Method, apparatus and medium for video processing

Abstract

An embodiment of the present disclosure provides a scheme for video processing. The method includes performing a conversion between a target video block of a video and a bitstream of the video according to a decoding compatibility constraint. The decoding compatibility constraint specifies that a decoder conforming to a first profile can decode at least a first picture of the bitstream if at least one condition applies, and the at least one condition includes a first condition that the bitstream is indicated to conform to at least one second profile. The first profile includes a still picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 250,772, filed September 30, 2021, the entire contents of which are incorporated herein by reference.

[0002] [Technical field] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to video coding techniques, and more particularly to specifying decoder capabilities for Versatile Video Coding (VVC) range extension profiles. [Background technology]

[0003] Video coding standards have evolved primarily through the development of well-known ITU-T and ISO / IEC standards. ITU-T created H.261 and H.263, ISO / IEC created MPEG-1 and MPEG-4 Visual, and the two organizations jointly created H.262 / MPEG-2 Video, H.264 / MPEG-4 Advanced Video Coding (AVC), and H.265 / HEVC standards. Since H.262, video coding standards have been based on a hybrid video coding structure in which temporal prediction plus transform coding is utilized. To explore future video coding technologies beyond HEVC, the Joint Video Exploration Team (JVET) was jointly established by VCEG and MPEG in 2015. Since then, many new methods have been adopted by JVET and incorporated into a reference software named Joint Exploration Model (JEM). Later, JVET was renamed to JVET when the VVC project was officially launched. VVC is a new encoding standard that aims to reduce the bitrate by 50% compared to HEVC.

[0004] The VVC standard and associated Versatile Supplemental Enhancement Information (VSEI) standard for Coded Video Bitstreams are designed to be used in the widest range of applications, including both traditional uses such as television broadcast, videoconferencing, or playback from storage media, and newer, more advanced uses such as adaptive bitrate streaming, video region extraction, content composition and combining from multiple coded video bitstreams, multiview video, scalable layered coding, and viewport adaptive 360-degree immersive media. The latest draft amendments to the VVC standard include the specification of range extension profiles and other aspects. Summary of the Invention

[0005] The embodiments of the present disclosure provide a solution for video processing.

[0006] In a first aspect, a video processing method is proposed. The method includes performing a conversion between a target video block of a video and a bitstream of the video according to a decoding compatibility constraint. The decoding compatibility constraint specifies that a decoder suitable for a first profile can decode at least a first picture of the bitstream if at least one condition applies, the at least one condition including a first condition that the bitstream is shown to conform to at least one second profile. The first profile includes a Still Picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth. The method according to the first aspect of the present disclosure improves decoder capabilities of a VVC range extension profile.

[0007] In a second aspect, an apparatus for processing video data is proposed, said apparatus comprising a processor and a non-transitory memory with instructions that, when executed by the processor, cause the processor to perform a method according to the first aspect.

[0008] In a third aspect, an apparatus for processing video data is proposed. A non-transitory computer-readable storage medium stores instructions for causing a processor to perform the method according to the first aspect.

[0009] In a fourth aspect, a non-transitory computer-readable storage medium is proposed. The non-transitory computer-readable storage medium stores a bitstream of a video generated by a method executed by a video processing device. The method includes generating the bitstream according to a decoding compatibility constraint. The decoding compatibility constraint specifies that a decoder conforming to a first profile can decode at least a first picture of the bitstream if at least one condition applies, the at least one condition including a first condition that the bitstream is indicated to conform to at least one second profile. The first profile includes a Still Picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth.

[0010] In a fifth aspect, a method for storing a bitstream of another video is proposed. The method includes generating the bitstream according to a decoding compatibility constraint and storing the bitstream in a non-transitory computer-readable storage medium. The decoding compatibility constraint specifies that a decoder conforming to a first profile can decode at least a first picture of the bitstream if at least one condition applies, and the at least one condition includes a first condition that the bitstream is indicated to conform to at least one second profile. The first profile includes a Still Picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth.

[0011] This description is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. [Brief description of the drawings]

[0012] The above and other objects, features, and advantages of exemplary embodiments of the present disclosure will become more apparent through the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals generally refer to like components.

[0013] [Figure 1] 1 shows a block diagram illustrating an example video encoding system according to some embodiments of the present disclosure.

[0014] [Diagram 2] 1 shows a block diagram illustrating a first example of a video encoder according to some embodiments of the present disclosure.

[0015] [Diagram 3] 1 shows a block diagram illustrating an example video decoder according to some embodiments of the present disclosure.

[0016] [Figure 4] 1 illustrates a flowchart of a video processing method according to some embodiments of the present disclosure.

[0017] [Diagram 5] FIG. 1 illustrates a block diagram of a computing device capable of implementing various embodiments of the present disclosure.

[0018] Throughout the drawings, the same or similar reference numbers typically refer to the same or similar elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Next, the principles of the present disclosure will be described with reference to some embodiments. It should be understood that these embodiments are provided for illustrative purposes only, to assist those skilled in the art in understanding and implementing the present disclosure, and do not imply any limitations on the scope of the present disclosure. The disclosure described herein can be implemented in various ways other than those described below.

[0020] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0021] References in this disclosure to "one embodiment," "one embodiment," "exemplary embodiment," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an exemplary embodiment, it is noted that it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0022] Terms such as "first" and "second" may be used herein to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that the terms "comprise," "comprise," "have," "have," "include," and / or "comprise," as used herein, specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0024] Example Environment 1 is a block diagram illustrating an example video encoding system 100 that may utilize techniques of this disclosure. As shown, video encoding system 100 may include a source device 110 and a destination device 120. Source device 110 may also be referred to as a video encoding device, and destination device 120 may also be referred to as a video decoding device. In operation, source device 110 may be configured to generate encoded video data, and destination device 120 may be configured to decode the encoded video data generated by source device 110. Source device 110 may include a video source 112, a video encoder 114, and an input / output (I / O) interface 116.

[0025] Video source 112 may include sources such as video capture devices. Examples of video capture devices include, but are not limited to, an interface that receives video data from a video content provider, a computer graphics system that generates video data, and / or combinations thereof.

[0026] The video data may include one or more pictures. The video encoder 114 encodes the video data from the video source 112 to generate a bitstream. The bitstream may include a series of bits that form an encoded representation of the video data. The bitstream may include encoded pictures and associated data. An encoded picture is an encoded representation of a picture. The associated data may include sequence parameter sets, picture parameter sets, and other syntax structures. The I / O interface 116 may include a modulator / demodulator and / or a transmitter. The encoded video data may be transmitted directly to the destination device 120 through the network 130A via the I / O interface 116. The encoded video data may be stored in a storage medium / server 130B for access by the destination device 120.

[0027] Destination device 120 may include an I / O interface 126, a video decoder 124, and a display device 122. I / O interface 126 may include a receiver and / or a modem. I / O interface 126 may obtain encoded video data from source device 110 or storage medium / server 130B. Video decoder 124 may decode the encoded video data. Display device 122 may display the decoded video data to a user. Display device 122 may be integrated with destination device 120 or may be external to destination device 120 configured to interface with an external display device.

[0028] The video encoder 114 and the video decoder 124 may operate according to a video compression standard, such as the High Efficiency Video Coding (HEVC) standard, the Versatile Video Coding (VVC) standard, and other current and / or future standards.

[0029] FIG. 2 is a block diagram illustrating an example of a video encoder 200, which may be an example of the video encoder 114 in the system 100 shown in FIG. 1, according to some embodiments of the disclosure.

