may further comprise a determining unit
configured for determining if the second list matches the third
list, [0100] wherein, if the second list matches the third list,
[0101] the first list creation unit is operable to create the first
list of reference pictures sorted based on the parameter or flag,
and [0102] the encoding section is operable to encode the current
picture of the video using at least the first list of reference
pictures; and [0103] wherein, if the second list does not match the
third list, [0104] the encoding section is operable to encode the
current picture of the video using the first list and the second
list.
[0105] In accordance to a fourth broad aspect of the present
invention, there is provided an apparatus for decoding video using
a plurality of reference pictures, the apparatus comprising: [0106]
a parsing unit configured for parsing one of a parameter or flag
from one or more reference pictures of the plurality of reference
pictures; [0107] a first list creation unit configured to create a
first list of reference pictures comprising the plurality of
reference pictures sorted based on the parameter or flag; and
[0108] a decoding section configured to decode a current picture of
the video using at least the first list of reference pictures.
[0109] The decoding section may comprise a motion prediction unit
configured to perform motion prediction for the current picture
using at least the first list of reference pictures.
[0110] The parsing unit may be configured to parse the parameter or
flag from a header of the reference picture.
[0111] In the case where the parsing unit is configured to parse
the flag from said one or more reference pictures, the apparatus
may further comprise: [0112] a determining unit configured to
determine if the flag is of a predefined value; [0113] wherein, if
the flag is of the predefined value, [0114] the first list creation
unit is operable to create the first list of reference pictures
sorted based on a quality of the reference pictures, and [0115]
wherein, if the flag is not of the predefined value, [0116] the
first list creation unit is operable to create the first list of
reference pictures sorted based on an inter-picture prediction
dependency of the reference pictures.
[0117] In the case where the parsing unit is configured to parse
the flag from said one or more reference pictures, the method may
further comprise: [0118] a determining unit configured to determine
if the reference picture comprises the flag having a predefined
value, for each of the plurality of reference picture; and [0119] a
labeling unit configured to label the reference picture, [0120]
wherein, if the flag of the reference picture is of a predefined
value; [0121] the labeling unit is operable to label the reference
picture as a first type of reference picture; [0122] wherein, if
the flag of the reference picture is not of a predefined value,
[0123] the labeling unit is operable to label the reference picture
as a second type of reference picture; and [0124] wherein the first
list creation unit is operable to create the first list of
reference pictures sorted by ordering the reference picture labeled
as the first type higher in the first list than the reference
picture labeled as the second type.
[0125] The labeling of the reference picture as a first type of
reference picture may comprise: [0126] labeling the reference
picture as a long-term reference picture; [0127] setting a
long-term index value to a predefined value; [0128] locating a
previously reconstructed long term reference picture in a memory
having said long-term index value; and [0129] replacing said long
term reference picture with said labeled picture if said long term
reference picture is located in said memory.
[0130] Preferably, the reference picture labeled as the first type
is ordered at the top of the first list.
[0131] The apparatus may further comprise a second list creation
unit configured to create a second list of reference pictures and a
third list creation unit configured to create a third list of
reference pictures, each of the second and third lists being sorted
based on a temporal distance to the current picture.
[0132] The determining unit may be further configured for
determining if the second list matches the third list, [0133]
wherein, if the second list matches the third list, [0134] the
first list creation unit is operable to create the first list of
reference pictures sorted based on the parameter or flag, and
[0135] the decoding section is operable to decode the current
picture of the video using at least the first list of reference
pictures; and [0136] wherein, if the second list does not match the
third list, the decoding section is operable to decode the current
picture of the video using the second list and the third list.
BRIEF DESCRIPTION OF DRAWINGS
[0137] FIG. 1 depicts a diagram illustrating an example of
bi-predictive inter picture prediction with both predictions in the
same direction;
[0138] FIG. 2 depicts a flowchart showing a video encoding process
according to a first exemplary embodiment of the present
invention;
[0139] FIG. 3 depicts a flowchart showing a video decoding process
according to the first exemplary embodiment of the present
invention;
[0140] FIG. 4 depicts a diagram illustrating an example of
assigning different quality levels for different pictures
consecutively according to embodiment(s) of the present
invention;
[0141] FIG. 5 depicts a flowchart showing a video encoding process
according to a second exemplary embodiment of the present
invention;
[0142] FIG. 6 depicts a flowchart showing a video decoding process
according to the second exemplary embodiment of the present
invention;
[0143] FIG. 7 depicts a block diagram illustrating an example
apparatus for a video encoder according to the second embodiment of
the present invention;
[0144] FIG. 8 depicts a block diagram illustrating an example
apparatus for a video decoder according to the second embodiment of
the present invention;
[0145] FIG. 9 depicts a diagram showing a preferred location of the
quality identifier parameter in a header of a picture;
[0146] FIG. 10A depicts a flowchart showing a video encoding
process according to a third embodiment of the present
invention;
[0147] FIG. 10B depicts a flowchart showing a video encoding
process according to an embodiment of the present invention;
[0148] FIG. 11A depicts a flowchart showing a video decoding
process according to the third embodiment of the present
invention;
[0149] FIG. 11B depicts a flowchart showing a video decoding
process according to an embodiment of the present invention;
[0150] FIG. 12 depicts a block diagram illustrating an example
apparatus for a video encoder according to the third embodiment of
the present invention;
[0151] FIG. 13 depicts a block diagram illustrating an example
apparatus for a video decoder according to the third embodiment of
the present invention;
[0152] FIG. 14 depicts a diagram showing a preferred location of
special picture flag in a header of a picture;
[0153] FIG. 15A depicts a flowchart showing a video encoding
process according to a fourth embodiment of the present
invention;
[0154] FIG. 15B depicts a flowchart showing a video encoding
process according to an embodiment of the present invention;
[0155] FIG. 16A depicts a flowchart showing video decoding process
according to the fourth embodiment of the present invention;
[0156] FIG. 16B depicts a flowchart showing video decoding process
according to an embodiment of the present invention;
[0157] FIG. 17 depicts a block diagram illustrating an example
apparatus for a video encoder according to the fourth embodiment of
the present invention;
[0158] FIG. 18 depicts a block diagram illustrating an example
apparatus for a video decoder according to the fourth embodiment of
the present invention;
[0159] FIG. 19 depicts a diagram showing a preferred location of
the reordering scheme selection parameter in a header of a
picture;
[0160] FIG. 20 depicts a flowchart showing a process to label a
picture as a special reference picture in the third embodiment of
the present invention;
[0161] FIG. 21 depicts a block diagram showing an example apparatus
to label a picture as a special reference picture in the third
embodiment of present invention;
[0162] FIG. 22 depicts an overall configuration of a content
providing system for implementing content distribution services
according to an embodiment of the present invention;
[0163] FIG. 23 depicts an overall configuration of a digital
broadcasting system according to an embodiment of the present
invention;
[0164] FIG. 24 depicts a block diagram illustrating an example of a
configuration of a television according to an embodiment of the
present invention;
[0165] FIG. 25 depicts a block diagram illustrating an example of a
configuration of an information reproducing/recording unit that
reads and writes information from or on a recording medium that is
an optical disk according to an embodiment of the present
invention;
[0166] FIG. 26 depicts a drawing showing an example of a
configuration of a recording medium that is an optical disk
according to an embodiment of the present invention.
[0167] FIG. 27A depicts a drawing illustrating an example of a
cellular phone according to an embodiment of the present
invention;
[0168] FIG. 27B depicts a block diagram showing an example of a
configuration of the cellular phone according to an embodiment of
the present invention;
[0169] FIG. 28 depicts a drawing showing a structure of multiplexed
data according to an embodiment of the present invention;
[0170] FIG. 29 depicts a drawing schematically illustrating how
each of the streams is multiplexed in multiplexed data according to
an embodiment of the present invention;
[0171] FIG. 30 depicts a drawing illustrating how a video stream is
stored in a stream of PES packets in more detail according to an
embodiment of the present invention;
[0172] FIG. 31 depicts a drawing showing a structure of TS packets
and source packets in the multiplexed data according to an
embodiment of the present invention;
[0173] FIG. 32 depicts a drawing showing a data structure of a PMT
according to an embodiment of the present invention;
[0174] FIG. 33 depicts a drawing showing an internal structure of
multiplexed data information according to an embodiment of the
present invention;
[0175] FIG. 34 depicts a drawing showing an internal structure of
stream attribute information according to an embodiment of the
present invention;
[0176] FIG. 35 depicts drawing showing steps for identifying video
data according to an embodiment of the present invention;
[0177] FIG. 36 depicts a block diagram illustrating an example of a
configuration of an integrated circuit for implementing the video
coding method and the video decoding method according to each of
Embodiments.
[0178] FIG. 37 depicts a drawing showing a configuration for
switching between driving frequencies according to an embodiment of
the present invention;
[0179] FIG. 38 depicts a drawing showing steps for identifying
video data and switching between driving frequencies according to
an embodiment of the present invention;
[0180] FIG. 39 depicts a drawing showing an example of a look-up
table in which the standards of video data are associated with the
driving frequencies according to an embodiment of the present
invention;
[0181] FIG. 40A depicts a drawing showing an example of a
configuration for sharing a module of a signal processing unit
according to an embodiment of the present invention; and
[0182] FIG. 40B depicts a drawing showing another example of a
configuration for sharing a module of a signal processing unit
according to an embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0183] According to exemplary embodiments of the present invention,
there are provided a method of encoding video using a plurality of
reference pictures/frames, a method of decoding video using a
plurality of reference pictures, and apparatuses thereof.
[0184] FIG. 2 depicts a flowchart illustrating a method of encoding
video using a plurality of reference pictures according to a first
exemplary embodiment of the present invention. As a first step 200,
the method comprises writing one of a parameter or a flag into one
or more reference pictures of the plurality of reference pictures.
For example, the parameter of a reference picture may include a
value representative of the quality of the reference picture such
as the level of quantization that was used to compress the
reference picture, and the flag of a reference picture may be a
signal indicative of a characteristic of the reference picture,
such as to indicate the reference picture as being special. These
and other examples will be described in further detail hereinafter.
It will be apparent to the person skilled in the art that the
present invention is not limited to the examples described herein,
and other types of parameter or flag are also encompassed within
the scope of the present invention.
[0185] The method of encoding video further comprises a step 202 of
creating a first list of reference pictures comprising the
plurality of reference pictures sorted based on the parameter or
flag. For example, in the case of the parameter being
representative of the quality of the reference picture, step 202
creates a first list of reference pictures sorted based on the
quality of the reference picture, more particular, higher or better
quality reference pictures are arranged so as to be at the top of
the first list.
[0186] The method of encoding video further comprises a step 204 of
encoding a current picture of the video using at least the first
list of reference pictures. For example, encoding the current
picture comprises performing motion estimation and motion
prediction for the current picture using at least the first list of
reference pictures.
[0187] FIG. 3 depicts a flowchart illustrating a method of decoding
video using a plurality of reference pictures according to the
first exemplary embodiment. As a first step 220, the method
comprises parsing one of a parameter or a flag from one or more
reference pictures of the plurality of reference pictures. As
described hereinbefore, by way of examples only, the parameter of a
reference picture may include a value representative of the quality
of the reference picture such as the level of quantization that was
used to compress the reference picture, and the flag of a reference
picture may be a signal indicative of a characteristic of the
reference picture, such as to indicate the reference picture as
being special.
