Techniques for simplified affine motion model coding with prediction offsets

An apparatus for video decoding, comprising:

• processing circuitry configured to:
• receive an input of a coded video bitstream that corresponds to a video sequence to be recovered by the apparatus for display;
• decode prediction information of a block in a current picture from the coded video bitstream, the prediction information including a plurality of offset indices for prediction offsets associated with an affine model in an inter prediction mode;
• determine parameters of the affine model based on the plurality of offset indices and a respective plurality of pre-defined mapping tables that each indexes and corresponding offset values, the parameters of the affine model being used to transform between the block and a reference block in a reference picture that has been reconstructed;
• and
• reconstruct at least a sample of the block in the current picture as part of the video sequence which has been recovered for display according to the affine model,
• wherein at least one of the pre-defined mapping tables includes distance offset indexes that are each a numerical value that is mapped to a pixel distance and at least another of the pre-defined mapping tables includes offset direction indexes that are each a numerical value that is mapped to a pair of directions respectively on the x-axis and the y-axis.

A non-transitory computer-readable medium storing instructions which when executed by a computer for video decoding cause the computer to perform a method comprising:

• receiving an input of a coded video bitstream that corresponds to a video sequence to be recovered by the computer for display;
• decoding prediction information of a block in a current picture from the coded video bitstream, the prediction information including a plurality of offset indices for prediction offsets associated with an affine model in an inter prediction mode;
• determining parameters of the affine model based on the plurality of offset indices and a respective plurality of pre-defined mapping tables that each include indexes and corresponding offset values, the parameters of the affine model being used to transform between the block and a reference block in a reference picture that has been reconstructed;
• and
• reconstructing at least a sample of the block in the current picture as part of the video sequence which has been recovered for display according to the affine model,
• wherein at least one of the pre-defined mapping tables includes distance offset indexes that are each a numerical value that is mapped to a pixel distance and at least another of the pre-defined mapping tables includes offset direction indexes that are each a numerical value that is mapped to a pair of directions respectively on the x-axis and the y-axis.