Integerization for interpolation filter design in video coding

A non-transitory computer-readable medium, storing a computer program and a bitstream, wherein the computer program, when executed by a processor, causes the processor to perform following operations to generate the bitstream, the operations comprising:

• accessing a picture of a video;
• and
• performing inter prediction for the picture using an integerized interpolation filter to generate a prediction residual for the picture, wherein the integerized interpolation filter is generated by:
• accessing an interpolation filter, the interpolation filter having floating-point filter coefficients;
• generating two integerized filter coefficient values for a filter coefficient of the interpolation filter,
• generating a set of filter candidates based on the two integerized filter coefficient values for the filter coefficient,
• calculating an error metric for a filter candidate in the set of filter candidates, and
• selecting an integerized interpolation filter for the interpolation filter from the set of filter candidates, the selected integerized interpolation filter having a lowest error metric among the set of filter candidates;
• and
• encoding a prediction residual for the picture into a bitstream representing the video.

A decoder for decoding a video from a video bitstream, the decoder comprising:

• a processing device;
• and
• a non-transitory computer-readable medium communicatively coupled to the processing device, wherein the processing device is configured to execute program code stored in the non-transitory computer-readable medium and thereby perform operations comprising:
• decoding a picture of the video from the video bitstream;
• performing inter prediction based on the picture using an integerized interpolation filter to decode another picture of the video, wherein the integerized interpolation filter is generated by:
• accessing an interpolation filter, the interpolation filter having floating-point filter coefficients;
• generating two integerized filter coefficient values for a filter coefficient of the interpolation filter,
• generating a set of filter candidates based on the two integerized filter coefficient values for the filter coefficient,
• calculating an error metric for a filter candidate in the set of filter candidates, and
• selecting an integerized interpolation filter for the interpolation filter from the set of filter candidates, the selected integerized interpolation filter having a lowest error metric among the set of filter candidates;
• and
• causing the decoded picture and the decoded another picture to be displayed.