Using luma information for chroma prediction with separate luma-chroma framework in video coding

An apparatus configured to decode video data, the apparatus comprising:

• a memory configured to store a bitstream of encoded video data;
• and
• one or more processors configured to:
• receive the bitstream of encoded video data, the encoded video data representing partitioned luma blocks and partitioned chroma blocks, wherein the chroma blocks are partitioned independently of the luma blocks;
• determine a respective coding mode corresponding to the respective partitioned luma blocks, wherein the respective coding mode includes one or more of a direct mode, a position dependent intra prediction combination mode, one or more second transform sets for a non-separable transform mode, an enhanced multiple transform mode, or an adaptive multiple transform mode;
• decode the respective partitioned luma blocks according to the determined respective coding modes;
• decode a first syntax element indicating that the respective coding modes associated with the respective partitioned luma blocks are to be used for decoding a first partitioned chroma block, wherein the first partitioned chroma block is aligned with two or more partitioned luma blocks;
• determine a chroma coding mode for the first partitioned chroma block according to a function of the respective coding mode of a luma sub-block of the two or more partitioned luma blocks;
• and
• decode the first partitioned chroma block in accordance with the determined chroma coding mode.

An apparatus configured to decode video data, the apparatus comprising:

• means for receiving a bitstream of encoded video data, the encoded video data representing partitioned luma blocks and partitioned chroma blocks, wherein the chroma blocks are partitioned independently of the luma blocks;
• means for determining a respective coding mode corresponding to the respective partitioned luma blocks, wherein the respective coding mode includes one or more of a direct mode, a position dependent intra prediction combination mode, one or more second transform sets for a non-separable transform mode, an enhanced multiple transform mode, or an adaptive multiple transform mode;
• means for decoding the respective partitioned luma blocks according to the determined respective coding modes;
• means for decoding a first syntax element indicating that the respective coding modes associated with the respective partitioned luma blocks are to be used for decoding a first partitioned chroma block, wherein the first partitioned chroma block is aligned with two or more partitioned luma blocks;
• means for determining a chroma coding mode for the first partitioned chroma block according to a function of the respective coding mode of a luma sub-block of the two or more partitioned luma blocks;
• and
• means for decoding the first partitioned chroma block in accordance with the determined chroma coding mode.

A non-transitory computer-readable storage medium having instructions stored thereon that, when executed, causes one or more processors configured to decoded video data to:

• receive the bitstream of encoded video data, the encoded video data representing partitioned luma blocks and partitioned chroma blocks, wherein the chroma blocks are partitioned independently of the luma blocks;
• determine a respective coding mode corresponding to the respective partitioned luma blocks, wherein the respective coding mode includes one or more of a direct mode, a position dependent intra prediction combination mode, one or more second transform sets for a non-separable transform mode, an enhanced multiple transform mode, or an adaptive multiple transform mode;
• decode the respective partitioned luma blocks according to the determined respective coding modes;
• decode a first syntax element indicating that the respective coding modes associated with the respective partitioned luma blocks are to be used for decoding a first partitioned chroma block, wherein the first partitioned chroma block is aligned with two or more partitioned luma blocks;
• determine a chroma coding mode for the first partitioned chroma block according to a function of the respective coding mode of a luma sub-block of the two or more partitioned luma blocks;
• and
• decode the first partitioned chroma block in accordance with the determined chroma coding mode.