Main concept of EQT, unequally four partitions and signaling

1. A method of processing visual media data, comprising:

applying, during a conversion between a current visual media block of a visual media and a bitstream of the visual media, an extended quad tree (EQT) partitioning process to the current visual media block that splits the current visual media block into exactly four sub-blocks including at least one sub-block that has a dimension different from half of a width of the current visual media block times half of a height of the current visual media block;

applying, during the conversion and to at least one of the four sub-blocks, at least one of a binary tree (BT) partitioning process, a ternary tree (TT) partitioning process, a quad tree (QT) partitioning process or the EQT partitioning process; and

performing, based on the four sub-blocks and the EQT partitioning process, the conversion,

wherein due to the EQT partitioning process, a first sub-block and a second sub-block of the four sub-blocks have a first dimension, and a third sub-block and a fourth sub-block of the four sub-blocks have a second dimension,

wherein the height (H) and the width (W) of the current visual media block are integers, and the first dimension and the second dimension have two cases:

(i) the first dimension is H/4×W, and the second dimension is H/2×W/2, or

(ii) the first dimension is H×W/4, and the second dimension is H/2×W/2,

wherein luma and chroma components of the four sub-blocks share a same recursive partition mode,

wherein, in response to at least one of the four sub-blocks meeting a size restriction, the EQT partitioning process is not applicable to the chroma component of the at least one of the four sub-blocks and the EQT partitioning process is applicable to the luma component of the at least one of the four sub-blocks to generate more leaf nodes,

wherein the BT partitioning process splits the at least one of the four sub-blocks into two equally sized sub-blocks, wherein the QT partitioning process splits the at least one of the four sub-blocks into four equally sized sub-blocks, and wherein the TT partitioning process splits the at least one of the four sub-blocks into three sub-blocks.

2. The method of claim 1 , wherein the bitstream comprises at least one first indication that denotes a usage of the EQT partitioning process for the current visual media block.

3. The method of claim 2 , wherein the bitstream comprises at least one second indication that denotes a usage of a quad tree (QT) partitioning process for another visual media block, wherein the at least one second indication is different from the at least one first indication, and wherein the QT partitioning process splits a visual media block into four equally sized sub-blocks.

4. The method of claim 1 , wherein the EQT partitioning process is an independent partition pattern to a quad tree (QT) partitioning process, and wherein the QT partitioning process splits a visual media block into four equally sized sub-blocks.

5. The method of claim 1 , wherein the bitstream comprises a third indication that denotes a usage of one of the EQT partitioning process or a quad tree (QT) partitioning process for the current visual media block, and when the third indication tells true, further a fourth indication that denotes the EQT partitioning process a usage of the EQT partitioning process instead of the QT partitioning process for the current visual media block is present in the bitstream, and wherein the QT partitioning process splits a visual media block into four equally sized sub-blocks.

6. The method of claim 1 , wherein a top-left coordinate of the current visual media block is denoted (x,y), and wherein the four sub-blocks have top-left coordinates and dimensions given as:

(i) top-left coordinate (x,y) with dimensions H/4×W;

(ii) top-left coordinate (x,y+H/4) with dimensions H/2×W/2;

(iii) top-left coordinate (x+W/2,y+H/4) with dimensions H/2×W/2; and

(iv) top-left coordinate (x,y+3×H/4) with dimensions H/4×W.

7. The method of claim 1 , wherein a top-left coordinate of the current visual media block is denoted (x,y), and wherein the four sub-blocks have top-left coordinates and dimensions given as:

(i) top-left coordinate (x,y) with dimensions H×W/4;

(ii) top-left coordinate (x+W/4,y) with dimensions H/2×W/2;

(iii) top-left coordinate (x+W/4,y+H/2) with dimensions H/2×W/2; and

(iv) top-left coordinate (x+3×W/4,y) with dimensions H×W/4.

8. The method of claim 1 , wherein each of the four sub-blocks is a leaf node.

9. The method of claim 1 , wherein the current visual media block comprises a video block.

10. The method of claim 1 , wherein the current visual media block comprises a single image block.

11. The method of claim 1 , wherein the conversion comprises decoding the current visual media block from the bitstream.

12. The method of claim 1 , wherein the conversion comprises encoding the current visual media block into the bitstream.

13. An apparatus for processing visual media data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

apply, during a conversion between a current visual media block of a visual media and a bitstream of the visual media, an extended quad tree (EQT) partitioning process to the current visual media block that splits the current visual media block into exactly four sub-blocks including at least one sub-block that has a dimension different from half of a width of the current visual media block times half of a height of the current visual media block;

apply, during the conversion and to at least one of the four sub-blocks, at least one of a binary tree (BT) partitioning process, a ternary tree (TT) partitioning process, a quad tree (QT) partitioning process or the EQT partitioning process; and

perform, based on the four sub-blocks and the EQT partitioning process, the conversion,

wherein due to the EQT partitioning process, a first sub-block and a second sub-block of the four sub-blocks have a first dimension, and a third sub-block and a fourth sub-block of the four sub-blocks have a second dimension,

wherein the height (H) and the width (W) of the current visual media block are integers, and the first dimension and the second dimension have two cases:

(i) the first dimension is H/4×W, and the second dimension is H/2×W/2, or

(ii) the first dimension is H×W/4, and the second dimension is H/2×W/2,

wherein luma and chroma components of the four sub-blocks share a same recursive partition mode,

wherein, in response to at least one of the four sub-blocks meeting a size restriction, the EQT partitioning process is not applicable to the chroma component of the at least one of the four sub-blocks and the EQT partitioning process is applicable to the luma component of the at least one of the four sub-blocks to generate more leaf nodes,

wherein the BT partitioning process splits the at least one of the four sub-blocks into two equally sized sub-blocks, wherein the QT partitioning process splits the at least one of the four sub-blocks into four equally sized sub-blocks, and wherein the TT partitioning process splits the at least one of the four sub-blocks into three sub-blocks.

