Encoding method and apparatus
A video decoding method, including: parsing a received bitstream to obtain prediction information of a coding unit (CU); obtaining a target transform mode of a residual transform unit (TU); parsing the received bitstream to obtain transform coefficients of the residual TU; applying an inverse quantization to the transform coefficients of the residual TU to obtain dequantized coefficients; applying, based on the target transform mode, an inverse transform to the dequantized coefficients to obtain a residual block of the residual TU; obtaining a prediction block of the CU based on the prediction information; obtaining a video block based on the residual block and the prediction block; and outputting a video sequence including a video frame that includes the video block.
1. A video processing method, comprising:
obtaining prediction information of a coding unit (CU);
obtaining, when the CU comprises only one residual transform unit (TU) and a size of the residual TU is less than a size of the CU, a TU partitioning mode of the CU and a residual position of the residual TU, wherein the residual TU comprises a residual for Cb, Cr, and Y components;
selecting, based on the TU partitioning mode and the residual position, a transform type of the residual TU from a transform type set;
applying, based on the transform type of the residual TU, an inverse transform to dequantized coefficients of the residual TU to obtain a residual block of the residual TU;
obtaining a prediction block of the CU based on the prediction information; and
obtaining a video block based on the residual block and the prediction block.
2. The video processing method according to claim 1 , wherein the transform type set includes two or more transform types.
3. The video processing method according to claim 2 , wherein the two or more transform types comprise:
transform type 1, wherein in the transform type 1 a horizontal transform is based on discrete sine transform (DST) type VII (DST-7) and a vertical transform is based on the DST-7;
transform type 2, wherein in the transform type 2 the horizontal transform is based on the DST-7 and the vertical transform is based on discrete cosine transform (DCT) type VIII (DCT-8);
transform type 3, wherein in the transform type 3 the horizontal transform is based on the DCT-8 and the vertical transform is based on the DST-7; and
transform type 4, wherein in the transform type 4 the horizontal transform is based on the DCT-8 and the vertical transform is based on the DCT-8.
4. The video processing method according to claim 1 , wherein:
the TU partitioning mode specifies that the CU is partitioned into 2 TUs arranged horizontally, wherein a size of a left TU is smaller than, greater than, or equal to a size of a right TU; or
the TU partitioning mode specifies that the CU is partitioned into 2 TUs arranged vertically, wherein a size of a top TU is smaller than, greater than, or equal to a size of a bottom TU.
5. The video processing method according to claim 4 , wherein:
the residual position is left or right when the CU is partitioned into 2 TUs arranged horizontally; or
the residual position is top or bottom when the CU is partitioned into 2 TUs arranged vertically.
6. The video processing method according to claim 5 , wherein the size of the CU is denoted by WxH, and wherein:
the transform type is a first transform type when the CU is partitioned into 2 TUs arranged vertically and the residual position is top, wherein in the first transform type a horizontal transform is based on discrete sine transform (DST) type VII (DST-7) and a vertical transform is based on discrete cosine transform (DCT) type VIII (DCT-8);
the transform type is a second transform type when the CU is partitioned into 2 TUs arranged vertically and the residual position is bottom, wherein in the second transform type the horizontal transform is based on the DST-7 and the vertical transform is based on the DST-7;
the transform type is a third transform type when the CU is partitioned into 2 TUs arranged horizontally and the residual position is left, wherein in the third transform type the horizontal transform is based on the DCT-8 and the vertical transform is based on the DST-7; and
the transform type is the second transform type when the CU is partitioned into 2 TUs arranged horizontally and the residual position is right.
7. The video processing method of claim 1 , wherein obtaining the prediction information comprises:
receiving a bitstream; and
parsing the bitstream to obtain the prediction information.
8. A video data decoding device, comprising:
a non-transitory memory storage configured to store video data in a form of a bitstream; and
one or more processor coupled to the non-transitory memory storage and configured to:
obtain prediction information of a coding unit (CU);
obtain, when the CU comprises only one residual transform unit (TU) and a size of the residual TU is less than a size of the CU, a TU partitioning mode of the CU and a residual position of the residual TU, wherein the residual TU comprises a residual for Cb, Cr, and Y components;
select, based on the TU partitioning mode and the residual position, a transform type of the residual TU from a transform type set;
apply, based on the transform type of the residual TU, an inverse transform to dequantized coefficients of the residual TU to obtain a residual block of the residual TU;
obtain a prediction block of the CU based on the prediction information; and
obtain a video block based on the residual block and the prediction block.
9. The video data decoding device according to claim 8 , wherein the transform type set includes two or more transform types.
10. The video data decoding device according to claim 9 , wherein the two or more transform types comprise:
transform type 1, wherein in the transform type 1 a horizontal transform is based on discrete sine transform (DST) type VII (DST-7) and a vertical transform is based on DST-7;
transform type 2, wherein in the transform type 2 the horizontal transform is based on the DST-7 and the vertical transform is based on discrete cosine transform (DCT) type VIII (DCT-8);
transform type 3, wherein in the transform type 3 the horizontal transform is based on the DCT-8 and the vertical transform is based on the DST-7; and
transform type 4, wherein in the transform type 4 the horizontal transform is based on the DCT-8 and the vertical transform is based on the DCT-8.
