Subblock-based adaptive interpolation filter in digital video coding

An apparatus, comprising:

• one or more processors to executing instructions;
• and
• one or more non-transitory computer-readable media storing instructions that, when executed by the one or more processors, cause the one or more processors to:
• receive an encoded bitstream, wherein:
• the encoded bitstream comprises an encoded reference block, interpolation filter information, and residual data for an encoded block;
• and
• the interpolation filter information indicates a first interpolation filter type for a first region of a predicted block and a second interpolation filter type for a second region of the predicted block that is different from the first interpolation filter type;
• decode the encoded reference block;
• generate the predicted block based on the decoded reference block;
• apply the first interpolation filter type to the first region of the predicted block to obtain a first region of a filtered block;
• apply the second interpolation filter type to the second region of the predicted block to obtain a second region of the filtered block;
• and
• output a reconstructed block of a reconstructed frame based on the filtered block and the residual data.

One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, cause the one or more processors to:

• receive an encoded bitstream, wherein:
• the encoded bitstream comprises an encoded reference block, interpolation filter information, and residual data for an encoded block;
• and
• the interpolation filter information indicates a first interpolation filter type for a first region of a predicted block and a second interpolation filter type for a second region of the predicted block that is different from the first interpolation filter type;
• decode the encoded reference block;
• generate the predicted block based on the decoded reference block;
• apply the first interpolation filter type to the first region of the predicted block to obtain a first region of a filtered block;
• apply the second interpolation filter type to the second region of the predicted block to obtain a second region of the filtered block;
• and
• output a reconstructed block of a reconstructed frame based on the filtered block and the residual data.