U.S. patent application number 16/904695 was filed with the patent office on 2020-12-10 for methods and apparatus for adaptive motion vector candidate ordering for video encoding and decoding.
The applicant listed for this patent is INTERDIGITAL VC HOLDINGS, INC.. Invention is credited to Liwei GUO, Xiaoan LU, Joel SOLE, Qian XU, Peng YIN, Yunfei ZHENG.
Application Number | 20200389664 16/904695 |
Document ID | / |
Family ID | 1000005049967 |
Filed Date | 2020-12-10 |
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United States Patent
Application |
20200389664 |
Kind Code |
A1 |
GUO; Liwei ; et al. |
December 10, 2020 |
METHODS AND APPARATUS FOR ADAPTIVE MOTION VECTOR CANDIDATE ORDERING
FOR VIDEO ENCODING AND DECODING
Abstract
Methods and apparatus are provided for adaptive motion vector
candidate ordering for video encoding and decoding. An apparatus
includes a video encoder (100) for encoding a block in a picture by
selecting an order of motion vector predictor candidates for the
block responsive to a characteristic available at both the video
encoder and a corresponding decoder. The characteristic excludes a
mode in which the block is partitioned.
Inventors: |
GUO; Liwei; (San Diego,
CA) ; YIN; Peng; (Ithaca, NY) ; ZHENG;
Yunfei; (San Jose, CA) ; SOLE; Joel; (San
Diego, CA) ; XU; Qian; (Folsom, CA) ; LU;
Xiaoan; (Princeton, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTERDIGITAL VC HOLDINGS, INC. |
Wilmington |
DE |
US |
|
|
Family ID: |
1000005049967 |
Appl. No.: |
16/904695 |
Filed: |
June 18, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16006914 |
Jun 13, 2018 |
10721490 |
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16904695 |
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15295354 |
Oct 17, 2016 |
10021412 |
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16006914 |
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13698468 |
Nov 16, 2012 |
9510009 |
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15295354 |
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PCT/US2011/036770 |
May 17, 2011 |
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13698468 |
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61346539 |
May 20, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N 19/52 20141101;
H04N 19/139 20141101; H04N 19/70 20141101; H04N 19/44 20141101;
H04N 19/567 20141101 |
International
Class: |
H04N 19/52 20060101
H04N019/52; H04N 19/139 20060101 H04N019/139; H04N 19/70 20060101
H04N019/70; H04N 19/44 20060101 H04N019/44; H04N 19/567 20060101
H04N019/567 |
Claims
1. A video encoder, comprising: a processor; and a memory wherein
the processor is configured to: encode a block in a picture by
selecting an order of motion vector predictor candidates for the
block, based on common information available at both the encoder
and a corresponding decoder, wherein said common information
comprise a reference frame index of the motion vector predictor
candidates which is not transmitted in an encoded bitstream, and
wherein candidates with higher frequency have smaller index.
2. The apparatus of claim 1, wherein a category classification is
performed to determine one of a plurality of categories to which
the block belongs, and the motion vector candidate selection
frequency is determined from the number of already encoded blocks
that belong to the same one of the plurality of categories as the
block.
3. The apparatus of claim 2, wherein a criterion for the category
classification is a block prediction type.
4. The apparatus of claim 2, wherein a criterion for the category
classification is a block partition type.
5. The apparatus of claim 2, wherein a criterion for the category
classification is a block location.
6. The apparatus of claim 1, wherein the consistency is a function
of a difference between the motion vector predictor candidates that
are available at both the video encoder and the corresponding
decoder.
7. The apparatus of claim 1, wherein the fidelity is a function of
corresponding reconstructed residue coefficients which are
available at both the video encoder and the corresponding
decoder.
8. The apparatus of claim 1, wherein the motion vector predictor
candidates comprise a first motion vector predictor candidate for a
first component of a motion vector and a second motion vector
predictor candidate for a second component of the motion vector,
and an order of the second motion vector predictor candidate for
the second component is adapted responsive to a predictor index of
the first component.
9. In a video encoder, a method, comprising: encoding a block in a
picture by selecting an order of motion vector predictor candidates
for the block, based on common information available at both the
encoder and a corresponding decoder, wherein said common
information comprise a reference frame index of the motion vector
predictor candidates which is not transmitted in an encoded
bitstream, and wherein candidates with higher frequency have
smaller index.
10. The method of claim 9, wherein a category classification is
performed to determine one of a plurality of categories to which
the block belongs, and the motion vector candidate selection
frequency is determined from the number of already encoded blocks
that belong to the same one of the plurality of categories as the
block (520).
11. The method of claim 10, wherein a criterion for the category
classification is a block prediction type (515).
12. The method of claim 10, wherein a criterion for the category
classification is a block partition type (515).
13. The method of claim 10, wherein a criterion for the category
classification is a block location (515).
14. The method of claim 9, wherein the consistency is a function of
a difference between the motion vector predictor candidates that
are available at both the video encoder and the corresponding
decoder.
15. The method of claim 9, wherein the fidelity is a function of
corresponding reconstructed residue coefficients which are
available at both the video encoder and the corresponding
decoder.
16. The method of claim 9, wherein the motion vector predictor
candidates comprise a first motion vector predictor candidate for a
first component of a motion vector and a second motion vector
predictor candidate for a second component of the motion vector,
and an order of the second motion vector predictor candidate for
the second component is adapted responsive to a predictor index of
the first component (1325).
17. A video decoder, comprising: a processor; and a memory wherein
the processor is configured to: decode a block in a picture by
selecting an order of motion vector predictor candidates for the
block, based on common information available at both the encoder
and a corresponding decoder, wherein said common information
comprise a reference frame index of the motion vector predictor
candidates which is not transmitted in an encoded bitstream, and
wherein candidates with higher frequency have smaller index.
18. The apparatus of claim 17, wherein a category classification is
performed to determine one of a plurality of categories to which
the block belongs, and the motion vector candidate selection
frequency is determined from the number of already encoded blocks
that belong to the same one of the plurality of categories as the
block.
19. The apparatus of claim 18, wherein a criterion for the category
classification is a block prediction type.
20. The apparatus of claim 18, wherein a criterion for the category
classification is a block partition type.
21. The apparatus of claim 18, wherein a criterion for the category
classification is a block location.
22. The apparatus of claim 17, wherein the consistency is a
function of a difference between the motion vector predictor
candidates that are available at both the video decoder and the
corresponding encoder.
23. The apparatus of claim 17, wherein the fidelity is a function
of corresponding reconstructed residue coefficients which are
available at both the video decoder and the corresponding
encoder.