[0030] Video encoder 200 may be configured to perform any or all of the techniques of this disclosure. In the example of FIG. 2, video encoder 200 includes multiple functional components. The techniques described in this disclosure may be shared among various components of video encoder 200. In some examples, a processor may be configured to perform any or all of the techniques described in this disclosure.

[0031] In some embodiments, the video encoder 200 may include a division unit 201, a prediction unit 202, which may include a mode selection unit 203, a motion estimation unit 204, a motion compensation unit 205, and an intra prediction unit 206, a residual generation unit 207, a transform unit 208, a quantization unit 209, an inverse quantization unit 210, an inverse transform unit 211, a reconstruction unit 212, a buffer 213, and an entropy coding unit 214.

[0032] In other examples, video encoder 200 may include more, fewer, or different functional components. In one example, prediction unit 202 may include an intra block copy (IBC) unit. The IBC unit may perform prediction in an IBC mode, where at least one reference picture is the picture in which the current video block is located.

[0033] Furthermore, some components, such as the motion estimation unit 204 and the motion compensation unit 205, may be integrated but are depicted separately in the example of FIG. 2 for illustrative purposes.

[0034] Division unit 201 may divide a picture into one or more video blocks. Video encoder 200 and video decoder 300 may support a variety of video block sizes.

[0035] The mode selection unit 203 may, for example, select one of intra or inter coding modes based on the error result, and provide the resulting intra-coded or inter-coded block to the residual generation unit 207 to generate residual block data, and to the reconstruction unit 212 to reconstruct the coded block and use it as a reference picture. In some examples, the mode selection unit 203 may select a combined intra- and inter-prediction (CIIP) mode, in which prediction is based on an inter prediction signal and an intra prediction signal. In the case of inter prediction, the mode selection unit 203 may select a resolution of the motion vector of the block (e.g., sub-pixel or integer pixel accuracy).

[0036] To perform inter prediction on the current video block, motion estimation unit 204 may generate motion information for the current video block by comparing one or more reference frames from buffer 213 with the current video block. Motion compensation unit 205 may determine a prediction video block for the current video block based on the motion information and decoded samples of pictures from buffer 213 other than the picture associated with the current video block.

[0037] Motion estimation unit 204 and motion compensation unit 205 may perform different operations on a current video block depending on whether the current video block is in an I slice, a P slice, or a B slice, for example. As used herein, an "I slice" may refer to a portion of a picture that is composed of macroblocks, all of which are based on macroblocks in the same picture. Additionally, as used herein, in some aspects, a "P slice" and a "B slice" may refer to a portion of a picture that is composed of macroblocks that are independent of macroblocks in the same picture.

[0038] In some examples, motion estimation unit 204 may perform unidirectional prediction on the current video block, and motion estimation unit 204 may look for a reference picture in list 0 or list 1 for a reference video block of the current video block. Motion estimation unit 204 may then generate a reference index indicating a reference picture in list 0 or list 1 that contains the reference video block, and a motion vector indicating a spatial displacement between the current video block and the reference video block. Motion estimation unit 204 may output the reference index, the prediction direction indicator, and the motion vector as motion information for the current video block. Motion compensation unit 205 may generate a predictive video block for the current video block based on the reference video block indicated by the motion information of the current video block.

[0039] Alternatively, in other examples, motion estimation unit 204 may perform bidirectional prediction on the current video block. Motion estimation unit 204 may look for a reference picture in list 0 for a reference video block of the current video block, and may look for a reference picture in list 1 for another reference video block of the current video block. Motion estimation unit 204 may then generate a reference index indicating the reference picture in list 0 and list 1 that contains the reference video block, and a motion vector indicating a spatial displacement between the reference video block and the current video block. Motion estimation unit 204 may output the reference index and the motion vector of the current video block as motion information of the current video block. Motion compensation unit 205 may generate a predictive video block for the current video block based on the reference video block indicated by the motion information of the current video block.

[0040] In some examples, motion estimation unit 204 may output a full set of motion information for the decoding process of the decoder. Alternatively, in some embodiments, motion estimation unit 204 may signal the motion information of the current video block with reference to motion information of another video block. For example, motion estimation unit 204 may determine that the motion information of the current video block is sufficiently similar to the motion information of a neighboring video block.

[0041] In one example, motion estimation unit 204 may indicate, in a syntax structure associated with the current video block, a value that indicates to video decoder 300 that the current video block has the same motion information as another video block.

[0042] In another example, motion estimation unit 204 may identify another video block and a motion vector differential (MVD) in a syntax structure associated with the current video block. The motion vector differential indicates a difference between the motion vector of the current video block and the motion vector of the indicated video block. Video decoder 300 may determine the motion vector of the current video block using the motion vector of the indicated video block and the motion vector differential.

[0043] As discussed above, video encoder 200 may predictively signal motion vectors. Two examples of predictive signaling techniques that may be implemented by video encoder 200 include advanced motion vector prediction (AMVP) and merge mode signaling.

[0044] Intra prediction unit 206 may perform intra prediction on the current video block. When intra prediction unit 206 performs intra prediction on the current video block, intra prediction unit 206 may generate predictive data for the current video block based on decoded samples of other video blocks in the same picture. The predictive data for the current video block may include a predicted video block and various syntax elements.

[0045] Residual generation unit 207 may generate residual data for the current video block by subtracting (e.g., as indicated by a minus sign) the prediction video block of the current video block from the current video block. The residual data for the current video block may include residual video blocks that correspond to different sample components of the samples in the current video block.

[0046] In other examples, such as in skip mode, residual data may not be present for the current video block, and residual generation unit 207 may not perform the subtraction operation.

[0047] Transform processing unit 208 may generate one or more transform coefficient video blocks for the current video block by applying one or more transforms to the residual video block associated with the current video block.

[0048] After transform processing unit 208 generates the transform coefficient video block associated with the current video block, quantization unit 209 may quantize the transform coefficient video block associated with the current video block based on one or more quantization parameter (QP) values ​​associated with the current video block.

[0049] Inverse quantization unit 210 and inverse transform unit 211 may apply inverse quantization and inverse transform, respectively, to the transform coefficient video block to reconstruct a residual video block from the transform coefficient video block. Reconstruction unit 212 may add the reconstructed residual video block to corresponding samples from one or more prediction video blocks generated by prediction unit 202 to generate a reconstructed video block associated with the current video block for storage in buffer 213.

[0050] After reconstruction unit 212 reconstructs the video blocks, a loop filtering operation may be performed to reduce video blocking artifacts in the video blocks.

[0051] Entropy encoding unit 214 may receive data from other functional components of video encoder 200. Once entropy encoding unit 214 receives the data, it may perform one or more entropy encoding operations to generate entropy encoded data and output a bitstream including the entropy encoded data.

[0052] FIG. 3 is a block diagram illustrating an example of a video decoder 300, which may be an example of the video decoder 124 in the system 100 shown in FIG. 1, according to some embodiments of the disclosure.

[0053] The video decoder 300 may be configured to perform any or all of the techniques of this disclosure. In the example of FIG. 3, the video decoder 300 includes multiple functional components. The techniques described in this disclosure may be shared among various components of the video decoder 300. In some examples, a processor may be configured to perform any or all of the techniques described in this disclosure.

[0054] 3, the video decoder 300 includes an entropy decoding unit 301, a motion compensation unit 302, an intra prediction unit 303, an inverse quantization unit 304, an inverse transform unit 305, a reconstruction unit 306, and a buffer 307. The video decoder 300 may, in some examples, perform a decoding path that is generally inverse to the encoding path described with respect to the video encoder 200.

