Inter-layer prediction with different coding block sizes

Abstract

Several techniques for video encoding and video decoding are described. An example method includes performing a conversion between a video unit of a current picture of a video and a bitstream of the video according to a rule. The rule specifies that, for a given picture that is available as a reference picture for motion information for the conversion, the given picture has a same coding tree unit size or a same coding tree block size as the current picture.

Description

[0001] Cross-reference to related applications

[0002] This is the national phase of International Patent Application No. PCT / CN2021 / 100316, filed on June 16, 2021, claiming priority and benefit to International Patent Application No. PCT / CN2020 / 097293, filed on June 20, 2020. The entire disclosure of the above application is incorporated herein by reference as part of the disclosure of this application. Technical Field

[0003] The patent document relates to image and video encoding and decoding. Background Technology

[0004] Digital video consumes the largest share of bandwidth in the internet and other digital communication networks. As the number of connected user devices capable of receiving and displaying video increases, the bandwidth demand for digital video is expected to continue to grow. Summary of the Invention

[0005] This document discloses techniques that can be used by video encoders and decoders to process encoded and decoded representations of video using control information useful for decoding encoded and decoded representations.

[0006] In one example, a method for processing video data includes performing a conversion between video units of a current frame of the video and the bitstream of the video, according to a rule. The rule specifies that, for a given frame that can be used as a reference frame for its motion information in the conversion, the given frame has the same codec tree unit size or the same codec tree block size as the current frame.

[0007] In another example, a video processing method is disclosed. This method includes performing a conversion between videos comprising one or more video images, wherein the encoded / decoded representation conforms to a format rule; wherein the format rule specifies that two or more syntax fields in a sequence parameter set control the reference image resolution (RPR) variation in the video.

[0008] In another example, a different video processing method is disclosed. This method includes performing a conversion between videos comprising one or more video images, wherein the encoded / decoded representation conforms to a format rule; wherein the format rule specifies that a single syntax field in a sequence parameter set controls the reference image resolution (RPR) variation in the video; and wherein the format rule specifies that resampling of the inter-layer reference images for use in the conversion is permitted regardless of the value of the single syntax field.

[0009] In another example, a different video processing method is disclosed. This method includes performing a transformation between videos comprising one or more layers, each layer comprising one or more images, each image comprising one or more sub-images, wherein the encoded / decoded representation conforms to a format rule; wherein the format rule specifies either a first constraint on cross-layer alignment or a second constraint on a combination of scalability of sub-images and inter-layer images.

[0010] In another example, a different video processing method is disclosed. This method includes performing a transformation between videos comprising one or more layers, each layer comprising one or more video images, each video image comprising one or more sub-images, wherein the transformation conforms to a format rule specifying that inter-layer reference images or long-term reference images are not permitted as co-position images of the current image used for the transformation.

[0011] In another example, a different video processing method is disclosed. This method includes performing a conversion between a video comprising multiple images and its codec representation, wherein the conversion conforms to a rule specifying that the value of each of scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset is identical for any two images within the same codec video sequence or a codec video sequence having the same pic_width_in_luma_samples and pic_height_in_luma_samples values.

[0012] In another example, a different video processing method is disclosed. This method includes performing a conversion between a video comprising multiple images and a codec representation of that video, wherein the conversion conforms to a rule specifying that inter-layer prediction is allowed only if the current image is an intra-frame random access point image, provided that the image resolution or scaling window differs for the current image and other images in the same access unit.

[0013] In another example, a different video processing method is disclosed. This method includes: for a current frame of video, a conversion between a video block and a encoded / decoded representation of the video; determining whether a rule is applied based on a comparison of a first size of the video block with a second size of the video block in a co-located video frame or an inter-frame frame; and performing the conversion based on that determination.

[0014] In yet another example, a video encoder apparatus is disclosed. The video encoder includes a processor configured to implement the methods described above.

[0015] In yet another example, a video decoder apparatus is disclosed. The video decoder includes a processor configured to implement the methods described above.

[0016] In yet another example, a computer-readable medium on which code is stored is disclosed. This code embodies one of the methods described herein in the form of processor-executable code.

[0017] These and other features will be described in this document. Attached Figure Description

[0018] Figure 1 An example of raster scan strip segmentation of an image is shown, in which the image is divided into 12 slices and 3 raster scan strips.

[0019] Figure 2 An example of rectangular strip segmentation of an image is shown, where the image is divided into 24 slices (6 slice columns and 4 slice rows) and 9 rectangular strips.

[0020] Figure 3 An example of an image divided into slices and rectangular strips is shown, where the image is divided into 4 slices (2 slice columns and 2 slice rows) and 4 rectangular strips.

[0021] Figure 4 The image is shown as being divided into 15 slices, 24 strips, and 24 sub-images.

[0022] Figure 5 This is a block diagram of an example video processing system.

[0023] Figure 6 This is a block diagram of a video processing device.

[0024] Figure 7 This is a flowchart of an example method for video processing.

[0025] Figure 8 This is a block diagram illustrating a video encoding / decoding system according to some embodiments of the present disclosure.

[0026] Figure 9 This is a block diagram illustrating an encoder according to some embodiments of the present disclosure.

[0027] Figure 10 This is a block diagram illustrating a decoder according to some embodiments of the present disclosure.

[0028] Figure 11 This illustrates a typical sub-image-based viewport dependency 360. o Examples of video encoding / decoding schemes.

[0029] Figure 12This demonstrates a viewport-dependent 360 based on sub-images and spatial scalability. o Video encoding and decoding solutions.

[0030] Figure 13 This is a flowchart representation of a video processing method according to one or more embodiments of the present technology. Detailed Implementation

[0031] The use of chapter headings in this document is for ease of understanding and not to limit the applicability of the techniques and embodiments disclosed in each chapter to that chapter only. Furthermore, the use of H.266 terminology in some descriptions is merely for ease of understanding and not to limit the scope of the disclosed techniques. Therefore, the techniques described herein are also applicable to other video codec protocols and designs. In this document, edit changes to the text relative to the current draft of the VVC specification are indicated by strikethrough indicating undoing, and highlighting indicating addition (including bold and italic).

[0032] 1. Overview

[0033] This document relates to video codec techniques. Specifically, it covers 1) combinations of two or more of Reference Picture Resampling (RPR), subpictures, and scalability in video codecs; 2) the use of RPR between a current picture and a reference picture with the same spatial resolution; and 3) combinations of long-term reference pictures and co-pictures. These ideas can be applied individually or in various combinations to any video codec standard or non-standard video codec that supports multi-layer video codecs, such as the Multi-Functional Video Codec (VVC) under development.

