Coefficient scaling for high precision image and 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:

• perform a conversion between a current block of a video and a bitstream of the video, wherein the conversion comprises:
• performing a scaling process for the current block of the video for deriving scaled transform coefficients of the current block;
• making a determination about whether a transformation process for the scaled transform coefficients is skipped for the current block according to a transform skip flag;
• and
• generating, based on the determination, intermediate residual samples for the current block according to a rule, wherein the intermediate residual samples are used to derive final residual samples for picture reconstruction and wherein the rule specifies that in a case where the determination is the transformation process for the scaled transform coefficients being skipped for the current block, the scaled transform coefficients are directly used as the intermediate residual samples.

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

• perform a conversion between a current block of a video and a bitstream of the video, wherein the conversion comprises:
• perform a scaling process for the current block of the video for deriving scaled transform coefficients of the current block;
• make a determination about whether a transformation process for the scaled transform coefficients is skipped for the current block according to a transform skip flag;
• and
• generate, based on the determination, intermediate residual samples for the current block according to a rule, wherein the intermediate residual samples are used to derive final residual samples for picture reconstruction and wherein the rule specifies that in a case where the determination is the transformation process for the scaled transform coefficients being skipped for the current block, the scaled transform coefficients are directly used as the intermediate residual samples.

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:

• generating the bitstream of the video based on a current block of the video, wherein the generating comprises:
• performing a scaling process for the current block of the video for deriving scaled transform coefficients of the current block;
• making a determination about whether a transformation process for the scaled transform coefficients is skipped for the current block according to a transform skip flag;
• and
• generating, based on the determination, intermediate residual samples for the current block according to a rule, wherein the intermediate residual samples are used to derive final residual samples for picture reconstruction and wherein the rule specifies that in a case where the determination is the transformation process for the scaled transform coefficients being skipped for the current block, the scaled transform coefficients are directly used as the intermediate residual samples.