CN-114208204-B - Unified context codec binary bit (CCB) counting method

Abstract

In one implementation, a context codec binary bit (CCB) counting method is unified between a transform residual codec process and a Transform Skip (TS) residual codec process. In one example, in TS residual codec, the coeff_sign_flag is excluded from the CCB count, so that the syntax for the CCB count is uniform for both residual codec processes. Furthermore, the maximum number of individual context codec bits (bins) may be specified and used only for coeff_sign_flag. In another example, in the TS residual codec, the maximum number of CCB counts is reduced from tb_size of 2 to tb_size of 1.75, or more generally, the maximum CCB counts of both the transform residual codec and the TS residual codec are set to the same value, such that the maximum CCB count is uniform for both residual codec processes.

Inventors

• CHEN YA
• F. Lelinek
• F. Garr Ping
• K. Nasser

Assignees

• 交互数字VC控股法国公司

Dates

Publication Date

20260508

Application Date

20200918

Priority Date

20190923

Claims (12)

1. 1. A method of video encoding or decoding, comprising: During a transform skip residual codec process, counting a first number of context codec bits used to encode or decode a set of syntax elements associated with level information of a prediction residual in a block, wherein the set of syntax elements indicates at least one of an importance of the prediction residual, whether an absolute value of the prediction residual is greater than a value, and a parity of the prediction residual for a prediction residual, wherein a limit is used to limit the first number of context codec bits, and wherein the set of syntax elements is context-coded before the first number of context codec bits reaches the limit of context codec bits, and then bypass-decoded after the first number of context codec bits exceeds the limit of context codec bits, and During the transform skip residual codec process, a second number of context codec bits for encoding or decoding a syntax flag set indicating a sign of the prediction residual in the block is counted, wherein the second number of context codec bits is limited using another limit, and wherein the syntax flag set is context-coded before the second number of context codec bits reaches the another limit of context codec bits and then bypass-coded after the second number of context codec bits exceeds the another limit of context codec bits.
2. 2. The method of claim 1, wherein the limit is set to 1.75 x tb_size, wherein tb_size indicates the number of samples in the block.
3. 3. The method of claim 1, wherein a syntax element indicating whether an absolute level of a prediction residual is greater than a value is excluded from counting a first number of the context codec bits.
4. 4. The method of claim 1, wherein the other limit is dependent on tb_size, wherein tb_size indicates the number of samples in the block.
5. 5. The method of claim 4, wherein the other limit is set to 0.5 x tb_size.
6. 6. An apparatus for video encoding or decoding, comprising one or more processors, wherein the one or more processors are configured to: Counting a first number of context codec bits for encoding or decoding a set of syntax elements associated with level information of a prediction residual in a block during a transform skip residual codec process, wherein a limit is used to limit the first number of context codec bits, and wherein the set of syntax elements is context-coded before the first number of context codec bits reaches the limit of context codec bits and then bypass-de-encoded after the first number of context codec bits exceeds the limit of context codec bits, and During the transform skip residual codec process, a second number of context codec bits for encoding or decoding a syntax flag set indicating a sign of the prediction residual in the block is counted, wherein the second number of context codec bits is limited using another limit, and wherein the syntax flag set is context-coded before the second number of context codec bits reaches the another limit of context codec bits and then bypass-coded after the second number of context codec bits exceeds the another limit of context codec bits.
7. 7. The apparatus of claim 6, wherein the limit is set to 1.75 x TB size, wherein TB size indicates the number of samples in the block.
8. 8. The apparatus of claim 6, wherein in the transform skip residual codec process, a syntax element indicating whether an absolute level of a prediction residual is greater than a value is excluded from counting a first number of the context codec bits.
9. 9. The apparatus of claim 6, wherein the other limit is dependent on a tb_size, wherein tb_size indicates a number of samples in the block.
10. 10. The apparatus of claim 9, wherein the other limit is set to 0.5 x tb_size.
11. 11. A non-transitory computer-readable storage medium storing instructions that when executed by a processor implement an encoding or decoding method comprising: Counting a first number of context codec bits for encoding or decoding a set of syntax elements associated with level information of a prediction residual in a block during a transform skip residual codec process, wherein a limit is used to limit the first number of context codec bits, and wherein the set of syntax elements is context-coded before the first number of context codec bits reaches the limit of context codec bits and then bypass-de-encoded after the first number of context codec bits exceeds the limit of context codec bits, and During the transform skip residual codec process, a second number of context codec bits for encoding or decoding a syntax flag set indicating a sign of the prediction residual in the block is counted, wherein the second number of context codec bits is limited using another limit, and wherein the syntax flag set is context-coded before the second number of context codec bits reaches the another limit of context codec bits and then bypass-coded after the second number of context codec bits exceeds the another limit of context codec bits.
12. 12. The medium of claim 11, wherein the other limit is dependent on TB size, wherein TB size indicates the number of samples in the block.