24. The apparatus of claim 17, wherein the motion vector predictor
candidates comprise a first motion vector predictor candidate for a
first component of a motion vector and a second motion vector
predictor candidate for a second component of the motion vector,
and an order of the second motion vector predictor candidate for
the second component is adapted responsive to a predictor index of
the first component.
25. In a video decoder, a method, comprising: decoding a block in a
picture by selecting an order of motion vector predictor candidates
for the block, based on common information available at both the
encoder and a corresponding decoder, wherein said common
information comprise a reference frame index of the motion vector
predictor candidates which is not transmitted in an encoded
bitstream, and wherein candidates with higher frequency have
smaller index.
26. The method of claim 25, wherein a category classification is
performed to determine one of a plurality of categories to which
the block belongs, and the motion vector candidate selection
frequency is determined from the number of already encoded blocks
that belong to the same one of the plurality of categories as the
block (625).
27. The method of claim 26, wherein a criterion for the category
classification is a block prediction type (620).
28. The method of claim 26, wherein a criterion for the category
classification is a block partition type (620).
29. The method of claim 26, wherein a criterion for the category
classification is a block location (620).
30. The method of claim 25, wherein the consistency is a function
of a difference between the motion vector predictor candidates that
are available at both the video decoder and the corresponding
encoder.
31. The method of claim 25, wherein the fidelity is a function of
corresponding reconstructed residue coefficients which are
available at both the video decoder and the corresponding
encoder.
32. The method of claim 25, wherein the motion vector predictor
candidates comprise a first motion vector predictor candidate for a
first component of a motion vector and a second motion vector
predictor candidate for a second component of the motion vector,
and an order of the second motion vector predictor candidate for
the second component is adapted responsive to a predictor index of
the first component (1425).
33. A non-transitory computer readable tangible media having a
signal stored thereon comprising: a block in a picture by selecting
an order of motion vector predictor candidates for the block, based
on common information available at both the encoder and a
corresponding decoder, wherein said common information comprise a
reference frame index of the motion vector predictor candidates
which is not transmitted in an encoded bitstream, and wherein
candidates with higher frequency have smaller index.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 13/698468, filed Nov. 16, 2012 which claims the benefit of
International Patent Application PCT/US2011/036770, filed May 17,
2011 and U.S. Provisional Application Ser. No. 61/346,539, filed
May 20, 2010, which are incorporated by reference herein in its
entirety.
TECHNICAL FIELD
[0002] The present principles relate generally to video encoding
and decoding and, more particularly, to methods and apparatus for
adaptive motion vector candidate ordering for video encoding and
decoding.
BACKGROUND
[0003] Motion estimation and compensation are widely used in video
compression to exploit the temporal redundancy included in a video
sequence. Motion information is typically included in motion
vectors. A motion vector is the displacement between the current
block and its temporal correspondence in the reference frame(s).
Such motion information is transmitted, conveyed, and/or otherwise
delivered to the decoder as overhead. To reduce the overhead bits
used for motion information, various predictive coding approaches
are used to encode the motion vector of each block by exploiting
the correlations among neighboring motion vectors.
[0004] In the current state of the art video coding standard,
namely the International Organization for
Standardization/International Electrotechnical Commission (ISO/IEC)
Moving Picture Experts Group-4 (MPEG-4) Part 10 Advanced Video
Coding (AVC) Standard/International Telecommunication Union,
Telecommunication Sector (ITU-T) H.264 Recommendation (hereinafter
the "MPEG-4 AVC Standard"), a motion vector is predicted by the
median of its spatial causal neighboring motion vectors.
[0005] In a first prior art approach, the motion vector predictor
selection procedure is incorporated into the rate-distortion
optimization of a coding block, which is called motion vector
competition (MVComp). In MVComp, a coding block has a set of motion
vector predictor candidates. This candidate set is composed of
motion vectors of spatially or temporally neighboring blocks. The
best motion vector predictor will be selected from the candidate
set based on the rate-distortion optimization. The index of the
motion vector predictor in the set will be explicitly transmitted
to the decoder if the set has more than one candidate. However,
transmitting this index may disadvantageously consume a lot of
bits.
SUMMARY
[0006] These and other drawbacks and disadvantages of the prior art
are addressed by the present principles, which are directed to
methods and apparatus for adaptive motion vector candidate ordering
for video encoding and decoding.
[0007] According to an aspect of the present principles, there is
provided an apparatus. The apparatus includes a video encoder for
encoding a block in a picture by selecting an order of motion
vector predictor candidates for the block responsive to a
characteristic available at both the video encoder and a
corresponding decoder. The characteristic excludes a mode in which
the block is partitioned.
[0008] According to another aspect of the present principles, there
is provided a method in a video encoder. The method includes
encoding a block in a picture by selecting an order of motion
vector predictor candidates for the block responsive to a
characteristic available at both the video encoder and a
corresponding decoder. The characteristic excludes a mode in which
the block is partitioned.
[0009] According to still another aspect of the present principles,
there is provided an apparatus. The apparatus includes a video
decoder for decoding a block in a picture by selecting an order of
motion vector predictor candidates for the block responsive to a
characteristic available at both the video decoder and a
corresponding encoder. The characteristic excludes a mode in which
the block is partitioned.
[0010] According to a further aspect of the present principles,
there is provided a method in a video decoder. The method includes
decoding a block in a picture by selecting an order of motion
vector predictor candidates for the block responsive to a
characteristic available at both the video decoder and a
corresponding encoder. The characteristic excludes a mode in which
the block is partitioned.
[0011] These and other aspects, features and advantages of the
present principles will become apparent from the following detailed
description of exemplary embodiments, which is to be read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present principles may be better understood in
accordance with the following exemplary figures, in which:
[0013] FIG. 1 is a block diagram showing an exemplary video encoder
to which the present principles may be applied, in accordance with
an embodiment of the present principles;
[0014] FIG. 2 is a block diagram showing an exemplary video decoder
to which the present principles may be applied, in accordance with
an embodiment of the present principles;
[0015] FIG. 3 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video encoder, in
accordance with an embodiment of the present principles;
[0016] FIG. 4 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video decoder, in
accordance with an embodiment of the present principles;
[0017] FIG. 5 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video encoder, in
accordance with an embodiment of the present principles;
[0018] FIG. 6 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video decoder, in
accordance with an embodiment of the present principles;
[0019] FIG. 7 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video encoder, in
accordance with an embodiment of the present principles;
[0020] FIG. 8 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video decoder, in
accordance with an embodiment of the present principles;
[0021] FIG. 9 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video encoder, in
accordance with an embodiment of the present principles;
[0022] FIG. 10 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video decoder, in
accordance with an embodiment of the present principles;
[0023] FIG. 11 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video encoder, in
accordance with an embodiment of the present principles;
[0024] FIG. 12 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video decoder, in
accordance with an embodiment of the present principles;
[0025] FIG. 13 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video encoder, in
accordance with an embodiment of the present principles; and
[0026] FIG. 14 is a flow diagram showing an exemplary method for
adaptive motion vector candidate ordering at a video decoder, in
accordance with an embodiment of the present principles.
