CN-122003865-A - Encoding/decoding method, code stream, encoder, decoder, and storage medium

Abstract

The embodiment of the application discloses a coding and decoding method, a code stream, an encoder, a decoder and a storage medium, wherein the method comprises the steps of analyzing the code stream and determining the value of first grammar identification information; if the first grammar identification information indicates that the current block uses a cross-component prediction export mode, analyzing the code stream to determine a value of second grammar identification information, if the second grammar identification information indicates that the current block uses the cross-component prediction export fusion mode, analyzing the code stream to determine at least one fusion type identification value corresponding to the current block, determining at least one chroma prediction mode corresponding to the current block according to the at least one fusion type identification value, performing chroma intra-prediction on the current block by using the at least one chroma prediction mode to determine at least one first prediction value, performing chroma intra-prediction on the current block by using the cross-component prediction export mode to determine a second prediction value, and determining the chroma prediction value corresponding to the current block based on the at least one first prediction value and the second prediction value. Thus, the prediction accuracy of the chroma fusion mode can be improved, and the coding and decoding efficiency can be improved.

Inventors

• HUANG HANG

Assignees

• OPPO广东移动通信有限公司

Dates

Publication Date

20260508

Application Date

20230928

Claims (20)

1. A decoding method applied to a decoder, the method comprising: Analyzing the code stream and determining the value of the first grammar identification information; if the first grammar identification information indicates that the current block uses a cross-component prediction export mode, analyzing a code stream and determining the value of second grammar identification information; if the second grammar identification information indicates that the current block uses cross-component prediction to derive a fusion mode, analyzing a code stream and determining at least one fusion type identification value corresponding to the current block; Determining at least one chroma prediction mode corresponding to the current block according to the at least one fusion type identification value; Performing intra-chroma prediction on the current block by using the at least one chroma prediction mode, and determining at least one first prediction value; performing chroma intra prediction on the current block by using a cross-component prediction export mode, and determining a second predicted value; And determining a chroma prediction value corresponding to the current block based on the at least one first prediction value and the second prediction value.
2. The method of claim 1, wherein the determining at least one chroma prediction mode corresponding to the current block according to the at least one fusion type-identifying value comprises: And determining at least one chroma prediction mode corresponding to the current block according to the at least one fusion type identification value in a preset corresponding relation between the fusion type identification value and the chroma prediction mode, wherein the preset corresponding relation comprises at least one preset fusion type identification value corresponding to the at least one preset chroma prediction mode.
3. The method of claim 2, wherein the at least one preset chroma prediction mode comprises at least one of a cross-component linear model prediction mode, MMLM mode, a convolutional cross-component model mode, a GLM mode, DIMD mode, and a DM mode.
4. A method according to any one of claims 1-3, wherein the method further comprises: and if the first grammar identification information indicates that the current block does not use a cross-component prediction export mode, performing chroma intra prediction on the current block through the cross-component prediction mode, and determining a chroma prediction value corresponding to the current block.
5. A method according to any one of claims 1-3, wherein the method further comprises: And if the second grammar identification information indicates that the current block does not use the cross-component prediction to derive a fusion mode, performing chroma intra prediction on the current block through the cross-component prediction derivation mode, and determining a chroma prediction value corresponding to the current block.
6. The method of any of claims 1-3, wherein the determining a chroma prediction value corresponding to the current block based on the at least one first prediction value and the second prediction value comprises: According to at least two preset weights, carrying out weighted summation on the at least one first predicted value and the second predicted value, and determining a weighted summation value; And determining a shifting factor according to the at least two preset weights, shifting the weighted summation value according to the shifting factor, and determining the chroma prediction value.
7. The method of claim 1, wherein the method further comprises: If the first grammar identification information indicates that the current block uses a cross-component prediction export mode, performing chroma intra prediction according to the cross-component prediction export mode and the cross-component prediction export fusion mode respectively based on a template area of the current block, and determining a first generation value corresponding to the cross-component prediction export mode and a second generation value corresponding to the cross-component prediction export fusion mode; Determining whether the current block derives a fusion mode using cross-component prediction according to the first cost value and the second cost value; if the current block is determined to use the cross-component prediction to derive a fusion mode, analyzing a code stream, and determining at least one fusion type identification value corresponding to the current block.
8. The method of claim 1 or 7, wherein the method further comprises: In the case that the current block uses cross-component prediction to derive a fusion mode, determining at least one chroma prediction mode corresponding to the current block according to chroma intra prediction on a template area of the current block.