[0188] The method of decoding video further comprises a step 222 of
creating a first list of reference pictures including the plurality
of reference pictures sorted based on the parameter or flag; and
decoding a current picture of the video using at least the first
list of reference pictures. For example, decoding the current
picture comprises performing motion prediction for the current
picture using at least the first list of reference pictures.
[0189] An apparatus for encoding video using a plurality of
reference pictures according to the first exemplary embodiment of
the present invention comprises a writing unit, a first list
creation unit, and an encoding section. The writing unit is
configured to write the parameter or flag into one or more
reference pictures of the plurality of reference pictures, the
first list creation unit is configured to create the first list of
reference pictures comprising the plurality of reference pictures
sorted based on the parameter or flag; and the encoding section is
configured to encode the current picture of the video using at
least the first list of reference pictures. For example, the
encoding section may comprise a motion estimation unit configured
to perform motion estimation for the current picture using at least
the first list of reference pictures and a motion prediction unit
configured to perform motion prediction for the current picture
using at least the first list of reference pictures.
[0190] An apparatus for decoding video using a plurality of
reference pictures according to the first exemplary embodiment of
the present invention comprises a parsing unit configured for
parsing the parameter or flag from one or more reference pictures
of the plurality of reference pictures, a first list creation unit
configured to create the first list of reference pictures
comprising the plurality of reference pictures sorted based on the
parameter or flag, and an decoding section configured to decode the
current picture of the video using at least the first list of
reference pictures. For example, the decoding section may comprise
a motion prediction unit configured to perform motion prediction
for the current picture using at least the first list of reference
pictures.
[0191] The first exemplary embodiment of the present invention has
been found to provide an improvement in encoding/decoding
efficiency. As discussed in the background, a problem with the
prior art is that reference pictures closest to the current picture
are always sorted to the top of the reference lists. However,
according to the first exemplary embodiment of the present
invention, a parameter or flag is written or embedded into the
reference pictures and at least one reference list is created with
reference pictures sorted based on the parameter or flag. For
example, the case where the parameter indicates the quality of the
reference picture is graphically illustrated in FIG. 4. Based on
prior art teaching, as an example, the reference list for Picture n
would be created only based on the temporal distance, that is,
Picture n+1 being closest to Picture n would be arranged at the top
of the reference list, followed by Picture n+2, Picture n+3 and
Picture n+4 being at the bottom of the reference list. However, due
to the poor quality of Picture n+1, this may not be the best
reference frame to use for inter picture prediction and thus it is
not efficient to arrange such a picture at the top of the list. In
contrast, according to the first exemplary embodiment, Picture n+4
having been assigned a parameter with the highest quality amongst
Picture n+1 to n+4 would be arranged at the top of the reference
list, followed by Picture n+2, Picture n+1 and Picture n+3. As a
result, the most suitable or appropriate reference(s) picture is
arranged at the top of the reference list which is therefore
represented with the least bits for use in inter picture
prediction. Accordingly, better encoding/decoding of video can be
achieved according to the first exemplary embodiment of the present
invention.
[0192] Further exemplary embodiments of the present invention will
now be described hereinafter with reference to Figures, providing
more specific examples of the first exemplary embodiments of the
present invention. It will be appreciated to the person skilled in
the art that the exemplary embodiments described hereinafter are
merely provided by way of examples and do not restrict the scope of
the present invention.
[0193] FIG. 5 shows a flowchart illustrating a process or method of
encoding video according to a second exemplary embodiment of the
present invention. As shown in FIG. 5, in step 300, a parameter
(e.g., a quality identifier parameter) is first written or embedded
into a header of a coded reference picture for indicating or
classifying the picture quality of the reference picture. For
example, the quality identifier parameter may comprise values that
ranks the different pictures based on the level of quantization
that was used to compress the pictures. It will be apparent to the
person skilled in the art that the quality of a picture can be
represented or indicated by other means. In step 302, a first list
of reference pictures sorted by a first scheme that uses temporal
distance to a current picture is created. Next in step 304, a
second list of reference pictures sorted by a second scheme that
also uses temporal distance to a current picture is created. And in
step 306, a comparison is performed to determine or judge if the
first list matches (e.g., identical to) the second list.
[0194] If the first list matches the second list, a third list of
reference pictures (e.g., corresponding to the first list of
reference pictures described in the first exemplary embodiment)
sorted by the quality of reference pictures is created in step 312.
Next, a motion estimation process is performed for a current
picture (e.g., a block of image samples) using at least the third
list of reference pictures in step 314 and a motion prediction
process is performed for the current picture using at least the
third list of reference pictures in step 316. For example, the
motion estimation process and/or the motion prediction process may
be performed using the second and third lists of reference
pictures, or using the first and third lists of reference
pictures.
[0195] If the first list does not match the second list in step
306, a motion estimation process is performed for a current picture
using the first and second lists of reference frames in step 308
and a motion prediction process is performed for the current
picture using the first and second lists of reference frames in
step 310.
[0196] In an embodiment, the logic at step 306 may be switched. In
particular, if the first list matches the second list, a motion
estimation process is performed for a current picture using the
first and second lists of reference frames in step 308 and a motion
prediction process is performed for the current picture using the
first and second lists of reference frames in step 310. On the
other hand, if the first list does not match the second list in
step 306, a third list of reference pictures (e.g., corresponding
to the first list of reference pictures described in the first
exemplary embodiment) sorted by the quality of reference pictures
is created in step 312. Next, a motion estimation process is
performed for a current picture (e.g., a block of image samples)
using at least the third list of reference pictures in step 314 and
a motion prediction process is performed for the current picture
using at least the third list of reference pictures in step 316.
Similarly, the motion estimation process and/or the motion
prediction process may be performed using the second and third
lists of reference pictures, or using the first and third lists of
reference pictures.
[0197] FIG. 6 shows a flowchart illustrating a process or method of
decoding video according to the second exemplary embodiment of the
present invention. As shown in FIG. 6, in step 400, a parameter
(e.g., a quality identifier parameter) is first parsed or retrieved
from a header of a coded reference picture for determining or
classifying the picture quality of the reference picture. For
example, the quality identifier parameter may comprise values that
ranks the different pictures based on the level of quantization
that was used to compress the pictures. In step 402, a first list
of reference pictures sorted by a first scheme that uses temporal
distance to a current picture is created. Next in step 404, a
second list of reference pictures sorted by a second scheme that
also uses temporal distance to a current picture is created. And in
step 406, a comparison is performed to determine or judge if the
first list matches (e.g., identical to) the second list.
[0198] If the first list matches the second list, a third list of
reference pictures (e.g., corresponding to the first list of
reference pictures described in the first exemplary embodiment)
sorted by the quality of reference pictures is created in step 410.
Next, a motion prediction process is performed for a current
picture (e.g., a block of image samples) using at least the third
list of reference pictures in step 412. For example, the motion
prediction process may be performed using the second and third
lists of reference pictures, or using the first and third lists of
reference pictures.
[0199] If the first list does not match the second list in step
406, a motion prediction process is performed for a current picture
using the first and second lists of reference frames in step
408.
[0200] In an embodiment, the logic at step 406 may also be
switched. In particular, if the first list matches the second list,
a motion prediction process is performed for a current picture
using the first and second lists of reference frames in step 408.
If the first list does not match the second list in step 406, a
third list of reference pictures (e.g., corresponding to the first
list of reference pictures described in the first exemplary
embodiment) sorted by the quality of reference pictures is created
in step 410. Next, a motion prediction process is performed for a
current picture (e.g., a block of image samples) using at least the
third list of reference pictures in step 412. Similarly, the motion
prediction process may be performed using the second and third
lists of reference pictures, or using the first and third lists of
reference pictures.
[0201] FIG. 7 shows a block diagram illustrating an example
apparatus for encoding video according to the second exemplary
embodiment of the present invention. For the sake of clarity, the
example encoding apparatus will be described corresponding to the
exemplary method as described with respect to FIG. 5 and whereby
the motion estimation process and the motion prediction process are
performed using the second and third lists of reference pictures.
However, it will be apparent to the person skilled in the art that
modifications can be made to the example apparatus shown in FIG. 7
to implement any one of the methods of encoding video disclosed
herein (e.g., the method as shown in FIG. 2) or other methods
without departing from the scope of the present invention. That is,
the apparatus for encoding video according to the present invention
is not limited to the components/elements, and the interconnections
thereof, as shown in FIG. 7.
[0202] The exemplary apparatus for encoding video comprises of a
motion estimation unit 500, a motion prediction unit 502, a first
list creation unit 504, a second list creation unit 516, a third
list creation unit 510, a first switch unit 506, a second switch
unit 508, a memory unit 512, a comparator unit or a determining
unit 514 and writing unit 518.
[0203] As shown in FIG. 7, the motion estimation unit 500 is
configured or operable to read a current picture (e.g., a block of
image samples) D501, a selected list of reference pictures D511, a
second list of reference pictures D519 and output a set of motion
vectors D503. The motion prediction unit 502 is configured to read
the set of motion vectors D503, the selected list of reference
pictures D511 and the second list of reference pictures D519 and
output a block of predicted samples D505. The first list creation
unit 504 is configured to read reference pictures D513 from the
memory unit 512 and output a first list of reference pictures
D1015. The second list creation unit 516 is configured to read
reference pictures D1017 from the memory unit 512 and output a
second list of reference pictures D519. The comparator unit 514 is
configured to read both the first list of reference pictures D515
and the second list of reference pictures D519 and output a control
signal D521 to control the first and second switch units 506 and
508. The first switch unit 504 is configured to send the first list
of reference pictures D515 to either the second switch unit 508 or
the third list creation unit 510 based on the control signal
[0204] D521. The third list creation unit 510 is configured to
create a third list of reference pictures D523 based on the first
list of reference pictures D509 and the parameter (e.g., the
quality identifier parameter of the reference pictures) D525 stored
in the memory unit 512. The second switch unit 508 is configured to
select either the first list of reference pictures D507 or the
third list of reference pictures D523 based on the control signal
D521. The writing unit 518 is configured to read the parameter and
write the parameter into a header of a coded picture D1029.
[0205] FIG. 8 shows a block diagram illustrating an example
apparatus for decoding video according to the second exemplary
embodiment of the present invention. For the sake of clarity, the
example decoding apparatus will be described corresponding to the
exemplary method as described with respect to FIG. 6 and whereby
the motion prediction process is performed using the second and
third lists of reference pictures. However, it will be apparent to
the person skilled in the art that modifications can be made to the
example apparatus shown in FIG. 8 to implement any one of the
methods of decoding video disclosed herein (e.g., as shown in FIG.
3) or other methods without departing from the scope of the present
invention. That is, the apparatus for decoding video according to
the present invention is not limited to the components/elements,
and the interconnections thereof, as shown in FIG. 8.
[0206] The example apparatus for decoding video comprises of a
parsing unit 600, a motion prediction Unit 602, a first list
creation unit 604, a second list creation unit 616, a third list
creation unit 610, a first switch unit 606, a second switch unit
608, a memory unit 612 and a comparator unit or a determining unit
614.