[0034] 2. Abbreviations

[0035] APS Adaptive Parameter Set

[0036] AU Access Unit

[0037] AUD Access Unit Delimiter

[0038] AVC Advanced Video Codec

[0039] CLVS video sequence via encoder / decoder layer

[0040] CCALF Cross Component Adaptive Loop Filter

[0041] CPB Encoder-Decoder Image Buffer

[0042] CRA Idle Random Access

[0043] CTU (Codec Tree Unit)

[0044] CVS encoded video sequence

[0045] DCI decoding capability information

[0046] DPB Decoded Image Buffer

[0047] End of EOB bitstream

[0048] End of EOS sequence

[0049] GDR Gradual Decoding and Refresh

[0050] HEVC High-Efficiency Video Encoding and Decoding

[0051] HRD Assumption Reference Decoder

[0052] IDR Instantaneous Decoding and Refresh

[0053] ILP Interlayer Prediction

[0054] ILRP interlayer reference image

[0055] IRAP Intra-Frame Random Access Image

[0056] JEM Joint Exploration Model

[0057] LTRP Long-Term Reference Image

[0058] MCTS Motion Restraint Piece Set

[0059] NAL Network Abstraction Layer

[0060] OLS Output Layer Set

[0061] PH Image Header

[0062] PPS Image Parameter Set

[0063] PTL profiles, hierarchies, and levels

[0064] PU Image Unit

[0065] RAP Random Access Point

[0066] RBSP raw byte sequence payload

[0067] SEI Supplemental Enhancement Information

[0068] SPS Sequence Parameter Set

[0069] STRP Short-Term Reference Image

[0070] SVC Scalable Video Codec

[0071] VCL (Video Codec Layer)

[0072] VPS Video Parameter Set

[0073] VTM VVC Test Model

[0074] VUI Video Availability Information

[0075] VVC Multi-Functional Video Encoding and Decoding

[0076] 3. Preliminary Discussion

[0077] Video codec standards have primarily evolved alongside the well-known ITU-T and ISO / IEC standards. ITU-T developed H.261 and H.263, while ISO / IEC developed MPEG-1 and MPEG-4 Visual. These two organizations jointly developed the H.262 / MPEG-2 video and H.264 / MPEG-4 Advanced Video Codec (AVC) and H.265 / HEVC standards. Since H.262, video codec standards have been based on a hybrid video codec architecture, utilizing temporal prediction plus transform coding. To explore future video codec technologies beyond HEVC, VCEG and MPEG jointly established the Joint Video Exploration Group (JVET) in 2015. Since then, JVET has adopted many new methods and incorporated them into reference software called the Joint Exploration Model (JEM). JVET meetings are held quarterly, and the goal of the new codec standard is to reduce the bitrate by 50% compared to HEVC. The new video codec standard was officially named Multifunctional Video Codec (VVC) at the JVET meeting in April 2018, and the first version of the VVC Test Model (VTM) was also released at that time. Due to ongoing efforts to standardize VVC, new codec technologies have been adopted into the VVC standard at each JVET meeting. The VVC working draft and the VTM test model are then updated after each meeting. The current goal of the VVC project is to achieve Technical Finality (FDIS) at the meeting in July 2020.

[0078] 3.1. Image Segmentation Schemes in HEVC

[0079] HEVC includes four different image segmentation schemes: regular striping, dependent striping, slice, and wavefront parallel processing (WPP), which can be used for maximum transmission unit (MTU) size matching, parallel processing, and reduced end-to-end latency.

[0080] Regular stripes are similar to those in H.264 / AVC. Each regular strip is encapsulated in its own NAL unit, and intra-image predictions (intra-sample prediction, motion information prediction, and encoding / decoding mode prediction) and entropy encoding / decoding dependencies across strip boundaries are disabled. Therefore, regular stripes can be reconstructed independently of other regular stripes within the same image (although interdependencies may still exist due to loop filtering operations).

[0081] Regular striping is the only tool available for parallelization, and it is also available in almost the same form in H.264 / AVC. Parallelization based on regular striping does not require much inter-processor or inter-core communication (except for inter-processor or inter-core data sharing for motion compensation when decoding predictive encode-decode images, which is typically much larger than inter-processor or inter-core data sharing due to intra-image prediction). However, for the same reason, using regular striping results in significant encoding / decoding overhead due to the bit cost of the stripe header and the lack of prediction across stripe boundaries. Furthermore, due to the intra-image independence of regular striping and the fact that each regular stripe is encapsulated in its own NAL unit, regular striping (compared to other tools mentioned below) also serves as a key mechanism for bitstream segmentation to match MTU size requirements. In many cases, the goals of parallelization and MTU size matching present conflicting requirements for stripe layout in images. This recognition led to the development of the parallelization tools mentioned below.

[0082] Dependency striping has a short stripe header and allows the bitstream to be split at tree block boundaries without disrupting any in-picture predictions. Essentially, dependency striping provides the segmentation of a regular stripe into multiple NAL units to provide reduced end-to-end latency by allowing a portion of the regular stripe to be sent out before the entire regular stripe is encoded.

[0083] In WPP, images are segmented into single-row codec tree blocks (CTBs). Entropy decoding and prediction are allowed to use data from CTBs in other segments. Parallel processing is possible through parallel decoding of CTB rows, where the start of decoding a CTB row is delayed by two CTBs, ensuring that data associated with the CTBs above and to the right of the subject CTB is available before the subject CTB is decoded. Using this staggered start (which looks like a wavefront when graphically represented), parallelization can use as many processors / cores as the number of CTB rows contained in the image. Because intra-image prediction between adjacent tree block rows within an image is allowed, the inter-processor / inter-core communication required to implement intra-image prediction can be substantial. WPP segmentation does not produce additional NAL units compared to when it is not applied, therefore WPP is not a tool for MTU size matching. However, if MTU size matching is required, regular striping can be used with WPP, but with some encoding / decoding overhead.

[0084] A slice defines the horizontal and vertical boundaries that divide an image into slice columns and slice rows. Slice columns extend from the top to the bottom of the image. Similarly, slice rows extend from the left to the right of the image. The number of slices in an image can be simply derived by multiplying the number of slice columns by the number of slice rows.

