Using combined inter intra prediction in video processing

An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

• determine, for a conversion between a block of a video and a bitstream of the video, whether a bi-prediction coding technique is applicable to the block based on a size of the block having a width W and a height H, W and H being positive integers;
• and
• perform the conversion according to the determining,
• wherein the bi-prediction coding technique is an inter-prediction coding technique in which a prediction block of reference list 0 and a prediction block of reference list 1 are used to derive a prediction block of the block, wherein the bi-prediction coding technique is not applicable in a case that one of at least one condition is satisfied, wherein the at least one condition comprises:
• W=T1 and H≤T2, T1 and T2 being positive integers;
• W≤T2 and H=T1, T1 and T2 being positive integers;
• or
• W≤T1 and H≤T2, T1 and T2 being positive integers, and
• wherein T1=4 and T2=4.

A non-transitory computer-readable storage medium storing instructions that cause a processor to:

• determine, for a conversion between a block of a video and a bitstream of the video, whether a bi-prediction coding technique is applicable to the block based on a size of the block having a width W and a height H, W and H being positive integers;
• and
• perform the conversion according to the determining,
• wherein the bi-prediction coding technique is an inter-prediction coding technique in which a prediction block of reference list 0 and a prediction block of reference list 1 are used to derive a prediction block of the block, wherein the bi-prediction coding technique is not applicable in a case that one of at least one condition is satisfied, wherein the at least one condition comprises:
• W=T1 and H≤T2, T1 and T2 being positive integers;
• W≤T2 and H=T1, T1 and T2 being positive integers;
• or
• W≤T1 and H≤T2, T1 and T2 being positive integers, and
• wherein T1=4 and T2=4.

A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:

• determining, for a block of a video, whether a bi-prediction coding technique is applicable to the block based on a size of the block having a width W and a height H, W and H being positive integers;
• and
• generating the bitstream from the block according to the determining,
• wherein the bi-prediction coding technique is an inter-prediction coding technique in which a prediction block of reference list 0 and a prediction block of reference list 1 are used to derive a prediction block of the block, wherein the bi-prediction coding technique is not applicable in a case that one of at least one condition is satisfied, wherein the at least one condition comprises:
• W=T1 and H≤T2, T1 and T2 being positive integers;
• W≤T2 and H=T1, T1 and T2 being positive integers;
• or
• W≤T1 and H≤T2, T1 and T2 being positive integers, and
• wherein T1=4 and T2=4.