JPWO2020047132A5

JPWO2020047132A5 -

Info

Publication number: JPWO2020047132A5
Application number: JP2021510159A
Authority: JP
Publication date: 2022-09-06

Claims

obtaining information identifying at least a first motion vector predictor and a second motion vector predictor for an affine coded block in a video;
obtaining at least a first differential motion vector and a second differential motion vector;
obtaining information identifying the accuracies of the first and second differential motion vectors from among a first set of available accuracies, wherein the first set of available accuracies is non- obtaining a second set of accuracies different from those available for affine inter-coding ;
at least (i) a first control point motion vector from the first motion vector predictor and the first differential motion vector; and (ii) from the second motion vector predictor and the second differential motion vector. generating a second control point motion vector;
generating a prediction for the block using an affine motion model, wherein the affine motion model is characterized by at least the first control point motion vector and the second control point motion vector; A method of encoding or decoding video comprising:

obtaining information identifying at least a first motion vector predictor and a second motion vector predictor for an affine coded block in a video;
obtaining at least a first differential motion vector and a second differential motion vector;
obtaining information identifying the accuracies of the first and second differential motion vectors from among a first set of available accuracies, wherein the first set of available accuracies is non- obtaining a second set of accuracies different from those available for affine inter-coding ;
at least (i) a first control point motion vector from the first motion vector predictor and the first differential motion vector; and (ii) from the second motion vector predictor and the second differential motion vector. generating a second control point motion vector;
generating a prediction for the block using an affine motion model, wherein the affine motion model is characterized by at least the first control point motion vector and the second control point motion vector; A video encoder or decoder apparatus comprising at least one processor configured to at least perform

3. The method of claim 1 or the apparatus of claim 2, wherein the first set of available accuracies includes 1/4 pixel precision, 1/16 pixel precision, and 1 pixel precision.

3. The method of claim 1 or the apparatus of claim 2, wherein the affine motion model is a four-parameter motion model.

the affine motion model is a 6-parameter motion model;
reading from the bitstream information identifying a third motion vector predictor;
reading a third differential motion vector having the specified precision from the bitstream;
generating a third control point motion vector from the third motion vector predictor and the third differential motion vector,
2. The method of claim 1, further comprising: said affine motion model is characterized by said first control point motion vector, said second control point motion vector, and said third control point motion vector. 3. A method or apparatus according to claim 2.

3. The method of claim 1 or the apparatus of claim 2, wherein the information identifying one of the plurality of precisions is read from a bitstream in blocks.

3. The method of claim 1 or the apparatus of claim 2, further comprising rounding at least one of the motion vector predictors to the specified precision.

3. The method of claim 1 or the apparatus of claim 2, wherein each of said control point motion vectors is generated by adding a corresponding differential motion vector to a respective motion vector predictor.

generating a prediction for the block;
determining a respective sub-block motion vector for each of a plurality of sub-blocks of the block using the affine motion model;
using the respective sub-block motion vectors to generate respective inter-predictions for the sub - blocks.

2. The method of claim 1, performed by a video encoder.

2. The method of claim 1, performed by a video decoder.

reading a residual for the block from a bitstream;
2. The method of claim 1, further comprising: reconstructing the block by adding the residual to the prediction of the block.

3. The device of Claim 2, wherein the device is a video encoder.

3. The device of Claim 2, wherein the device is a video decoder.