DETAILED DESCRIPTION
[0027] The present principles are directed to methods and apparatus
for adaptive motion vector candidate ordering for video encoding
and decoding.
[0028] The present description illustrates the present principles.
It will thus be appreciated that those skilled in the art will be
able to devise various arrangements that, although not explicitly
described or shown herein, embody the present principles and are
included within its spirit and scope.
[0029] All examples and conditional language recited herein are
intended for pedagogical purposes to aid the reader in
understanding the present principles and the concepts contributed
by the inventor(s) to furthering the art, and are to be construed
as being without limitation to such specifically recited examples
and conditions.
[0030] Moreover, all statements herein reciting principles,
aspects, and embodiments of the present principles, as well as
specific examples thereof, are intended to encompass both
structural and functional equivalents thereof. Additionally, it is
intended that such equivalents include both currently known
equivalents as well as equivalents developed in the future, i.e.,
any elements developed that perform the same function, regardless
of structure.
[0031] Thus, for example, it will be appreciated by those skilled
in the art that the block diagrams presented herein represent
conceptual views of illustrative circuitry embodying the present
principles. Similarly, it will be appreciated that any flow charts,
flow diagrams, state transition diagrams, pseudocode, and the like
represent various processes which may be substantially represented
in computer readable media and so executed by a computer or
processor, whether or not such computer or processor is explicitly
shown.
[0032] The functions of the various elements shown in the figures
may be provided through the use of dedicated hardware as well as
hardware capable of executing software in association with
appropriate software. When provided by a processor, the functions
may be provided by a single dedicated processor, by a single shared
processor, or by a plurality of individual processors, some of
which may be shared. Moreover, explicit use of the term "processor"
or "controller" should not be construed to refer exclusively to
hardware capable of executing software, and may implicitly include,
without limitation, digital signal processor ("DSP") hardware,
read-only memory ("ROM") for storing software, random access memory
("RAM"), and non-volatile storage.
[0033] Other hardware, conventional and/or custom, may also be
included. Similarly, any switches shown in the figures are
conceptual only. Their function may be carried out through the
operation of program logic, through dedicated logic, through the
interaction of program control and dedicated logic, or even
manually, the particular technique being selectable by the
implementer as more specifically understood from the context.
[0034] In the claims hereof, any element expressed as a means for
performing a specified function is intended to encompass any way of
performing that function including, for example, a) a combination
of circuit elements that performs that function or b) software in
any form, including, therefore, firmware, microcode or the like,
combined with appropriate circuitry for executing that software to
perform the function. The present principles as defined by such
claims reside in the fact that the functionalities provided by the
various recited means are combined and brought together in the
manner which the claims call for. It is thus regarded that any
means that can provide those functionalities are equivalent to
those shown herein.
[0035] Reference in the specification to "one embodiment" or "an
embodiment" of the present principles, as well as other variations
thereof, means that a particular feature, structure,
characteristic, and so forth described in connection with the
embodiment is included in at least one embodiment of the present
principles. Thus, the appearances of the phrase "in one embodiment"
or "in an embodiment", as well any other variations, appearing in
various places throughout the specification are not necessarily all
referring to the same embodiment.
[0036] It is to be appreciated that the use of any of the following
"/", "and/or", and "at least one of", for example, in the cases of
"A/B", "A and/or B" and "at least one of A and B", is intended to
encompass the selection of the first listed option (A) only, or the
selection of the second listed option (B) only, or the selection of
both options (A and B). As a further example, in the cases of "A,
B, and/or C" and "at least one of A, B, and C", such phrasing is
intended to encompass the selection of the first listed option (A)
only, or the selection of the second listed option (B) only, or the
selection of the third listed option (C) only, or the selection of
the first and the second listed options (A and B) only, or the
selection of the first and third listed options (A and C) only, or
the selection of the second and third listed options (B and C)
only, or the selection of all three options (A and B and C). This
may be extended, as readily apparent by one of ordinary skill in
this and related arts, for as many items listed.
[0037] Also, as used herein, the words "picture" and "image" are
used interchangeably and refer to a still image or a picture from a
video sequence. As is known, a picture may be a frame or a
field.
[0038] Additionally, as used herein, the phrase "motion vector
competition" refers to the adaptive selection of the order of
motion vector candidates to be used as predictors. Such motion
vector competition can be performed at the encoder side and/or the
decoder side. According to the present principles, it is to be
appreciated that the order of the motion vector candidates is
adaptable responsive to some common characteristics available at
both the encoder and decoder. Exemplary characteristics will be
disclosed and described later herein.
[0039] Moreover, as used herein, the phrase "consistency of the
motion vectors" refers to the similarity between the motion
vectors. Such similarity can be judged, for example, responsive to
one or more criterion as specified herein as well as readily
contemplated by one of skill in this and related arts, given the
teachings of the present principles provided herein.
[0040] Further, as used herein, the phrase "block prediction type"
refers to a prediction type used to classify one or more blocks
under consideration for the purposes of the present principles.
Also, as used herein, the phrase "block partition type" refers to a
partition type used to classify one or more blocks under
consideration for the purposes of the present principles.
Additionally, as used herein, the phrase "block location" refers to
a location of one or more blocks under consideration for the
purposes of the present principles. For example, the blocks may
pertain to, e.g., one or more slices, one or more pictures, and so
forth. Such blocks may be in the same slice or picture as the
current block being encoded or decoded, or may be in neighboring
slices or pictures.