[0085] Before decoding the top-left CTB of the next slice in the order of slice raster scans of the image, the scan order of the CTBs is changed to be local within the slice (in the order of slice CTB raster scans). Similar to regular stripes, slices break the intra-image prediction dependencies and entropy decoding dependencies. However, they do not need to be included in a single NAL unit (the same as WPP in this respect); therefore, slices cannot be used for MTU size matching. Each slice can be processed by one processor / core, and the inter-processor / inter-core communication required for intra-image prediction between processing units decoding adjacent slices is limited to transmitting a shared slice header when a slice spans more than one slice, and loop filtering associated with the sharing of reconstructed samples and metadata. When a slice includes more than one slice or WPP segment, the entry point byte offset of each slice or WPP segment in the slice, except for the first slice or WPP segment, is signaled in the slice header.

[0086] For simplicity, HEVC specifies restrictions on the application of four different image segmentation schemes. A given encoded video sequence cannot simultaneously include slices and wavefronts of most of the profiles specified in the HEVC standard. For each strip and slice, one or both of the following conditions must be met: 1) All encoded tree blocks in a strip belong to the same slice; 2) All encoded tree blocks in a slice belong to the same strip. Finally, a wavefront segment contains exactly one CTB line, and when using WPP, if a strip begins within a CTB line, it must end within the same CTB line.

[0087] In the recent HEVC amendment, HEVC specified three types of SEI messages related to MCTS: i.e., domain MCTS SEI message, MCTS extract information set SEI message, and MCTS extract information nested SEI message.

[0088] The temporal MCTS SEI message indicates the presence of an MCTS in the bitstream, and signaling notifies the MCTS. For each MCTS, motion vectors are restricted to pointing to full-sample locations within the MCTS and fractional-sample locations that require interpolation only from full-sample locations within the MCTS, and motion vector candidates derived from blocks outside the MCTS for temporal motion vector prediction are not allowed. In this way, each MCTS can be decoded independently, and there are no slices not included in the MCTS.

[0089] The MCTS Extraction Information Set (SEI) message provides supplementary information (specified as part of the semantics of the SEI message) that can be used in MCTS sub-bitstream extraction to generate a bitstream conforming to the MCTS set. This information consists of multiple extraction information sets, each defining multiple MCTS sets and containing RBSP bytes that will replace the VPS, SPS, and PPS during the MCTS sub-bitstream extraction process. When extracting a sub-bitstream according to the MCTS sub-bitstream extraction process, the parameter sets (VPS, SPS, and PPS) need to be rewritten or replaced, and the slice header needs to be slightly updated because one or all slice address-related syntax elements (including first_slice_segment_in_pic_flag and slice_segment_address) typically need to have different values.

[0090] 3.2. Image Segmentation in VVC

[0091] In VVC, an image is divided into one or more slice rows and one or more slice columns. A slice is a series of CTUs that cover a rectangular area of ​​the image. The CTUs in a slice are scanned in raster scan order within that slice.

[0092] A strip consists of an integer number of consecutive complete CTU lines within an integer number of complete slices or images.

[0093] Two stripe modes are supported: raster scan stripe mode and rectangular stripe mode. In raster scan stripe mode, a stripe contains a complete sequence of slices in a sheet raster scan of the image. In rectangular stripe mode, a stripe contains multiple complete slices that together form a rectangular region of the image, and multiple consecutive complete CTU rows of a slice that together form a rectangular region of the image. Slices within a rectangular stripe are scanned in sheet raster scan order within the rectangular region corresponding to that stripe.

[0094] A sub-image contains one or more stripes that collectively cover a rectangular area of ​​the image.

[0095] Figure 1 An example of raster scan strip segmentation of an image is shown, in which the image is divided into 12 slices and 3 raster scan strips.

[0096] Figure 2 An example of rectangular strip segmentation of an image is shown, where the image is divided into 24 slices (6 slice columns and 4 slice rows) and 9 rectangular strips.

[0097] Figure 3 An example of an image divided into slices and rectangular strips is shown, where the image is divided into 4 slices (2 slice columns and 2 slice rows) and 4 rectangular strips.

[0098] Figure 4 An example of sub-image segmentation of an image is shown, where the image is segmented into 18 slices. The 12 slices on the left each cover a 4×4 CTU strip, and the 6 slices on the right each cover two vertically stacked 2×2 CTU strips, resulting in a total of 24 strips and 24 sub-images of different sizes (each strip is a sub-image).

[0099] 3.3. Changes in image resolution within a sequence

[0100] In AVC and HEVC, the spatial resolution of an image cannot be changed unless a new sequence with a new SPS begins with an IRAP image. VVC allows changing the resolution of images within a sequence at locations where an IRAP image is not encoded; this IRAP image is always intra-frame encoded / decoded. This feature is sometimes called Reference Image Resampling (RPR) because it requires resampling the reference image used for inter-frame prediction when the reference image has a different resolution than the current image being decoded.

[0101] The scaling ratio is limited to greater than or equal to 1 / 2 (2x downsampling from the reference image to the current image) and less than or equal to 8 (8x upsampling). Three sets of resampling filters with different frequency cutoffs are specified to handle various scaling ratios between the reference and current images. The three sets of resampling filters are applied to scaling ratios ranging from 1 / 2 to 1 / 1.75, from 1 / 1.75 to 1 / 1.25, and from 1 / 1.25 to 8, respectively. Each set of resampling filters has 16 phases for luma and 32 phases for chroma, which is the same as in the case of motion-compensated interpolation filters. In fact, the normal MC interpolation process is a special case of the resampling process where the scaling ratio ranges from 1 / 1.25 to 8. The horizontal and vertical scaling ratios are derived based on the image width and height and the left, right, top, and bottom scaling offsets specified for the reference and current images.

[0102] Other aspects of the VVC design that support this feature that differ from HEVC include: i) Picture resolution and the corresponding consistency window are signaled in the PPS instead of the SPS, where the maximum picture resolution is signaled in the SPS. ii) For a single-layer bitstream, each picture storage (the slot in the DPB used to store one decoded picture) occupies the buffer size required to store the decoded picture with the maximum picture resolution.

[0103] 3.4. General Cases and Scalable Video Codec (SVC) in VVC

[0104] Scalable video codec (SVC, sometimes also called scalability in video codec) refers to video codec that uses a base layer (BL) (sometimes called a reference layer (RL)) and one or more scalable enhancement layers (EL). In SVC, the base layer can carry video data with a basic quality level. One or more enhancement layers can carry additional video data to support, for example, higher spatial, temporal, and / or signal-to-noise ratio (SNR) levels. Enhancement layers can be defined relative to previously encoded layers. For example, the bottom layer can be used as a BL, while the top layer can be used as an EL. Intermediate layers can act as ELs or RLs or both. For example, an intermediate layer (e.g., a layer that is neither the lowest nor the highest layer) can be an EL of a layer below the intermediate layer (such as a base layer or any enhancement layer in between) while also acting as an RL of one or more enhancement layers above the intermediate layer. Similarly, in the multi-view or 3D extension of the HEVC standard, there can be multiple views, and information from one view can be used to codec (e.g., encode or decode) information from another view (e.g., motion estimation, motion vector prediction, and / or other redundancy).

