Significant coefficient signaling in video coding

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 first conversion between a first video block of a video and a bitstream of the video, a first indication, wherein the first video block is coded using an inter mode;
• infer, in response to the first indication indicating the first video block being divided into multiple first sub-blocks, a second indication for each first sub-block, wherein the second indication is not included in the bitstream and is inferred to indicate whether a luma component of a corresponding first sub-block includes non-zero coefficient values;
• and
• perform the first conversion at least based on the second indication.

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

• determine, for a first conversion between a first video block of a video and a bitstream of the video, a first indication, wherein the first video block is coded using an inter mode;
• infer, in response to the first indication indicating the first video block being divided into multiple first sub-blocks, a second indication for each first sub-block, wherein the second indication is not included in the bitstream and is inferred to indicate whether a luma component of a corresponding first sub-block includes non-zero coefficient values;
• and
• perform the first conversion at least based on the second indication.

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

• determining a first indication for a first video block of a video, wherein the first video block is coded using an inter mode;
• inferring, in response to the first indication indicating the first video block being divided into multiple first sub-blocks, a second indication for each first sub-block, wherein the second indication is not included in the bitstream and is inferred to indicate whether a luma component of a corresponding first sub-block includes non-zero coefficient values;
• and
• generating the bitstream at least based on the second indication.