[0041] For purposes of illustration and description, examples are
described herein in the context of improvements over the MPEG-4 AVC
Standard, using the MPEG-4 AVC Standard as the baseline for our
description and explaining the improvements and extensions beyond
the MPEG-4 AVC Standard. However, it is to be appreciated that the
present principles are not limited solely to the MPEG-4 AVC
Standard and/or extensions thereof. Given the teachings of the
present principles provided herein, one of ordinary skill in this
and related arts would readily understand that the present
principles are equally applicable and would provide at least
similar benefits when applied to extensions of other standards, or
when applied and/or incorporated within standards not yet
developed. That is, it would be readily apparent to those skilled
in the art that other standards may be used as a starting point to
describe the present principles and their new and novel elements as
changes and advances beyond that standard or any other. It is to be
further appreciated that the present principles also apply to video
encoders and video decoders that do not conform to standards, but
rather confirm to proprietary definitions.
[0042] Turning to FIG. 1, an exemplary video encoder to which the
present principles may be applied is indicated generally by the
reference numeral 100. The video encoder 100 includes a frame
ordering buffer 110 having an output in signal communication with a
non-inverting input of a combiner 185. An output of the combiner
185 is connected in signal communication with a first input of a
transformer and quantizer 125. An output of the transformer and
quantizer 125 is connected in signal communication with a first
input of an entropy coder 145 and a first input of an inverse
transformer and inverse quantizer 150. An output of the entropy
coder 145 is connected in signal communication with a first
non-inverting input of a combiner 190. An output of the combiner
190 is connected in signal communication with a first input of an
output buffer 135.
[0043] A first output of an encoder controller 105 is connected in
signal communication with a second input of the frame ordering
buffer 110, a second input of the inverse transformer and inverse
quantizer 150, an input of a picture-type decision module 115, a
first input of a macroblock-type (MB-type) decision module 120, a
second input of an intra prediction module 160, a second input of a
deblocking filter 165, a first input of a motion compensator 170, a
first input of a motion estimator 175, and a second input of a
reference picture buffer 180.
[0044] A second output of the encoder controller 105 is connected
in signal communication with a first input of a Supplemental
Enhancement Information (SEI) inserter 130, a second input of the
transformer and quantizer 125, a second input of the entropy coder
145, a second input of the output buffer 135, and an input of the
Sequence Parameter Set (SPS) and Picture Parameter Set (PPS)
inserter 140.
[0045] An output of the SEI inserter 130 is connected in signal
communication with a second non-inverting input of the combiner
190.
[0046] A first output of the picture-type decision module 115 is
connected in signal communication with a third input of the frame
ordering buffer 110. A second output of the picture-type decision
module 115 is connected in signal communication with a second input
of a macroblock-type decision module 120.
[0047] An output of the Sequence Parameter Set (SPS) and Picture
Parameter Set (PPS) inserter 140 is connected in signal
communication with a third non-inverting input of the combiner
190.
[0048] An output of the inverse quantizer and inverse transformer
150 is connected in signal communication with a first non-inverting
input of a combiner 119. An output of the combiner 119 is connected
in signal communication with a first input of the intra prediction
module 160 and a first input of the deblocking filter 165. An
output of the deblocking filter 165 is connected in signal
communication with a first input of a reference picture buffer 180.
An output of the reference picture buffer 180 is connected in
signal communication with a second input of the motion estimator
175 and a third input of the motion compensator 170. A first output
of the motion estimator 175 is connected in signal communication
with a second input of the motion compensator 170. A second output
of the motion estimator 175 is connected in signal communication
with a third input of the entropy coder 145.
[0049] An output of the motion compensator 170 is connected in
signal communication with a first input of a switch 197. An output
of the intra prediction module 160 is connected in signal
communication with a second input of the switch 197. An output of
the macroblock-type decision module 120 is connected in signal
communication with a third input of the switch 197. The third input
of the switch 197 determines whether or not the "data" input of the
switch (as compared to the control input, i.e., the third input) is
to be provided by the motion compensator 170 or the intra
prediction module 160. The output of the switch 197 is connected in
signal communication with a second non-inverting input of the
combiner 119 and an inverting input of the combiner 185.
[0050] A first input of the frame ordering buffer 110 and an input
of the encoder controller 105 are available as inputs of the
encoder 100, for receiving an input picture. Moreover, a second
input of the Supplemental Enhancement Information (SEI) inserter
130 is available as an input of the encoder 100, for receiving
metadata. An output of the output buffer 135 is available as an
output of the encoder 100, for outputting a bitstream.
[0051] Turning to FIG. 2, an exemplary video decoder to which the
present principles may be applied is indicated generally by the
reference numeral 200. The video decoder 200 includes an input
buffer 210 having an output connected in signal communication with
a first input of an entropy decoder 245. A first output of the
entropy decoder 245 is connected in signal communication with a
first input of an inverse transformer and inverse quantizer 250. An
output of the inverse transformer and inverse quantizer 250 is
connected in signal communication with a second non-inverting input
of a combiner 225. An output of the combiner 225 is connected in
signal communication with a second input of a deblocking filter 265
and a first input of an intra prediction module 260. A second
output of the deblocking filter 265 is connected in signal
communication with a first input of a reference picture buffer 280.
An output of the reference picture buffer 280 is connected in
signal communication with a second input of a motion compensator
270.
[0052] A second output of the entropy decoder 245 is connected in
signal communication with a third input of the motion compensator
270, a first input of the deblocking filter 265, and a third input
of the intra predictor 260. A third output of the entropy decoder
245 is connected in signal communication with an input of a decoder
controller 205. A first output of the decoder controller 205 is
connected in signal communication with a second input of the
entropy decoder 245. A second output of the decoder controller 205
is connected in signal communication with a second input of the
inverse transformer and inverse quantizer 250. A third output of
the decoder controller 205 is connected in signal communication
with a third input of the deblocking filter 265. A fourth output of
the decoder controller 205 is connected in signal communication
with a second input of the intra prediction module 260, a first
input of the motion compensator 270, and a second input of the
reference picture buffer 280.
[0053] An output of the motion compensator 270 is connected in
signal communication with a first input of a switch 297. An output
of the intra prediction module 260 is connected in signal
communication with a second input of the switch 297. An output of
the switch 297 is connected in signal communication with a first
non-inverting input of the combiner 225.
[0054] An input of the input buffer 210 is available as an input of
the decoder 200, for receiving an input bitstream. A first output
of the deblocking filter 265 is available as an output of the
decoder 200, for outputting an output picture.