14. A non-transitory computer-readable storage medium storing instructions that cause a processor to:

apply, during a conversion between a current visual media block of a visual media and a bitstream of the visual media, an extended quad tree (EQT) partitioning process to the current visual media block that splits the current visual media block into exactly four sub-blocks including at least one sub-block that has a dimension different from half of a width of the current visual media block times half of a height of the current visual media block;

apply, during the conversion and to at least one of the four sub-blocks, at least one of a binary tree (BT) partitioning process, a ternary tree (TT) partitioning process, a quad tree (QT) partitioning process or the EQT partitioning process; and

perform, based on the four sub-blocks and the EQT partitioning process, the conversion,

wherein due to the EQT partitioning process, a first sub-block and a second sub-block of the four sub-blocks have a first dimension, and a third sub-block and a fourth sub-block of the four sub-blocks have a second dimension,

wherein the height (H) and the width (W) of the current visual media block are integers, and the first dimension and the second dimension have two cases:

(i) the first dimension is H/4×W, and the second dimension is H/2×W/2, or

(ii) the first dimension is H×W/4, and the second dimension is H/2×W/2,

wherein luma and chroma components of the four sub-blocks share a same recursive partition mode,

wherein, in response to at least one of the four sub-blocks meeting a size restriction, the EQT partitioning process is not applicable to the chroma component of the at least one of the four sub-blocks and the EQT partitioning process is applicable to the luma component of the at least one of the four sub-blocks to generate more leaf nodes,

wherein the BT partitioning process splits the at least one of the four sub-blocks into two equally sized sub-blocks, wherein the QT partitioning process splits the at least one of the four sub-blocks into four equally sized sub-blocks, and wherein the TT partitioning process splits the at least one of the four sub-blocks into three sub-blocks.

15. A non-transitory computer-readable recording medium storing a bitstream which is generated by a method performed by a visual media processing apparatus, wherein the method comprises:

applying, during a conversion between a current visual media block of a visual media and the bitstream of the visual media, an extended quad tree (EQT) partitioning process to the current visual media block that splits the current visual media block into exactly four sub-blocks including at least one sub-block that has a dimension different from half of a width of the current visual media block times half of a height of the current visual media block;

applying, during the conversion and to at least one of the four sub-blocks, at least one of a binary tree (BT) partitioning process, a ternary tree (TT) partitioning process, a quad tree (QT) partitioning process or the EQT partitioning process; and

generating the bitstream, based on the four sub-blocks and the EQT partitioning process,

wherein due to the EQT partitioning process, a first sub-block and a second sub-block of the four sub-blocks have a first dimension, and a third sub-block and a fourth sub-block of the four sub-blocks have a second dimension,

wherein the height (H) and the width (W) of the current visual media block are integers, and the first dimension and the second dimension have two cases:

(i) the first dimension is H/4×W, and the second dimension is H/2×W/2, or

(ii) the first dimension is H×W/4, and the second dimension is H/2×W/2,

wherein luma and chroma components of the four sub-blocks share a same recursive partition mode,

wherein, in response to at least one of the four sub-blocks meeting a size restriction, the EQT partitioning process is not applicable to the chroma component of the at least one of the four sub-blocks and the EQT partitioning process is applicable to the luma component of the at least one of the four sub-blocks to generate more leaf nodes,

wherein the BT partitioning process splits the at least one of the four sub-blocks into two equally sized sub-blocks, wherein the QT partitioning process splits the at least one of the four sub-blocks into four equally sized sub-blocks, and wherein the TT partitioning process splits the at least one of the four sub-blocks into three sub-blocks.

16. The apparatus of claim 13 , wherein the bitstream comprises at least one first indication that denotes a usage of the EQT partitioning process for the current visual media block.

17. The apparatus of claim 16 , wherein the bitstream comprises at least one second indication that denotes a usage of a quad tree (QT) partitioning process for another visual media block, wherein the at least one second indication is different from the at least one first indication, and wherein the QT partitioning process splits a visual media block into four equally sized sub-blocks.

18. The apparatus of claim 13 , wherein the EQT partitioning process is an independent partition pattern to a quad tree (QT) partitioning process, and wherein the QT partitioning process splits a visual media block into four equally sized sub-blocks.

19. The apparatus of claim 13 , wherein the bitstream comprises a third indication that denotes a usage of one of the EQT partitioning process or a quad tree (QT) partitioning process for the current visual media block, and when the third indication tells true, further a fourth indication that denotes the EQT partitioning process a usage of the EQT partitioning process instead of the QT partitioning process for the current visual media block is present in the bitstream, and wherein the QT partitioning process splits a visual media block into four equally sized sub-blocks.

20. The non-transitory computer-readable storage medium of claim 14 , wherein the bitstream comprises at least one first indication that denotes a usage of the EQT partitioning process for the current visual media block.