9. An encoding method applied to an encoder, the method comprising: Determining the value of first grammar identification information; If the first grammar identification information indicates that the current block uses a cross-component prediction export mode, determining the value of second grammar identification information; And if the second grammar identification information indicates that the current block uses cross-component prediction to derive a fusion mode, determining at least one chroma prediction mode corresponding to the current block and determining at least one fusion type identification value corresponding to the at least one chroma prediction mode, wherein the at least one fusion type identification value is used for determining at least one first prediction value of chroma intra-frame prediction of the fusion mode, which is derived by the current block based on cross-component prediction, by a decoder.
10. The method of claim 9, wherein the determining at least one chroma prediction mode corresponding to the current block comprises: determining at least one coding cost corresponding to the at least one preset chroma prediction mode; The at least one chroma prediction mode is determined from the at least one preset chroma prediction mode based on the at least one coding cost.
11. The method of claim 9 or 10, wherein the at least one preset chroma prediction mode comprises at least one of a cross-component linear model prediction mode, MMLM mode, a convolutional cross-component model mode, a GLM mode, a DIMD mode, and a DM mode.
12. The method of claim 11, wherein the determining at least one fusion type identification value corresponding to the at least one chroma prediction mode comprises: And determining at least one fusion type identification value corresponding to the current block in a preset corresponding relation between the fusion type identification value and the chroma prediction mode according to the at least one chroma prediction mode, wherein the preset corresponding relation comprises at least one preset fusion type identification value corresponding to the at least one preset chroma prediction mode.
13. The method of claim 10, wherein the determining at least one coding cost corresponding to the at least one preset chroma prediction mode comprises: determining a first chroma prediction value corresponding to each preset chroma prediction mode in the at least one preset chroma prediction mode; and determining the coding cost corresponding to each preset chroma prediction mode according to the first chroma prediction value corresponding to each preset chroma prediction mode and the chroma value of the current block, thereby determining the at least one coding cost.
14. The method of claim 13, wherein the method further comprises: Determining at least one first chroma prediction value corresponding to the at least one chroma prediction mode according to the first chroma prediction value corresponding to each preset chroma prediction mode; performing chroma intra prediction on the current block by using a cross-component prediction export mode, and determining a second predicted value; And determining a chroma prediction value corresponding to the current block based on the at least one first prediction value and the second prediction value.
15. The method of claim 14, wherein the determining, based on the at least one first predictor and the second predictor, a chroma prediction value corresponding to the current block comprises: According to at least two preset weights, carrying out weighted summation on the at least one first predicted value and the second predicted value, and determining a weighted summation value; And determining a shifting factor according to the at least two preset weights, shifting the weighted summation value according to the shifting factor, and determining the chroma prediction value.
16. The method of claim 9, wherein the method further comprises: If the first grammar identification information indicates that the current block uses a cross-component prediction export mode, performing chroma intra prediction according to the cross-component prediction export mode and the cross-component prediction export fusion mode respectively based on a template area of the current block, and determining a first generation value corresponding to the cross-component prediction export mode and a second generation value corresponding to the cross-component prediction export fusion mode; Determining whether the current block derives a fusion mode using cross-component prediction according to the first cost value and the second cost value; And if the current block is determined to use the cross-component prediction to derive a fusion mode, determining at least one fusion type identification value corresponding to the current block.
17. The method according to claim 9 or 16, wherein the method further comprises: And under the condition that the current block uses cross-component prediction to derive a fusion mode, determining at least one fusion type identification value corresponding to the current block according to intra-chroma prediction on a template area of the current block.
18. The method of claim 9, wherein the method further comprises: If the fact that the current block does not use the cross-component prediction export mode is determined, determining a predicted value of chroma intra prediction of the current block through the cross-component prediction mode as a chroma predicted value corresponding to the current block.
19. The method of claim 9, wherein the method further comprises: and if the current block is determined not to use the cross-component prediction to derive the fusion mode, determining a predicted value of the intra-chroma prediction of the current block through the cross-component prediction derivation mode as a chroma predicted value corresponding to the current block.
20. The method of any of claims 9, 10, 12-16, wherein the method further comprises: Determining a residual error corresponding to the current block according to the chroma predicted value corresponding to the current block and the chroma value of the current block; generating a code stream based on the residual, the first syntax identification information, the second syntax identification information, and the at least one fusion type identification value.