11. The video data decoding device according to claim 8 , wherein:
the TU partitioning mode specifies that the CU is partitioned into 2 TUs arranged horizontally, wherein a size of a left TU is smaller than, greater than, or equal to a size of a right TU; or
the TU partitioning mode specifies that the CU is partitioned into 2 TUs arranged vertically, wherein a size of a top TU is smaller than, greater than, or equal to a size of a bottom TU.
12. The video data decoding device according to claim 11 , wherein:
the residual position is left or right when the CU is partitioned into 2 TUs arranged horizontally; or
the residual position is top or bottom when the CU is partitioned into 2 TUs arranged vertically.
13. The video data decoding device according to claim 12 , wherein the size of the CU is denoted by W×H, and wherein:
the transform type is a first transform type when the CU is partitioned into 2 TUs arranged vertically and the residual position is top, wherein in the first transform type a horizontal transform is based on discrete sine transform (DST) type VII (DST-7) and a vertical transform is based on discrete cosine transform (DCT) type VIII (DCT-8);
the transform type is a second transform type when the CU is partitioned into 2 TUs arranged vertically and the residual position is bottom, wherein in the second transform type the horizontal transform is based on the DST-7 and the vertical transform is based on the DST-7;
the transform type is a third transform type when the CU is partitioned into 2 TUs arranged horizontally and the residual position is left, wherein in the third transform type the horizontal transform is based on the DCT-8 and the vertical transform is based on the DST-7; and
the transform type is the second transform type when the CU is partitioned into 2 TUs arranged horizontally and the residual position is right.
14. The video data decoding device according to claim 8 , wherein the one or more processors are further configured to parse the bitstream to obtain the prediction information.
15. A non-transitory computer readable storage medium storing computer program code, which when executed by a processor, causes a video data decoding device to:
obtain prediction information of a coding unit (CU);
obtain, when the CU comprises only one residual transform unit (TU) and a size of the residual TU is less than a size of the CU, a TU partitioning mode of the CU and a residual position of the residual TU, wherein the residual TU comprises a residual for Cb, Cr, and Y components;
select, based on the TU partitioning mode and the residual position, a transform type of the residual TU from a transform type set;
apply, based on the transform type of the residual TU, an inverse transform to dequantized coefficients of the residual TU to obtain a residual block of the residual TU;
obtain a prediction block of the CU based on the prediction information; and
obtain a video block based on the residual block and the prediction block.
16. The non-transitory computer readable storage medium according to claim 15 , wherein the transform type set includes two or more transform types.
17. The non-transitory computer readable storage medium according to claim 16 , wherein the two or more transform types comprise:
transform type 1, wherein in the transform type 1 a horizontal transform is based on discrete sine transform (DST) type VII (DST-7) and a vertical transform is based on DST-7;
transform type 2, wherein in the transform type 2 the horizontal transform is based on the DST-7 and the vertical transform is based on discrete cosine transform (DST) type VIII (DCT-8);
transform type 3, wherein in the transform type 3 the horizontal transform is based on the DCT-8 and the vertical transform is based on the DST-7; and
transform type 4, wherein in the transform type 4 the horizontal transform is based on the DCT-8 and the vertical transform is based on the DCT-8.
18. The non-transitory computer readable storage medium according to claim 15 , wherein:
the TU partitioning mode specifies that the CU is partitioned into 2 TUs arranged horizontally, wherein a size of a left TU is smaller than, greater than, or equal to a size of a right TU; or
the TU partitioning mode specifies that the CU is partitioned into 2 TUs arranged vertically, wherein a size of a top TU is smaller than, greater than, or equal to a size of a bottom TU.
19. The non-transitory computer readable storage medium according to claim 18 , wherein:
the residual position is left or right when the CU is partitioned into 2 TUs arranged horizontally; or
the residual position is top or bottom when the CU is partitioned into 2 TUs arranged vertically.
20. The non-transitory computer readable storage medium according to claim 19 , wherein the size of the CU is denoted by W×H, and wherein:
the transform type is a first transform type when the CU is partitioned into 2 TUs arranged vertically and the residual position is top, wherein in the first transform type a horizontal transform is based on discrete sine transform (DST) type VII (DST-7) and a vertical transform is based on discrete cosine transform (DCT) type VIII (DCT-8);
the transform type is a second transform type when the CU is partitioned into 2 TUs arranged vertically and the residual position is bottom, wherein in the second transform type the horizontal transform is based on the DST-7 and the vertical transform is based on the DST-7;
the transform type is a third transform type when the CU is partitioned into 2 TUs arranged horizontally and the residual position is left, wherein in the third transform type the horizontal transform is based on the DCT-8 and the vertical transform is based on the DST-7; and
the transform type is the second transform type when the CU is partitioned into 2 TUs arranged horizontally and the residual position is right.