Methods and devices for decoder-side intra mode derivation

An apparatus, comprising:

• one or more processors;
• and
• a memory configured to store instructions executable by the one or more processors;
• wherein the one or more processors, upon execution of the instructions, are configured to:
• determine an intra prediction coding mode with a fusion of multiple intra predictions of a video block is applied to the video block;
• and
• determine prediction sample values of the video block based on position-dependent intra prediction combination (PDPC) operations for one or more intra predictions among the multiple intra predictions, wherein the PDPC operations modify results of the one or more intra predictions based on a combination of boundary reference samples,
• wherein
• in response to determining that a direct current (DC) mode or a planar mode is applied in the multiple intra predictions, disable the PDPC operations for the DC mode or the planar mode;
• or
• in response to determining that an angular mode is applied in the multiple intra predictions, disable the PDPC operations for the angular mode.

A non-transitory computer-readable storage medium storing a bitstream to be decoded by a decoding method comprising:

• determining an intra prediction coding mode with a fusion of multiple intra predictions of a video block is applied to the video block;
• and
• determining prediction sample values of the video block based on position-dependent intra prediction combination (PDPC) operations for one or more intra predictions among the multiple intra predictions, wherein the PDPC operations modify results of the one or more intra predictions based on a combination of boundary reference samples,
• wherein
• in response to determining that a direct current (DC) mode or a planar mode is applied in the multiple intra predictions, disabling the PDPC operations for the DC mode or the planar mode;
• or
• in response to determining that an angular mode is applied in the multiple intra predictions, disabling the PDPC operations for the angular mode.