Description

Encoding/decoding method, code stream, encoder, decoder, and storage medium Technical Field The embodiment of the application relates to the technical field of video encoding and decoding, in particular to an encoding and decoding method, a code stream, an encoder, a decoder and a storage medium. Background On the basis of the latest video coding standard H.266/multifunctional video coding (VERSATILE VIDEO CODING, VVC) reference software test platform, a new generation of reference software model, namely an enhanced compression model (Enhanced Compression Model, ECM), is proposed by the joint video expert group (Joint Video Experts Team, JVET). In the ECM, the intra prediction part may include luminance intra prediction and chrominance intra prediction. The chroma intra prediction comprises a prediction method for deriving a fusion mode through component prediction. The cross component prediction derived fusion mode is to fuse the cross component prediction derived mode with a default cross component prediction mode, the fusion mode is single, and the advantages of the fusion mode cannot be exerted, so that the encoding and decoding efficiency is low. Disclosure of Invention The embodiment of the application provides a coding and decoding method, a code stream, an encoder, a decoder and a storage medium, which can improve the prediction accuracy of a cross-component prediction derived fusion mode, thereby improving coding and decoding efficiency. The technical scheme of the embodiment of the application can be realized as follows: In a first aspect, an embodiment of the present application provides a decoding method, applied to a decoder, including: Analyzing the code stream and determining the value of the first grammar identification information; if the first grammar identification information indicates that the current block uses a cross-component prediction export mode, analyzing a code stream and determining the value of second grammar identification information; if the second grammar identification information indicates that the current block uses cross-component prediction to derive a fusion mode, analyzing a code stream and determining at least one fusion type identification value corresponding to the current block; Determining at least one chroma prediction mode corresponding to the current block according to the at least one fusion type identification value; Performing intra-chroma prediction on the current block by using the at least one chroma prediction mode, and determining at least one first prediction value; performing chroma intra prediction on the current block by using a cross-component prediction export mode, and determining a second predicted value; And determining a chroma prediction value corresponding to the current block based on the at least one first prediction value and the second prediction value. In a second aspect, an embodiment of the present application provides an encoding method, applied to an encoder, including: Determining the value of first grammar identification information; If the first grammar identification information indicates that the current block uses a cross-component prediction export mode, determining the value of second grammar identification information; And if the second grammar identification information indicates that the current block uses cross-component prediction to derive a fusion mode, determining at least one chroma prediction mode corresponding to the current block and determining at least one fusion type identification value corresponding to the at least one chroma prediction mode, wherein the at least one fusion type identification value is used for determining at least one first prediction value of chroma intra-frame prediction of the fusion mode, which is derived by the current block based on cross-component prediction, by a decoder. In a third aspect, an embodiment of the present application provides a code stream, where the code stream is generated by performing bit encoding according to information to be encoded, where the information to be encoded at least includes at least one of the following: The value of the first grammar identification information, the value of the second grammar identification information and at least one fusion type identification value; The first grammar identification information is used for indicating whether the current block uses a cross-component prediction export mode, the second grammar identification information is used for indicating whether the current block uses the cross-component prediction export fusion mode, and the at least one fusion type identification value is used for indicating at least one chroma prediction mode corresponding to the current block. In a fourth aspect, an embodiment of the present application provides an encoder, including a first determining portion configured to determine a value of first syntax identification information, if the first syntax identification information indic