[0105] In SVC, the parameters used by the encoder or decoder are grouped into parameter sets based on the codec level they might be used at (e.g., video level, sequence level, picture level, stripe level, etc.). For example, parameters that can be used by one or more encoded video sequences from different layers in a bitstream can be included in the Video Parameter Set (VPS), and parameters that can be used by one or more pictures in an encoded video sequence can be included in the Sequence Parameter Set (SPS). Similarly, parameters used by one or more stripes in a picture can be included in the Picture Parameter Set (PPS), and additional parameters specific to a single strip can be included in the stripe header. Likewise, indications of which parameter set(s) a particular layer uses at a given time can be provided at various codec levels.

[0106] Because VVC supports Reference Picture Resampling (RPR), it's possible to design bitstream support with multiple layers (e.g., two layers with SD and HD resolutions in VVC) without any additional signal processing-level codec tools, as the upsampling required for spatial scalability support can be achieved using only RPR upsampling filters. However, supporting scalability requires a higher level of syntax variation (compared to not supporting scalability at all). Scalability support was specified in VVC version 1. Unlike scalability support in any earlier video codec standards (including extensions to AVC and HEVC), VVC's scalability is designed to be as friendly as possible to single-layer decoder designs. The decoding capability of a multi-layer bitstream is specified as if there were only a single layer in the bitstream. For example, decoding capabilities can be specified in a way that is independent of the number of layers in the bitstream to be decoded, such as the DPB size. Essentially, a decoder designed for a single-layer bitstream doesn't require many changes to decode a multi-layer bitstream. Compared to the multi-layer extension designs of AVC and HEVC, HLS is significantly simplified at the expense of some flexibility. For example, IRAP AU requires a picture of every layer present in CVS.

[0107] 3.5. Viewport Dependency Based on Sub-Images (360°) o video stream

[0108] In 360 oIn streaming video (also known as omnidirectional video), at any given moment, only a subset of the entire omnidirectional video sphere (e.g., the current viewport) is presented to the user, who can change their viewing orientation at any time by turning their head, thus changing the current viewport. While it's desirable to have at least some lower-quality representations of areas not covered by the current viewport available at the client end, ready to be rendered to the user in case they suddenly change their viewing orientation anywhere on the sphere, the high-quality representation of the omnidirectional video is only needed for the current viewport being rendered to the user. This optimization is achieved by breaking down the high-quality representation of the entire omnidirectional video into sub-pictures with appropriate granularity. Using VVC, these two representations can be encoded as two independent layers.

[0109] Figure 11 This illustrates a typical sub-image-based viewport dependency 360. o The video transmission scheme involves a higher resolution representation of the full video consisting of sub-pictures, while a lower resolution representation does not use sub-pictures and can be encoded and decoded using fewer random access points compared to the higher resolution representation. The client receives the full video at the lower resolution, and for the higher resolution video, it only receives and decodes the sub-pictures covering the current viewport.

[0110] 3.6. Parameter Set

[0111] AVC, HEVC, and VVC specify parameter sets. Parameter set types include SPS, PPS, APS, and VPS. AVC, HEVC, and VVC all support SPS and PPS. VPS was introduced with HEVC and is included in both HEVC and VVC. APS is not included in AVC or HEVC, but is included in the latest VVC draft text.

[0112] The Sequence-Level Prefix (SPS) is designed to carry sequence-level header information, while the Picture-Level Prefix (PPS) is designed to carry infrequently changing picture-level header information. Using SPS and PPS, infrequently changing information does not need to be repeated for each sequence or picture, thus avoiding redundant signaling. Furthermore, the use of SPS and PPS enables out-of-band transmission of important header information, thereby not only avoiding the need for redundant transmission but also improving error resilience.

[0113] The VPS was introduced to carry sequence-level header information that is common to all layers in a multi-layer bitstream.

[0114] The purpose of APS is to carry such image-level or strip-level information, which requires a considerable number of bits to encode and decode, can be shared by multiple images, and can have a considerable number of different variations in a sequence.

[0115] The following are the semantics of SPS / PPS / APS in some embodiments:

[0116] sps_seq_parameter_set_id provides an identifier for SPS, which is then referenced by other syntax elements.

[0117] Regardless of the nuh_layer_id value, SPS NAL units share the same value space of sps_seq_parameter_set_id.

[0118] Let spsLayerId be the nuh_layer_id value of a specific SPS NAL unit, and vclLayerId be the nuh_layer_id value of a specific VCL NAL unit. A specific VCL NAL unit should not reference a specific SPS NAL unit unless spsLayerId is less than or equal to vclLayerId, and the decoded OLS contains layers with nuh_layer_id equal to spsLayerId and layers with nuh_layer_id equal to vclLayerId.

[0119] The pps_pic_parameter_set_id identifies the PPS referenced by other syntax elements. The value of pps_pic_parameter_set_id should be in the range of 0 to 63 (inclusive).

[0120] Regardless of the nuh_layer_id value, PPS NAL units share the same value space of pps_pic_parameter_set_id.

[0121] Let ppsLayerId be the nuh_layer_id value of a specific PPS NAL unit, and vclLayerId be the nuh_layer_id value of a specific VCL NAL unit. A specific VCL NAL unit should not reference a specific PPS NAL unit unless ppsLayerId is less than or equal to vclLayerId, and the decoded OLS contains layers with nuh_layer_id equal to ppsLayerId and layers with nuh_layer_id equal to vclLayerId.

[0122] The adaptation_parameter_set_id provides an identifier for APS, which is then referenced by other syntax elements.

[0123] When aps_params_type is equal to ALF_APS or SCALING_APS, the value of adaptation_parameter_set_id should be in the range of 0 to 7 (inclusive).

[0124] When aps_params_type equals LMCS_APS, the value of adaptation_parameter_set_id should be in the range of 0 to 3 (inclusive).

[0125] Let apsLayerId be the nuh_layer_id value of a specific APS NAL unit, and vclLayerId be the nuh_layer_id value of a specific VCL NAL unit. A specific VCL NAL unit should not reference a specific APS NAL unit unless apsLayerId is less than or equal to vclLayerId, and the decoded OLS contains layers with nuh_layer_id equal to apsLayerId and layers with nuh_layer_id equal to vclLayerId.

