| CPC H04N 19/96 (2014.11) [H04N 19/124 (2014.11); H04N 19/126 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/463 (2014.11); H04N 19/61 (2014.11)] | 3 Claims |
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1. A method of encoding video data, the method comprising:
receiving transform coefficient values associated with a chroma coding block, wherein:
the chroma coding block is one of a plurality of chroma coding blocks resulting from partitioning a chroma coding tree block,
the chroma coding tree block and a corresponding luma coding tree block are associated with a coding tree unit,
the corresponding luma coding tree block is partitioned into luma coding blocks and the luma coding blocks are organized into quantization groups such that a plurality of luma quantization parameters is determined for the corresponding luma coding tree block, and
the chroma coding block is misaligned with the luma coding blocks;
identifying one of the plurality of luma quantization parameters that is mapped to the chroma coding block;
deriving a predictive quantization parameter for the chroma coding block by using a value derived from the identified one of the plurality of luma quantization parameters as an index in a look-up table;
determining a chroma quantization parameter for the chroma coding block by adding a delta quantization parameter to the predictive quantization parameter, wherein the delta quantization parameter is associated with the chroma coding block; and
generating level values corresponding to the chroma coding block based on the determined chroma quantization parameter and the received transform coefficient values.
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