Derivation of collocated motion vectors

Patent metadata

Field	Value
Publication number	US-11595658-B2
Application number	US-202217691867-A
Country	US
Kind code	B2
Filing date	Mar 10, 2022
Priority date	Sep 13, 2019
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A method of video processing is described. The method includes: making a first determination about whether a collocated video block of a video block of a video is coded using an inter coding mode or a non-inter coding mode; making a second determination, based on the first determination, about availability of motion vectors of the collocated video block or a mode of derivation of motion vectors for the collocated video block; and performing a conversion between the video block and a coded representation of the video based on the second determination.

First claim

What is claimed is:

1. A method of processing video data, comprising:
performing a conversion between a video block of a current picture of a video and a bitstream of the video based on a prediction mode, wherein in the prediction mode, the video block is divided into at least one subblock, and motion information of the at least one subblock is derived based on motion information of a collocated video block in a collocated picture of the current picture, and wherein a position of the collocated video block is derived based on a temporal motion information which is initialized to a default motion information and is set to specific motion information related to a specific neighboring block A 1 which is adjacent to a lower left corner to the video block in response to the specific neighboring block being available,
wherein in the prediction mode, a derivation process for the motion information of the collocated video block comprises:
making a first determination about whether the collocated video block is coded with a first coding mode different from an intra coding mode, wherein in the first coding mode, reconstructed samples are represented by a set of representative color values, and the set of representative color values comprises at least one of 1) palette predictors, 2) escaped samples, or 3) palette information included in the bitstream; and
making a second determination, based on the first determination, about an availability of motion vectors of the collocated video block and values of motion vectors of the collocated video block, and wherein the second determination is performed such that the second determination is identical for the collocated video block coded with the first coding mode and for the collocated video block coded with the intra coding mode or a second coding mode, wherein in the second coding mode, prediction samples are derived from blocks of sample values of same decoded slice as determined by a block vector,
wherein in response to the first determination that the collocated video block is coded with the first coding mode, a flag indicating the availability of motion vectors of the collocated video block is set to 0, and both components of a motion vector of the collocated video block coded with the first coding mode are set to 0.

2. The method of claim 1 , wherein the second determination determines the availability of motion vectors of the collocated video block to be unavailable in response to the first determination that the collocated video block is coded with the first coding mode.

3. The method of claim 1 , wherein the availability of motion vectors of the collocated video block coded with the first coding mode is identical for the availability of motion vectors of the collocated video block coded with the intra coding mode or the second coding mode.

4. The method of claim 1 , wherein the second determination determines the values of motion vectors of the collocated video block coded with the first coding mode to be equal to the values of motion vectors of the collocated video block coded with the intra coding mode or the second coding mode.

5. The method of claim 1 , wherein
in response to a determination that the collocated video block is coded with the intra coding mode or the second coding mode, the flag indicating the availability of motion vectors of the collocated video block is set to 0 and the both components of a motion vector for the collocated video block are set to 0.

6. The method of claim 1 , wherein the derivation process for the motion information of the collocated video block coded with the first coding mode, the intra coding mode or the second coding mode is different from the derivation process for the motion information of the collocated video block coded with an inter coding mode.

7. The method of claim 1 , wherein the prediction mode is a subblock-based temporal motion vector prediction (SbTMVP) mode, the first coding mode is a palette mode and the second coding mode is an intra-block copy (IBC) mode.

8. The method of claim 1 , wherein the conversion includes encoding the video block into the bitstream.

9. The method of claim 1 , wherein the conversion includes decoding the video block from the bitstream.

10. An apparatus for processing 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:
perform a conversion between a video block of a current picture of a video and a bitstream of the video based on a prediction mode, wherein in the prediction mode, the video block is divided into at least one subblock, and motion information of the at least one subblock is derived based on motion information of a collocated video block in a collocated picture of the current picture, and wherein a position of the collocated video block is derived based on a temporal motion information which is initialized to a default motion information and is set to specific motion information related to a specific neighboring block A 1 which is adjacent to a lower left corner to the video block in response to the specific neighboring block being available,
wherein in the prediction mode, a derivation process for the motion information of the collocated video block comprises:
making a first determination about whether the collocated video block is coded with a first coding mode different from an intra coding mode, wherein in the first coding mode, reconstructed samples are represented by a set of representative color values, and the set of representative color values comprises at least one of 1) palette predictors, 2) escaped samples, or 3) palette information included in the bitstream; and
making a second determination, based on the first determination, about an availability of motion vectors of the collocated video block and values of motion vectors of the collocated video block, and wherein the second determination is performed such that the second determination is identical for the collocated video block coded with the first coding mode and for the collocated video block coded with the intra coding mode or a second coding mode, wherein in the second coding mode, prediction samples are derived from blocks of sample values of same decoded slice as determined by a block vector,
wherein in response to the first determination that the collocated video block is coded with the first coding mode, a flag indicating the availability of motion vectors of the collocated video block is set to 0, and both components of a motion vector of the collocated video block coded with the first coding mode are set to 0.

11. The apparatus of claim 10 , wherein the second determination determines the availability of motion vectors of the collocated video block to be unavailable in response to the first determination that the collocated video block is coded with the first coding mode.

12. The apparatus of claim 10 , wherein the availability of motion vectors of the collocated video block coded with the first coding mode is identical for the availability of motion vectors of the collocated video block coded with the intra coding mode or the second coding mode.

13. The apparatus of claim 10 , wherein the second determination determines the values of motion vectors of the collocated video block coded with the first coding mode to be equal to the values of motion vectors of the collocated video block coded with the intra coding mode or the second coding mode.

14. A non-transitory computer-readable storage medium storing instructions that cause a processor to:
perform a conversion between a video block of a current picture of a v

Assignees

• Beijing Bytedance Network Tech Co Ltd
• Bytedance Inc

Inventors

• Wang Yang
• Liu Hongbin
• Zhang Li
• Zhang Kai
• Xu Jizheng
• Wang Yue

Classifications

• H04N19/50

  using predictive coding (H04N19/61 takes precedence) · CPC title

• H04N19/184

  the unit being bits, e.g. of the compressed video stream · CPC title

• H04N19/132 Primary

  Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking · CPC title

• H04N19/103 Primary

  Selection of coding mode or of prediction mode · CPC title

• H04N19/105

  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