[0126] 3.7. Sub-bit Stream Extraction Process

[0127] The inputs to this process are the bitstream inBitstream, the target OLS index targetOlsIdx, and the highest target TemporalId value tIdTarget.

[0128] The output of this process is the sub-bit stream outBitstream.

[0129] The requirement for bitstream consistency of the input bitstream is that any output sub-bitstream that satisfies all of the following conditions should be a consistent bitstream:

[0130] – The output sub-bitstream is the output of the procedure specified in this clause, where the bitstream, targetOlsIdx is equal to the index of the OLS list specified by the VPS, and tIdTarget is any value in the range of 0 to 6 (inclusive) as input.

[0131] – The output sub-bitstream contains at least one VCL NAL unit, where nuh_layer_id is equal to each nuh_layer_id value in LayerIdInOls[ targetOlsIdx ].

[0132] – The output sub-bitstream contains at least one VCL NAL unit, where TemporalId is equal to tIdTarget.

[0133] Note – A consistent bitstream contains one or more encoded stripe NAL units where TemporalId equals 0, but not necessarily encoded stripe NAL units where nuh_layer_id equals 0.

[0134] The output sub-bitstream OutBitstream is derived as follows:

[0135] – The bitstream outBitstream is set to be the same as the bitstream inBitstream.

[0136] - Remove all NAL cells from outBitstream where TemporalId is greater than tIdTarget.

[0137] – Remove from outBitstream all NAL units whose nal_unit_type is not equal to any of VPS_NUT, DCI_NUT, and EOB_NUT and whose nuh_layer_id is not included in the list LayerIdInOls[ targetOlsIdx ].

[0138] – Remove all NAL cells from outBitstream that are true for all of the following conditions:

[0139] –nal_unit_type is not equal to IDR_W_RADL, IDR_N_LP or CRA_NUT.

[0140] – For the value of j in the range of 0 to NumLayersInOls[targetOlsIdx] - 1 (inclusive), nuh_layer_id is equal to LayerIdInOls[targetOlsIdx][j].

[0141] –TemporalId is greater than or equal to NumSubLayersInLayerInOLS[targetOlsIdx][j].

[0142] – Remove all SEI NAL cells from outBitstream that contain scalable nested SEI messages with nesting_ols_flag equal to 1 and no value of i in the range of 0 to nesting_num_olss_minus1 (inclusive), so NestingOlsIdx[i] equals targetOlsIdx.

[0143] – When LayerIdInOls[targetOlsIdx] does not include all values ​​of nuh_layer_id for all NAL units in the bitstream, the following applies:

[0144] - Remove all SEI NAL units from outBitstream that contain non-scalable nested SEI messages in which payloadType is equal to 0 (buffer period) or 130 (decoding unit information).

[0145] – When general_same_pic_timing_in_all_ols_flag equals 0, remove all SEI NAL units from outBitstream that contain non-scalable nested SEI messages where payloadType equals 1 (picture timing).

[0146] – When outBitstream contains SEI NAL units (which contain scalable nested SEI messages where nesting_ols_flag equals 1, and are applicable to outBitstream (NestingOlsIdx[i] equals targetOlsIdx)), the following applies:

[0147] – If same_pic_timing_within_ols_flag equals 0, extract the appropriate non-scalable nested SEI messages from the scalable nested SEI messages where payloadType equals 0 (buffer period), 1 (picture timing), or 130 (decoding unit information), and include these SEI messages in outBitstream.

[0148] - Otherwise (same_pic_timing_within_ols_flag equals 1), extract the appropriate non-scalable nested SEI messages from the scalable nested SEI messages where payloadType equals 0 (buffer period) or 130 (decoding unit information), and include these SEI messages in outBitstream.

[0149] 4. The technical problem solved by the disclosed technical solution

[0150] The existing design in the latest VVC documentation has the following issues:

[0151] 1) Current VVC design supports 360° o Typical video encoding and decoding schemes, such as Figure 11 As shown. However, although the current VVC design supports scalability, as... Figure 12 The improved 360 shown o The video codec scheme is not supported. Figure 11 The only difference between the methods shown is Figure 12 The method shown applies inter-layer prediction (ILP).

[0152] The following two places in the VVC draft do not allow the combination of subpixels and spatial scalability:

[0153] a. Spatial scalability design in VVC relies on RPR features. However, the combination of RPR and sub-images is currently not permitted by the following semantic constraints:

[0154] When res_change_in_clvs_allowed_flag equals 1, the value of subpic_info_present_flag should be equal to 0.

[0155] Therefore, the improved encoding / decoding scheme is not allowed because, for SPS referenced by a higher layer, the above constraints do not allow setting subpic_info_present_flag to 1 (to use multiple subpics per picture) and simultaneously setting res_change_in_clvs_allowed_flag to 1 (to enable RPR, which is required for ILP spatial scalability).

[0156] b. The current VVC draft imposes the following constraints on the combination of sub-images and scalability:

[0157] When subpic_treated_as_pic_flag[i] equals 1, the requirement for bitstream consistency is that for each output layer and its reference layer in an OLS that includes the layer containing the i-th subpic as the output layer, all of the following conditions are true:

[0158] – All images in the output layer and its reference layer should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0159] For each value of j in the range of 0 to sps_num_subpics_minus1 (inclusive), all SPS referenced by the output layer and its reference layer should have the same sps_num_subpics_minus1 value, and should have the same ssubpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], subpic_width_minus1[j], subpic_height_minus1[j], and loop_filter_across_subpic_enabled_flag[j] values ​​respectively.

[0160] – For each value of j in the range of 0 to sps_num_subpics_minus1 (inclusive), all pictures in each access unit of the output layer and its reference layer should have the same SubpicIdVal[j] value.

[0161] Apart from the restricted combination of sub-images and SNR scalability, the above constraints essentially do not allow any other combination of sub-images and ILP scalability, where each layer within a dependency tree must have the same spatial resolution and the same sub-image layout.

[0162] 2) When `subpic_treated_as_pic_flag[i]` equals 1, the subpicture boundary of the i-th subpicture will be considered as the picture boundary in motion compensation. In the VVC draft text, this is achieved by applying certain clipping operations during the decoding process related to motion compensation. However, for Figure 12 The improved encoding / decoding scheme shown does not require such cropping in this case, since the lower layers are fully available to the decoder and not just the region corresponding to the i-th sub-image, thus avoiding unnecessary loss of encoding / decoding efficiency.