[0207] As shown in FIG. 8, the motion prediction unit 602 is
configured or operable to read a decoded set of motion vectors
D601, a selected list of reference pictures D611 and a second list
of reference pictures D619 and output a block of predicted samples
D605. The first list creation unit 604 is configured to read
reference pictures D613 from the memory unit 612 and output a first
list of reference pictures D615. The second list creation unit 616
is configured to read reference pictures D617 from the memory unit
612 and output a second list of reference pictures D619. The
comparator unit 614 is configured to read both the first list of
reference pictures D615 and the second list of reference pictures
D619 and output a control signal D621 to control the first and
second switch units 606 and 608. The first switch unit 604 is
configured to send the first list of reference pictures D615 to
either the second switch unit 608 or the third list creation unit
610 based on the control signal D621. The third list creation unit
610 is configured to create a third list of reference pictures D623
based on the first list of reference pictures D609 and the
parameter (e.g., the quality identifier parameter) of the reference
pictures D625 stored in the memory unit 612. The second switch unit
608 is configured to select either the first list of reference
pictures D607 or the third list of reference pictures D623 based on
the control signal D621. The parsing unit 600 is configured to
parse a header of a coded picture D627 and outputs the parameter
D603 into a memory unit 612.
[0208] FIG. 9 shows a diagram illustrating a preferred location of
the parameter in a header of a picture according to the second
exemplary embodiment of the present invention. In the case of the
parameter being a quality identifier parameter, for example, the
value of the quality identifier parameter is determined according
to the level of quantization used to compress the picture.
[0209] FIG. 10A shows a flowchart illustrating a process or method
of encoding video according to a third exemplary embodiment of the
present invention. As shown in FIG. 10A, in step 800, a special
reference picture flag is first written or embedded into a header
of a coded reference picture to label a reference picture as a
special reference picture or a normal reference picture. For
example, a special reference picture may be a picture with a lower
level of quantization among a group of pictures. In step 802, a
comparison is performed to determine or judge if this flag has or
is of a predefined value. A reference picture is labeled as a
special reference picture in step 804 if the flag is of a
predefined value and labeled as a normal reference picture in step
806 if the flag does not have a predefined value.
[0210] In step 808, a first list of reference pictures is sorted by
a first scheme that uses temporal distance to a current picture is
created. Next in step 810, a second list of reference pictures
sorted by a second scheme that also uses temporal distance to a
current picture is created. In step 812, a comparison is performed
to determine or judge if the first list matches (e.g., identical
to) the second list.
[0211] If the first list matches the second list, the special
reference pictures in the first list of reference frames is
identified in step 814 and a third list of reference pictures
(e.g., corresponding to the first list of reference pictures
described in the first exemplary embodiment), which is sorted by
placing the special reference pictures to the top of the list, is
created in step 820. Next, a motion estimation process is performed
for a current picture (e.g., a block of image samples) using at
least the third list of reference pictures in step 822 and a motion
prediction process is performed for the current picture using at
least the third list of reference pictures in step 824. For
example, the motion estimation process and/or the motion prediction
process may be performed using the second and third lists of
reference pictures, or using the first and third lists of reference
pictures.
[0212] If the first list does not match the second list in step
812, a motion estimation process is performed for the current
picture using the first and second lists of reference frames in
step 816 and a motion prediction process is performed for the
current picture using the first and second lists of reference
frames in step 818.
[0213] In an embodiment, the logic at step 812 may be switched. In
particular, if the first list matches the second list, a motion
estimation process is performed for the current picture using the
first and second lists of reference frames in step 816 and a motion
prediction process is performed for the current picture using the
first and second lists of reference frames in step 818. If the
first list does not match the second list in step 812, the special
reference pictures in the first list of reference frames is
identified in step 814 and a third list of reference pictures
(e.g., corresponding to the first list of reference pictures
described in the first exemplary embodiment), which is sorted by
placing the special reference pictures to the top of the list, is
created in step 820. Next, a motion estimation process is performed
for a current picture (e.g., a block of image samples) using at
least the third list of reference pictures in step 822 and a motion
prediction process is performed for the current picture using at
least the third list of reference pictures in step 824. Similarly,
the motion estimation process and/or the motion prediction process
may be performed using the second and third lists of reference
pictures, or using the first and third lists of reference
pictures.
[0214] Yet another embodiment is shown in FIG. 10B. In particular,
the steps 808, 810, 812, 816 and 818 as shown in FIG. 10A are
omitted. Accordingly, after step 804 or 806, the reference pictures
labeled as special are identified in step 864 and a first list of
reference pictures (e.g., corresponding to the first list of
reference pictures described in the first exemplary embodiment),
which is sorted by placing the special reference pictures to the
top of the list, is created in step 820. Next, a motion estimation
process is performed for a current picture (e.g., a block of image
samples) using at least the first list of reference pictures in
step 872 and a motion prediction process is performed for the
current picture using at least the first list of reference pictures
in step 874.
[0215] FIG. 11A shows a flowchart illustrating a process or method
for decoding video according to the third exemplary embodiment of
the present invention. As shown in FIG. 11A, in step 900, a special
reference picture flag is first parsed or retrieved from a header
of a coded reference picture to label a reference picture as a
special reference picture or a normal reference picture. For
example, a special reference picture may be a picture with a lower
level of quantization among a group of pictures. In step 902, a
comparison is performed to determine or judge if this flag has or
is of a predefined value. A reference picture is labeled as a
special reference picture in step 904 if the flag is of a
predefined value and labeled as a normal reference picture in step
906 if the flag is not of a predefined value.
[0216] In step 908, a first list of reference pictures sorted by a
first scheme that uses temporal distance to a current picture is
created. Next in step 910, a second list of reference pictures
sorted by a second scheme that also uses temporal distance to a
current picture is created. And in step 912, a comparison is
performed to determine or judge if the first list matches (e.g.,
identical to) the second list.
[0217] If the first list matches the second list, the special
reference pictures in the first list of reference frames is
identified in step 914 and a third list of reference pictures,
which is sorted by placing the special reference pictures to the
top of the list, is created in step 916. Next, a motion prediction
process is performed for a current picture (a block of image
samples) using at least the third list of reference pictures in
step 918.
[0218] If the first list does not match the second list in step
912, a motion prediction process is performed for the current
picture using the first and second lists of reference frames in
step 920.
[0219] In an embodiment, the logic at step 912 may be switched. In
particular, if the first list matches the second list, a motion
prediction process is performed for the current picture using the
first and second lists of reference frames in step 920. If the
first list does not match the second list in step 812, the special
reference pictures in the first list of reference frames is
identified in step 914 and a third list of reference pictures,
which is sorted by placing the special reference pictures to the
top of the list, is created in step 916. Next, a motion prediction
process is performed for a current picture (a block of image
samples) using at least the third list of reference pictures in
step 918. Similarly, the motion prediction process may be performed
using the second and third lists of reference pictures, or using
the first and third lists of reference picture.
[0220] Yet another embodiment is shown in FIG. 11B. In particular,
the steps 908, 910, 912 and 920 as shown in FIG. 11A are omitted.
Accordingly, after step 904 or 906, the reference pictures labeled
as special are identified in step 964 and a first list of reference
pictures, which is sorted by placing the special reference pictures
to the top of the list, are created in step 966. Next, a motion
prediction process is performed for a current picture (a block of
image samples) using at least the first list of reference pictures
in step 968.
[0221] FIG. 12 shows a block diagram illustrating an example
apparatus for encoding video according to the third embodiment of
the present invention. For the sake of clarity, the example
encoding apparatus will be described corresponding to the exemplary
method as described with respect to FIG. 10A and whereby the motion
estimation process and the motion prediction process are performed
using the second and third lists of reference pictures. However, as
previously mentioned, it will be apparent to the person skilled in
the art that modifications can be made to the example apparatus
shown in FIG. 12 to implement any one of the methods of encoding
video disclosed herein or other methods without departing from the
scope of the present invention.
[0222] The exemplary apparatus for encoding video comprises of a
motion estimation unit 1000, a motion prediction unit 1002, a first
list creation unit 1004, a second list creation unit 1016, a third
list creation unit 1010, a first switch unit 1006, a second switch
unit 1008, a memory unit 1012, a comparator unit or a determining
unit 1014 and a writing unit 1018.
[0223] As shown in FIG. 12, the motion estimation unit 1000 is
configured to read a block of image samples D1001, a selected list
of reference pictures D1011, a second list of reference pictures
D1019 and output a set of motion vectors D1003. The motion
prediction unit 1002 is configured to read the set of motion
vectors D1003, the selected list of reference pictures D1011 and
the second list of reference pictures D1019 and output a block of
predicted samples D1005. The first list creation unit 1004 is
configured to read reference pictures D1013 from the memory unit
1012 and outputs a first list of reference pictures D1015. The
second list creation unit 1016 is configured to read reference
pictures D1017 from the memory unit 1012 and outputs a second list
of reference pictures D1019. The comparator unit 1014 is configured
to read both the first list of reference pictures D1015 and the
second list of reference pictures D1019 and outputs a control
signal D1021 to control the first and second switch units 1006
& 1008. The first switch unit 1004 is configured to send the
first list of reference pictures D1015 to either the second switch
unit 1008 or the third list creation unit 1010 based on the control
signal D1021. The third list creation unit 1010 is configured to
create a third list of reference pictures D1023 based on the first
list of reference pictures D1009 and the special reference picture
flags of the reference pictures D1025 stored in the memory unit
1012. The second switch unit 1008 is configured to select either
the first list of reference pictures D1007 or the third list of
reference pictures D1023 based on the control signal D1021. The
writing unit 1018 is configured to read the special reference
picture flag and write the flag into a header of a coded picture
D1029.
[0224] FIG. 13 shows a block diagram illustrating an example
apparatus for encoding video according to the third embodiment of
the present invention. For the sake of clarity, the example
decoding apparatus will be described corresponding to the exemplary
method as described with respect to FIG. 11A and whereby the motion
prediction process is performed using the second and third lists of
reference pictures. However, it will be apparent to the person
skilled in the art that modifications can be made to the example
apparatus shown in FIG. 13 to implement any one of the methods of
decoding video disclosed herein or other methods without departing
from the scope of the present invention.
[0225] The example apparatus for encoding video comprises of a
parsing unit 1100, a motion prediction unit 1102, a first list
creation unit 1104, a second list creation unit 1116, a third list
creation unit 1110, a first switch unit 1106, a second switch unit
1108, a memory unit 1112 and a comparator unit or a determining
unit 1114.
[0226] As shown in FIG. 13, the motion prediction unit 1102 is
configured to read a decoded set of motion vectors D1101, a
selected list of reference pictures D1111 and a second list of
reference pictures D1119 and output a block of predicted samples
D1105. The first list creation unit 1104 is configured to read
reference pictures D1113 from the memory unit 1112 and output a
first list of reference pictures D1115. The second list creation
unit 1116 is configured to read reference pictures D1117 from the
memory unit 1112 and output a second list of reference pictures
D1119. The comparator unit 1114 is configured to read both the
first list of reference pictures D1115 and the second list of
reference pictures D1119 and output a control signal D1121 to
control the first and second switch units 1106 and 1108. The first
switch unit 1104 is configured to send the first list of reference
pictures D1115 to either the second switch unit 1108 or the third
list creation unit 1110 based on the control signal D1121. The
third list creation unit 1110 is configured to create a third list
of reference pictures D1123 based on the first list of reference
pictures D1109 and the special reference picture flags of the
reference pictures D1125 stored in the memory unit 1112. The second
switch unit 1108 is configured to select either the first list of
reference pictures D1107 or the third list of reference pictures
D1123 based on the control signal D1121. The parsing unit 1100 is
configured to parse a header of a coded picture D1127 and output
the special reference picture flag parameter D1103 into a memory
unit 1112.
