Patent ID: 11962778
Assignee: APPLE INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A non-transitory machine-readable medium storing instructions that, when executed, are configured to cause one or more processing units to perform operations comprising:
receiving, in a bitstream, an encoded group of video pictures, including an encoded first video picture with a hierarchical coding structure having at least a first coding level, a second coding level and a third coding level, the encoded first video picture comprising two or more sets of chroma quantization parameter (QP) offset values at the first coding level and the second coding level, each set of chroma QP offset values providing information about chroma QPs of video units encompassed by one level of the hierarchical coding structure, the encoded first video picture further comprising one or more chroma quantization groups (QGs) at the third coding level;
for a particular chroma QG of the one or more chroma QGs at the third coding level, identifying an additional set of chroma QP offsets, the identifying comprising:
determining, based on information included in the first coding level or the second coding level, a parameter specifying the maximum length of a binary string in the bitstream, and
identifying the additional set of chroma QP offsets using the parameter; and

decoding the encoded first video picture by computing chroma QP values corresponding to the one or more chroma QGs of the encoded first video picture, the decoding comprising, for the particular chroma QG:
selecting the identified additional set of chroma QP offsets, and
computing the chroma QP values corresponding to the particular chroma QG using the selected set of the chroma QP offsets.