Methods for quantization parameter control for video coding with joined pixel/transform based quantization

A device for processing video data, the device comprising:

• memory configured to store the video data;
• and
• one or more processors implemented in circuitry and communicatively coupled to the memory, the one or more processors being configured to:
• adjust a chroma dynamic range adjustment (DRA) scale value based on a luma DRA scale value;
• determine a chroma quantization parameter (QP) based on the adjusted chroma DRA scale value, wherein the chroma QP comprises an integer component and a fractional component;
• determine an integer chroma QP offset based on the integer component of the chroma QP;
• determine a fractional chroma QP offset based on the fractional component of the chroma QP;
• determine a DRA chroma scale adjustment value based on the integer chroma QP offset and the fractional chroma QP offset;
• and
• process the video data based on the DRA chroma scale adjustment value.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors to:

• adjust a chroma dynamic range adjustment (DRA) scale value based on a luma DRA scale value;
• determine a chroma quantization parameter (QP) based on the luma adjusted chroma DRA scale value, wherein the chroma QP comprises an integer component and a fractional component;
• determine an integer chroma QP offset based on the integer component of the chroma QP;
• determine a fractional chroma QP offset based on the fractional component of the chroma QP;
• determine a DRA chroma scale adjustment value based on the integer chroma QP offset and the fractional chroma QP offset;
• and
• process video data based on the DRA chroma scale adjustment value.