[0227] FIG. 14 shows a diagram illustrating a preferred location of
the special picture flag in a header of a picture according to the
third exemplary embodiment of the present invention. For example,
the special picture may be defined as a picture with a lower level
of quantization among a group of pictures.
[0228] FIG. 15A shows a flowchart illustrating a process or method
of encoding video using the fourth embodiment of the present
invention. As shown in FIG. 15A, in step 1300, a flag (e.g., a
reordering scheme selection flag) is first written or embedded into
a header of a current picture. For example, the flag is used to
signal the two different schemes used for the reordering of the
reference pictures in one of the two lists.
[0229] In step 1302, a first list of reference pictures sorted by a
first scheme that uses temporal distance to a current picture is
created. Next in step 1304, a second list of reference pictures
sorted by a second scheme that also uses temporal distance to a
current picture is created. And in step 1306, a comparison is
performed to determine or judge if the first list matches (e.g.,
identical to) the second list.
[0230] If the first list matches the second list, a comparison is
performed to determine or judge if the value of the reordering
scheme selection flag has or is of a predefined value. If the flag
is of a predefined value, a third list of reference pictures (e.g.,
corresponding to the first list of reference pictures described in
the first exemplary embodiment), which is sorted by placing higher
quality reference pictures to the top of the list, is created in
step 1314. If the flag is not of a predefined value, a third list
of reference pictures, which is sorted by prediction dependency of
the reference pictures, is created in step 1320. The prediction
dependency of the reference pictures refers to the dependency in
inter-picture motion compensated prediction among the reference
frames. Next, a motion estimation process is performed for a
current picture (e.g., a block of image samples) using at least the
third list of reference pictures in step 1316 and a motion
prediction process is performed for the block of image samples
using at least the third list of reference pictures in step 1318.
For example, the motion estimation process and/or the motion
prediction process may be performed using the second and third
lists of reference pictures, or using the first and third lists of
reference pictures.
[0231] If the first list does not match the second list in step
1306, a motion estimation process is performed for a current
picture using the first and second lists of reference frames in
step 1308 and a motion prediction process is performed for the
current picture using the first and second lists of reference
frames in step 1310.
[0232] In an embodiment, the logic at step 1306 may be switched. In
particular, if the first list matches the second list, a motion
estimation process is performed for a current picture using the
first and second lists of reference frames in step 1308 and a
motion prediction process is performed for the current picture
using the first and second lists of reference frames in step 1310.
On the other hand, if the first list does not match the second list
in step 812, a comparison is performed to determine or judge if the
value of the reordering scheme selection flag has or is of a
predefined value. If the flag is of a predefined value, a third
list of reference pictures (e.g., corresponding to the first list
of reference pictures described in the first exemplary embodiment),
which is sorted by placing higher quality reference pictures to the
top of the list, is created in step 1314. If the flag is not of a
predefined value, a third list of reference pictures, which is
sorted by prediction dependency of the reference pictures, is
created in step 1320. The prediction dependency of the reference
pictures refers to the dependency in inter-picture motion
compensated prediction among the reference frames. Next, a motion
estimation process is performed for a current picture (e.g., a
block of image samples) using at least the third list of reference
pictures in step 1316 and a motion prediction process is performed
for the block of image samples using at least the third list of
reference pictures in step 1318. Similarly, the motion estimation
process and/or the motion prediction process may be performed using
the second and third lists of reference pictures, or using the
first and third lists of reference pictures.
[0233] Yet another embodiment is shown in FIG. 15B. In particular,
steps 1302, 1304, 1306, 1308 and 1310 shown in FIG. 15A are
omitted. Accordingly, after step 1300, a comparison is performed to
determine or judge if the value of the reordering scheme selection
flag has or is of a predefined value. If the flag is of a
predefined value, a first list of reference pictures (e.g.,
corresponding to the first list of reference pictures described in
the first exemplary embodiment), which is sorted by placing higher
quality reference pictures to the top of the list, is created in
step 1364. If the flag is not of a predefined value, a first list
of reference pictures, which is sorted by prediction dependency of
the reference pictures, is created in step 1370. The prediction
dependency of the reference pictures refers to the dependency in
inter-picture motion compensated prediction among the reference
frames. Next, a motion estimation process is performed for a
current picture (e.g., a block of image samples) using at least the
first list of reference pictures in step 1366 and a motion
prediction process is performed for the block of image samples
using at least the first list of reference pictures in step
1368.
[0234] FIG. 16A shows a flowchart illustrating a process or method
of decoding video according to the fourth exemplary embodiment of
the present invention. As shown in
[0235] FIG. 16A, in step 1400, a flag (e.g., a reordering scheme
selection flag) is first parsed or retrieved from a header of a
current picture. For example, the flag is used to select the two
different schemes used for the reordering of the reference pictures
in one of the two lists.
[0236] In step 1402, a first list of reference pictures sorted by a
first scheme that uses temporal distance to a current picture is
created. Next in step 1404, a second list of reference pictures
sorted by a second scheme that also uses temporal distance to a
current picture is created. And in step 1306, a comparison is
performed to determine or judge if the first list matches (e.g.,
identical to) the second list.
[0237] If the first list matches the second list, a comparison is
performed to determine or judge if the value of the reordering
scheme selection flag has or is of a predefined value. If the flag
is of a predefined value, a third list of reference pictures (e.g.,
corresponding to the first list of reference pictures described in
the first exemplary embodiment), which is sorted by placing higher
quality reference pictures to the top of the list, is created in
step 1412. If the flag is not of a predefined value, a third list
of reference pictures, which is sorted by prediction dependency of
the reference pictures, is created in step 1416. The prediction
dependency of the reference pictures refers to the dependency in
inter-picture motion compensated prediction among the reference
frames. Next, a motion prediction process is performed for a
current picture (e.g., a block of image samples) using at least the
third list of reference pictures in step 1414. For example, the
motion prediction process may be performed using the second and
third lists of reference pictures, or using the first and third
lists of reference pictures.
[0238] If the first list does not match the second list in step
1406, a motion prediction process is performed for the current
picture using the first and second lists of reference frames in
step 1410.
[0239] In an embodiment, the logic at step 1406 may also be
switched. In particular, if the first list matches the second list,
a motion prediction process is performed for the current picture
using the first and second lists of reference frames in step 1410.
On the other hand, if the first list does not match the second list
in step 1406, a comparison is performed to determine or judge if
the value of the reordering scheme selection flag has or is of a
predefined value. If the flag is of a predefined value, a third
list of reference pictures (e.g., corresponding to the first list
of reference pictures described in the first exemplary embodiment),
which is sorted by placing higher quality reference pictures to the
top of the list, is created in step 1412. If the flag is not of a
predefined value, a third list of reference pictures, which is
sorted by prediction dependency of the reference pictures, is
created in step 1416. The prediction dependency of the reference
pictures refers to the dependency in inter-picture motion
compensated prediction among the reference frames. Next, a motion
prediction process is performed for a current picture (e.g., a
block of image samples) using at least the third list of reference
pictures in step 1414. Similarly, for example, the motion
prediction process may be performed using the second and third
lists of reference pictures, or using the first and third lists of
reference pictures.
[0240] Yet another embodiment is shown in FIG. 16B. In particular,
steps 1402, 1404, 1406 and 1410 shown in FIG. 16A are omitted.
Accordingly, after step 1400, a comparison is performed to
determine or judge if the value of the reordering scheme selection
flag has or is of a predefined value in step 1458. If the flag is
of a predefined value, a first list of reference pictures (e.g.,
corresponding to the first list of reference pictures described in
the first exemplary embodiment), which is sorted by placing higher
quality reference pictures to the top of the list, is created in
step 1462. If the flag is not of a predefined value, a first list
of reference pictures, which is sorted by prediction dependency of
the reference pictures, is created in step 1466. The prediction
dependency of the reference pictures refers to the dependency in
inter-picture motion compensated prediction among the reference
frames. Next, a motion prediction process is performed for a
current picture (e.g., a block of image samples) using at least the
first list of reference pictures in step 1464.
[0241] FIG. 17 shows a block diagram illustrating an example
apparatus for encoding video according to the fourth exemplary
embodiment of the present invention. For the sake of clarity, the
example encoding apparatus will be described corresponding to the
exemplary method as described with respect to FIG. 15A and whereby
the motion estimation process and the motion prediction process are
performed using the second and third lists of reference pictures.
However, as previously mentioned, it will be apparent to the person
skilled in the art that modifications can be made to the example
apparatus shown in FIG. 17 to implement any one of the methods of
encoding video disclosed herein or other methods without departing
from the scope of the present invention.
[0242] The example apparatus for encoding video comprises of a
motion estimation unit 1500, a motion prediction unit 1502, a first
list creation unit 1516, a second list creation unit 1522, a third
list creation unit 1508, a fourth list creation unit 1510, a first
switch unit 1504, a second switch unit 1506, a third switch unit
1512, a fourth switch unit 1514, a memory unit 1518, a comparator
unit or a determining unit 1520 and a writing unit 1524.
[0243] As shown in FIG. 17, the motion estimation unit 1500 is
configured to read a block of image samples D1501, a selected list
of reference pictures D1533, a second list of reference pictures
D1531 and output a set of motion vectors D1503. The motion
prediction unit 1502 is configured to read the set of motion
vectors D1503, the selected list of reference pictures D1533 and
the second list of reference pictures D1531 and output a block of
predicted samples D1539. The first list creation unit 1516 is
configured to read reference pictures D1507 from the memory unit
1518 and output a first list of reference pictures D1505. The
second list creation unit 1522 is configured to read reference
pictures D1509 from the memory unit 1518 and output a second list
of reference pictures D1511. The comparator unit 1520 is configured
to read both the first list of reference pictures D1505 and the
second list of reference pictures D1511 and output a control signal
D1513 to control the first and second switch units 1504 & 1506.
The first switch unit 1504 is configured to send the first list of
reference pictures D1505 to either the second switch unit 1506 or
the third switch unit 1512. The third switch unit 1512 is
configured to, based on a flag (e.g., a reordering scheme selection
flag) D1515, send the first list of reference frames D1517 to
either the third list creation unit 1508 or the fourth list
creation unit 1510. The third list creation unit 1508 is configured
to, based on the first list D1521, create a new list of reference
frames D1525. The fourth list creation unit 1510 is configured to,
based on the first list D1523, create a new list of reference
frames D1527. The fourth switch unit 1514 is configured to, based
on the flag D1515, select one of the new list D1529 and send it to
the second switch unit 1506. The second switch unit 1506 is
configured to select either the first list of reference pictures
D1519 or the selected new list of reference pictures D1529 based on
the control signal D1513. The writing unit 1524 is configured to
read the flag D1515 and write the flag into a header of a current
picture D1537.
[0244] FIG. 18 shows a block diagram illustrating an example
apparatus for decoding video according to the fourth embodiment of
the present invention. For the sake of clarity, the example
decoding apparatus will be described corresponding to the exemplary
method as described with respect to FIG. 16A and whereby the motion
prediction process is performed using the second and third lists of
reference pictures. However, it will be apparent to the person
skilled in the art that modifications can be made to the example
apparatus shown in FIG. 18 to implement any one of the methods of
decoding video disclosed herein or other methods without departing
from the scope of the present invention.