[0055] As noted above, the present principles are directed to
methods and apparatus for adaptive motion vector candidate ordering
for video encoding and decoding. In a second prior art approach,
the order of motion vector predictor candidates is adjusted based
on the current prediction mode to place the most probable motion
predictor in the first position. We have noticed that the method
described in the second prior art approach utilizes only very
limited information, i.e., the prediction mode of the current
block. The prediction mode refers to the manner in which a block is
partitioned. We have recognized the limitations inherent in the
second prior art approach, namely, limiting the ordering based on
the manner in which a block is partitioned. Advantageously and in
accordance with the present principles, we have developed methods
and apparatus for using more readily available information to
determine the order of motion vector candidates such that the
motion vector predictor that is more frequently selected tends to
have a smaller index and, thus, the overhead bits for the motion
vector predictor index can be reduced.
[0056] Thus, in accordance with the present principles, we provide
an adaptive motion vector competition scheme (that is, a motion
vector ordering scheme), where the order of motion vector predictor
candidates is adaptively determined based on some common
information available at both the encoder and the decoder. In one
or more embodiments, the common information includes, but is not
limited to, one or more of the following: the selection frequency
of the motion vector predictor candidates in the already encoded
blocks; the block type of the current block; the consistency of the
motion vector predictor candidates; the fidelity of the motion
vector predictor candidates; the reference index of the motion
vector predictor candidates; and the predictor index of the first
motion vector component.
[0057] In an embodiment utilizing adaptive ordering, smaller
indices are assigned to the motion vector predictors that tend to
be more frequently selected and, thus, the overhead bits for the
motion vector predictor index can be reduced. That is, we provide
methods and apparatus for performing adaptive motion vector
competition to reduce the overhead bits of conveying the index of
the selected motion vector predictor and improve the coding
efficiency.
[0058] For purposes of clarity and definition, we use the term
motion vector competition to mean that the encoder and decoder
adaptively select the order of motion vector candidates to be used
as predictors. This means that the order is adaptable depending
upon some common characteristic(s) available at both the encoder
and decoder. Some exemplary characteristics are described herein.
The candidates in the motion vector predictor set are motion
vectors of the spatially neighboring blocks (e.g., the left block,
the right block, the top block, the right top block, and so forth),
motion vectors of the temporally neighboring blocks (e.g., the
co-located block(s) in the reference frame(s)), and the function
(e.g., the median value or some other value) of some motion vector
candidates. In addition, candidates may be selected and ordered
that are not in spatially or temporally neighboring blocks, but
rather selected and ordered by some other defining characteristic.
In an embodiment, the order of these candidates in the set is
determined according to some common information available at both
the encoder and the decoder such that the motion vector predictor
that is more frequently selected tends to have a smaller index.
Therefore, the overhead bits for the motion vector predictor index
can be reduced. It should be noted that the adaptive ordering of
the motion vector predictor is equivalent to the adaptive index of
the motion vector predictor and, thereafter, we will use these two
terms interchangeably.
Embodiment 1
[0059] In Embodiment 1, we use the selection frequency of the
motion vector candidates in the already encoded blocks to determine
the order of the motion vector candidates. One example is as
follows: before encoding a block in the current frame, the encoder
collects the frequency of a motion vector predictor candidate being
selected in a number of previously encoded blocks, slices, or
frames. Let MV.sub.i be a motion vector candidate, and f(MV.sub.i)
be the frequency at which that motion vector candidate is selected.
For encoding the current block, we arrange the motion vector
candidates in a descending order of the selection frequency
f(MV.sub.i), i.e., a motion vector candidate with a higher
frequency has a smaller index. The same procedure is applied at the
decoder with information available at the decoder and therefore the
same determination is made at the decoder implicitly, thereby
reducing the required bit overhead.
[0060] Turning to FIG. 3, an exemplary method for adaptive motion
vector candidate ordering at a video encoder is indicated generally
by the reference numeral 300. The method 300 corresponds to
Embodiment 1. The method 300 includes a start block 305 that passes
control to a loop limit block 310. The loop limit block 310 begins
a loop using a variable i having a range from 0 to the num blocks
minusl, and passes control to a function block 315. The function
block 315 sets the order of the motion vector predictor candidates
based on the selection frequency in already encoded blocks from a
number of previous blocks or a number of previous slices or a
number of previous frames, and passes control to a function block
320. The function block 320 performs motion estimation to find the
motion vector of the current block, selects the motion vector
predictor from the candidates, and passes control to a function
block 325. The function block 325 encodes the block, and passes
control to a function block 330. The function block 330 writes the
index of the selected motion vector predictor and other information
into a bitstream, and passes control to a loop limit block 335. The
loop limit block 335 ends the loop, and passes control to an end
block 399.
[0061] Turning to FIG. 4, an exemplary method for adaptive motion
vector candidate ordering at a video decoder is indicated generally
by the reference numeral 400. The method 400 corresponds to
Embodiment 1. The method 400 includes a start block 405 that passes
control to a loop limit block 410. The loop limit block 410 begins
a loop using a variable i having a range from 0 to the num blocks
minusl, and passes control to a function block 415. The function
block 415 sets the order of the motion vector predictor candidates
based on the selection frequency in already encoded blocks from a
number of previous blocks or a number of previous slices or a
number of previous frames, and passes control to a function block
420. The function block 420 decodes the index of the motion vector
predictor and other information from the bitstream, and passes
control to a function block 425. The function block 425 obtains the
motion vector predictor according to the index, reconstructs the
motion vector, reconstructs the block, and passes control to a loop
limit block 430. The loop limit block 430 ends the loop, and passes
control to an end block 499.
Embodiment 2
[0062] In Embodiment 2, we first classify blocks into different
categories. The classification criterion can be the prediction type
of a block (e.g., predictive (P) or bi-predictive (B) type
prediction), the partition type of a block (e.g., partition size),
the location of a block relative to available predictors (e.g., the
nearest available predictor block is often the best candidate, but
is not always so), and so forth. We collect the selection frequency
of the motion vector candidates for the already encoded blocks in
each category. Let MV.sub.i be a motion vector candidate, and
f(MV.sub.i, C.sub.j) be the selection frequency of that motion
vector candidate for category C.sub.j blocks in a number of the
previously encoded blocks, slices or frames. Presuming that the
current block belonging to category C.sub.j, we adjust the motion
vector candidate index according to f(MV.sub.i, C.sub.j).
Specifically, a motion vector candidate MV.sub.k with a higher
frequency f(MV.sub.k, C.sub.j) has a smaller index. The same
procedure is applied at the decoder with information available at
the decoder and, therefore, the same determination is made at the
decoder implicitly, thereby reducing the required bit overhead.
