Lossless mode for versatile video coding

An apparatus for decoding coefficients for a block of pixels of an image or video comprising a processor configured to:

• obtain a first flag indicating that a block of pixels of an image or video is a transform skip block, wherein transform skip residual coding should be used for coding a transform block associated with the block of pixels of the image or video;
• obtain a second flag indicating that regular residual coding is used for transform skip blocks;
• decode coefficients of the transform block using regular residual coding;
• and
• decode the block using the decoded coefficients.

A method comprising:

• based on a rate distortion optimization, for a block of pixels of an image or video, determining that transform skip and residual coding should be used;
• encoding coefficients of the block using regular residual coding;
• and
• encoding a first flag indicating that the block of pixels of the image or video is a transform skip block and a second flag indicating that regular residual coding is used for transform skip blocks.

An apparatus comprising a processor configured to:

• based on a rate distortion optimization, determine that transform skip and residual coding should be used for a block of pixels of an image or video;
• and
• on a condition that transform skip and residual coding should be used:
• encode coefficients of the block using regular residual coding;
• and
• encode a first flag indicating that the block of pixels of the image or video is a transform skip block and a second flag indicating that regular residual coding is used for transform skip blocks.