Cross-component coding order derivation
Method and apparatus for using block size restrictions in video decoding are described. In a representative aspect, a method for video decoding includes receiving a bitstream representation of video data including a block wherein the block comprises samples associated with a first component and second components, wherein samples associated with the first component of the block have a dimension M×N; and decoding the first component and the second components of the block; wherein decoding the first component of the block comprises, based on the dimension, decoding a plurality of sub-blocks for the first component of the block, and the plurality of the sub-blocks are generated by performing a splitting operation only on the samples associated with the first component of the block and not on the samples associated with the second components of the block.
1. A method of coding video data, comprising:
generating a luma parent coding block from a luma coding tree block (CTB) of a video, based on a first luma partition scheme, wherein first luma partition scheme includes recursive partition operations;
generating a chroma parent coding block from a chroma coding tree block (CTB) based on a first chroma partition scheme, wherein the first chroma partition scheme has same recursive partition operations with the first luma partition scheme;
determining to apply a further partition operation on the luma parent coding block based on a color format of the luma and chroma CTB, a coding mode and a dimension of the parent luma coding block meeting certain conditions to generate multiple luma coding blocks and not to apply the further partition operation on the chroma parent coding block; and
performing a conversion between the multiple luma coding blocks and a bitstream of the video and a conversion between the chroma parent coding block and the bitstream.
2. The method of claim 1 , wherein the dimension of the parent luma coding block meets the certain conditions in a case that the parent luma coding block has a dimension 8×8, the coding mode of the parent luma coding block is intra mode type and the color format is 4:2:0.
3. The method of claim 1 , wherein the dimension of the parent luma coding block meets certain conditions in a case that the parent luma coding block has a dimension 4×8 or 8×4 without considering the color format of the luma and chroma CTB and the coding mode of the luma parent coding block.
4. The method of claim 1 , wherein the further partition operation comprises a Quad Tree (QT) partition structure, a Ternary Tree (TT) partition structure or a Binary Tree (BT) partition structure.
5. The method of claim 1 , wherein in response to applying the further partition operation on the luma parent coding block, the luma parent coding block is partitioned into multiple luma sub-partitions, and wherein the multiple luma sub-partitions are decoded before the chroma parent coding block.
6. The method of claim 1 , wherein the chroma parent coding block comprises a Cb block and a Cr block, and the Cb block is decoded before the Cr component.
7. The method of claim 1 , wherein the conversion includes decoding the multiple luma coding blocks and the chroma parent coding block from the bitstream.
8. The method of claim 1 , wherein the conversion includes encoding the multiple luma coding blocks and the chroma parent coding block into the bitstream.
9. An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:
generate a luma parent coding block from a luma coding tree block (CTB) of a video, based on a first luma partition scheme, wherein first luma partition scheme includes recursive partition operations;
generate a chroma parent coding block from a chroma coding tree block (CTB) based on a first chroma partition scheme, wherein the first chroma partition scheme has same recursive partition operations with the first luma partition scheme;
determine to apply a further partition operation on the luma parent coding block based on a color format of the luma and chroma CTB, a coding mode and a dimension of the parent luma coding block meeting certain conditions to generate multiple luma coding blocks and not to apply the further partition operation on the chroma parent coding block; and
perform a conversion between the multiple luma coding blocks and a bitstream of the video and a conversion between the chroma parent coding block and the bitstream.
10. The apparatus of claim 9 , wherein the dimension of the parent luma coding block meets the certain conditions in a case that the parent luma coding block has a dimension 8×8.
11. The apparatus of claim 9 , wherein the dimension of the parent luma coding block meets certain conditions in a case that the parent luma coding block has a dimension 4×8 or 8×4 without considering the color format of the luma and chroma CTB and the coding mode of the luma parent coding block.
12. The apparatus of claim 9 , wherein the further partition operation comprises a Quad Tree (QT) partition structure, a Ternary Tree (TT) partition structure or a Binary Tree (BT) partition structure.
13. A non-transitory computer-readable storage medium storing instructions that cause a processor to:
generate a luma parent coding block from a luma coding tree block (CTB) of a video, based on a first luma partition scheme, wherein first luma partition scheme includes recursive partition operations;
generate a chroma parent coding block from a chroma coding tree block (CTB) based on a first chroma partition scheme, wherein the first chroma partition scheme has same recursive partition operations with the first luma partition scheme;
determine to apply a further partition operation on the luma parent coding block based on a color format of the luma and chroma CTB, a coding mode and a dimension of the parent luma coding block meeting certain conditions to generate multiple luma coding blocks and not to apply the further partition operation on the chroma parent coding block; and
perform a conversion between the multiple luma coding blocks and a bitstream of the video and a conversion between the chroma parent coding block and the bitstream.
14. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:
generating a luma parent coding block from a luma coding tree block (CTB) of the video, based on a first luma partition scheme, wherein first luma partition scheme includes recursive partition operations;
generating a chroma parent coding block from a chroma coding tree block (CTB) based on a first chroma partition scheme, wherein the first chroma partition scheme has same recursive partition operations with the first luma partition scheme;
determining to apply a further partition operation on the luma parent coding block based on a color format of the luma and chroma CTB, a coding mode and a dimension of the parent luma coding block meeting certain conditions to generate multiple luma coding blocks and not to apply the further partition operation on the chroma parent coding block; and
generating the bitstream based on the above determining.