Prediction image generation device, moving image decoding device, and moving image coding device
AssigneeGuangdong Oppo Mobile Telecommunications Corp., Ltd.
InventorTomohiro IKAI
Life of this patent
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Abstract
Coding efficiency is improved. A motion compensation filter unit acts on a motion vector applied image obtained by acting a motion vector on a reference image. The motion compensation filter unit causes filter coefficients mcFilter[i][k] designated by a phase i and a filter coefficient position k to act on the motion vector applied image. The filter coefficients mcFilter[i][k] includes filter coefficients calculated by using filter coefficients mcFilter[p][k] (p≠i) and filter coefficients mcFilter[q][k] (q≠i).
Claims3
A video decoding method, applied to a video decoding device, comprising:
- deriving a difference motion vector by using a motion vector difference value;
- decoding a flag, from a coded data, specifying an accuracy of a motion vector, in a case that the motion vector difference value is not equal to zero;
- decoding a prediction motion vector index;
- determining a shift value used for a rounding process of a prediction motion vector by using the flag, the prediction motion vector is selected from a motion vector prediction list by using the prediction motion vector index;
- generating a prediction image by using a motion vector based on the difference motion vector and the prediction motion vector;
- and
- decoding a coding target image by adding a residual image to the prediction image or subtracting the residual image from the prediction image.
A video coding method, performed by a video coding device, comprising:
- deriving a difference motion vector by using a motion vector difference value;
- determining a flag specifying an accuracy of a motion vector in a case that the difference motion vector is not equal to zero;
- determining a prediction motion vector index;
- determining, by using the flag, a shift value used for a rounding process of a prediction motion vector, the prediction motion vector is selected from a motion vector prediction list by using the prediction motion vector index;
- generating a prediction image by using a motion vector based on the difference motion vector and the prediction motion vector;
- and
- coding a residual of the prediction image and a coding target image.
A non-transitory computer-readable storage medium, having a computer program and a bitstream stored thereon, wherein the computer program, when executed by a processor, enables the processor to perform the following operations to generate the bitstream:
- deriving a difference motion vector by using a motion vector difference value;
- determining a flag specifying an accuracy of a motion vector in a case that the difference motion vector is not equal to zero;
- determining a prediction motion vector index;
- determining, by using the flag, a shift value used for a rounding process of a prediction motion vector, the prediction motion vector is selected from a motion vector prediction list by using the prediction motion vector index;
- generating a prediction image by using a motion vector based on the difference motion vector and the prediction motion vector;
- and
- coding a residual of the prediction image and a coding target image.
Dependencies are inferred from the claim text.