[0245] The example apparatus for decoding video comprises of a
parsing unit 1600, a motion prediction unit 1602, a first list
creation unit 1616, a second list creation unit 1622, a third list
creation unit 1608, a fourth list creation unit 1610, a first
switch unit 1604, a second switch unit 1606, a third switch unit
1612, a fourth switch unit 1614, a memory unit 1618 and a
comparator unit or a determining unit 1620.
[0246] As shown in FIG. 18, the parsing unit 1600 is configured to
parse a header of a current picture and output the flag (e.g., the
reordering scheme selection flag) D1615. The motion prediction unit
1602 is configured to read the set of motion vectors D1603, the
selected list of reference pictures D1633 and the second list of
reference pictures D1631 and output a block of predicted samples
D1603. The first list creation unit 1616 is configured to read
reference pictures D1607 from the memory unit 1618 and output a
first list of reference pictures D1605. The second list creation
unit 1622 is configured to read reference pictures D1609 from the
memory unit 1518 and output a second list of reference pictures
D1611. The comparator unit 1620 is configured to read both the
first list of reference pictures D1605 and the second list of
reference pictures D1611 and output a control signal D1613 to
control the first and second switch units 1604 and 1606. The first
switch unit 1604 is configured to send the first list of reference
pictures D1605 to either the second switch unit 1606 or the third
switch unit 1612. The third switch unit 1612 is configured to,
based on the flag D1615, send the first list of reference frames
D1617 to either the third list creation unit 1608 or the fourth
list creation unit 1610. The third list creation unit 1608 is
configured to, based on the first list D1621, create a new list of
reference frames D1625. The fourth list creation unit 1610 is
configured to, based on the first list D1623, create a new list of
reference frames D1627. The fourth switch unit 1614 is configured
to, based on the flag D1615, select one of the new lists D1629 and
send it to the second switch unit 1606. The second switch unit 1606
is configured to select either the first list of reference pictures
D1619 or the selected new list of reference pictures D1629 based on
the control signal D1613.
[0247] FIG. 19 shows a diagram illustrating a preferred location of
the flag in a header of a picture. In the case of the flag being a
reordering scheme selection flag, for example, the flag is used to
switch the scheme to create a list of reference pictures.
[0248] FIG. 20 shows a flowchart describing a process or method to
label a reference picture as a special picture in the third
exemplary embodiment of the present invention. As shown in the
diagram, in step 1800, the current picture is labeled as a special
long-term reference picture. And in step 1802, a long term index
value is set to a predefined value. In step 1804, a previously
reconstructed long term reference picture having the long term
index equal to the predefined value is located in the memory. And
finally in step 1806, the long term reference picture, if located
in the memory, is replaced with the current picture in the
memory.
[0249] FIG. 21 shows a diagram illustrating an example apparatus to
label a picture as a special reference picture in the third
embodiment of present invention. The example apparatus comprises a
labeling unit 1900, an assignment unit 1902, a searching unit 1906,
a replacement unit 1904 and a memory unit 1908. Firstly, the
assignment unit 1902 is configured to read a predefined value D1907
and assign it to the long-term index value of a picture D1909). The
labeling unit 1900 is configured to read a picture D1901 and the
long-term index value D1909 and output a long-term reference
picture with the assigned long-term index value D1903. The
searching unit 1906 is configured to read the long-term index value
D1907, search the reference pictures D1911 in the memory unit 1908
and locate the location of a long-term reference picture in the
memory D1905. The replacement unit 1904 is configured to read the
labeled picture D1903 and place the picture at the location of the
long-term reference picture in the memory D1913.
Embodiment 5
[0250] The processing described in each of Embodiments can be
simply implemented in an independent computer system, by recording,
in a recording medium, a program for implementing the
configurations of the video coding method and the video decoding
method described in each of Embodiments. The recording media may be
any recording media as long as the program can be recorded, such as
a magnetic disk, an optical disk, a magnetic optical disk, an IC
card, and a semiconductor memory.
[0251] Hereinafter, the applications to the video coding method and
the video decoding method described in each of Embodiments and
systems using thereof will be described.
[0252] FIG. 22 illustrates an overall configuration of a content
providing system ex100 for implementing content distribution
services. The area for providing communication services is divided
into cells of desired size, and base stations ex106, ex107, ex108,
ex109, and ex110 which are fixed wireless stations are placed in
each of the cells.
[0253] The content providing system ex100 is connected to devices,
such as a computer ex111, a personal digital assistant (PDA) ex112,
a camera ex113, a cellular phone ex114 and a game machine ex115,
via the Internet ex101, an Internet service provider ex102, a
telephone network ex104, as well as the base stations ex106 to
ex110, respectively.
[0254] However, the configuration of the content providing system
ex100 is not limited to the configuration shown in FIG. 22, and a
combination in which any of the elements are connected is
acceptable. In addition, each device may be directly connected to
the telephone network ex104, rather than via the base stations
ex106 to ex110 which are the fixed wireless stations. Furthermore,
the devices may be interconnected to each other via a short
distance wireless communication and others.
[0255] The camera ex113, such as a digital video camera, is capable
of capturing video. A camera ex116, such as a digital video camera,
is capable of capturing both still images and video. Furthermore,
the cellular phone ex114 may be the one that meets any of the
standards such as Global System for Mobile Communications (GSM),
Code Division Multiple Access (CDMA), Wideband-Code Division
Multiple Access (W-CDMA), Long Term Evolution (LTE), and High Speed
Packet Access (HSPA). Alternatively, the cellular phone ex114 may
be a Personal Handyphone System (PHS).
[0256] In the content providing system ex100, a streaming server
ex103 is connected to the camera ex113 and others via the telephone
network ex104 and the base station ex109, which enables
distribution of images of a live show and others. In such a
distribution, a content (for example, video of a music live show)
captured by the user using the camera ex113 is coded as described
above in each of Embodiments, and the coded content is transmitted
to the streaming server ex103. On the other hand, the streaming
server ex103 carries out stream distribution of the transmitted
content data to the clients upon their requests. The clients
include the computer ex111, the PDA ex112, the camera ex113, the
cellular phone ex114, and the game machine ex115 that are capable
of decoding the above-mentioned coded data. Each of the devices
that have received the distributed data decodes and reproduces the
coded data.
[0257] The captured data may be coded by the camera ex113 or the
streaming server ex103 that transmits the data, or the coding
processes may be shared between the camera ex113 and the streaming
server ex103. Similarly, the distributed data may be decoded by the
clients or the streaming server ex103, or the decoding processes
may be shared between the clients and the streaming server ex103.
Furthermore, the data of the still images and video captured by not
only the camera ex113 but also the camera ex116 may be transmitted
to the streaming server ex103 through the computer ex111. The
coding processes may be performed by the camera ex116, the computer
ex111, or the streaming server ex103, or shared among them.
[0258] Furthermore, the coding and decoding processes may be
performed by an LSI ex500 generally included in each of the
computer ex111 and the devices. The LSI ex500 may be configured of
a single chip or a plurality of chips. Software for coding and
decoding video may be integrated into some type of a recording
medium (such as a CD-ROM, a flexible disk, and a hard disk) that is
readable by the computer ex111 and others, and the coding and
decoding processes may be performed using the software.
Furthermore, when the cellular phone ex114 is equipped with a
camera, the image data obtained by the camera may be transmitted.
The video data is data coded by the LSI ex500 included in the
cellular phone ex114.
[0259] Furthermore, the streaming server ex103 may be composed of
servers and computers, and may decentralize data and process the
decentralized data, record, or distribute data.
[0260] As described above, the clients may receive and reproduce
the coded data in the content providing system ex100. In other
words, the clients can receive and decode information transmitted
by the user, and reproduce the decoded data in real time in the
content providing system ex100, so that the user who does not have
any particular right and equipment can implement personal
broadcasting.
[0261] Aside from the example of the content providing system
ex100, at least one of the video coding apparatus and the video
decoding apparatus described in each of Embodiments may be
implemented in a digital broadcasting system ex200 illustrated in
FIG. 23. More specifically, a broadcast station ex201 communicates
or transmits, via radio waves to a broadcast satellite ex202,
multiplexed data obtained by multiplexing audio data and others
onto video data. The video data is data coded by the video coding
method described in each of Embodiments. Upon receipt of the
multiplexed data, the broadcast satellite ex202 transmits radio
waves for broadcasting. Then, a home-use antenna ex204 with a
satellite broadcast reception function receives the radio
waves.
[0262] Next, a device such as a television (receiver) ex300 and a
set top box (STB) ex217 decodes the received multiplexed data, and
reproduces the decoded data.
[0263] Furthermore, a reader/recorder ex218 (i) reads and decodes
the multiplexed data recorded on a recording media ex215, such as a
DVD and a BD, or (i) codes video signals in the recording medium
ex215, and in some cases, writes data obtained by multiplexing an
audio signal on the coded data. The reader/recorder ex218 can
include the video decoding apparatus or the video coding apparatus
as shown in each of Embodiments. In this case, the reproduced video
signals are displayed on the monitor ex219, and can be reproduced
by another device or system using the recording medium ex215 on
which the multiplexed data is recorded. It is also possible to
implement the video decoding apparatus in the set top box ex217
connected to the cable ex203 for a cable television or to the
antenna ex204 for satellite and/or terrestrial broadcasting, so as
to display the video signals on the monitor ex219 of the television
ex300. The video decoding apparatus may be implemented not in the
set top box but in the television ex300.
[0264] FIG. 24 illustrates the television (receiver) ex300 that
uses the video coding method and the video decoding method
described in each of Embodiments. The television ex300 includes: a
tuner ex301 that obtains or provides multiplexed data obtained by
multiplexing audio data onto video data, through the antenna ex204
or the cable ex203, etc. that receives a broadcast; a
modulation/demodulation unit ex302 that demodulates the received
multiplexed data or modulates data into multiplexed data to be
supplied outside; and a multiplexing/demultiplexing unit ex303 that
demultiplexes the modulated multiplexed data into video data and
audio data, or multiplexes video data and audio data coded by a
signal processing unit ex306 into data.
[0265] The television ex300 further includes: a signal processing
unit ex306 including an audio signal processing unit ex304 and a
video signal processing unit ex305 that decode audio data and video
data and code audio data and video data, respectively; and an
output unit ex309 including a speaker ex307 that provides the
decoded audio signal, and a display unit ex308 that displays the
decoded video signal, such as a display. Furthermore, the
television ex300 includes an interface unit ex317 including an
operation input unit ex312 that receives an input of a user
operation. Furthermore, the television ex300 includes a control
unit ex310 that controls overall each constituent element of the
television ex300, and a power supply circuit unit ex311 that
supplies power to each of the elements. Other than the operation
input unit ex312, the interface unit ex317 may include: a bridge
ex313 that is connected to an external device, such as the
reader/recorder ex218; a slot unit ex314 for enabling attachment of
the recording medium ex216, such as an SD card; a driver ex315 to
be connected to an external recording medium, such as a hard disk;
and a modem ex316 to be connected to a telephone network. Here, the
recording medium ex216 can electrically record information using a
non-volatile/volatile semiconductor memory element for storage. The
constituent elements of the television ex300 are connected to each
other through a synchronous bus.