[0055] The entropy decoding unit 301 may retrieve an encoded bitstream. The encoded bitstream may include entropy encoded video data (e.g., encoded blocks of video data). The entropy decoding unit 301 may decode the entropy encoded video data, and from the entropy decoded video data, the motion compensation unit 302 may determine motion information including motion vectors, motion vector precision, reference picture list indexes, and other motion information. The motion compensation unit 302 may determine such information by, for example, performing AMVP and merge mode. AMVP is used and includes derivation of some most likely candidates based on data from neighboring PB and reference pictures. The motion information typically includes horizontal and vertical motion vector displacement values, one or two reference picture indexes, and, in the case of prediction regions in B slices, identification of which reference picture list is associated with each index. As used herein, in some aspects, "merge mode" may refer to deriving motion information from spatially or temporally neighboring blocks.

[0056] The motion compensation unit 302 may generate a motion-compensated block, possibly performing interpolation based on an interpolation filter. An identifier of the interpolation filter used with sub-pixel precision may be included in the syntax element.

[0057] Motion compensation unit 302 may calculate interpolated values ​​for sub-integer pixels of a reference block using an interpolation filter used by video encoder 200 during encoding of the video block. Motion compensation unit 302 may determine the interpolation filter used by video encoder 200 according to received syntax information and generate a predictive block using the interpolation filter.

[0058] The motion compensation unit 302 may use at least a portion of the syntax information to determine the size of blocks used to code frames and / or slices of the coded video sequence, partition information describing how each macroblock of a picture of the coded video sequence is divided, a mode indicating how each partition is coded, one or more reference frames (and reference frame lists) for each inter-encoded block, and other information for decoding the coded video sequence. As used herein, in some aspects, a "slice" may refer to a data structure that can be decoded independently from other slices of the same picture with respect to entropy coding, signal prediction, and residual signal reconstruction. A slice may be either an entire picture or a region of a picture.

[0059] The intra prediction unit 303 may form a prediction block from spatially neighboring blocks, e.g., using an intra prediction mode received in the bitstream. The inverse quantization unit 304 inverse quantizes, or dequantizes, the quantized video block coefficients provided in the bitstream and decoded by the entropy decoding unit 301. The inverse transform unit 305 applies an inverse transform.

[0060] The reconstruction unit 306 may obtain a decoded block, for example, by adding the residual block and a corresponding prediction block generated by the motion compensation unit 302 or the intra prediction unit 303. Optionally, a deblocking filter may be applied to filter the decoded block to remove blockiness artifacts. The decoded video block is then stored in a buffer 307, which provides reference blocks for subsequent motion compensation / intra prediction, and also generates the decoded video for presentation on a display device.

[0061] Some exemplary embodiments of the present disclosure will be described in detail below. Section headings are used herein for ease of understanding, but it should be understood that they do not limit the embodiments disclosed in a section to only that section. Furthermore, although certain embodiments are described with reference to versatile video encoding or other specific video codecs, the disclosed techniques are applicable to other video encoding techniques. Furthermore, although some embodiments describe video encoding steps in detail, it will be understood that a corresponding decoding step that undoes the encoding is performed by a decoder. Furthermore, the term video processing encompasses video encoding or compression, video decoding or decompression, and video transcoding, which represents video pixels from one compressed format to another compressed format or at a different compressed bit rate.

[0062] Detailed Plan 1. Overview The present disclosure relates to image / video coding technology, and in particular to specifying decoder capabilities for the VVC Range Extension Profile. The embodiments of the present disclosure may be applied individually or in various combinations to any codec, such as a video bitstream encoded by the Versatile Video Coding (VVC) standard.

[0063] 2. Abbreviation APS Adaptation Parameter Set AU Access Unit CLVS Coded Layer Video Sequence CLVSS Coded Layer Video Sequence Start CRC Cyclic Redundancy Check CTI Colour Transform Information CVS Coded Video Sequence FIR Finite Impulse Response IRAP Intra Random Access Point NAL Network Abstraction Layer PPS Picture Parameter Set PU Picture Unit RASL Random Access Skipped Leading SAR Sample Aspect Ratio SARI Sample Aspect Ratio Information SEI Supplemental Enhancement Information VCL Video Coding Layer VSEI versatile supplemental enhancement Information (Rec. ITU-T H.274 | ISO / IEC 23002-7) VUI Video Usability Information VVC versatile video coding (Rec. ITU-T H.266 | ISO / IEC 23090-3)

[0064] 3.Background 3.1.Video Coding Standards Video coding standards have evolved mainly through the development of well-known ITU-T and ISO / IEC standards. ITU-T created H.261 and H.263, ISO / IEC created MPEG-1 and MPEG-4 Visual, and the two organizations jointly created H.262 / MPEG-2 Video, H.264 / MPEG-4 Advanced Video Coding (AVC), and H.265 / HEVC standards. Since H.262, video coding standards have been based on a hybrid video coding structure where temporal prediction plus transform coding is utilized. To explore future video coding technologies beyond HEVC, the Joint Video Exploration Team (JVET) was jointly established by VCEG and MPEG in 2015. Since then, many new methods have been adopted by JVET and incorporated into a reference software named Joint Exploration Model (JEM). JVET was later renamed to Joint Video Experts Team (JVET) when the Versatile Video coding (VVC) project was officially launched. VVC is a new coding standard that aims for a 50% bitrate reduction compared to HEVC, and was finalized by JVET at its 19th meeting, which ended on July 1, 2020.

[0065] The Versatile Video Coding (VVC) standard (ITU-T H.266 | ISO / IEC 23090-3) and the associated Versatile Supplemental Enhancement Information (VSEI) standard for coded video bitstreams (ITU-T H.274 | ISO / IEC 23002-7) are designed to be used in the widest range of applications, including both traditional applications such as television broadcasting, videoconferencing, or playback from storage media, and newer, more advanced applications such as adaptive bitrate streaming, video region extraction, composition and combining of content from multiple coded video bitstreams, multiview video, scalable layered coding, and viewport adaptive 360° immersive media.

[0066] The Essential Video Coding (EVC) standard (ISO / IEC 23094-1) is another video coding standard recently developed by MPEG.

[0067] The latest draft of the proposed amendments to the VVC standard is available in JVET-W2005, which includes the specification of range extension profiles and other aspects.

[0068] 3.2. VVC Range Extension Profile Draft text for specifying the VVC Range Extension Profile in JVET-W2005 is provided below.

[0069] A3.5 Format Range Extension Profile The following profiles, collectively known as Format Range Extension Profiles, are specified in this subclause:

[0070] - Main 12, Main 12 4:4:4 and Main 16 4:4:4 profiles - Main 12 Intra, Main 12 4:4:4 Intra and Main 16 4:4:4 Intra profiles - Main 12 Still Picture, Main 12 4:4:4 Still Picture and Main 16 4:4:4 Still Picture profiles

[0071] A bitstream conforming to the Format Range Extension Profile shall obey the following constraints: - The ptl_multilayer_enabled_flag of the referenced SPS shall be equal to 0. - In bitstreams conforming to the Main 12 Still Picture, Main 12 4:4:4 Still Picture and Main 16 4:4:4 Still Picture profiles, the bitstream shall contain only one picture. - In bitstreams conforming to the Main 12, Main 12 4:4:4, Main 16 4:4:4, Main 12 Intra, Main 12 4:4:4 Intra, or Main 16 4:4:4 Intra profiles, general_level_idc for all values ​​of i in an active SPS shall not be equal to 255 (indicating level 15.5). - The hierarchical and level constraints specified for the Main 12, Main 12 4:4:4, Main 16 4:4:4, Main 12 Intra, Main 12 4:4:4 Intra or Main 16 4:4:4 Intra profiles in subclause A.4 shall be fulfilled, where applicable.