Description

Unified context codec binary bit (CCB) counting method Technical Field The present embodiments relate generally to a context codec binary bit (CCB) scheme for unifying a transform residual and a transform skip residual mode. Background To achieve high compression efficiency, image and video coding schemes typically employ prediction and transformation to exploit spatial and temporal redundancy in video content. In general, intra or inter prediction is used to exploit intra or inter picture correlation, and then the difference between the original block and the predicted block (often denoted as prediction error or prediction residual) is transformed, quantized and entropy coded. To reconstruct video, the compressed data is decoded by an inverse process corresponding to entropy encoding, quantization, transformation, and prediction. Disclosure of Invention According to an embodiment, there is provided a method of video encoding, comprising obtaining prediction residues of a block to be encoded in a picture, counting a number of context codec bits used to encode the prediction residues in the block, wherein the prediction residues of the block are to be encoded using one of a transform residual codec process and a transform skip residual codec process, wherein the transform residual codec process and the transform skip residual codec process use the same boundary to limit the number of context codec bits, and adjusting an entropy codec method of one or more syntax elements in one of the transform residual codec process and the transform skip residual codec process in response to the boundary and the number of context codec bits. According to another embodiment, there is provided a method of video decoding comprising counting a number of context codec bits used to decode a prediction residual in the block, wherein the prediction residual of the block is to be decoded using one of a transform residual decoding process and a transform skip residual decoding process, wherein the transform residual decoding process and the transform skip residual decoding process use the same boundary to limit the number of context codec bits, adjusting an entropy decoding method of one or more syntax elements in one of the transform residual decoding process and the transform skip residual decoding process in response to the boundary and the number of context codec bits, and obtaining a prediction residual of a block to be decoded in a picture. According to another embodiment, an apparatus for video encoding includes one or more processors configured to obtain prediction residues of a block to be encoded in a picture, count a number of context codec bits used to encode the prediction residues in the block, wherein the prediction residues of the block are to be encoded using one of a transform residual codec process and a transform skip residual codec process, wherein the transform residual codec process and the transform skip residual codec process use a same boundary to limit the number of context codec bits, and adjust an entropy codec method of one or more syntax elements in one of the transform residual codec process and the transform skip residual codec process in response to the boundary and the number of context codec bits. According to another embodiment, an apparatus for video decoding includes one or more processors, wherein the one or more processors are configured to count a number of context codec bits used to decode a prediction residual in the block, wherein the prediction residual of the block is to be decoded using one of a transform residual decoding process and a transform skip residual decoding process, wherein the transform residual decoding process and the transform skip residual decoding process use a same boundary to limit the number of context codec bits, adjust an entropy decoding method of one or more syntax elements in one of the transform residual decoding process and the transform skip residual decoding process in response to the boundary and the number of context codec bits, and obtain a prediction residual of a block to be decoded in a picture. One or more embodiments also provide a computer program comprising instructions that, when executed by one or more processors, cause the one or more processors to perform an encoding method or a decoding method according to any of the embodiments described above. One or more of the present embodiments also provides a computer-readable storage medium having instructions stored thereon for encoding or decoding video data according to the above-described method. One or more embodiments also provide a computer readable storage medium having stored thereon a bitstream generated according to the above method. One or more embodiments also provide a method and apparatus for transmitting or receiving a bitstream generated according to the above method. Drawings FIG. 1 illustrates a block diagram of a system in which aspects of the present embodiments may be implemente