[0266] First, the configuration in which the television ex300
decodes multiplexed data obtained from outside through the antenna
ex204 and others and reproduces the decoded data will be described.
In the television ex300, upon a user operation through a remote
controller ex220 and others, the multiplexing/demultiplexing unit
ex303 demultiplexes the multiplexed data demodulated by the
modulation/demodulation unit ex302, under control of the control
unit ex310 including a CPU. Furthermore, the audio signal
processing unit ex304 decodes the demultiplexed audio data, and the
video signal processing unit ex305 decodes the demultiplexed video
data, using the decoding method described in each of Embodiments,
in the television ex300. The output unit ex309 provides the decoded
video signal and audio signal outside, respectively. When the
output unit ex309 provides the video signal and the audio signal,
the signals may be temporarily stored in buffers ex318 and ex319,
and others so that the signals are reproduced in synchronization
with each other. Furthermore, the television ex300 may read
multiplexed data not through a broadcast and others but from the
recording media ex215 and ex216, such as a magnetic disk, an
optical disk, and a SD card. Next, a configuration in which the
television ex300 codes an audio signal and a video signal, and
transmits the data outside or writes the data on a recording medium
will be described. In the television ex300, upon a user operation
through the remote controller ex220 and others, the audio signal
processing unit ex304 codes an audio signal, and the video signal
processing unit ex305 codes a video signal, under control of the
control unit ex310 using the coding method described in each of
Embodiments. The multiplexing/demultiplexing unit ex303 multiplexes
the coded video signal and audio signal, and provides the resulting
signal outside. When the multiplexing/demultiplexing unit ex303
multiplexes the video signal and the audio signal, the signals may
be temporarily stored in the buffers ex320 and ex321, and others so
that the signals are reproduced in synchronization with each other.
Here, the buffers ex318, ex319, ex320, and ex321 may be plural as
illustrated, or at least one buffer may be shared in the television
ex300. Furthermore, data may be stored in a buffer so that the
system overflow and underflow may be avoided between the
modulation/demodulation unit ex302 and the
multiplexing/demultiplexing unit ex303, for example.
[0267] Furthermore, the television ex300 may include a
configuration for receiving an AV input from a microphone or a
camera other than the configuration for obtaining audio and video
data from a broadcast or a recording medium, and may code the
obtained data. Although the television ex300 can code, multiplex,
and provide outside data in the description, it may be capable of
only receiving, decoding, and providing outside data but not the
coding, multiplexing, and providing outside data.
[0268] Furthermore, when the reader/recorder ex218 reads or writes
multiplexed data from or on a recording medium, one of the
television ex300 and the reader/recorder ex218 may decode or code
the multiplexed data, and the television ex300 and the
reader/recorder ex218 may share the decoding or coding.
[0269] As an example, FIG. 25 illustrates a configuration of an
information reproducing/recording unit ex400 when data is read or
written from or on an optical disk. The information
reproducing/recording unit ex400 includes constituent elements
ex401, ex402, ex403, ex404, ex405, ex406, and ex407 to be described
hereinafter. The optical head ex401 irradiates a laser spot in a
recording surface of the recording medium ex215 that is an optical
disk to write information, and detects reflected light from the
recording surface of the recording medium ex215 to read the
information. The modulation recording unit ex402 electrically
drives a semiconductor laser included in the optical head ex401,
and modulates the laser light according to recorded data. The
reproduction demodulating unit ex403 amplifies a reproduction
signal obtained by electrically detecting the reflected light from
the recording surface using a photo detector included in the
optical head ex401, and demodulates the reproduction signal by
separating a signal component recorded on the recording medium
ex215 to reproduce the necessary information. The buffer ex404
temporarily holds the information to be recorded on the recording
medium ex215 and the information reproduced from the recording
medium ex215. The disk motor ex405 rotates the recording medium
ex215. The servo control unit ex406 moves the optical head ex401 to
a predetermined information track while controlling the rotation
drive of the disk motor ex405 so as to follow the laser spot. The
system control unit ex407 controls overall the information
reproducing/recording unit ex400. The reading and writing processes
can be implemented by the system control unit ex407 using various
information stored in the buffer ex404 and generating and adding
new information as necessary, and by the modulation recording unit
ex402, the reproduction demodulating unit ex403, and the servo
control unit ex406 that record and reproduce information through
the optical head ex401 while being operated in a coordinated
manner. The system control unit ex407 includes, for example, a
microprocessor, and executes processing by causing a computer to
execute a program for read and write.
[0270] Although the optical head ex401 irradiates a laser spot in
the description, it may perform high-density recording using near
field light.
[0271] FIG. 26 illustrates the recording medium ex215 that is the
optical disk. On the recording surface of the recording medium
ex215, guide grooves are spirally formed, and an information track
ex230 records, in advance, address information indicating an
absolute position on the disk according to change in a shape of the
guide grooves. The address information includes information for
determining positions of recording blocks ex231 that are a unit for
recording data. Reproducing the information track ex230 and reading
the address information in an apparatus that records and reproduces
data can lead to determination of the positions of the recording
blocks. Furthermore, the recording medium ex215 includes a data
recording area ex233, an inner circumference area ex232, and an
outer circumference area ex234. The data recording area ex233 is an
area for use in recording the user data. The inner circumference
area ex232 and the outer circumference area ex234 that are inside
and outside of the data recording area ex233, respectively are for
specific use except for recording the user data. The information
reproducing/recording unit 400 reads and writes coded audio, coded
video data, or multiplexed data obtained by multiplexing the coded
audio and video data, from and on the data recording area ex233 of
the recording medium ex215.
[0272] Although an optical disk having a layer, such as a DVD and a
BD is described as an example in the description, the optical disk
is not limited to such, and may be an optical disk having a
multilayer structure and capable of being recorded on a part other
than the surface. Furthermore, the optical disk may have a
structure for multidimensional recording/reproduction, such as
recording of information using light of colors with different
wavelengths in the same portion of the optical disk and for
recording information having different layers from various
angles.
[0273] Furthermore, a car ex210 having an antenna ex205 can receive
data from the satellite ex202 and others, and reproduce video on a
display device such as a car navigation system ex211 set in the car
ex210, in the digital broadcasting system ex200. Here, a
configuration of the car navigation system ex211 will be a
configuration, for example, including a GPS receiving unit from the
configuration illustrated in FIG. 24. The same will be true for the
configuration of the computer ex111, the cellular phone ex114, and
others.
[0274] FIG. 27A illustrates the cellular phone ex114 that uses the
video coding method and the video decoding method described in
Embodiments. The cellular phone ex114 includes: an antenna ex350
for transmitting and receiving radio waves through the base station
ex110; a camera unit ex365 capable of capturing moving and still
images; and a display unit ex358 such as a liquid crystal display
for displaying the data such as decoded video captured by the
camera unit ex365 or received by the antenna ex350. The cellular
phone ex114 further includes: a main body unit including an
operation key unit ex366; an audio output unit ex357 such as a
speaker for output of audio; an audio input unit ex356 such as a
microphone for input of audio; a memory unit ex367 for storing
captured video or still pictures, recorded audio, coded or decoded
data of the received video, the still pictures, e-mails, or others;
and a slot unit ex364 that is an interface unit for a recording
medium that stores data in the same manner as the memory unit
ex367.
[0275] Next, an example of a configuration of the cellular phone
ex114 will be described with reference to FIG. 27B. In the cellular
phone ex114, a main control unit ex360 designed to control overall
each unit of the main body including the display unit ex358 as well
as the operation key unit ex366 is connected mutually, via a
synchronous bus ex370, to a power supply circuit unit ex361, an
operation input control unit ex362, a video signal processing unit
ex355, a camera interface unit ex363, a liquid crystal display
(LCD) control unit ex359, a modulation/demodulation unit ex352, a
multiplexing/demultiplexing unit ex353, an audio signal processing
unit ex354, the slot unit ex364, and the memory unit ex367.
[0276] When a call-end key or a power key is turned ON by a user's
operation, the power supply circuit unit ex361 supplies the
respective units with power from a battery pack so as to activate
the cell phone ex114.
[0277] In the cellular phone ex114, the audio signal processing
unit ex354 converts the audio signals collected by the audio input
unit ex356 in voice conversation mode into digital audio signals
under the control of the main control unit ex360 including a CPU,
ROM, and RAM. Then, the modulation/demodulation unit ex352 performs
spread spectrum processing on the digital audio signals, and the
transmitting and receiving unit ex351 performs digital-to-analog
conversion and frequency conversion on the data, so as to transmit
the resulting data via the antenna ex350.
[0278] Also, in the cellular phone ex114, the transmitting and
receiving unit ex351 amplifies the data received by the antenna
ex350 in voice conversation mode and performs frequency conversion
and the analog-to-digital conversion on the data. Then, the
modulation/demodulation unit ex352 performs inverse spread spectrum
processing on the data, and the audio signal processing unit ex354
converts it into analog audio signals, so as to output them via the
audio output unit ex356.
[0279] Furthermore, when an e-mail in data communication mode is
transmitted, text data of the e-mail inputted by operating the
operation key unit ex366 and others of the main body is sent out to
the main control unit ex360 via the operation input control unit
ex362. The main control unit ex360 causes the
modulation/demodulation unit ex352 to perform spread spectrum
processing on the text data, and the transmitting and receiving
unit ex351 performs the digital-to-analog conversion and the
frequency conversion on the resulting data to transmit the data to
the base station ex110 via the antenna ex350. When an e-mail is
received, processing that is approximately inverse to the
processing for transmitting an e-mail is performed on the received
data, and the resulting data is provided to the display unit
ex358.
[0280] When video, still images, or video and audio in data
communication mode is or are transmitted, the video signal
processing unit ex355 compresses and codes video signals supplied
from the camera unit ex365 using the video coding method shown in
each of Embodiments, and transmits the coded video data to the
multiplexing/demultiplexing unit ex353. In contrast, during when
the camera unit ex365 captures video, still images, and others, the
audio signal processing unit ex354 codes audio signals collected by
the audio input unit ex356, and transmits the coded audio data to
the multiplexing/demultiplexing unit ex353.
[0281] The multiplexing/demultiplexing unit ex353 multiplexes the
coded video data supplied from the video signal processing unit
ex355 and the coded audio data supplied from the audio signal
processing unit ex354, using a predetermined method.
[0282] Then, the modulation/demodulation unit ex352 performs spread
spectrum processing on the multiplexed data, and the transmitting
and receiving unit ex351 performs digital-to-analog conversion and
frequency conversion on the data so as to transmit the resulting
data via the antenna ex350.
[0283] When receiving data of a video file which is linked to a Web
page and others in data communication mode or when receiving an
e-mail with video and/or audio attached, in order to decode the
multiplexed data received via the antenna ex350, the
multiplexing/demultiplexing unit ex353 demultiplexes the
multiplexed data into a video data bit stream and an audio data bit
stream, and supplies the video signal processing unit ex355 with
the coded video data and the audio signal processing unit ex354
with the coded audio data, through the synchronous bus ex370. The
video signal processing unit ex355 decodes the video signal using a
video decoding method corresponding to the coding method shown in
each of Embodiments, and then the display unit ex358 displays, for
instance, the video and still images included in the video file
linked to the Web page via the LCD control unit ex359. Furthermore,
the audio signal processing unit ex354 decodes the audio signal,
and the audio output unit ex357 provides the audio.