[0163] 3) Without considering the impact on Figure 12 With support for the improved encoding / decoding scheme shown, the existing constraints on the combination of sub-pictures and ILP scalability (described in the description of Problem 1b) have the following problems:

[0164] a. This constraint should also apply when the layer containing the i-th sub-image is not an output layer of OLS. The entire constraint should be specified in a way that does not consider whether the layer is an output layer of OLS.

[0165] b. It should include the requirement that the value of subpic_treated_as_pic_flag[i] be aligned across layers, otherwise it will be impossible to extract subpicture sequences with the same index across layers.

[0166] c. The requirement for cross-layer alignment of the value of loop_filter_across_subpic_enabled_flag[i] should be excluded because regardless of the value of this flag, as long as subpic_treated_as_pic_flag[i] is equal to 1, the subpic sequence can be extracted. The setting of the value of loop_filter_across_subpic_enabled_flag[i] should be left to the encoder to determine the trade-off between the quality of a single extractable subpic sequence and the quality of multiple extractable subpic sequences, just as these two flags are signaled independently of each other.

[0167] d. The entire constraint should only be applied when sps_num_subpics_minus1 is greater than 0, to avoid the constraint unintentionally covering all cases of a subpic within each subpic.

[0168] e. The time domain range of the applied constraints needs to be clearly specified, such as the AU set.

[0169] f. Requirements should be included for the values ​​of each of the scaling window parameters scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset for cross-layer alignment, to ensure that ITRP's RPR is not required when each image has multiple sub-images.

[0170] 4) Currently, the collocated picture of the current image can be either a long-term reference picture (LTRP) in the same layer as the current image, or an inter-layer reference picture (ILRP), such as a reference picture in a different layer than the current image. However, in either case, POC-based motion vector scaling will not be applied, so encoding and decoding performance is expected to be very low due to allowing this. Therefore, it is best to disallow the collocated picture of the current image to be either an LTRP or an ILRP.

[0171] 5) Currently, images with the same spatial resolution in CLVS are allowed to have different scaling windows. However, this should not be allowed; otherwise, the SPS flag and the general constraint flag of RPR would not be able to be used to completely disable the RPR tool.

[0172] 6) Currently, when performing sub-bitstream extraction, the parameter sets (SPS / PPS / VPS) of layers not included in the current / target OLS can also be included in the extracted bitstream. However, it is not by design that as long as an OLS containing both layer A and layer B is defined in the VPS, even if layer A and layer B are not included in the current OLS being decoded, the stripes in layer A referencing the parameter set in layer B is not intended.

[0173] 7) The number of allowed APSs depends on the APS type. However, the signaling for the APS ID is fixed at u(5), regardless of the allowed APSs, which may waste unnecessary bits.

[0174] 8) Currently, the scaling window offset is signaled as a positive value, therefore only positive vertical and horizontal offsets are supported. However, it is possible to allow signaling of negative scaling window offsets, making it possible to derive negative vertical and horizontal offsets even when the reference image does not include the scaling window. Allowing scaling factors greater than 1 will also benefit 360. o Sub-image usage in video encoding and decoding, for example, with a full 360... o The video content consists of a base layer with a lower resolution, followed by enhancements for a specific viewport encoded and decoded at a higher resolution (similar to zooming in on an image in the base layer). However, several places in the current specification should be modified to support this functionality.

[0175] 9) Currently, when Transform Skip Residual Coding (TSRC) is enabled, Symbol Data Hiding (SDH) and Dependent Quantization (DQ) can also be used, which violates the concept of lossless coding. TSRC is a mode that encodes and decodes the quantization indexes of all scan positions in a transform block. SDH is a technique that omits the coding and decoding of non-zero index symbols. DQ is a mode in which the quantization of a sample depends on the state of the previous sample.

[0176] 10) When the CTU size of the co-located image is the same as the size of the current image, memory loading can be performed sequentially since only the motion information of blocks in the co-located CTU or the CTU to the right of the co-located CTU needs to be retrieved. However, due to inter-layer prediction, where the co-located image can be an inter-layer reference image (i.e., in different layers), this will lead to hardware implementation issues regarding memory load when the CTU size of the co-located image is different from the CTU size of the current image (which may occur when using inter-layer prediction).

[0177] 5. List of technical solutions and embodiments

[0178] To address the aforementioned and other issues, the following summarized methods are presented. These items should be considered as examples for explaining general concepts, not as narrow interpretations. Furthermore, these items can be used individually or in combination in any way.

[0179] 1) To address issue 1a, instead of having only one SPS flag (e.g., res_change_in_clvs_allowed_flag as in the current VVC draft) for controlling RPR, multiple (such as two) SPS flags can be specified and / or signaled for this purpose.

[0180] a. For example, the first flag (e.g., ref_pic_resampling_enabled_flag) specifies whether RPR is required to decode one or more images, while the second flag (e.g., res_change_in_clvs_allowed_flag) specifies whether the image resolution is allowed to change within CLVS.

[0181] b. Alternatively, the second flag is signaled only if the first flag indicates that RPR may be needed to decode one or more images. Furthermore, when no signaling notification is received, the value of the second flag is inferred to be a value that specifies the image resolution must not be changed within the CLVS.

[0182] i. Alternatively, these two signs signal independently of each other.

[0183] c. Alternatively, add one or more general constraint flags such that each of the first and second flags has a general constraint flag.

[0184] d. In addition, combinations of multiple sub-images for each image with res_change_in_clvs_allowed_flag equal to 1 are not allowed, but combinations of multiple sub-images for each image with ref_pic_resampling_enabled_flag equal to 1 are allowed.

[0185] e. Furthermore, the constraint on the value of scaling_window_explicit_signalling_flag based on the value of res_change_in_clvs_allowed_flag is changed to the value based on the value of ref_pic_resampling_enabled_flag, as follows: when When the value is 0, the value of scaling_window_explicit_signalling_flag should be 0.

[0186] f. Alternatively, signaling can be used in the VPS instead of the SPS to notify one or all of multiple (such as two) flags.

[0187] i. In one example, one or all of the multiple (such as two) flags in the VPS are applied to all tiers specified by the VPS.

[0188] ii. In another example, one or all of the multiple (such as two) flags in a VPS may each have multiple instances of signaling notification in the VPS, and each instance applies to all layers in a dependency tree.

[0189] g. In one example, l bits u(1) are used to encode each of the multiple flags into an unsigned integer.

[0190] h. Alternatively, for example in SPS / VPS, a syntax element can be signaled using a non-binary value to specify the use of RPR during decoding and the allowance for image resolution changes within CLVS.