[0063] Turning to FIG. 5, an exemplary method for adaptive motion
vector candidate ordering at a video encoder is indicated generally
by the reference numeral 500. The method 500 corresponds to
Embodiment 2. The method 500 includes a start block 505 that passes
control to a loop limit block 510. The loop limit block 510 begins
a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 515. The
function block 515 obtains the category of the current block based
on block prediction type, block partition type, block location, and
so forth, and passes control to a function block 520. The function
block 520 sets the order of the motion vector predictor candidates
based on the selection frequency in already encoded blocks
belonging to the same category, which are from a number of previous
blocks or a number of previous slices or a number of previous
frames, and passes control to a function block 525. The function
block 525 performs motion estimation to find the motion vector of
the current block, selects the motion vector predictor from the
candidates, and passes control to a function block 530. The
function block 530 encodes the block, and passes control to a
function block 535. The function block 535 writes the index of the
selected motion vector predictor and other information into a
bitstream, and passes control to a loop limit block 540. The loop
limit block 540 ends the loop, and passes control to an end block
599.
[0064] Turning to FIG. 6, an exemplary method for adaptive motion
vector candidate ordering at a video decoder is indicated generally
by the reference numeral 600. The method 600 corresponds to
Embodiment 2. The method 600 includes a start block 605 that passes
control to a loop limit block 610. The loop limit block 610 begins
a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 615. The
function block 615 decodes the syntax of the current block from the
bitstream, and passes control to a function block 620. The function
block 620 obtains the category of the current block based on block
prediction type, block partition type, block location, and so
forth, and passes control to a function block 625. The function
block 625 sets the order of the motion vector predictor candidates
based on the selection frequency in already decoded blocks from a
number of previous blocks or a number of previous slices or a
number of previous frames, and passes control to a function block
630. The function block 630 obtains the motion vector predictor
according to the received motion vector predictor index, and passes
control to a function block 635. The function block 635
reconstructs the motion vector, reconstructs the block, and passes
control to a loop limit block 640. The loop limit block 640 ends
the loop, and passes control to an end block 699.
Embodiment 3
[0065] In Embodiment 3, we first classify the motion vector
candidates of the current block into different categories based on
the consistency of the motion vectors. As noted above, the
consistency of the motion vectors refers to the similarity between
the motion vectors. An example method of grouping motion vectors
based on their consistency (similarity) is as follows: Let C.sub.i
be a group, for any two motion vectors, e.g., MV.sub.a=(MVX.sub.a,
MVY.sub.a) and MV.sub.b=(MVX.sub.b, MVY.sub.b) belonging two this
group, their difference is smaller than a threshold T, i.e.,
|MVX.sub.a-MVX.sub.b|+|MVY.sub.a-MVY.sub.b|<T. Suppose we have N
categories, C.sub.0, C.sub.1, . . . C.sub.N-1. We assign the index
of motion vector predictor in an interleaving manner. An example is
as follows: index 0 to index N-1 are given to the first elements in
C.sub.0 to C.sub.N-1 respectively; index N to index 2N-1 are given
to the second elements in C.sub.0 to C.sub.N-1 respectively; and so
forth. The same procedure is applied at the decoder with
information available at the decoder and therefore the same
determination is made at the decoder implicitly, thereby reducing
the required bit overhead.
[0066] Turning to FIG. 7, an exemplary method for adaptive motion
vector candidate ordering at a video encoder is indicated generally
by the reference numeral 700. The method 700 corresponds to
Embodiment 3. The method 700 includes a start block 705 that passes
control to a loop limit block 710. The loop limit block 710 begins
a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 715. The
function block 715 sets the order of the motion vector predictor
candidates based on their consistency, and passes control to a
function block 720. The function block 720 performs motion
estimation to find the motion vector of the current block, selects
the motion vector predictor from the candidates, and passes control
to a function block 725. The function block 725 encodes the block,
and passes control to a function block 730. The function block 730
writes the index of the selected motion vector predictor and other
information into a bitstream, and passes control to a loop limit
block 735. The loop limit block 735 ends the loop, and passes
control to an end block 799.
[0067] Turning to FIG. 8, an exemplary method for adaptive motion
vector candidate ordering at a video decoder is indicated generally
by the reference numeral 800. The method 800 corresponds to
Embodiment 3. The method 800 includes a start block 805 that passes
control to a loop limit block 810. The loop limit block 810 begins
a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 815. The
function block 815 sets the order of the motion vector predictor
candidates based on their consistency, and passes control to a
function block 820. The function block 820 decodes the index of the
motion vector predictor and other information from the bitstream,
and passes control to a function block 825. The function block 825
obtains the motion vector predictor according to the index,
reconstructs the motion vector, reconstructs the block, and passes
control to a loop limit block 830. The loop limit block 830 ends
the loop, and passes control to an end block 899.
Embodiment 4
[0068] In Embodiment 4, we calculate a fidelity value for each
motion vector candidate of the current block. The fidelity value
reflects the accuracy of the motion vector. One example of
calculating the fidelity value is as follows: Let candidate
MV.sub.1 be the MV from block Blk.sub.i. The fidelity value of
MV.sub.i, F(MV.sub.i) is the function of the reconstructed residue
E.sub.i of block Blk.sub.i, calculated as follows:
F(MV.sub.i)=f(E.sub.i).
[0069] The function should be a decreasing function of residue
E.sub.i, which means a larger residue results in a lower fidelity.
We arrange the motion vector candidates in descending order of the
fidelity value, i.e., a motion vector candidate with a higher
fidelity value F(MV.sub.i) has a smaller index. The same procedure
is applied at the decoder with information available at the decoder
and therefore the same determination is made at the decoder
implicitly, thereby reducing the required bit overhead.
[0070] Turning to FIG. 9, an exemplary method for adaptive motion
vector candidate ordering at a video encoder is indicated generally
by the reference numeral 900. The method 900 corresponds to
Embodiment 4. The method 900 includes a start block 905 that passes
control to a loop limit block 910. The loop limit block 910 begins
a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 915. The
function block 915 sets the order of the motion vector predictor
candidates based on their fidelity, and passes control to a
function block 920. The function block 920 performs motion
estimation to find the motion vector of the current block, selects
the motion vector predictor from the candidates, and passes control
to a function block 925. The function block 925 encodes the block,
and passes control to a function block 930. The function block 930
writes the index of the selected motion vector predictor and other
information into a bitstream, and passes control to a loop limit
block 935. The loop limit block 935 ends the loop, and passes
control to an end block 999.