[0072] [Table 1]

[0073] A bitstream conforming to the Main12 profile is indicated by general_profile_idc equal to 2.

[0074] That a bitstream conforms to the Main 12 Intra profile is indicated by general_profile_idc equal to 10.

[0075] That a bitstream conforms to the Main 12 Still Picture profile is indicated by general_profile_idc equal to 66.

[0076] A bitstream conforming to the Main 12 4:4:4 profile is indicated by general_profile_idc equal to 34.

[0077] That a bitstream conforms to the Main 12 4:4:4 Intra profile is indicated by general_profile_idc equal to 42.

[0078] A bitstream conforming to the Main 12 4:4:4 Still Picture profile is indicated by general_profile_idc equal to 98.

[0079] A bitstream conforming to the Main 16 4:4:4 profile is indicated by general_profile_idc equal to 36.

[0080] A bitstream conforming to the Main 16 4:4:4 Intra profile is indicated by general_profile_idc equal to 44.

[0081] A bitstream conforming to the Main 16 4:4:4 Still Picture profile is indicated by general_profile_idc equal to 100.

[0082] All other combinations of the syntax elements in Table A.1 where general_profile_idc is equal to 2, 10, 66, 34, 42, 98, 36, 44, or 100 are reserved for future use by ITU-T | ISO / IEC. Such combinations shall not exist in bitstreams conforming to this document. However, decoders conforming to the Format Range Extension Profile shall permit the other combinations specified below in this subclause to appear in the bitstream.

[0083] [Table 2]

[0084] A decoder that conforms to the Format Range Extension profile at a particular level (identified by a particular value of general_level_idc) of a particular tier (identified by a particular value of general_tier_flag) shall be able to decode all bitstream and sub-layer representations for which all of the following conditions apply: - One of the following conditions applies: - The decoder is indicated as conforming to the Main 12 4:4:4 or Main 16 4:4:4 profile and the bitstream or sub-layer representation is indicated as conforming to the Main 10 profile or the Main 10 Still Picture profile. - The decoder is indicated to conform to the Main 12 4:4:4 Intra, Main 16 4:4:4 Intra, Main 12 Still Picture, Main 12 4:4:4 Still Picture or Main 16 4:4:4 Still Picture Profile and the bitstream or sub-layer representation conforms to the Main 10 Still Picture Profile. - the bitstream's general_profile_idc is equal to 2, 10, 66, 34, 42, 98, 36, 44, or 100 and the value of each constraint flag listed in Table A.1 is greater than or equal to the value specified in that row of Table A.1 for the format range extension profile for which decoder conformance is being evaluated. - A bitstream or sub-layer representation is indicated to conform to a layer below the specified layer. - A bitstream or sub-layer representation is indicated as conforming to a specified level or lower, but not to level 15.5.

[0085] 4.Problems The current definition of the VVC range extension profiles (including the specification of the decoder capabilities of these profiles) has at least the following problems: 1) For the Main 12 Intra, Main 12 4:4:4 Intra, and Main 16 4:4:4 Intra profiles, there is a lack of constraint that does not allow the use of inter prediction. 2) The requirement that a decoder conforming to the Main 12 profile be able to decode bitstreams conforming to the Main 10 or Main 10 Still Picture profiles is missing. 3) The requirement that a decoder conforming to the Main 12 4:4:4 or Main 16 4:4:4 profile be able to decode a bitstream conforming to the Main 10 4:4:4 profile or the Main 10 4:4:4 Still Picture profile is missing. 4) The requirement that a decoder conforming to the Main 12 Intra profile be able to decode a bitstream conforming to the Main 10 Still Picture profile is missing. 5) The requirement that a decoder that conforms to the Main 12 4:4:4 Intra, Main 16 4:4:4 Intra, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profile be able to decode a bitstream that conforms to the Main 10 4:4:4 Still Picture profile is missing. 6) The following paragraphs are the key pieces of text that specify decoder capabilities for decoding bitstreams that conform to the Range Extension Profile: The general_profile_idc for the bitstream is equal to 2, 10, 66, 34, 42, 98, 36, 44, or 100, and the value of each constraint flag listed in Table A.1 is greater than or equal to the value specified in the row of Table A.1 for the format range extension profile for which decoder conformance is being evaluated. There are several issues that make the specification inaccurate, and the decoder capabilities are not specified correctly: a) A higher value for each syntax element in Table A.1 indicates higher capability rather than lower capability. b) Two aspects are missing from Table A.1: 1) allowing multiple pictures; and 2) allowing intercoding. 7) The requirement that a decoder conforming to the Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profile be able to decode the first picture of a particular bitstream is missing.

[0086] 5.Details In order to solve the above problems, the method summarized below is disclosed. The embodiments of the present disclosure should be considered as examples to explain the general concept, and should not be interpreted narrowly. Moreover, these embodiments can be applied individually or in any combination.

[0087] 1) To solve problem 1, it is assumed that all slices in a bitstream that conforms to the Main 12 Intra, Main 12 4:4:4 Intra, or Main 16 4:4:4 Intra profile are I-slices. a. Alternatively, in a bitstream that conforms to the Main 12 Intra, Main 12 4:4:4 Intra, or Main 16 4:4:4 Intra profile, the value of sh_slice_type shall be equal to 2 for all slices. b. Alternatively, in a bitstream that conforms to the Main 12 Intra, Main 12 4:4:4 Intra, or Main 16 4:4:4 Intra profile, the value of gci_intra_only_constraint_flag shall be equal to 1.

[0088] 2) To solve problem 2, the following is specified: A decoder that conforms to the Main 12 profile at a particular level in a particular hierarchical layer shall be able to decode bitstreams that conform to the Main 10 profile or the Main 10 Still Picture profile, that conform to a hierarchical layer at or below the specified hierarchical layer, and that are indicated as conforming to a level at or below the specified level but not to level 15.5.

[0089] 3) To solve problem 3, the following is specified: A decoder that conforms to the Main 12 4:4:4 or Main 16 4:4:4 profile at a particular level in a particular layer shall be able to decode bitstreams that conform to the Main 10 4:4:4 or Main 10 4:4:4 Still Picture profile, that conform to a layer at or below the specified layer, and that are indicated as conforming to the specified level or below but not to level 15.5.

[0090] 4) To solve problem 4, the following is specified: A decoder that conforms to the Main 12 Intra profile at a particular level in a particular hierarchical layer shall be able to decode bitstreams that conform to the Main 10 Still Picture profile, that conform to a hierarchical layer at or below the specified hierarchical layer, and that are indicated as conforming to a level at or below the specified level but not to level 15.5.

[0091] 5) To solve problem 5, the following is specified: A decoder that conforms to the Main 12 4:4:4 Intra, Main 16 4:4:4 Intra, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profile at a particular level in a particular layer shall be able to decode bitstreams that conform to the Main 10 4:4:4 Still Picture profile, that conform to a layer at or below the specified layer, and that are indicated as conforming to the specified level or below but not to level 15.5.

