RU2023120513A

RU2023120513A - ENCODER, DECODER AND CORRESPONDING METHODS USING DCT2 HIGH LEVEL PERMISSION FLAG

Info

Publication number: RU2023120513A
Application number: RU2023120513A
Authority: RU
Inventors: Хань ГАО; Цзянле ЧЕН; Семих ЭСЕНЛИК; Ананд Меер КОТРА; Бяо ВАН
Original assignee: Хуавэй Текнолоджиз Ко., Лтд.
Priority date: 2019-01-11
Filing date: 2020-01-11
Publication date: 2023-08-11

Claims

1. A method containing:

receiving a bitstream, the bitstream including a sequence parameter set (SPS), the SPS including a flag indicating whether a Type 2 Discrete Cosine Transform (DCT2) transform kernel is used for the current block;

receiving the residual signal of the current block;

determining whether a DCT2 transformation core is used for the current block based on said flag;

in response to determining that a DCT2 transform kernel is used for the current block, performing an inverse transform on the residual signal of the current block using the DCT2 transform kernel to obtain a reconstructed residual block;

obtaining a reconstructed block based on the reconstructed residual block.

2. The method of claim 1, wherein said flag is referred to as sps_dct2_enabled_flag.

3. The method of claim 2, wherein the SPS further includes sps_mts_intra_enabled_flag and sps_mts_inter_enabled_flag.

4. The method of claim 3, wherein the SPS includes the following structure:

seq_parameter_set_rbsp( ) { Descriptor … ue(v) sps_dct2_enabled_flag if (! sps_dct2_enabled_flag) { sps_mts_intra_enabled_flag u(1) sps_mts_inter_enabled_flag u(1) } …… u(1) }

5. The method of claim 1, wherein said flag, equal to the first value, specifies that a DCT2 transform kernel is used for the transform.

6. The method of claim 1, wherein said flag, equal to the second value, specifies that a different transformation core than DCT2 is used for the transformation.

7. The method of claim 6, wherein the other transform kernel comprises a type 7 discrete sine transform (DST7) or a type 8 discrete cosine transform (DCT8).

8. Video encoding method, comprising:

getting the current block;

obtaining a residual block corresponding to the current block;

determining a transform kernel for the residual block, wherein the transform kernel is either a Type 2 Discrete Cosine Transform (DCT2) transform kernel or a different transform kernel than DCT2;

performing a transform on the residual block using the determined transform kernel to obtain transform coefficients of the current block;

bitstream generation includes a sequence parameter set (SPS) and encoded image data obtained based on transform coefficients, wherein the SPS includes a flag indicating whether a DCT2 transform kernel or another transform kernel is used for the current block.

9. The method of claim 8, wherein said flag is referred to as sps_dct2_enabled_flag.

10. The method of claim 9, wherein the SPS further includes sps_mts_intra_enabled_flag and sps_mts_inter_enabled_flag.

11. The method of claim 10, wherein the SPS includes the following structure:

12. The method of claim 8, wherein said flag, equal to the first value, specifies that a DCT2 transform kernel is used for the transformation.

13. The method of claim 8, wherein said flag, equal to the second value, specifies that a different transformation core than DCT2 is used for the transformation.

14. The method of claim 13, wherein the other transform kernel comprises a type 7 discrete sine transform (DST7) or a type 8 discrete cosine transform (DCT8).

15. A decoding device, comprising:

a receiver configured to receive a bitstream for video signals, the bitstream comprising a sequence parameter set (SPS) and encoded picture data, the encoded picture data being obtained based on the transform coefficients of the current block, the transform coefficients being obtained by performing a transformation on the residual block of the current frame using a transform kernel, wherein the transform kernel is either a Type 2 Discrete Cosine Transform (DCT2) transform kernel or a different transform kernel than DCT2; and the SPS includes a flag indicating whether a DCT2 transform core or another transform core is used for the current block; a decoder configured to decode the bit stream by performing the method according to any one of claims 1-7.