[0284] Furthermore, similarly to the television ex300, a terminal
such as the cellular phone ex114 probably have 3 types of
implementation configurations including not only (i) a transmitting
and receiving terminal including both a coding apparatus and a
decoding apparatus, but also (ii) a transmitting terminal including
only a coding apparatus and (iii) a receiving terminal including
only a decoding apparatus. Although the digital broadcasting system
ex200 receives and transmits the multiplexed data obtained by
multiplexing audio data onto video data in the description, the
multiplexed data may be data obtained by multiplexing not audio
data but character data related to video onto video data, and may
be not multiplexed data but video data itself
[0285] As such, the video coding method and the video decoding
method in each of Embodiments can be used in any of the devices and
systems described. Thus, the advantages described in each of
Embodiments can be obtained.
[0286] Furthermore, the present invention is not limited to
Embodiments, and various modifications and revisions are possible
without departing from the scope of the present invention.
Embodiment 6
[0287] Video data can be generated by switching, as necessary,
between (i) the video coding method or the video coding apparatus
shown in each of Embodiments and (ii) a video coding method or a
video coding apparatus in conformity with a different standard,
such as MPEG-2, MPEG4-AVC, and VC-1.
[0288] Here, when a plurality of video data that conforms to the
different standards is generated and is then decoded, the decoding
methods need to be selected to conform to the different standards.
However, since to which standard each of the plurality of the video
data to be decoded conform cannot be detected, there is a problem
that an appropriate decoding method cannot be selected.
[0289] In order to solve the problem, multiplexed data obtained by
multiplexing audio data and others onto video data has a structure
including identification information indicating to which standard
the video data conforms. The specific structure of the multiplexed
data including the video data generated in the video coding method
and by the video coding apparatus shown in each of Embodiments will
be hereinafter described. The multiplexed data is a digital stream
in the MPEG2-Transport Stream format.
[0290] FIG. 28 illustrates a structure of the multiplexed data. As
illustrated in FIG. 28, the multiplexed data can be obtained by
multiplexing at least one of a video stream, an audio stream, a
presentation graphics stream (PG), and an interactive graphics
stream. The video stream represents primary video and secondary
video of a movie, the audio stream (IG) represents a primary audio
part and a secondary audio part to be mixed with the primary audio
part, and the presentation graphics stream represents subtitles of
the movie. Here, the primary video is normal video to be displayed
on a screen, and the secondary video is video to be displayed on a
smaller window in the primary video. Furthermore, the interactive
graphics stream represents an interactive screen to be generated by
arranging the GUI components on a screen. The video stream is coded
in the video coding method or by the video coding apparatus shown
in each of Embodiments, or in a video coding method or by a video
coding apparatus in conformity with a conventional standard, such
as MPEG-2, MPEG4-AVC, and VC-1. The audio stream is coded in
accordance with a standard, such as Dolby-AC-3, Dolby Digital Plus,
MLP, DTS, DTS-HD, and linear PCM.
[0291] Each stream included in the multiplexed data is identified
by PID. For example, 0x1011 is allocated to the video stream to be
used for video of a movie, 0x1100 to 0x111F are allocated to the
audio streams, 0x1200 to 0x121F are allocated to the presentation
graphics streams, 0x1400 to 0x141F are allocated to the interactive
graphics streams, 0x1B00 to 0x1B1F are allocated to the video
streams to be used for secondary video of the movie, and 0x1A00 to
0x1A1F are allocated to the audio streams to be used for the
secondary video to be mixed with the primary audio.
[0292] FIG. 29 schematically illustrates how data is multiplexed.
First, a video stream ex235 composed of video frames and an audio
stream ex238 composed of audio frames are transformed into a stream
of PES packets ex236 and a stream of PES packets ex239, and further
into TS packets ex237 and TS packets ex240, respectively.
Similarly, data of a presentation graphics stream ex241 and data of
an interactive graphics stream ex244 are transformed into a stream
of PES packets ex242 and a stream of PES packets ex245, and further
into TS packets ex243 and TS packets ex246, respectively. These TS
packets are multiplexed into a stream to obtain multiplexed data
ex247.
[0293] FIG. 30 illustrates how a video stream is stored in a stream
of PES packets in more detail. The first bar in FIG. 30 shows a
video frame stream in a video stream. The second bar shows the
stream of PES packets. As indicated by arrows denoted as yy1, yy2,
yy3, and yy4 in FIG. 30, the video stream is divided into pictures
as I pictures, B pictures, and P pictures each of which is a video
presentation unit, and the pictures are stored in a payload of each
of the PES packets. Each of the PES packets has a PES header, and
the PES header stores a Presentation Time-Stamp (PTS) indicating a
display time of the picture, and a Decoding Time-Stamp (DTS)
indicating a decoding time of the picture.
[0294] FIG. 31 illustrates a format of TS packets to be finally
written on the multiplexed data. Each of the TS packets is a
188-byte fixed length packet including a 4-byte TS header having
information, such as a PID for identifying a stream and a 184-byte
TS payload for storing data. The PES packets are divided, and
stored in the TS payloads, respectively. When a BD ROM is used,
each of the TS packets is given a 4-byte TP_Extra_Header, thus
resulting in 192-byte source packets. The source packets are
written on the multiplexed data. The TP_Extra_Header stores
information such as an Arrival Time Stamp (ATS). The ATS shows a
transfer start time at which each of the TS packets is to be
transferred to a PID filter. The source packets are arranged in the
multiplexed data as shown at the bottom of FIG. 31. The numbers
incrementing from the head of the multiplexed data are called
source packet numbers (SPNs).
[0295] Each of the TS packets included in the multiplexed data
includes not only streams of audio, video, subtitles and others,
but also a Program Association Table (PAT), a Program Map Table
(PMT), and a Program Clock Reference (PCR). The PAT shows what a
PID in a PMT used in the multiplexed data indicates, and a PID of
the PAT itself is registered as zero. The PMT stores PIDs of the
streams of video, audio, subtitles and others included in the
multiplexed data, and attribute information of the streams
corresponding to the PIDs. The PMT also has various descriptors
relating to the multiplexed data. The descriptors have information
such as copy control information showing whether copying of the
multiplexed data is permitted or not. The PCR stores STC time
information corresponding to an ATS showing when the PCR packet is
transferred to a decoder, in order to achieve synchronization
between an Arrival Time Clock (ATC) that is a time axis of ATSs,
and an System Time Clock (STC) that is a time axis of PTSs and
DTSs.
[0296] FIG. 32 illustrates the data structure of the PMT in detail.
A PMT header is disposed at the top of the PMT. The PMT header
describes the length of data included in the PMT and others. A
plurality of descriptors relating to the multiplexed data is
disposed after the PMT header. Information such as the copy control
information is described in the descriptors. After the descriptors,
a plurality of pieces of stream information relating to the streams
included in the multiplexed data is disposed. Each piece of stream
information includes stream descriptors each describing
information, such as a stream type for identifying a compression
codec of a stream, a stream PID, and stream attribute information
(such as a frame rate or an aspect ratio). The stream descriptors
are equal in number to the number of streams in the multiplexed
data.
[0297] When the multiplexed data is recorded on a recording medium
and others, it is recorded together with multiplexed data
information files.
[0298] Each of the multiplexed data information files is management
information of the multiplexed data as shown in FIG. 33. The
multiplexed data information files are in one to one correspondence
with the multiplexed data, and each of the files includes
multiplexed data information, stream attribute information, and an
entry map.
[0299] As illustrated in FIG. 33, the multiplexed data includes a
system rate, a reproduction start time, and a reproduction end
time. The system rate indicates the maximum transfer rate at which
a system target decoder to be described later transfers the
multiplexed data to a PID filter. The intervals of the ATSs
included in the multiplexed data are set to not higher than a
system rate. The reproduction start time indicates a PTS in a video
frame at the head of the multiplexed data. An interval of one frame
is added to a PTS in a video frame at the end of the multiplexed
data, and the PTS is set to the reproduction end time.
[0300] As shown in FIG. 34, a piece of attribute information is
registered in the stream attribute information, for each PID of
each stream included in the multiplexed data. Each piece of
attribute information has different information depending on
whether the corresponding stream is a video stream, an audio
stream, a presentation graphics stream, or an interactive graphics
stream. Each piece of video stream attribute information carries
information including what kind of compression codec is used for
compressing the video stream, and the resolution, aspect ratio and
frame rate of the pieces of picture data that is included in the
video stream. Each piece of audio stream attribute information
carries information including what kind of compression codec is
used for compressing the audio stream, how many channels are
included in the audio stream, which language the audio stream
supports, and how high the sampling frequency is. The video stream
attribute information and the audio stream attribute information
are used for initialization of a decoder before the player plays
back the information.
[0301] In Embodiment 6, the multiplexed data to be used is of a
stream type included in the PMT. Furthermore, when the multiplexed
data is recorded on a recording medium, the video stream attribute
information included in the multiplexed data information is used.
More specifically, the video coding method or the video coding
apparatus described in each of Embodiments includes a step or a
unit for allocating unique information indicating video data
generated by the video coding method or the video coding apparatus
in each of Embodiments, to the stream type included in the PMT or
the video stream attribute information. With the configuration, the
video data generated by the video coding method or the video coding
apparatus described in each of Embodiments can be distinguished
from video data that conforms to another standard.
[0302] Furthermore, FIG. 35 illustrates steps of the video decoding
method according to Embodiment 6. In Step exS100, the stream type
included in the PMT or the video stream attribute information is
obtained from the multiplexed data. Next, in Step exS101, it is
determined whether or not the stream type or the video stream
attribute information indicates that the multiplexed data is
generated by the video coding method or the video coding apparatus
in each of Embodiments. When it is determined that the stream type
or the video stream attribute information indicates that the
multiplexed data is generated by the video coding method or the
video coding apparatus in each of Embodiments, in Step exS102,
decoding is performed by the video decoding method in each of
Embodiments. Furthermore, when the stream type or the video stream
attribute information indicates conformance to the conventional
standards, such as MPEG-2, MPEG4-AVC, and VC-1, in Step exS103,
decoding is performed by a video decoding method in conformity with
the conventional standards.
[0303] As such, allocating a new unique value to the stream type or
the video stream attribute information enables determination
whether or not the video decoding method or the video decoding
apparatus that is described in each of Embodiments can perform
decoding. Even when multiplexed data that conforms to a different
standard, an appropriate decoding method or apparatus can be
selected. Thus, it becomes possible to decode information without
any error. Furthermore, the video coding method or apparatus, or
the video decoding method or apparatus in Embodiment 6 can be used
in the devices and systems described above.
Embodiment 7
[0304] Each of the video coding method, the video coding apparatus,
the video decoding method, and the video decoding apparatus in each
of Embodiments is typically achieved in the form of an integrated
circuit or a Large Scale Integrated (LSI) circuit. As an example of
the LSI, FIG. 36 illustrates a configuration of the LSI ex500 that
is made into one chip. The LSI ex500 includes elements ex501,
ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 to be
described below, and the elements are connected to each other
through a bus ex510. The power supply circuit unit ex505 is
activated by supplying each of the elements with power when the
power supply circuit unit ex505 is turned on.
