BR-112022005046-B1 - Video data processing method, device for processing video data, computer-readable non-transitary storage medium, and computer-readable non-transitary recording medium.

BR112022005046B1BR 112022005046 B1BR112022005046 B1BR 112022005046B1BR-112022005046-B1

Abstract

A method for processing video data, an apparatus for processing video data, a computer-readable non-transient storage medium, and a computer-readable non-transient recording medium. Methods, systems, and devices for signaling the use of adaptive loop filtering in image and video coding are described. An exemplary video processing method includes determining, for a conversion between a current region of a video and a bitstream representation of the video, whether an adaptive luma loop filter is used during the conversion and whether the adaptive luma loop filter coefficients are included in the bitstream representation, wherein a single syntax element in the bitstream representation is indicative of the use of the adaptive luma loop filter and signaling the adaptive luma loop filter coefficients and performing, based on the determination, the conversion.

Inventors

Li Zhang
Hongbin Liu
Kai Zhang
Yue Wang

Assignees

BYTEDANCE INC.
BEIJING BYTEDANCE NETWORK TECHNOLOGY CO., LTD

Dates

Publication Date: 20260310
Application Date: 20200918
Priority Date: 20190918

Claims (14)

1. A video data processing method characterized in that it comprises: performing a conversion between a current block of a current region of a video and a bitstream of the video, wherein the conversion comprises using an adaptive loop filter for the current block and wherein the bitstream is configured to indicate the adaptive loop filter using multiple syntax elements including: a first syntax element of the multiple syntax elements, the first syntax element being alf_use_aps_flag, and the first syntax element indicating whether a fixed filter set or a filter set from an Adaptive Parameter Set (APS) is applied to the current block, and a second syntax element of the multiple syntax elements, the second syntax element being alf_luma_prev_filter_idx, and the second syntax element indicating an index of the APS filter set and specifying a previous filter that is applied to a luma coding tree block, CTB, and a third syntax element of the multiple syntax elements, the third syntax element being alf_luma_fixed_filter_idx, and the third syntax element indicating an index of the fixed filter set, wherein the bitstream comprises a fourth syntax element in a slice header, the fourth syntax element being slice_num_alf_aps_ids_luma, and the fourth syntax element indicating a number of adaptive loop filter APSs used for the current region, wherein the first syntax element is included in the bitstream when a value of the fourth syntax element in the slice header is greater than one and the first syntax element is included in the bitstream when the value of the fourth syntax element in the slice header is equal to one, wherein the second syntax element indicating the index of the APS filter set is included in the bitstream when a value of the first syntax element is equal to one and the value of the fourth syntax element in a slice header is greater than one, and wherein the third syntax element is included in the bitstream when the value of the first syntax element is equal to zero.
2. Method, according to claim 1, characterized in that the first syntax element being zero indicates that the fixed filter set is applied to the current block.
3. Method, according to claim 1, characterized in that the first syntax element being a indicates that the APS filter set is applied to the current block.
4. A method according to claim 1, characterized in that the bitstream excludes the first syntax element in response to the value of the fourth syntax element in the slice header being equal to zero, and wherein the first syntax element is inferred to indicate that the fixed filter set is applied to the current block.
5. Method, according to claim 1, characterized in that the second syntax element indicating the index of the APS filter set is deleted in the bitstream in response to the value of the fourth syntax element in the slice header being equal to 1.
6. Method according to claim 1, characterized in that the current region is a slice.
7. Method, according to claim 1, characterized in that the second syntax element indicating the index of the APS filter set is encoded with a truncated binary method.
8. Method, according to claim 1, characterized in that a maximum value of the second syntax element indicating the index of the APS filter set is defined as a number of ALF APSs allowed for the current region minus K, where K = 1.
9. Method, according to claim 1, characterized in that all bins of a binarized bin chain of the second syntax element indicating the index of the APS filter set are bypass encoded.
10. Method according to claim 1, characterized in that the conversion includes encoding the video into a bitstream.
11. Method, according to claim 1, characterized in that the conversion includes decoding the video from the bitstream.