[0071] Turning to FIG. 10, an exemplary method for adaptive motion
vector candidate ordering at a video decoder is indicated generally
by the reference numeral 1000. The method 1000 corresponds to
Embodiment 4. The method 1000 includes a start block 1005 that
passes control to a loop limit block 1010. The loop limit block
1010 begins a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 1015. The
function block 1015 sets the order of the motion vector predictor
candidates based on their fidelity, and passes control to a
function block 1020. The function block 1020 decodes the index of
the motion vector predictor and other information from the
bitstream, and passes control to a function block 1025. The
function block 1025 obtains the motion vector predictor according
to the index, reconstructs the motion vector, reconstructs the
block, and passes control to a loop limit block 1030. The loop
limit block 1030 ends the loop, and passes control to an end block
1099.
Embodiment 5
[0072] Motion vector candidates are motion vectors of the spatially
or temporal neighboring blocks, and each of them is associated with
a reference frame index. In Embodiment 5, we arrange the order of
the motion vector candidates based on the reference frame index.
One example is as follows: suppose r.sub.c is the reference frame
index of the current block. For a motion vector predictor candidate
MV.sub.i with reference frame index r.sub.i, we calculate its
reference frame difference with respect to the current block,
d.sub.i=abs(r.sub.i-r.sub.c), and arrange the motion vector
candidate in a descending order of the reference frame index
difference d.sub.i. The same procedure is applied at the decoder
with information available at the decoder and therefore the same
determination is made at the decoder implicitly, thereby reducing
the required bit overhead.
[0073] Turning to FIG. 11, an exemplary method for adaptive motion
vector candidate ordering at a video encoder is indicated generally
by the reference numeral 1100. The method 1100 corresponds to
Embodiment 5. The method 1100 includes a start block 1105 that
passes control to a loop limit block 1110. The loop limit block
1110 begins a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 1115. The
function block 1115 sets the order of the motion vector predictor
candidates based on the reference frame index, and passes control
to a function block 1120. The function block 1120 performs motion
estimation to find the motion vector of the current block, selects
the motion vector predictor from the candidates, and passes control
to a function block 1125. The function block 1125 encodes the
block, and passes control to a function block 1130. The function
block 1130 writes the index of the selected motion vector predictor
and other information into a bitstream, and passes control to a
loop limit block 1135. The loop limit block 1135 ends the loop, and
passes control to an end block 1199.
[0074] Turning to FIG. 12, an exemplary method for adaptive motion
vector candidate ordering at a video decoder is indicated generally
by the reference numeral 1200. The method 1200 corresponds to
Embodiment 5. The method 1200 includes a start block 1205 that
passes control to a loop limit block 1210. The loop limit block
1210 begins a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 1215. The
function block 1215 decodes the syntax of the current block from
the bitstream, and passes control to a function block 1220. The
function block 1220 sets the order of the motion vector predictor
candidates based on the reference frame index, and passes control
to a function block 1225. The function block 1225 obtains the
motion vector predictor according to the received index,
reconstructs the motion vector, reconstructs the block, and passes
control to a loop limit block 1230. The loop limit block 1230 ends
the loop, and passes control to an end block 1299.
Embodiment 6
[0075] Motion vector candidate selection (MVComp) can be applied to
each component of a motion vector. Using the motion vector
horizontal component mv_x as an example, such component can have
multiple predictor candidates, which are the horizontal components
of the motion vector of the spatially and temporally neighboring
blocks, and an index idx_x is transmitted to signal which predictor
is used. Similarly, the vertical component mv_y also can have
multiple predictor candidates, and an index idx_y is transmitted.
Suppose idx_x is transmitted before transmitting mv_y. The order of
predictor candidates for mv_y can be adjusted based on the value of
idx_x. One example is as follows: suppose candidate mv_x.sub.i
belonging to mv.sub.i is selected as the predictor of mv_x, and its
index is idx_x.sub.i. Let mv_y.sub.j belonging to mv.sub.j be a
candidate of mv_y. We calculate the difference between mv.sub.j and
mv.sub.i. For example, an mv_y.sub.j with a larger difference will
have a larger index. At the decoder side, the decoder obtains
mv_x.sub.i based on the received idx_x.sub.i. The same procedure is
applied at the decoder with information available at the decoder
and therefore the same determination is made at the decoder
implicitly, thereby reducing the required bit overhead.
[0076] Turning to FIG. 13, an exemplary method for adaptive motion
vector candidate ordering at a video encoder is indicated generally
by the reference numeral 1300. The method 1300 corresponds to
Embodiment 6. The method 1300 includes a start block 1305 that
passes control to a loop limit block 1310. The loop limit block
1310 begins a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 1315. The
function block 1315 performs motion estimation to find the motion
vector (MV) of the current block, and passes control to a function
block 1320. The function block 1320 selects the motion vector
predictor for the first component, and passes control to the
function block 1325. The function block 1325 sets the order of the
motion vector predictor candidates of the second component based on
the predictor of the first component, and passes control to the
function block 1330. The function block 1330 encodes the block, and
passes control to the function block 1335. The function block 1335
writes the predictor index of both motion vector components and
other information into a bitstream, and passes control to a loop
limit block 1340. The loop limit block 1340 ends the loop, and
passes control to an end block 1399.
[0077] Turning to FIG. 14, an exemplary method for adaptive motion
vector candidate ordering at a video decoder is indicated generally
by the reference numeral 1400. The method 1400 corresponds to
Embodiment 6. The method 1400 includes a start block 1405 that
passes control to a loop limit block 1410. The loop limit block
1410 begins a loop using a variable i having a range from 0 to the
num_blocks_minus1, and passes control to a function block 1415. The
function block 1415 decodes the syntax of the current block from
the bitstream, and passes control to a function block 1420. The
function block 1420, with the received predictor index of the first
motion vector component, obtains the motion vector predictor of the
first component, and passes control to a function block 1425. The
function block 1425 sets the order of the motion vector predictor
candidates for the second motion vector components based on the
motion vector predictor of the first component, and passes control
to a function block 1430. The function block 1430, with the
received predictor index of the second motion vector component,
obtains the motion vector predictor of the second component, and
passes control to a function block 1435. The function block 1435
reconstructs the motion vector, reconstructs the block, and passes
control to a loop limit block 1440. The loop limit block 1440 ends
the loop, and passes control to an end block 1499.
Syntax
[0078] TABLE 1 shows exemplary slice header syntax, in accordance
with an embodiment of the present principles.