[0305] For example, when coding is performed, the LSI ex500
receives an AV signal from a microphone ex117, a camera ex113, and
others through an AV IO ex509 under control of a control unit ex501
including a CPU ex502, a memory controller ex503, a stream
controller ex504, and a driving frequency control unit ex512. The
received AV signal is temporarily stored in an external memory
ex511, such as an SDRAM. Under control of the control unit ex501,
the stored data is segmented into data portions according to the
processing amount and speed to be transmitted to a signal
processing unit ex507. Then, the signal processing unit ex507 codes
an audio signal and/or a video signal. Here, the coding of the
video signal is the coding described in each of Embodiments.
Furthermore, the signal processing unit ex507 sometimes multiplexes
the coded audio data and the coded video data, and a stream IO
ex506 provides the multiplexed data outside. The provided
multiplexed data is transmitted to the base station ex107, or
written on the recording media ex215. When data sets are
multiplexed, the data should be temporarily stored in the buffer
ex508 so that the data sets are synchronized with each other.
[0306] Although the memory ex511 is an element outside the LSI
ex500, it may be included in the LSI ex500. The buffer ex508 is not
limited to one buffer, but may be composed of buffers. Furthermore,
the LSI ex500 may be made into one chip or a plurality of
chips.
[0307] Furthermore, although the control unit ex510 includes the
CPU ex502, the memory controller ex503, the stream controller
ex504, the driving frequency control unit ex512, the configuration
of the control unit ex510 is not limited to such. For example, the
signal processing unit ex507 may further include a CPU. Inclusion
of another CPU in the signal processing unit ex507 can improve the
processing speed. Furthermore, as another example, the CPU ex502
may serve as or be a part of the signal processing unit ex507, and,
for example, may include an audio signal processing unit. In such a
case, the control unit ex501 includes the signal processing unit
ex507 or the CPU ex502 including a part of the signal processing
unit ex507.
[0308] The name used here is LSI, but it may also be called IC,
system LSI, super LSI, or ultra LSI depending on the degree of
integration.
[0309] Moreover, ways to achieve integration are not limited to the
LSI, and a special circuit or a general purpose processor and so
forth can also achieve the integration. Field Programmable Gate
Array (FPGA) that can be programmed after manufacturing LSIs or a
reconfigurable processor that allows re-configuration of the
connection or configuration of an LSI can be used for the same
purpose.
[0310] In the future, with advancement in semiconductor technology,
a brand-new technology may replace LSI. The functional blocks can
be integrated using such a technology. The possibility is that the
present invention is applied to biotechnology.
Embodiment 8
[0311] When video data generated in the video coding method or by
the video coding apparatus described in each of Embodiments is
decoded, compared to when video data that conforms to a
conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1 is
decoded, the processing amount probably increases. Thus, the LSI
ex500 needs to be set to a driving frequency higher than that of
the CPU ex502 to be used when video data in conformity with the
conventional standard is decoded. However, when the driving
frequency is set higher, there is a problem that the power
consumption increases.
[0312] In order to solve the problem, the video decoding apparatus,
such as the television ex300 and the LSI ex500 is configured to
determine to which standard the video data conforms, and switch
between the driving frequencies according to the determined
standard. FIG. 37 illustrates a configuration ex800 in Embodiment
8. A driving frequency switching unit ex803 sets a driving
frequency to a higher driving frequency when video data is
generated by the video coding method or the video coding apparatus
described in each of Embodiments. Then, the driving frequency
switching unit ex803 instructs a decoding processing unit ex801
that executes the video decoding method described in each of
Embodiments to decode the video data. When the video data conforms
to the conventional standard, the driving frequency switching unit
ex803 sets a driving frequency to a lower driving frequency than
that of the video data generated by the video coding method or the
video coding apparatus described in each of Embodiments. Then, the
driving frequency switching unit ex803 instructs the decoding
processing unit ex802 that conforms to the conventional standard to
decode the video data.
[0313] More specifically, the driving frequency switching unit
ex803 includes the CPU ex502 and the driving frequency control unit
ex512 in FIG. 36. Here, each of the decoding processing unit ex801
that executes the video decoding method described in each of
Embodiments and the decoding processing unit ex802 that conforms to
the conventional standard corresponds to the signal processing unit
ex507 in FIG. 34. The CPU ex502 determines to which standard the
video data conforms. Then, the driving frequency control unit ex512
determines a driving frequency based on a signal from the CPU
ex502. Furthermore, the signal processing unit ex507 decodes the
video data based on the signal from the CPU ex502. For example, the
identification information described in Embodiment 6 is probably
used for identifying the video data. The identification information
is not limited to the one described in Embodiment 6 but may be any
information as long as the information indicates to which standard
the video data conforms. For example, when which standard video
data conforms to can be determined based on an external signal for
determining that the video data is used for a television or a disk,
etc., the determination may be made based on such an external
signal. Furthermore, the CPU ex502 selects a driving frequency
based on, for example, a look-up table in which the standards of
the video data are associated with the driving frequencies as shown
in FIG. 39. The driving frequency can be selected by storing the
look-up table in the buffer ex508 and in an internal memory of an
LSI, and with reference to the look-up table by the CPU ex502.
[0314] FIG. 38 illustrates steps for executing a method in
Embodiment 8. First, in Step exS200, the signal processing unit
ex507 obtains identification information from the multiplexed data.
Next, in Step exS201, the CPU ex502 determines whether or not the
video data is generated by the coding method and the coding
apparatus described in each of Embodiments, based on the
identification information. When the video data is generated by the
video coding method and the video coding apparatus described in
each of Embodiments, in Step exS202, the CPU ex502 transmits a
signal for setting the driving frequency to a higher driving
frequency to the driving frequency control unit ex512. Then, the
driving frequency control unit ex512 sets the driving frequency to
the higher driving frequency. On the other hand, when the
identification information indicates that the video data conforms
to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1,
in Step exS203, the CPU ex502 transmits a signal for setting the
driving frequency to a lower driving frequency to the driving
frequency control unit ex512. Then, the driving frequency control
unit ex512 sets the driving frequency to the lower driving
frequency than that in the case where the video data is generated
by the video coding method and the video coding apparatus described
in each of Embodiment.
[0315] Furthermore, along with the switching of the driving
frequencies, the power conservation effect can be improved by
changing the voltage to be applied to the LSI ex500 or an apparatus
including the LSI ex500. For example, when the driving frequency is
set lower, the voltage to be applied to the LSI ex500 or the
apparatus including the LSI ex500 is probably set to a voltage
lower than that in the case where the driving frequency is set
higher.
[0316] Furthermore, when the processing amount for decoding is
larger, the driving frequency may be set higher, and when the
processing amount for decoding is smaller, the driving frequency
may be set lower as the method for setting the driving frequency.
Thus, the setting method is not limited to the ones described
above. For example, when the processing amount for decoding video
data in conformity with MPEG4-AVC is larger than the processing
amount for decoding video data generated by the video coding method
and the video coding apparatus described in each of Embodiments,
the driving frequency is probably set in reverse order to the
setting described above.
[0317] Furthermore, the method for setting the driving frequency is
not limited to the method for setting the driving frequency lower.
For example, when the identification information indicates that the
video data is generated by the video coding method and the video
coding apparatus described in each of Embodiments, the voltage to
be applied to the LSI ex500 or the apparatus including the LSI
ex500 is probably set higher. When the identification information
indicates that the video data conforms to the conventional
standard, such as MPEG-2, MPEG4-AVC, and VC-1, the voltage to be
applied to the LSI ex500 or the apparatus including the LSI ex500
is probably set lower. As another example, when the identification
information indicates that the video data is generated by the video
coding method and the video coding apparatus described in each of
Embodiments, the driving of the CPU ex502 does not probably have to
be suspended. When the identification information indicates that
the video data conforms to the conventional standard, such as
MPEG-2, MPEG4-AVC, and VC-1, the driving of the CPU ex502 is
probably suspended at a given time because the CPU ex502 has extra
processing capacity. Even when the identification information
indicates that the video data is generated by the video coding
method and the video coding apparatus described in each of
Embodiments, in the case where the CPU ex502 has extra processing
capacity, the driving of the CPU ex502 is probably suspended at a
given time. In such a case, the suspending time is probably set
shorter than that in the case where when the identification
information indicates that the video data conforms to the
conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1.
[0318] Accordingly, the power conservation effect can be improved
by switching between the driving frequencies in accordance with the
standard to which the video data conforms. Furthermore, when the
LSI ex500 or the apparatus including the LSI ex500 is driven using
a battery, the battery life can be extended with the power
conservation effect.
Embodiment 9
[0319] There are cases where a plurality of video data that
conforms to different standards, is provided to the devices and
systems, such as a television and a mobile phone. In order to
enable decoding the plurality of video data that conforms to the
different standards, the signal processing unit ex507 of the LSI
ex500 needs to conform to the different standards. However, the
problems of increase in the scale of the circuit of the LSI ex500
and increase in the cost arise with the individual use of the
signal processing units ex507 that conform to the respective
standards.
[0320] In order to solve the problem, what is conceived is a
configuration in which the decoding processing unit for
implementing the video decoding method described in each of
[0321] Embodiments and the decoding processing unit that conforms
to the conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1
are partly shared. Ex900 in FIG. 40A shows an example of the
configuration. For example, the video decoding method described in
each of Embodiments and the video decoding method that conforms to
MPEG4-AVC have, partly in common, the details of processing, such
as entropy coding, inverse quantization, deblocking filtering, and
motion compensated prediction. The details of processing to be
shared probably includes use of a decoding processing unit ex902
that conforms to MPEG4-AVC. In contrast, a dedicated decoding
processing unit ex901 is probably used for other processing unique
to the present invention. Since the present invention is
characterized by a transformation unit in particular, for example,
the dedicated decoding processing unit ex901 is used for inverse
transform. Otherwise, the decoding processing unit is probably
shared for one of the entropy coding, inverse quantization,
deblocking filtering, and motion compensated prediction, or all of
the processing. The decoding processing unit for implementing the
video decoding method described in each of Embodiments may be
shared for the processing to be shared, and a dedicated decoding
processing unit may be used for processing unique to that of
MPEG4-AVC.
[0322] Furthermore, ex1000 in FIG. 40B shows another example in
that processing is partly shared. This example uses a configuration
including a dedicated decoding processing unit ex1001 that supports
the processing unique to the present invention, a dedicated
decoding processing unit ex1002 that supports the processing unique
to another conventional standard, and a decoding processing unit
ex1003 that supports processing to be shared between the video
decoding method in the present invention and the conventional video
decoding method. Here, the dedicated decoding processing units
ex1001 and ex1002 are not necessarily specialized for the
processing of the present invention and the processing of the
conventional standard, respectively, and may be the ones capable of
implementing general processing. Furthermore, the configuration of
Embodiment 9 can be implemented by the LSI ex500.
[0323] As such, reducing the scale of the circuit of an LSI and
reducing the cost are possible by sharing the decoding processing
unit for the processing to be shared between the video decoding
method in the present invention and the video decoding method in
conformity with the conventional standard.
INDUSTRIAL APPLICABILITY
[0324] The present invention is applicable to a coding apparatus
which codes audio, still images, and video and to a decoding
apparatus which decodes data coded by the coding apparatus. For
example, the present invention is applicable to various
audio-visual devices such as audio devices, cellular phones,
digital cameras, BD recorders, and digital televisions.
* * * * *