KR-102963122-B1 - Zero residual flag coding

Abstract

The present disclosure relates to an improved video coding method for zero residual or zero count flags. For example, a method for decoding a current block in a video stream is disclosed. The method comprises the steps of: determining a zero skip flag of one or more neighbor blocks of the current block as a reference zero skip flag; determining a prediction mode for the current block as an intra prediction mode or an inter prediction mode; deriving one or more contexts for decoding a zero skip flag of the current block based on the reference zero skip flag and the current prediction mode; and decoding a zero skip flag of the current block according to the one or more contexts.

Inventors

• 자오 량
• 리우 샨

Assignees

• 텐센트 아메리카 엘엘씨

Dates

Publication Date

20260512

Application Date

20220128

Priority Date

20220111

Claims (20)

1. As a video decoding method, A step of receiving a video bitstream containing a plurality of blocks including the current block; A step of determining the value of a first reference zero-skip flag of a first neighbor block of the current block; A step of deriving at least one first context for decoding the zero skip flag of the current block based on the value of the first reference zero skip flag; A step of decoding the zero skip flag of the current block according to at least one first context; A step of deriving at least one second context for decoding the prediction mode (is-inter) flag of the current block based on the value of the zero skip flag; The step of decoding the is-inter flag of the current block according to at least one second context; and A step of decoding the current block according to the zero skip flag and the is-inter flag. A method including
2. In paragraph 1, The method further includes the step of determining the value of a second reference zero skip flag of a second neighbor block of the current block, and A method in which at least one first context for decoding the zero skip flag of the current block is additionally based on the value of the second reference zero skip flag.
3. In paragraph 2, A method for deriving the at least one first context based on the first reference zero skip flag and the second reference zero skip flag, comprising deriving the at least one first context based on the sum of the first reference zero skip flag and the second reference zero skip flag.
4. In paragraph 2, A method in which the first neighbor block and the second neighbor block each include the upper neighbor block and the left neighbor block of the current block.
5. In paragraph 1, A method in which at least one second context for decoding the above is-inter flag is additionally based on the first reference zero skip flag of the first neighbor block.
6. In paragraph 5, A method in which the first neighbor block includes an upper neighbor block or a left neighbor block.
7. In paragraph 1, The step of deriving at least one second context for decoding the is-inter flag of the current block based on the value of the zero skip flag is: When the value of the zero skip flag is equal to 0, the step of selecting a first set of one or more contexts as the at least one second context; and A method comprising the step of selecting a second set of one or more contexts as at least one second context when the value of the zero skip flag is not equal to 0.
8. In paragraph 1, A method in which the above zero skip flag is signaled before the above is-inter flag in the above video bitstream.
9. As a computing system, Control circuit; and It includes a memory for storing one or more programs configured to be executed by the above-mentioned control circuit, and the one or more programs are Receiving video data corresponding to multiple blocks containing the current block; Determining the value of the first reference zero skip flag of the first neighbor block of the above current block; Deriving at least one first context for encoding the zero skip flag of the current block based on the value of the first reference zero skip flag; Encoding the zero skip flag of the current block according to at least one first context; Deriving at least one second context for encoding the prediction mode (is-inter) flag of the current block based on the value of the zero skip flag; Encoding the is-inter flag of the current block according to at least one second context; and A computing system comprising instructions for encoding the current block according to the above zero skip flag and the above is-inter flag.
10. In Paragraph 9, A computing system comprising one or more of the above programs further including the encoded zero skip flag, the encoded is-inter flag, and instructions for signaling the encoded current block in a video bitstream.
11. In Paragraph 10, A computing system in which the encoded zero skip flag is signaled before the encoded is-inter flag in the video bitstream.
12. In Paragraph 9, A computing system for encoding the at least one first context for encoding the zero skip flag of the current block, which is additionally based on the value of the second reference zero skip flag of the second neighbor block of the current block.
13. In Paragraph 12, A computing system in which at least one first context for encoding the zero skip flag of the current block is based on the sum of the first reference zero skip flag and the second reference zero skip flag.
14. In Paragraph 12, A computing system in which the first neighbor block and the second neighbor block each include the top neighbor block and the left neighbor block of the current block.
15. In Paragraph 9, A computing system in which the at least one second context for encoding the above is-inter flag is additionally based on the first reference zero skip flag of the above first neighbor block.
16. In paragraph 15, A computing system in which the first neighbor block includes an upper neighbor block or a left neighbor block.
17. In Paragraph 9, Deriving at least one second context for encoding the is-inter flag of the current block based on the value of the zero skip flag is: When the value of the above zero skip flag is equal to 0, selecting a first set of one or more contexts as the at least one second context; and A computing system comprising selecting a second set of one or more contexts as at least one second context when the value of the zero skip flag is not equal to 0.
18. A non-transient computer-readable storage medium for storing one or more programs to be executed by a control circuit of a computing system, wherein the one or more programs are Acquiring a source video sequence; and Includes instructions for performing conversion between the source video sequence and the video bitstream according to format rules, The above video bitstream is, A plurality of encoded blocks corresponding to the above source video sequence - the plurality of encoded blocks include the current block -; The encoded zero skip flag for the current block above; and Includes an encoded prediction mode (is-inter) flag for the current block above; The above format rules are, At least one first context for decoding the encoded zero skip flag is based on the value of a first reference zero skip flag of a first neighbor block of the current block; A non-transient computer-readable storage medium specifying that at least one second context for decoding the encoded is-inter flag is based on the value of the encoded zero-skip flag.
19. In Paragraph 18, A non-transient computer-readable storage medium, wherein the above format rule also specifies that the at least one first context for decoding the encoded zero skip flag is additionally based on the value of a second reference zero skip flag of a second neighbor block of the current block.
20. In Paragraph 18, A non-transient computer-readable storage medium, wherein the above format rule also specifies that the at least one second context for decoding the encoded is-inter flag is additionally based on the first reference zero skip flag of the first neighbor block.