12. Apparatus for processing video data characterized in that it comprises a processor and a non-transient memory with instructions therein, wherein the instructions, upon execution by the processor, cause the processor to: perform a conversion between a current block of a current region of a video and a bitstream of the video, wherein the conversion comprises using an adaptive loop filter for the current block and wherein the bitstream is configured to indicate the adaptive loop filter using multiple syntax elements including: a first syntax element of the multiple syntax elements, the first syntax element being alf_use_aps_flag, and the first syntax element indicating whether a fixed filter set or a filter set from an Adaptive Parameter Set (APS) is applied to the current block and a second syntax element of the multiple syntax elements, the second syntax element being alf_luma_prev_filter_idx, and the second syntax element indicating an index of the APS filter set and specifying a previous filter that is applied to a coding tree block, CTB, of luma, eum third syntax element of multiple syntax elements, the third syntax element being alf_luma_fixed_filter_idx, and the third syntax element indicating an index of the fixed filter set wherein the bitstream comprises a fourth syntax element in a slice header, the fourth syntax element being slice_num_alf_aps_ids_luma, and the fourth syntax element indicating a number of adaptive loop filter APSs used for the current region, wherein the first syntax element is included in the bitstream when a value of the fourth syntax element in the slice header is greater than one and the first syntax element is included in the bitstream when the value of the fourth syntax element in the slice header is equal to one, wherein the second syntax element indicating the index of the APS filter set is included in the bitstream when a value of the first syntax element is equal to one and the value of the fourth syntax element in a slice header is greater than one and wherein the third syntax element is included in the bitstream when the value of the first syntax element is equal to zero.
13. A non-transient, computer-readable storage medium characterized in that it stores instructions that cause a processor to: perform a conversion between a current block of a current region of a video and a bitstream of the video, wherein the conversion comprises using an adaptive loop filter for the current block and wherein the bitstream is configured to indicate the adaptive loop filter using multiple syntax elements including: a first syntax element of the multiple syntax elements, the first syntax element being alf_use_aps_flag, and the first syntax element indicating whether a fixed filter set or a filter set from an Adaptive Parameter Set (APS) is applied to the current block; a second syntax element of the multiple syntax elements, the second syntax element being alf_luma_prev_filter_idx, and the second syntax element indicating an index of the fixed filter set or the APS set and specifying a previous filter that is applied to a coding tree block, CTB, of luma; and a third syntax element of the multiple syntax elements, the third syntax element being alf_luma_fixed_filter_idx, and the third syntax element indicating an index of the fixed filter set, wherein the bitstream comprises a fourth syntax element in a slice header, the fourth syntax element being slice_num_alf_aps_ids_luma, and the fourth syntax element indicating a number of adaptive loop filter APSs used for the current region, wherein the first syntax element is included in the bitstream when a value of the fourth syntax element in the slice header is greater than one and the first syntax element is included in the bitstream when the value of the fourth syntax element in the slice header is equal to one, wherein the second syntax element indicating the index of the APS filter set is included in the bitstream when a value of the first syntax element is equal to one and the value of the fourth syntax element in a slice header is greater than one and wherein the third syntax element is included in the bitstream when the value of the first syntax element is equal to zero.
14. A non-transient, computer-readable recording medium characterized in that it stores a bitstream of a video that is generated by a method performed by a video processing device, wherein the method comprises: generating the bitstream for a current block of a current region of the video, wherein the generation comprises using an adaptive loop filter for the current block and wherein the bitstream is configured to indicate the adaptive loop filter using multiple syntax elements including: a first syntax element of the multiple syntax elements, the first syntax element being alf_use_aps_flag, and the first syntax element indicating whether a fixed filter set or a filter set from an Adaptive Parameter Set (APS) is applied to the current block; a second syntax element of the multiple syntax elements, the second syntax element being alf_luma_prev_filter_idx, and the second syntax element indicating an index of the APS filter set and specifying a previous filter that is applied to a luma coding tree block, CTB; and a third syntax element of the multiple syntax elements, the third syntax element being alf_luma_fixed_filter_idx, and the third syntax element indicating an index of the fixed filter set, wherein the bitstream comprises a fourth syntax element in a slice header, the fourth syntax element being slice_num_alf_aps_ids_luma, and the fourth syntax element indicating a number of adaptive loop filter APSs used for the current region, wherein the first syntax element is included in the bitstream when a value of the fourth syntax element in the slice header is greater than one and the first syntax element is included in the bitstream when the value of the fourth syntax element in the slice header is equal to one, wherein the second syntax element indicating the index of the APS filter set is included in the bitstream when a value of the first syntax element is equal to one and the value of the fourth syntax element in a slice header is greater than one and wherein the third syntax element is included in the bitstream when the value of the first syntax element is equal to zero.