[0191] i. In one example, when the value of the syntax element is equal to 0, it specifies that RPR is not required to decode one or more images.

[0192] ii. In one example, when the value of the syntax element is equal to 1, it specifies that RPR may be needed to decode one or more images, while the image resolution is not allowed to be changed within CLVS.

[0193] iii. In one example, when the value of the syntax element is equal to 2, it specifies that RPR may be needed to decode one or more images, while allowing the image resolution to be changed within CLVS.

[0194] iv. Alternatively, how signaling notification syntax elements are configured may depend on whether inter-layer prediction is allowed.

[0195] v. In one example, the syntax element is encoded using ue(v), which indicates an unsigned integer 0-order Exp-Golomb-coded syntax element that is first left-bit.

[0196] vi. In another example, N bits u (N) are used to encode and decode syntax elements into unsigned integers, for example, N equals 2.

[0197] 2) Alternatively, or in addition to item 1 used to address problem 1a, there is still only one flag, such as res_change_in_clvs_allowed_flag, but the semantics can be changed so that resampling of interlayer reference images is allowed regardless of the value of the flag.

[0198] a. In one example, the semantics can be changed as follows: res_change_in_clvs_allowed_flag equal to 1 specifies that the image spatial resolution can be changed within the CLVS of the reference SPS. A value of 0 for `res_change_in_clvs_allowed_flag` indicates that the image spatial resolution remains unchanged within any CLVS referenced to the SPS.

[0199] b. With this change, even when res_change_in_clvs_allowed_flag equals 0, the decoding of sub-pictures / pictures can still use the RPR of the interlayer reference picture (ILRP).

[0200] 3) To address problem 1b, update the constraint on the combination of sub-images and ILP scalability so that the constraint only applies cross-layer alignment constraints to the current layer and all higher layers that depend on the current layer, and does not apply cross-layer alignment constraints to higher or lower layers that do not depend on the current layer.

[0201] a. Alternatively, update the constraints to apply cross-layer alignment constraints only to the current layer and all layers above the current layer.

[0202] b. Alternatively, update the constraints to apply cross-layer alignment constraints only to the current layer and all higher layers in each OLS that contains the current layer.

[0203] c. Alternatively, update the constraints to apply cross-layer alignment constraints only to the current layer and all lower layers that serve as the reference layer for the current layer.

[0204] d. Alternatively, update the constraints to apply cross-layer alignment constraints only to the current layer and all layers below it.

[0205] e. Alternatively, update the constraints to apply cross-layer alignment constraints only to the current layer and all lower layers in each OLS that contains the current layer.

[0206] f. Alternatively, update the constraints to apply cross-layer alignment restrictions only to all layers below the highest layer.

[0207] g. Alternatively, update the constraints to apply cross-layer alignment restrictions only to all layers above the lowest layer.

[0208] 4) To address issue 2, the following changes are applied to one or more decoding processes involving cropping operations in inter-frame prediction correlation processes that treat sub-image boundaries as image boundaries in motion compensation / motion prediction (e.g., the derivation of temporal luma motion vector prediction in clause 8.5.2.11, the luma sample bilinear interpolation process in clause 8.5.3.2.2, the derivation of sub-block-based temporal merge candidates in clause 8.5.5.3, the derivation of sub-block-based temporal merge basic motion data in clause 8.5.5.4, the derivation of constructed affine control point motion vector merge candidates in clause 8.5.5.6, the luma sample interpolation filtering process in clause 8.5.6.3.2, the luma integer sample acquisition process in clause 8.5.6.3.3, and the chromaticity sample interpolation process in clause 8.5.6.3.4).

[0209] a. In one example, the process is modified so that if subpic_treated_as_pic_flag[CurrSubpicIdx] equals 1 and the reference image refPicLX has a sps_num_subpics_minus1 greater than 0, then the cropping operation is applied; otherwise, it is not.

[0210] i. Alternatively, when the co-image of an image is not allowed to be an ILRP, as described above, only the process of changing the reference image refPicLX to not be a co-image is changed, without changing the process of changing the reference image refPicLX to be a co-image.

[0211] b. In one example, the process is modified so that if `subpic_treated_as_pic_flag[CurrSubpicIdx]` equals 1 and the current stripe's `nal_unit_type` value is not equal to `IDR_W_RADL`, `IDR_N_LP`, or `CRA_NUT`, then the cropping operation is applied; otherwise, it is not. Additionally, ILP is only allowed for encoding and decoding IRAP images.

[0212] c. In one example, these decoding processes are not changed. For example, if subpic_treated_as_pic_flag[CurrSubpicIdx] equals 1, the clipping operation is applied; otherwise, it is not applied, just like in the current VVC text.

[0213] 5) To address problem 3a, update the constraint on the combination of subgraph and ILP scalability such that the constraint imposes a cross-layer alignment restriction on all layers in each dependency tree. The dependency tree contains a specific layer, all layers that use that specific layer as a reference layer, and all reference layers of that specific layer, regardless of whether any of these layers is an output layer of the OLS.

[0214] 6) To address problem 3b, update the constraint on the combination of subpic and ILP scalability such that the constraint imposes a cross-layer alignment constraint on the value of subpic_treated_as_pic_flag[i].

[0215] 7) To address problem 3c, update the constraint on the combination of subpic and ILP scalability so that the constraint does not impose cross-layer alignment restrictions on the value of loop_filter_across_subpic_enabled_flag[i].

[0216] 8) To address the 3D issue, update the constraints on the combination of subpics and ILP scalability so that the constraints are not applied when sps_num_subpics_minus1 equals 0.

[0217] a. Alternatively, update the constraints so that no constraints are applied when subpic_info_present_flag equals 0.

[0218] 9) To address problem 3e, update the constraint on the combination of sub-images and ILP scalability so that the constraint imposes cross-layer alignment restrictions on images in certain target AU sets.

[0219] a. In one example, for each CLVS of the current layer of the reference SPS, let the target AU set targetAuSet be all AUs (including the first and last images) from the AU containing the first image of the CLVS in decoding order to the AU containing the last image of the CLVS in decoding order.

[0220] 10) To address problem 3f, update the constraint on the combination of sub-image and ILP scalability such that the constraint imposes cross-layer alignment constraints on the values ​​of each of the scaling window parameters scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset.

[0221] 11) To solve problem 4, constrain the current image's co-image to not be a long-term reference image (LTRP).

[0222] a. Alternatively, constrain the current image's co-image not to be an interlayer reference image (ILRP).

[0223] b. Alternatively, constrain the current image's co-image to not be an LTRP or ILRP.