Description

Zero residual flag coding Integration by reference This application is based on and claims priority to U.S. Patent Application No. 17/573,299, filed on January 11, 2022, which claims priority to U.S. Provisional Application No. 63/209,261, filed on June 10, 2021, titled "ZERO RESIDUAL FLAG CODING". The entire contents of both of the above applications are incorporated into this application by reference. The present disclosure generally relates to a set of advanced video coding/decoding techniques, and more specifically to an improved coding method for zero residual or zero coefficient flags. The background description provided in this specification is generally intended to provide the context of the present disclosure. Within the scope of the works described in this background section, the works of the currently named inventors and aspects of the description that may not be recognized as prior art at the time of filing this application are not recognized as prior art of the present disclosure, either expressly or impliedly. Video coding and decoding can be performed using inter-picture prediction along with motion compensation. Uncompressed digital video may contain a series of pictures, each having a spatial dimension of, for example, 1920×1080 luminance samples (also called luminance samples) and associated full or partial sampled chrominance samples (also called chroma samples). The series of pictures may have a fixed or variable picture rate (or frame rate), for example, 60 pictures per second or 60 frames per second. Uncompressed video has specific bitrate requirements for streaming or data processing. For example, video with a pixel resolution of 1920×1080, a frame rate of 60 frames/second, and 4:2:0 chroma sampling at 8 bits per pixel per color channel requires bandwidth close to 1.5 Gbit/s. One hour of such video requires more than 600 GB of storage space. One objective of video coding and decoding may be to reduce the redundancy of the uncompressed input video signal through compression. Compression can help reduce the aforementioned bandwidth and/or storage requirements by more than double orders of magnitude in some cases. Both lossless compression and lossy compression, as well as combinations thereof, can be used. Lossless compression refers to a technique that allows an exact copy of the original signal to be reconstructed from the compressed original signal during the decoding process. Lossy compression refers to a coding/decoding process where the original video information is not fully preserved during coding and cannot be fully recovered during decoding. When using lossy compression, the reconstructed signal may not be identical to the original signal, but the distortion between the original and reconstructed signals is made small enough that the reconstructed signal remains useful for the intended application despite some information loss. For video, lossy compression is widely adopted in many applications. The amount of acceptable distortion varies depending on the application. For example, users of certain consumer video streaming applications may tolerate higher distortion than users of movie or television broadcast applications. The compression ratios achievable by specific coding algorithms can be selected or adjusted to reflect various distortion tolerances: higher acceptable distortion generally allows for coding algorithms that produce higher loss and higher compression ratios. Video encoders and decoders can utilize techniques from various broad categories and stages, including, for example, motion compensation, Fourier transform, quantization, and entropy coding. Video codec technology may include a technique known as intra coding. In intra coding, sample values are represented without reference to samples of a previously reconstructed reference picture or other data. In some video codecs, a picture is spatially subdivided into blocks of samples. If all blocks of samples are coded in intra mode, the picture may be referred to as an intra picture. Derivations such as the intra picture and the independent decoder refresh picture can be used to reset the decoder state and thus serve as the first picture or still image of the coded video bitstream and video session. Block samples following intra prediction can then undergo a transformation into the frequency domain, and the resulting transformation coefficients can be quantized before entropy coding. Intra prediction refers to a technique that minimizes sample values in the pre-transform domain. In some cases, the smaller the DC value after conversion and the smaller the AC coefficient, the fewer bits are required at a given quantization step size to represent the block after entropy coding. For example, traditional intra-coding, such as that known from MPEG-2 generative coding techniques, does not use intra-prediction. However, some new video compression techniques include methods that attempt to code/decode blocks based on metadat