TABLE-US-00001 TABLE 1 Descriptor slice_header( ) { ...
adaptive_mvp_ordering_flag u(1) ... if (adaptive_mvp_ordering_flag)
{ adaptive_mvp_ordering_mode u(v) } ... }
[0079] The semantics of the syntax elements shown in TABLE 1 are as
follows:
[0080] adaptive_mvp_ordering_flag specifies whether adaptive motion
vector competition is used. adaptive_mvp_ordering_flag equal to 1
means adaptive ordering is used for motion vector competition.
adaptive_mvp_ordering_flag equal to 0 means adaptive ordering is
not used for motion vector competition
[0081] adaptive_mvp_ordering_mode specifies the adaptive ordering
method used for this slice. adaptive_mvp_ordering_mode=0 indicates
that adaptive ordering based on the selection frequency of motion
vector candidate in the already encoded blocks is used (an example
method is given in Embodiment 1). adaptive_mvp_ordering_mode=1
indicates that adaptive ordering based on the selection frequency
of motion vector candidate in the already encoded blocks belonging
to the same category as the current block is used (an example
method is given in Embodiment 2). adaptive_mvp_ordering_mode=2
indicates that adaptive ordering based on the consistency of motion
vector predictor candidates is used (an example method is given in
Embodiment 3). adaptive_mvp_ordering_mode=3 indicates that adaptive
ordering based on the fidelity of motion vector predictor
candidates is used (an example method is given in Embodiment 4).
adaptive_mvp_ordering_mode=4 indicates that adaptive ordering based
on the reference frame index of motion vector predictor candidates
is used (an example method is given in Embodiment 5).
adaptive_mvp_ordering_mode=5 indicates that each motion vector
component has its own predictor index, and the predictor candidates
ordering of the second component is adapted on the received
predictor index of the first component (an example method is given
in Embodiment 6).
[0082] A description will now be given of some of the many
attendant advantages/features of the present invention, some of
which have been mentioned above. For example, one advantage/feature
is an apparatus having a video encoder for encoding a block in a
picture by selecting an order of motion vector predictor candidates
for the block responsive to a characteristic available at both the
video encoder and a corresponding decoder, wherein the
characteristic excludes a mode in which the block is
partitioned.
[0083] Another advantage/feature is the apparatus having the video
encoder as described above, wherein the characteristic includes a
motion vector candidate selection frequency in a number of already
encoded blocks.
[0084] Yet another advantage/feature is the apparatus having the
video encoder wherein the characteristic includes a motion vector
candidate selection frequency in a number of already encoded blocks
as described above, wherein a category classification is performed
to determine one of a plurality of categories to which the block
belongs, and the motion vector candidate selection frequency is
determined from the number of already encoded blocks that belong to
the same one of the plurality of categories as the block.
[0085] Still another advantage/feature is the apparatus having the
video encoder wherein a category classification is performed to
determine one of a plurality of categories to which the block
belongs, and the motion vector candidate selection frequency is
determined from the number of already encoded blocks that belong to
the same one of the plurality of categories as the block as
described above, wherein a criterion for the category
classification is a block prediction type.
[0086] Moreover, another advantage/feature is the apparatus having
the video encoder wherein a category classification is performed to
determine one of a plurality of categories to which the block
belongs, and the motion vector candidate selection frequency is
determined from the number of already encoded blocks that belong to
the same one of the plurality of categories as the block as
described above, wherein a criterion for the category
classification is a block partition type.
[0087] Further, another advantage/feature is the apparatus having
the video encoder wherein a category classification is performed to
determine one of a plurality of categories to which the block
belongs, and the motion vector candidate selection frequency is
determined from the number of already encoded blocks that belong to
the same one of the plurality of categories as the block as
described above, wherein a criterion for the category
classification is a block location.
[0088] Also, another advantage/feature is the apparatus having the
video encoder as described above, wherein the characteristic
includes a consistency of the motion vector predictor
candidates.
[0089] Additionally, another advantage/feature is the apparatus
having the video encoder wherein the characteristic includes a
consistency of the motion vector predictor candidates as described
above, wherein the consistency is a function of a difference
between the motion vector predictor candidates that are available
at both the video encoder and the corresponding decoder.
[0090] Moreover, another advantage/feature is the apparatus having
the video encoder as described above, wherein the characteristic
includes a fidelity of the motion vector predictor candidates.
[0091] Further, another advantage/feature is the apparatus having
the video encoder wherein the characteristic includes a fidelity of
the motion vector predictor candidates as described above, wherein
the fidelity is a function of corresponding reconstructed residue
coefficients which are available at both the video encoder and the
corresponding decoder.
[0092] Also, another advantage/feature is the apparatus having the
video encoder as described above, wherein the characteristic
includes a reference frame index of the motion vector predictor
candidates.
[0093] Additionally, another advantage/feature is the apparatus
having the video encoder as described above, wherein the motion
vector predictor candidates include a first motion vector predictor
candidate for a first component of a motion vector and a second
motion vector predictor candidate for a second component of the
motion vector, and an order of the second motion vector predictor
candidate for the second component is adapted responsive to a
predictor index of the first component.
[0094] These and other features and advantages of the present
principles may be readily ascertained by one of ordinary skill in
the pertinent art based on the teachings herein. It is to be
understood that the teachings of the present principles may be
implemented in various forms of hardware, software, firmware,
special purpose processors, or combinations thereof.
[0095] Most preferably, the teachings of the present principles are
implemented as a combination of hardware and software. Moreover,
the software may be implemented as an application program tangibly
embodied on a program storage unit. The application program may be
uploaded to, and executed by, a machine comprising any suitable
architecture. Preferably, the machine is implemented on a computer
platform having hardware such as one or more central processing
units ("CPU"), a random access memory ("RAM"), and input/output
("I/O") interfaces. The computer platform may also include an
operating system and microinstruction code. The various processes
and functions described herein may be either part of the
microinstruction code or part of the application program, or any
combination thereof, which may be executed by a CPU. In addition,
various other peripheral units may be connected to the computer
platform such as an additional data storage unit and a printing
unit.
[0096] It is to be further understood that, because some of the
constituent system components and methods depicted in the
accompanying drawings are preferably implemented in software, the
actual connections between the system components or the process
function blocks may differ depending upon the manner in which the
present principles are programmed. Given the teachings herein, one
of ordinary skill in the pertinent art will be able to contemplate
these and similar implementations or configurations of the present
principles.
[0097] Although the illustrative embodiments have been described
herein with reference to the accompanying drawings, it is to be
understood that the present principles is not limited to those
precise embodiments, and that various changes and modifications may
be effected therein by one of ordinary skill in the pertinent art
without departing from the scope or spirit of the present
principles. All such changes and modifications are intended to be
included within the scope of the present principles as set forth in
the appended claims.
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