[0092] 6) To solve problem 6, specify the following in one or more of subsections 6.ai to 6.a.ix: A decoder that conforms to the Format Range Extension profile at a particular level (identified by a particular value of general_level_idc) of a particular tier (identified by a particular value of general_tier_flag) shall be able to decode all bitstream and sub-layer representations for which all of the following conditions apply: a. Any of the following conditions apply: i. The decoder conforms to the Main 12 profile and the bitstream is indicated as conforming to the Main 10, Main 10 Still Picture, Main 12, Main 12 Intra, or Main 12 Still Picture profile. ii. The decoder conforms to the Main 12 4:4:4 profile and the bitstream is indicated as conforming to the Main 10, Main 10 Still Picture, Main 10 4:4:4, Main 10 4:4:4 Still Picture, Main 12, Main 12 Intra, Main 12 Still Picture, Main 12 4:4:4, Main 12 4:4:4 Intra, or Main 12 4:4:4 Still Picture profile. iii. The decoder conforms to the Main 16 4:4:4 profile and the bitstream is indicated as conforming to either the Main 10, Main 10 Still Picture, Main 10 4:4:4, Main 10 4:4:4 Still Picture, or Format Range Extended profile. The iV. decoder conforms to the Main 12 Intra profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 12 Intra, or Main 12 Still Picture profiles. V. The decoder is indicated as conforming to the Main 12 4:4:4 Intra profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Intra, Main 12 4:4:4 Intra, Main 12 Still Picture, or Main 12 4:4:4 Still Picture profiles. The Vi. decoder conforms to the Main 16 4:4:4 Intra profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Intra, Main 12 4:4:4 Intra, Main 16 4:4:4 Intra, Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profile. Vii. The decoder conforms to the Main 12 Still Picture profile and the bitstream is indicated as conforming to the Main 10 Still Picture or Main 12 Still Picture profile. Viii. The decoder conforms to the Main 12 4:4:4 Still Picture profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Still Picture or 12 4:4:4 Still Picture profile. ix. The decoder is indicated as conforming to the Main 16 4:4:4 Still Picture profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profile. b. The bitstream is shown to conform to a hierarchical level equal to or lower than the specified hierarchical level. c. The bitstream is shown to conform to a level equal to or lower than the specified level but not to Level 15.5.

[0093] 7) To solve problem 4, one or more of the following items are specified: a. A decoder that conforms to the Main 12 Still Picture Profile at a particular level in a particular hierarchy shall also be able to decode the first picture at the beginning of the bitstream if both of the following conditions are true: i. The bitstream conforms to the Main 10, Main 12, or Main 12 Intra profile, conforms to a specified level or lower, and is shown to conform to the specified level or lower but not to level 15.5. ii. The picture is an IRAP picture or a GDR picture with ph_recovery_poc_cnt equal to 0, is in the output layer, and ph_pic_output_flag equal to 1. b. A decoder that conforms to the Main 12 4:4:4 Still Picture Profile at a particular level of a particular hierarchy shall also be able to decode the first picture of the bitstream if both of the following conditions are true: i. The bitstream conforms to the Main 10, Main 10 4:4:4, Main 12, Main 12 Intra, Main 12 4:4:4, or Main 12 4:4:4 Intra profile, conforms to a specified level or lower, and is shown to conform to a level or lower than the specified level but not to level 15.5. ii. The picture is an IRAP picture or a GDR picture with ph_recovery_poc_cnt equal to 0, is in the output layer, and ph_pic_output_flag equal to 1. c. A decoder that conforms to the Main 16 4:4:4 Still Picture Profile at a particular level of a particular hierarchy shall also be able to decode the first picture of the bitstream if both of the following conditions are true: i. the bitstream conforms to the Main 10, Main 10 4:4:4, Main 12, Main 12 Intra, Main 12 4:4:4, Main 12 4:4:4 Intra, Main 16 4:4:4, or Main 16 4:4:4 Intra profile, conforms to a specified level or lower, and is indicated as conforming to a level or lower than the specified level but not to level 15.5. ii. The picture is an IRAP picture or a GDR picture with ph_recovery_poc_cnt equal to 0, is in the output layer, and has ph_pic_output_flag equal to 1.

[0094] 6. Embodiment Below are some example embodiments of all of the aspects according to embodiments of the present disclosure, including subitems, summarized above in Section 5.

[0095] 6.1. First embodiment This embodiment is applicable to VVC. Most of the relevant parts that have been added or changed are underlined. The changes that were made will be highlighted in << and the parts that were deleted will be highlighted in <<>>. There may be several other changes that are not highlighted because they are editorial in nature.

[0096] A3.5 Format Range Extension Profile The following profiles, collectively known as Format Range Extension Profiles, are specified in this subclause: - Main 12, Main 12 4:4:4 and Main 16 4:4:4 profiles - Main 12 Intra, Main 12 4:4:4 Intra and Main 16 4:4:4 Intra profiles - Main 12 Still Picture, Main 12 4:4:4 Still Picture and Main 16 4:4:4 Still Picture profiles

[0097] A bitstream conforming to the Format Range Extension Profile shall obey the following constraints: - The ptl_multilayer_enabled_flag of the referenced SPS shall be equal to 0. - In a bitstream conforming to the Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture Profile, the bitstream shall contain only one picture. - In a bitstream conforming to the Main 12 Intra, Main 12 4:4:4 Intra, or Main 16 4:4:4 Intra profile, the value of sh_slice_type shall be equal to 2 for all slices. - In bitstreams conforming to the Main 12, Main 12 4:4:4, Main 16 4:4:4, Main 12 Intra, Main 12 4:4:4 Intra, or Main 16 4:4:4 Intra profiles, general_level_idc for all values ​​of i in any active SPS shall not be equal to 255 (indicating level 15.5). - The allowed values ​​of syntax elements specified in Table A.1 shall be followed. - The hierarchical and level constraints specified for the Main 12, Main 12 4:4:4, Main 16 4:4:4, Main 12 Intra, Main 12 4:4:4 Intra or Main 16 4:4:4 Intra profiles in subclause A.4 shall be fulfilled, where applicable.

[0098] [Table 3]

[0099] A bitstream conforming to the Main 12 profile is indicated by general_profile_idc equal to 3.

[0100] That a bitstream conforms to the Main 12 Intra profile is indicated by general_profile_idc equal to 11.

[0101] A bitstream conforming to the Main 12 Still Picture profile is indicated by general_profile_idc equal to 67.

[0102] A bitstream conforming to the Main 12 4:4:4 profile is indicated by general_profile_idc equal to 35.

[0103] A bitstream conforming to the Main 12 4:4:4 Intra profile is indicated by general_profile_idc equal to 43.

[0104] A bitstream conforming to the Main 12 4:4:4 Still Picture profile is indicated by general_profile_idc equal to 99.

[0105] A bitstream conforming to the Main 16 4:4:4 profile is indicated by general_profile_idc equal to 37.

[0106] A bitstream conforming to the Main 16 4:4:4 Intra profile is indicated by general_profile_idc equal to 45.

[0107] That a bitstream conforms to the Main 16 4:4:4 Still Picture profile is indicated by general_profile_idc equal to 101.