Description

CROSS-REFERENCE TO RELATED REQUESTS [001] This application is based on International Patent Application No. PCT/CN2020/116086, filed on September 18, 2020, which claims the priority and benefits of International Patent Application No. PCT/CN2019/106420 filed on September 18, 2019. All patent applications mentioned above are incorporated herein by reference in their entirety. TECHNICAL FIELD [002] This patent document relates to video decoding and encoding. BACKGROUND [003] Despite advances in video compression, digital video is still responsible for the largest use of bandwidth on the Internet and other digital communication networks. As the number of connected user devices capable of receiving and displaying video increases, the demand for bandwidth for digital video use is expected to continue to grow. SUMMARY [004] Devices, systems and methods relating to digital video encoding and, specifically, to video and image encoding and decoding in which adaptive loop filtering is used. [005] In an exemplary aspect a video processing method is disclosed. The method includes determining, for a conversion between a current region of a video and a bitstream representation of the video, whether an adaptive luma loop filter is used during the conversion and whether the adaptive luma loop filter coefficients are included in the bitstream representation, wherein a single syntax element in the bitstream representation is indicative of the use of the adaptive luma loop filter and signaling the adaptive luma loop filter coefficients and performing, based on the determination, the conversion. [006] In another exemplary aspect a video processing method is disclosed. The method involves performing a conversion between a current region of a video and a bitstream representation of the video, wherein an adaptive loop filter is used during the conversion and wherein the bitstream representation conforms to a syntax rule which specifies that signaled adaptive loop filter coefficients in the bitstream representation include zero-value adaptive loop filter coefficients. [007] In yet another exemplary aspect a video processing method is disclosed. The method involves determining, for a conversion between a current region of a video and a bitstream representation of the video, that the zero-valued adaptive loop filter coefficients of a previous video region signaled in the bitstream representation are not used in the conversion, and performing, based on the determination, the conversion. [008] In yet another exemplary aspect a video processing method is disclosed. The method involves performing a conversion between a current region of a video and a bitstream representation of the video, wherein the bitstream representation conforms to a syntax rule that specifies a flag indicating whether loop filtering is used so that the conversion is included in the bitstream representation at a video unit level comprising the current region which is smaller than a video slice level. [009] In yet another exemplary aspect a video processing method is disclosed. The method involves performing a conversion between a current region of a video and a bitstream representation of the video, wherein the conversion comprises using an adaptive loop filter and wherein the bitstream representation is configured to indicate the adaptive loop filter using a two-part signaling including a first part indicating a technique for determining the adaptive loop filter and a second part indicating an index used by the technique. [010] In yet another exemplary aspect a video processing method is disclosed. The method involves determining, based on a property of a video, a size of a current region of the video that shares a common loop filtering definition for a conversion between the current region and a bitstream representation of the video, and performing, based on the determination, the conversion. [011] In yet another exemplary aspect a video processing method is disclosed. The method involves performing a lossless conversion between a current region of the video and a bitstream representation of the video, wherein the bitstream representation conforms to a syntax rule that restricts a value of a syntax field associated with the current region in the bitstream representation due to the conversion being lossless. [012] In yet another exemplary aspect, the method described above is incorporated in the form of processor-executable code and stored in a computer-readable program medium. [013] In yet another exemplary aspect, a device that is configured or operable to perform the method described above is disclosed. The device may include a processor that is programmed to implement this method. [014] In yet another exemplary aspect, a video decoder device may implement a method as described in the present invention. [015] The above and other aspects and features of the disclosed technology are described in more detail in the drawings, description and claims. BRIEF DESCRIPTI