Simplified entropy coding for sub-block based motion information list

Patent metadata

Field	Value
Publication number	US-11006106-B2
Application number	US-202016998348-A
Country	US
Kind code	B2
Filing date	Aug 20, 2020
Priority date	Oct 31, 2008
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

Devices, systems and methods for digital video coding, which include adaptive control point selection for affine coding, are described. An exemplary method for video processing includes selecting, for a conversion between a current block of a video and a bitstream representation of the video, a plurality of control points for the current block, the plurality of control points comprising at least one non-corner point of the current block, and each of the plurality of control points being representative of an affine motion of the current block; and performing, based on the plurality of control points, the conversion between the current block and the bitstream representation.

First claim

What is claimed is:

1. A method of coding video data, comprising:
determining, for a conversion between a current video block of a video and a bitstream of the video, that at least one of a plurality of bins used to code a merge index of a sub-block merge-based merge candidate list uses bypass coding, wherein the sub-block merge-based merge candidate list is constructed based on a sub-block temporal motion vector prediction (SbTMVP) candidate; and
performing the conversion based on the determining,
wherein the SbTMVP candidate is derived based on a temporal motion shift from a spatial neighboring block of the current video block, and wherein a reference picture related to the temporal motion shift is same as a collocated picture of the current video block;
wherein the sub-block merge-based merge candidate list is constructed further based on an inherited affine candidate, a constructed affine candidate, or a zero candidate, and
wherein control point motion vectors of an inherited affine candidate is derived from control point motion vectors of a spatial neighboring block that is coded in affine mode, wherein the control point motion vectors and motion vectors in inter perdition mode are all stored with 1/16-pel precision.

2. The method of claim 1 , wherein the temporal motion shift is used to locate at least one region in a picture different from a current picture comprising the current video block.

3. The method of claim 1 , wherein a first bin of the plurality of bins is coded with at least one context, and wherein all other bins of the plurality of bins are bypass coded.

4. The method of claim 3 , wherein the at least one context consists of one context.

5. The method of claim 1 , wherein each of a first K bins of the plurality of bins is coded with at least one context, wherein all other bins of the plurality of bins are bypass coded, wherein K is a non-negative integer, wherein 0≤K≤maxSubMrgListLen−1, and wherein maxSubMrgListLen is a maximum length of the plurality of bins.

6. The method of claim 1 , wherein the conversion generates the current video block from the bitstream.

7. The method of claim 1 , wherein the conversion generates the bitstream from the current video block.

8. An apparatus for coding video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:
determining, for a conversion between a current video block of a video and a bitstream of the video, that at least one of a plurality of bins used to code a merge index of a sub-block merge-based merge candidate list uses bypass coding, wherein the sub-block merge-based merge candidate list is constructed based on a sub-block temporal motion vector prediction (SbTMVP) candidate; and
performing the conversion based on the determining,
wherein the SbTMVP candidate is derived based on a temporal motion shift from a spatial neighboring block of the current video block, and wherein a reference picture related to the temporal motion shift is same as a collocated picture of the current video block,
wherein the sub-block merge-based merge candidate list is constructed further based on an inherited affine candidate, a constructed affine candidate, or a zero candidate, and
wherein control point motion vectors of an inherited affine candidate is derived from control point motion vectors of a spatial neighboring block that is coded in affine mode, wherein the control point motion vectors and motion vectors in inter perdition mode are all stored with 1/16-pel precision.

9. The apparatus of claim 8 , wherein the temporal motion shift is used to locate at least one region in a picture different from a current picture comprising the current video block.

10. The apparatus of claim 8 , wherein a first bin of the plurality of bins is coded with at least one context, and wherein all other bins of the plurality of bins are bypass coded.

11. The apparatus of claim 10 , wherein the at least one context consists of one context.

12. The apparatus of claim 8 , wherein the conversion generates the current video block from the bitstream.

13. The apparatus of claim 8 , wherein the conversion generates the bitstream from the current video block.

14. A non-transitory computer-readable storage medium storing instruction that cause a processor to:
determining, for a conversion between a current video block of a video and a bitstream of the video, that at least one of a plurality of bins used to code a merge index of a sub-block merge-based merge candidate list uses bypass coding, wherein the sub-block merge-based merge candidate list is constructed based on a sub-block temporal motion vector prediction (SbTMVP) candidate; and
performing the conversion based on the determining,
wherein the SbTMVP candidate is derived based on a temporal motion shift from a spatial neighboring block of the current video block, and wherein a reference picture related to the temporal motion shift is same as a collocated picture of the current video block,
wherein the sub-block merge-based merge candidate list is constructed further based on an inherited affine candidate, a constructed affine candidate, or a zero candidate, and
wherein control point motion vectors of an inherited affine candidate is derived from control point motion vectors of a spatial neighboring block that is coded in affine mode, wherein the control point motion vectors and motion vectors in inter perdition mode are all stored with 1/16-pel precision.

15. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:
determining, for a conversion between a current video block of a video and a bitstream of the video, that at least one of a plurality of bins used to code a merge index of a sub-block merge-based merge candidate list uses bypass coding, wherein the sub-block merge-based merge candidate list is constructed based on a sub-block temporal motion vector prediction (SbTMVP) candidate; and
generating the bitstream from the current video block based on the determining,
wherein the SbTMVP candidate is derived based on a temporal motion shift from a spatial neighboring block of the current video block, and wherein a reference picture related to the temporal motion shift is same as a collocated picture of the current video block,
wherein the sub-block merge-based merge candidate list is constructed further based on an inherited affine candidate, a constructed affine candidate, or a zero candidate, and
wherein control point motion vectors of an inherited affine candidate is derived from control point motion vectors of a spatial neighboring block that is coded in affine mode, wherein the control point motion vectors and motion vectors in inter perdition mode are all stored with 1/16-pel precision.

Assignees

• Beijing Bytedance Network Tech Co Ltd
• Bytedance Inc

Inventors

• Liu Hongbin
• Zhang Li
• Zhang Kai
• Wang Yue

Classifications

• H04N19/91

  Entropy coding, e.g. variable length coding [VLC] or arithmetic coding · CPC title

• H04N19/13

  Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/105 Primary

  Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction · CPC title

• H04N19/139

  Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability · CPC title