[0108] A decoder that conforms to the Format Range Extension profile at a particular level (identified by a particular value of general_level_idc) of a particular tier (identified by a particular value of general_tier_flag) shall be able to decode all bitstream and sub-layer representations for which all of the following conditions apply: - One of the following conditions applies: - <<The decoder is indicated as conforming to the Main 12 4:4:4 or Main 16 4:4:4 profile and the bitstream or sublayer representation is indicated as conforming to the Main 10 profile or the Main 10 Still Picture profile. - The decoder is shown to conform to the Main 12 4:4:4 Intra, Main 16 4:4:4 Intra, Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture Profile and the bitstream or sublayer representation conforms to the Main 10 Still Picture Profile. - The decoder is indicated as conforming to the Main 12 profile and the bitstream is indicated as conforming to the Main 10, Main 10 Still Picture, Main 12, Main 12 Intra, or Main 12 Still Picture profiles. - The decoder conforms to the Main 12 4:4:4 profile and the bitstream is indicated as conforming to the Main 10, Main 10 Still Picture, Main 10 4:4:4, Main 10 4:4:4 Still Picture, Main 12, Main 12 Intra, Main 12 Still Picture, Main 12 4:4:4, Main 12 4:4:4 Intra, or Main 12 4:4:4 Still Picture profiles. - The decoder conforms to the Main 16 4:4:4 profile and the bitstream is indicated as conforming to either the Main 10, Main 10 Still Picture, Main 10 4:4:4, Main 10 4:4:4 Still Picture, or the Format Range Extended profile. - The decoder conforms to the Main 12 Intra profile, and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 12 Intra, or Main 12 Still Picture profiles. - The decoder is indicated as conforming to the Main 12 4:4:4 Intra profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Intra, Main 12 4:4:4 Intra, Main 12 Still Picture, or Main 12 4:4:4 Still Picture profiles. - The decoder conforms to the Main 16 4:4:4 Intra profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Intra, Main 12 4:4:4 Intra, Main 16 4:4:4 Intra, Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profiles. - The decoder conforms to the Main 12 Still Picture profile and the bitstream is indicated as conforming to the Main 10 Still Picture or Main 12 Still Picture profile. - The decoder is indicated as conforming to the Main 12 4:4:4 Still Picture profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Still Picture or Main 12 4:4:4 Still Picture profile. - The decoder is indicated as conforming to the Main 16 4:4:4 Still Picture profile and the bitstream is indicated as conforming to the Main 10 Still Picture, Main 10 4:4:4 Still Picture, Main 12 Still Picture, Main 12 4:4:4 Still Picture, or Main 16 4:4:4 Still Picture profile. - <<The bitstream's general_profile_idc is equal to 2, 10, 66, 34, 42, 98, 36, 44, or 100 and the value of each constraint flag listed in Table A.1 is greater than or equal to the value specified in that row of Table A.1 for the format range extension profile for which decoder conformance is being evaluated.>> - The bitstream is indicated as conforming to a specified stratum or lower. - The bitstream is shown to conform to a level below the specified level, but not to level 15.5.

[0109] A decoder that conforms to the Main 12 Still Picture Profile at a particular level of a particular hierarchy shall also be able to decode the first picture of the bitstream if both of the following conditions are true: - The bitstream conforms to the Main 10, Main 12, or Main 12 Intra profile, conforms to a level at or below the specified level, and is indicated as conforming to a level at or below the specified level but not to level 15.5. - The picture is an IRAP picture or a GDR picture with ph_recovery_poc_cnt equal to 0, is in the output layer, and has ph_pic_output_flag equal to 1.

[0110] A decoder that conforms to the Main 12 4:4:4 Still Picture Profile at a particular level of a particular hierarchy shall also be able to decode the first picture of the bitstream if both of the following conditions are true: - The bitstream conforms to the Main 10, Main 10 4:4:4, Main 12, Main 12 Intra, Main 12 4:4:4, or Main 12 4:4:4 Intra profile, conforms to a level below the specified level, and is indicated as conforming to a level below the specified level but not to level 15.5. - The picture is an IRAP picture or a GDR picture with ph_recovery_poc_cnt equal to 0, is in the output layer, and has ph_pic_output_flag equal to 1.

[0111] A decoder that conforms to the Main 16 4:4:4 Still Picture Profile at a particular level of a particular hierarchy shall also be able to decode the first picture of the bitstream if both of the following conditions are true: - The bitstream conforms to the Main 10, Main 10 4:4:4, Main 12, Main 12 Intra, Main 12 4:4:4, Main 12 4:4:4 Intra, Main 16 4:4:4, or Main 16 4:4:4 Intra profile, conforms to a level below the specified level, and is indicated as conforming to a level below the specified level but not to level 15.5. - The picture is an IRAP picture or a GDR picture with ph_recovery_poc_cnt equal to 0, is in the output layer, and has ph_pic_output_flag equal to 1.

[0112] The embodiments of the present disclosure relate to specifying decoder capabilities for a VVC range extension profile. These embodiments can be applied individually or in various combinations to any codec, e.g., video bitstreams encoded according to the VVC standard.

[0113] As used herein, the term "block" may refer to a slice, a tile, a brick, a subpicture, a coding tree unit (CTU), a coding tree block (CTB), a CTU row, a CTB row, one or more coding units (CUs), one or more coding blocks (CBs), one or more CTUs, one or more CTBs, one or more virtual pipeline data units (VPDUs), a sub-region within a picture / slice / tile / brick, an inference block, etc. In some embodiments, a block may include one or more samples or one or more pixels in a video.

[0114] As discussed above, video bitstreams conforming to currently specified format range extension profiles are subject to a significant number of constraints. However, the current definitions for the VVC range extension profiles (including the specification of the decoder capabilities for these profiles) have some problems. For example, for the Main 12 Intra, Main 12 4:4:4 Intra, and Main 16 4:4:4 Intra profiles, the constraints that do not allow the use of inter prediction are missing. There is also no requirement that decoders conforming to some profiles be able to decode bitstreams conforming to some other profiles. Furthermore, some decoder capabilities are not specified correctly.

[0115] To address at least some of these and other potential issues, embodiments of the present disclosure propose a VVC range extension profile approach, as described with reference to Figure 4. It should be understood that these embodiments are examples for illustrating the general concept and should not be construed narrowly. It should also be understood that these embodiments can be applied individually or in any combination.

[0116] FIG. 4 illustrates a flowchart of a video processing method 400 according to some embodiments of the present disclosure. As shown in FIG. 4, at 402, a conversion between a target video block of a video and a bitstream of a video is performed according to a decoding compatibility constraint. The decoding compatibility constraint specifies that a decoder conforming to a first profile can decode at least a first picture of the bitstream if at least one condition applies. The at least one condition includes a first condition that the bitstream is indicated to conform to at least one second profile. The first profile includes a still picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth.

[0117] In some embodiments, the predefined value may be 10. That is, the first profile includes a still image profile corresponding to a first bit depth higher than 10, e.g., 12, 16, etc.

[0118] In some embodiments, the at least one second bit depth may be less than or equal to the first bit depth. For example, if the first bit depth is 12, the second bit depth may be 10 or 12. As another example, if the first bit depth is 16, the second bit depth may be 10, 12, or 16.

[0119] In some embodiments, the first profile may include a Main 12 Still Picture profile, and the at least one second profile may include a Main 10 profile, a Main 12 profile, a Main 12 Intra profile, or the like.

[0120] In some embodiments, the first profile may include a Main 12 4:4:4 Still Picture profile, and the at least one second profile may include at least one of a Main 10 profile, a Main 10 4:4:4 profile, a Main 12 profile, a Main 12 Intra profile, a Main 12 4:4:4 profile, or a Main 12 4:4:4 Intra profile.

[0121] In some embodiments, the first profile may include a Main 16 4:4:4 Still Picture profile, and the at least one second profile may include at least one of a Main 10 profile, a Main 10 4:4:4 profile, a Main 12 profile, a Main 12 Intra profile, a Main 12 4:4:4 profile, a Main 12 4:4:4 Intra profile, a Main 16 4:4:4 profile, or a Main 16 4:4:4 Intra profile.

