Control of memory bandwidth consumption of affine mode in versatile video coding

A semiconductor device comprising:

• circuitry configured to:
• perform a decoding of at least a portion of video data, the decoding comprising:
• calculating a reference block bounding box size for a prediction unit of the video data based on control point motion vectors received for the prediction unit, the prediction unit being divided into subblocks;
• setting a bounding box size threshold to a first value in response to the prediction unit being coded using a unidirectional prediction mode and setting the bounding box size threshold to a second value in response to the prediction unit being coded using a bidirectional prediction mode;
• determining if the reference block bounding box size exceeds the bounding box size threshold;
• in response to a determination that the reference block bounding box size does not exceed the bounding box size threshold, generating a respective motion vector for each subblock of the prediction unit;
• in response to a determination that the reference block bounding box size exceeds the bounding box size threshold, generating a common motion vector for all subblocks of the prediction unit;
• and
• providing the respective motion vectors or the common motion vector for performing motion compensation on the prediction unit.

A non-transitory, computer-readable storage medium storing instructions that, when executed by one or more processors, control the one or more processors to perform a method of video decoding comprising:

• calculating a reference block bounding box size for a prediction unit of the video data based on control point motion vectors received for the prediction unit, the prediction unit being divided into subblocks;
• setting a bounding box size threshold to a first value;
• determining if the reference block bounding box size exceeds the bounding box size threshold;
• in response to a determination that the reference block bounding box size does not exceed the bounding box size threshold, generating a respective motion vector for each subblock of the prediction unit;
• in response to a determination that the reference block bounding box size exceeds the bounding box size threshold, generating a common motion vector for all subblocks of the prediction unit;
• and
• providing the respective motion vectors or the common motion vector for performing motion compensation on the prediction unit.