Prediction image generation device, video decoding device and video coding device
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 filler coefficients mcFilter[q][k] (q≠i).
1. A prediction image generation device for generating a prediction image, the prediction image generation device comprising:
an inter-prediction parameter decoding control circuitry that derives a difference motion vector by using a motion vector difference absolute value and that decodes a flag, from a coded data, specifying an accuracy of a motion vector, in a case that the difference motion vector is not equal to zero; and
a prediction image generation circuitry that generates a prediction image by using a motion vector based on the difference motion vector,
wherein
the inter-prediction parameter decoding control circuitry determines a shift value used for a rounding process of a motion vector by using the flag and a parameter for a block.
2. A video decoding device comprising:
the prediction image generation device of claim 1 , wherein
the video decoding device decodes a coding target image by adding a residual image to the prediction image or subtracting the residual image from the prediction image.
3. A video coding device comprising:
the prediction image generation device of claim 1 , wherein
the video coding device codes a residual of the prediction image and a coding target image.