[0122] In some embodiments, the decoding compatibility constraint may further specify that if the at least one condition applies, a decoder conforming to the first profile at a first level of a first hierarchy can decode at least a first picture of the bitstream.

[0123] In some embodiments, the at least one condition may further include a second condition that the bitstream is indicated as conforming to a tier lower than the first tier, and / or a third condition that the bitstream is indicated as conforming to a level lower than the first level but not to level 15.5.

[0124] In some embodiments, the at least one condition may further include a fourth condition that the first picture of the bitstream is an IRAP (Intra Random Access Point) picture or a GDR (Gradual Decoding Refresh) picture with a recovery point of pictures coded in output order equal to 0, a fifth condition that the first picture is in an output layer, and / or a sixth condition that the first picture has a picture output flag set to a predefined value. For example, in the fourth condition, ph_recovery_poc_cnt may be equal to 0. As another example, in the sixth condition, the first picture may have ph_pic_output_flag equal to 1.

[0125] In some embodiments, the conversion may include encoding the target video block into the bitstream. Alternatively, the conversion may include decoding the target video block from the bitstream. In other words, method 400 may be performed at both an encoder and a decoder of a bitstream.

[0126] According to a further embodiment of the present invention, a bitstream of a video may be stored in a non-transitory computer-readable storage medium. The bitstream is generated by a method executed by a video processing device according to a decoding compatibility constraint. The decoding compatibility constraint specifies that a decoder conforming to a first profile can decode at least a first picture of the bitstream if at least one condition applies. The at least one condition includes a first condition that the bitstream is indicated to conform to at least one second profile. The first profile includes a still image profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still image profile corresponding to at least one second bit depth.

[0127] In some embodiments, a method for storing a video bitstream is proposed. The bitstream is generated according to a decoding compatibility constraint. The decoding compatibility constraint specifies that a decoder conforming to a first profile can decode at least a first picture of the bitstream if at least one condition applies. The at least one condition includes a first condition that the bitstream is indicated to conform to at least one second profile. The first profile includes a still image profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile includes at least one non-still image profile corresponding to at least one second bit depth. The bitstream is then stored in a non-transitory computer-readable storage medium.

[0128] Implementations of the present disclosure can be described in light of the following clauses, the features of which can be combined in any reasonable manner.

[0129] Clause 1. A video processing method comprising: performing a conversion between a target video block of a video and a bitstream of the video in accordance with a decoding compatibility constraint, the decoding compatibility constraint specifying that a decoder suitable for a first profile can decode at least a first picture of the bitstream if at least one condition applies, the at least one condition including a first condition that the bitstream is indicated to conform to at least one second profile, the first profile including a Still Picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile including at least one non-still picture profile corresponding to at least one second bit depth.

[0130] Clause 2. The method of clause 1, wherein the predefined value is 10.

[0131] Clause 3. The method of clause 1 or 2, wherein the at least one second bit depth is less than or equal to the first bit depth.

[0132] Clause 4. The method of any one of clauses 1 to 3, wherein the first profile comprises a Main 12 Still Picture profile and the at least one second profile comprises at least one of a Main 10 profile, a Main 12 profile, or a Main 12 Intra profile.

[0133] Clause 5. The method of any one of clauses 1 to 4, wherein the first profile comprises a Main 12 4:4:4 Still Picture profile and the at least one second profile comprises at least one of a Main 10 profile, a Main 10 4:4:4 profile, a Main 12 profile, a Main 12 Intra profile, a Main 12 4:4:4 profile, or a Main 12 4:4:4 Intra profile.

[0134] Clause 6. The method of any one of clauses 1 to 5, wherein the first profile comprises a Main 16 4:4:4 Still Picture profile and the at least one second profile comprises at least one of a Main 10 profile, a Main 10 4:4:4 profile, a Main 12 profile, a Main 12 Intra profile, a Main 12 4:4:4 profile, a Main 12 4:4:4 Intra profile, a Main 16 4:4:4 profile, or a Main 16 4:4:4 Intra profile.

[0135] Clause 7. The method of any one of clauses 1 to 6, wherein the decoding compatibility constraint further specifies that if the at least one condition applies, a decoder conforming to the first profile at a first level of a first hierarchy can decode at least a first picture of the bitstream.

[0136] Clause 8. The method of clause 7, wherein the at least one condition further includes at least one of a second condition that the bitstream is indicated as conforming to a hierarchical level lower than the first hierarchical level, or a third condition that the bitstream is indicated as conforming to a level lower than the first level but not to level 15.5.

[0137] Clause 9. The method of any one of clauses 1 to 8, wherein the at least one condition further includes at least one of a fourth condition that the first picture of the bitstream is an IRAP (Intra Random Access Point) picture or a GDR (Gradual Decoding Refresh) picture whose recovery point of pictures coded in output order is equal to 0, a fifth condition that the first picture is in an output layer, or a sixth condition that the first picture has a picture output flag set to a predefined value.

[0138] Clause 10. The method of any one of clauses 1 to 9, wherein the transforming includes encoding the target video block into the bitstream.

[0139] Clause 11. The method of any one of clauses 1 to 9, wherein the converting includes decoding the target video block from the bitstream.

[0140] Clause 12. An apparatus for processing video data comprising a processor and a non-transitory memory comprising instructions which, when executed by the processor, cause the processor to perform a method according to any one of clauses 1 to 11.

[0141] Clause 13. A non-transitory computer-readable storage medium storing instructions that cause a processor to perform the method of any one of clauses 1 to 11.

[0142] Clause 14. A non-transitory computer-readable storage medium storing a bitstream of video generated by a method performed by a video processing device, the method comprising a step of generating the bitstream according to a decoding compatibility constraint, the decoding compatibility constraint specifying that a decoder suitable for a first profile can decode at least a first picture of the bitstream if at least one condition applies, the at least one condition comprising a first condition that the bitstream is indicated to conform to at least one second profile, the first profile comprising a Still Picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile comprising at least one non-still picture profile corresponding to at least one second bit depth.

[0143] Clause 15. A method for storing a video bitstream, comprising: generating the bitstream according to a decoding compatibility constraint, the decoding compatibility constraint specifying that a decoder suitable for a first profile can decode at least a first picture of the bitstream if at least one condition applies, the at least one condition including a first condition that the bitstream is indicated to conform to at least one second profile, the first profile including a Still Picture profile corresponding to a first bit depth higher than a predefined value, and the at least one second profile including at least one non-still picture profile corresponding to at least one second bit depth; and storing the bitstream in a non-transitory computer-readable storage medium.

[0144] Exemplary Devices 5 illustrates a block diagram of a computing device 500 capable of implementing various embodiments of the present disclosure. The computing device 500 may be implemented as or included in the source device 110 (or the video encoder 114 or 200) or the destination device 120 (or the video decoder 124 or 300).

[0145] It will be appreciated that the computing device 500 illustrated in FIG. 5 is for illustrative purposes only and is not intended to suggest any limitation on the functionality and scope of the embodiments of the present disclosure.

[0146] 5, the computing device 500 includes a general purpose computing device 500. The computing device 500 may include at least one or more processors or processing units 510, a memory 520, a storage unit 530, one or more communication units 540, one or more input devices 550, and one or more output devices 560.

