Deriving motion information for sub-blocks in video coding

Patent metadata

Field	Value
Publication number	US-2016286232-A1
Application number	US-201615080480-A
Country	US
Kind code	A1
Filing date	Mar 24, 2016
Priority date	Mar 27, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

In an example, a method of processing video data includes splitting a current block of video data into a plurality of sub-blocks for deriving motion information of the current block, where the motion information indicates motion of the current block relative to reference video data. The method also includes deriving, separately for each respective sub-block of the plurality of sub-blocks, motion information comprising performing a motion search for a first set of reference data that corresponds to a second set of reference data outside of each respective sub-block. The method also includes decoding the plurality of sub-blocks based on the derived motion information and without decoding syntax elements representative of the motion information.

First claim

What is claimed is:

1 . A method of processing video data, the method comprising:
splitting a current block of video data into a plurality of sub-blocks for deriving motion information of the current block, wherein the motion information indicates motion of the current block relative to reference video data; and deriving, separately for each respective sub-block of the plurality of sub-blocks, motion information comprising performing a motion search for a first set of reference data that corresponds to a second set of reference data outside of each respective sub-block; and decoding the plurality of sub-blocks based on the derived motion information and without decoding syntax elements representative of the motion information.

2 . The method of claim 1 , wherein the motion information for each of the sub-blocks comprises at least one motion vector and at least one reference index of a reference picture in a reference picture list.

3 . The method of claim 1 , wherein the size of the sub-blocks comprises at least one of 1×1, 2×2, 4×4, 8×8, 16×16, or 32×32.

4 . The method of claim 1 , wherein the current block comprises a prediction unit (PU) and the sub-blocks comprise sub-PUs.

5 . The method of claim 1 , wherein splitting the current block comprises splitting the current block to form sub-blocks of a fixed size regardless of the size of the current block.

6 . The method of claim 1 , wherein splitting the current block comprises splitting the current block based on a minimum sub-block size.

7 . The method of claim 6 , further comprising determining the minimum sub-block size based on a split depth parameter D that indicates a maximum split depth for the block.

8 . The method of claim 1 , wherein deriving the motion information for the respective sub-blocks comprises:
deriving motion information for the block; determining a search window in a reference picture based on the derived motion information for the block; searching for respective best match reference data for the respective sub-blocks within the search window; and deriving the motion information for the respective sub-blocks based on the respective best match reference blocks.

9 . The method of claim 8 , further comprising:
generating a candidate list comprising a plurality of candidate motion vectors, the candidate list including the derived motion information for the block as a candidate of the plurality of candidate motion vectors; determining a candidate motion vector based on a best match of reference data from reference data indicated by each candidate of the plurality of candidate motion vectors; searching for respective best match reference blocks for the respective sub-blocks based on the determined candidate motion vector.

10 . The method of claim 1 , further comprising applying a transform to the current block such that the transform is applied to all of the sub-blocks.

11 . The method of claim 1 , wherein splitting the current block comprises splitting the current block based on one or more syntax elements obtained from an encoded bitstream, and wherein decoding the plurality of sub-blocks comprises:
determining a reference block in a reference picture for the respective sub-blocks based on the derived motion information; decoding residual data for respective sub-blocks from an encoded bitstream; and combining the decoded residual for the respective sub-blocks and the reference block for the respective sub-blocks to reconstruct the respective sub-blocks.

12 . A method of processing video data, the method comprising:
splitting a current block of video data into a plurality of sub-blocks for deriving motion information of the current block, wherein the motion information indicates motion of the current block relative to reference video data; and deriving, separately for each respective sub-block of the plurality of sub-blocks, motion information comprising performing a motion search for a first set of reference data that corresponds to a second set of reference data outside of each respective sub-block; and encoding the plurality of sub-blocks based on the derived motion information and without encoding syntax elements representative of the motion information.

13 . The method of claim 12 , wherein the motion information for each of the sub-blocks comprises at least one motion vector and at least one reference index of a reference picture in a reference picture list.

14 . The method of claim 12 , wherein the size of the sub-blocks comprises at least one of 1×1, 2×2, 4×4, 8×8, 16×16, or 32×32.

15 . The method of claim 12 , wherein the current block comprises a prediction unit (PU) and the sub-blocks comprise sub-PUs.

16 . The method of claim 12 , wherein splitting the current block comprises splitting the current block to form sub-blocks of a fixed size regardless of the size of the current block.

17 . The method of claim 12 , wherein splitting the current block comprises splitting the current block based on a minimum sub-block size.

18 . The method of claim 17 , further comprising determining the minimum sub-block size based on a split depth parameter D that indicates a maximum split depth for the block.

19 . The method of claim 12 , wherein deriving the motion information for the respective sub-blocks comprises:
deriving motion information for the block; determining a search window in a reference picture based on the derived motion information for the block; searching for respective best match reference data for the respective sub-blocks within the search window; and deriving the motion information for the respective sub-blocks based on the respective best match reference blocks.

20 . The method of claim 19 , further comprising:
generating a candidate list comprising a plurality of candidate motion vectors, the candidate list including the derived motion information for the block as a candidate of the plurality of candidate motion vectors; determining a candidate motion vector based on a best match of reference data from reference data indicated by each candidate of the plurality of candidate motion vectors; searching for respective best match reference blocks for the respective sub-blocks based on the determined candidate motion vector.

21 . The method of claim 12 , further comprising applying a transform to the current block such that the transform is applied to all of the sub-blocks.

22 . The method of claim 12 , wherein encoding the plurality of sub-blocks comprises encoding residual data for the respective sub-blocks an encoded bitstream, wherein the encoded bitstream does not include data indicating the derived motion vector.

23 . A device for processing video data, the device comprising:
a memory configured to store a current block of video data; and one or more processors configured to:
split a current block of video data into a plurality of sub-blocks for deriving motion information of the current block, wherein the motion information indicates motion of the current block relative to reference video data; and
derive, separately for each respective sub-block of the plurality of sub-blocks, motion information comprising performing a motion search for a first set of reference data that corresponds to a second set of reference data outside of each respective sub-block; and
code the plurality of sub-blocks based on the derived motion information and without coding syntax elements representative of the motion

Assignees

• Qualcomm Inc

Inventors

• Li Xiang
• Chen Ying
• Zhang Li
• Liu Hongbin
• Chen Jianle
• Karczewicz Marta

Classifications

• H04N19/513 Primary

  Processing of motion vectors · CPC title

• H04N19/109 Primary

  among a plurality of temporal predictive coding modes · CPC title

• H04N19/56 Primary

  Motion estimation with initialisation of the vector search, e.g. estimating a good candidate to initiate a search · CPC title

• H04N19/44

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title

• H04N19/176

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