[0147] In some embodiments, the computing device 500 may be implemented as any user terminal or server terminal having computing capabilities. The server terminal may be a server provided by a service provider, a large-scale computing device, etc. The user terminal may be any type of mobile, fixed, or portable terminal, including, for example, a mobile phone, a station, a unit, a device, a multimedia computer, a multimedia tablet, an Internet node, a communicator, a desktop computer, a laptop computer, a notebook computer, a netbook computer, a tablet computer, a personal communication system (PCS) device, a personal navigation device, a personal digital assistant (PDA), an audio / video player, a digital camera / camcorder, a positioning device, a television receiver, a radio broadcast receiver, an electronic book device, a gaming device, or any combination thereof (including accessories and peripherals of these devices, or any combination thereof). It is contemplated that the computing device 500 may support any type of interface to a user, such as "wearable" circuitry.

[0148] The processing unit 510 may be a physical or virtual processor and may perform various processes based on programs stored in the memory 520. In a multiprocessor system, multiple processing units execute computer-executable instructions in parallel to increase the parallel processing capabilities of the computing device 500. The processing unit 510 may be referred to as a central processing unit (CPU), a microprocessor, a controller, or a microcontroller.

[0149] Computing device 500 typically includes a variety of computer storage media. Such media may be any media accessible by computing device 500, including but not limited to volatile and non-volatile media, or removable and non-removable media. Memory 520 may be volatile memory (e.g., registers, cache, random access memory (RAM)), non-volatile memory (e.g., read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory), or any combination thereof. Storage unit 530 may be any removable or non-removable media, including machine-readable media such as memory, flash memory drives, magnetic disks, or other media that can be used to store information and / or data and that can be accessed by computing device 500.

[0150] The computing device 500 may further include additional removable / non-removable, volatile / non-volatile memory media. Although not shown in FIG. 5, a magnetic disk drive that reads from and writes to a removable non-volatile magnetic disk and an optical disk drive that reads from and writes to a removable non-volatile optical disk may be provided. In such a case, each drive may be connected to a bus (not shown) via one or more data media interfaces.

[0151] The communication unit 540 communicates with further computing devices via a communication medium. Furthermore, the functionality of the components in the computing device 500 may be implemented by a single computing cluster or multiple computing machines that may communicate via a communication connection. Thus, the computing device 500 may operate in a networked environment using logical connections with one or more other servers, networked personal computers (PCs), or further general network nodes.

[0152] The input device 550 may be one or more of a variety of input devices such as a mouse, a keyboard, a tracking ball, a voice input device, etc. The output device 560 may be one or more of a variety of output devices such as a display, a speaker, a printer, etc. The communication unit 540 allows the computing device 500 to further communicate with one or more external devices (not shown), such as a storage device and a display device, one or more devices allowing a user to interact with the computing device 500, or any device (such as a network card, a modem, etc.) allowing the computing device 500 to communicate with one or more other computing devices, as needed. Such communication may be performed via an input / output (I / O) interface (not shown).

[0153] In some embodiments, instead of being integrated into a single device, some or all of the components of the computing device 500 may be located in a cloud computing architecture. In a cloud computing architecture, the components may be provided remotely and work together to perform the functions described in this disclosure. In some embodiments, cloud computing provides computing, software, data access and storage services without the end user needing to be aware of the physical location or configuration of the systems or hardware providing these services. In various embodiments, cloud computing provides services over a wide area network (such as the Internet) using appropriate protocols. For example, a cloud computing provider provides applications over a wide area network that can be accessed through a web browser or other computing components. The software or components of the cloud computing architecture and corresponding data may be stored on a server located in a remote location. Computing resources in a cloud computing environment may be consolidated or distributed at remote data center locations. A cloud computing infrastructure may act as a single access point for users but provide services through a shared data center. Thus, a cloud computing architecture may be used to provide the components and functions described herein from a service provider located in a remote location. Alternatively, they may be provided from a traditional server or installed directly or otherwise on a client device.

[0154] The computing device 500 may be used to perform video encoding / decoding in embodiments of the present disclosure. The memory 520 may include one or more video encoding modules 525 having one or more program instructions. These modules are accessible and executable by the processing unit 510 to perform the functions of various embodiments described herein.

[0155] In an example embodiment performing video encoding, the input device 550 may receive video data to be encoded as an input 570. The video data may be processed, for example, by the video encoding module 525 to generate an encoded bitstream. The encoded bitstream may be provided as an output 580 via the output device 560.

[0156] In an example embodiment performing video decoding, input device 550 may receive an encoded bitstream as input 570. The encoded bitstream may be processed, for example, by video encoding module 525 to generate decoded video data. The decoded video data may be provided as output 580 via output device 560.

[0157] Although the present disclosure has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application as defined by the appended claims. Such variations are intended to be within the scope of the present application. Accordingly, the foregoing description of the embodiments of the present application is not intended to be limiting.

Claims

1. A video processing method, in a decoder, obtaining a bitstream of a video conforming to a first profile, including the step of decoding at least the first picture of the video in the bitstream in the decoder when at least one condition is satisfied, the at least one condition includes a first condition that the bitstream is shown to conform to at least one second profile, the first profile includes a still picture profile corresponding to a first bit depth higher than 10, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth that is less than or equal to the first bit depth.

2. the first profile includes a Main 12 Still Picture profile, the at least one second profile includes at least one of a Main 10 profile, a Main 12 profile, or a Main 12 Intra profile, the method according to claim 1.

3. the first profile includes a Main 12 4:4:4 Still Picture profile, the at least one second profile includes at least one of a Main 10 profile, a Main 10 4:4:4 profile, a Main 12 profile, a Main 12 Intra profile, a Main 12 4:4:4 profile, or a Main 12 4:4:4 Intra profile, the method according to claim 1.

4. the first profile includes a Main 16 4:4:4 Still Picture profile, The method according to claim 1, wherein the at least one second profile includes at least one of a Main 10 profile, a Main 10 4:4:4 profile, a Main 12 profile, a Main 12 Intra profile, a Main 12 4:4:4 profile, a Main 12 4:4:4 Intra profile, a Main 16 4:4:4 profile, or a Main 16 4:4:4 Intra profile.

5. The method according to claim 1, wherein when the at least one condition is applied, a decoder that conforms to the first profile at a first level of the first tier can decode at least the first picture of the bitstream.

6. The at least one condition is a second condition indicating that the bitstream conforms to a tier below the first tier, or The method according to claim 5, further comprising at least one of a third condition indicating that the bitstream conforms to a level below the first level and not at level 15.

5.

7. The at least one condition is a fourth condition that the first picture of the bitstream is an Intra Random Access Point (IRAP) picture or a Gradual Decoding Refresh (GDR) picture with a recovery point of an encoded picture whose output order is equal to 0, a fifth condition that the first picture is in the output layer, or The method according to claim 1, further comprising at least one of a sixth condition that the first picture has a picture output flag set to 1.

8. An apparatus for processing video data comprising a processor and a non-transitory memory storing instructions, An apparatus, wherein when the command is executed by the processor, the processor is caused to execute the method according to any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium storing instructions that cause a processor to execute the method according to any one of claims 1 to 7.

10. A method for storing a video bitstream, comprising: generating the bitstream; and storing the bitstream in a non-transitory computer-readable recording medium, wherein a decoder conforming to a first profile can decode the first picture of the bitstream according to at least one condition being satisfied, wherein the at least one condition includes a first condition that the bitstream is shown to conform to at least one second profile, the first profile includes a still picture profile corresponding to a first bit depth higher than 10, and the at least one second profile includes at least one non-still picture profile corresponding to at least one second bit depth less than or equal to the first bit depth. A method comprising the above.

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