[0224] c. Alternatively, if the co-image of the current image is LTRP or ILRP, scaling should not be applied to obtain the motion vector pointing to the co-image.

[0225] 12) To solve problem 5, the values ​​of each of the constraints scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset should be identical for any two images within the same CLVS that have the same pic_width_in_luma_samples and pic_height_in_luma_samples values, respectively.

[0226] a. Alternatively, replace “within the same CLVS” above with “within the same CVS”.

[0227] b. Alternatively, the constraints are specified as follows:

[0228] Let ppsA and ppsB be any two PPSs referencing the same SPS. The requirement for bitstream consistency is that when ppsA and ppsB have the same pic_width_in_luma_samples and pic_height_in_luma_samples values, respectively, ppsA and ppsB should also have the same scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset values, respectively.

[0229] c. Alternatively, the constraints are specified as follows:

[0230] For any two images within the same CVS, the values ​​of scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset should be the same, and all of the following conditions should be met:

[0231] i. These two images have the same pic_width_in_luma_samples and pic_height_in_luma_samples values, respectively.

[0232] ii. These two images belong to the same layer or two layers, with one layer serving as a reference layer for the other.

[0233] 13) It was proposed that when the image resolution / scaling window is different for the current image and other images in the same access unit, ILP should only be allowed if the current image is an IRAP image.

[0234] 14) In this document, image resolution may refer to the width and / or height of the image, or the width and / or height and / or top-left corner position of the image's zoom window and / or consistency window.

[0235] 15) In this document, not using RPR may mean that any reference image of the current image has the same resolution as the current image.

[0236] 16) Regarding the bitstream extraction for solving problem 6, one or more of the following solutions are proposed:

[0237] a. In one example, to derive the output sub-bitstream, remove the parameter set with nuh_layer_id that is not included in the list LayerIdInOls[ targetOlsIdx ] (e.g., SPS / PPS / APS NAL units).

[0238] b. For example, the derivation of the output sub-bitstream OutBitstream may depend on one or more of the following:

[0239] i. Remove all NAL units from outBitstream whose nal_unit_type is equal to SPS_NUT and whose nuh_layer_id is not included in the list LayerIdInOls[ targetOlsIdx ].

[0240] ii. Remove all NAL units from outBitstream whose nal_unit_type is equal to PPS_NUT and whose nuh_layer_id does not include any of the NAL units in the list LayerIdInOls[targetOlsIdx].

[0241] iii. Remove all NAL units from outBitstream whose nal_unit_type is equal to APS_NUT and whose nuh_layer_id is not included in the list LayerIdInOls[ targetOlsIdx ].

[0242] iv. Remove all NAL units from outBitstream whose nal_unit_type is equal to any one of SPS_NUT, PPS_NUT, and APS_NUT and any of the following conditions are true:

[0243] 1. For at least one value of j in the range of 0 to NumLayersInOls[targetOlsIdx] - 1 (inclusive), nuh_layer_id is greater than LayerIdInOls[targetOlsIdx][j].

[0244] 2. nuh_layer_id is not included in the list LayerIdInOls[ targetOlsIdx ].

[0245] v. When the first NAL unit, whose nal_unit_type is equal to any one of SPS_NUT, PPS_NUT, and APS_NUT, is deleted during extraction, the second NAL unit referencing the first NAL unit should also be deleted.

[0246] c. For example, the derivation of the output sub-bitstream OutBitstream may depend on one or more of the following:

[0247] i. Remove all NAL units from outBitstream whose nal_unit_type is equal to any of VPS_NUT, DCI_NUT, and EOB_NUT and whose nuh_layer_id is not included in the list LayerIdInOls[ targetOlsIdx ].

[0248] 17) The bits required for signaling to notify the APS ID (e.g., adaptation_parameter_set_id) depend on the APS type.

[0249] a. The bits required for signaling notification of APS ID (e.g., adaptation_parameter_set_id) are changed from u(3) to u(v).

[0250] i. In one example, for an adaptive loop filter (ALF) APS, the APS ID can be encoded and decoded using u(a).

[0251] ii. In one example, for a luminance map with chroma scaling (LMCS), the APS ID can be encoded and decoded using u(b).

[0252] iii. In one example, for a scaled list APS, the APS ID can be encoded and decoded using u(c).

[0253] iv. In one example, a / b / c depends on the maximum allowed number of APS of the corresponding type.

[0254] 1. In one example, a > b and a > c.

[0255] 2. In one example, a >= b and a > c.

[0256] 3. In one example, c > b.

[0257] 4. In one example, b = 2.

[0258] 5. In one example, c = 3.

[0259] 6. In one example, a = 3 or greater than 3 (e.g., 4, 5, 6, 7, 8, 9).

[0260] 18) The encoding / decoding order of the APS ID (e.g., adaptation_parameter_set_id) and the APS type (e.g., aps_params_type in VVC text) is swapped so that the APS type appears before the APS ID in the bitstream.

[0261] 19) The total number of filters allowed in APS can be limited based on encoding / decoding information, such as image / strip type, encoding / decoding structure (dual tree or single tree), and layer information.

[0262] a. The total number of filters allowed in an APS can include the total number of ALFs in all APS NAL units with PUs and the total number of luminance / chrominance ALFs and CC-ALFs in the APS.

[0263] b. The total number of filters allowed in the APS may include the total number of adaptive loop filter classes for the luminance component (or luminance ALF filter), the total number of alternative filters for the chrominance component (chrominance ALF filter), and / or the total number of cross component filters in all APS NAL units with PU.

[0264] 20) Regarding the scaling factor greater than 1 in solving the eighth problem, one or more of the following solutions are proposed:

[0265] a. In one example, the scaling window offset applied to the image size for scaling ratio calculation can be negative.

[0266] i. For example, syntax elements for scaling window offsets (e.g., scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, scaling_win_bottom_offset) can be encoded and decoded using signed binary representations such as ae(v), f(n), i(n), se(v), etc.

[0267] b. In one example, how the scaling window offset is constrained based on the image size (e.g., image width / height) may depend on whether the scaling window offset is negative.

[0268] i. For example, the constraint between the offset and the image width / height can be specified differently depending on whether the scaling window offset is negative.

[0269] 1. For example, one or more constraints can be specified based on whether both left and right offsets are negative, and / or whether one of the left and right offsets is negative / positive, and / or whether both left and right offsets are positive.

[0270] 2. For example, one or more constraints can be specified based on whether both the top and bottom offsets are negative, and / or whether one of the top and bottom offsets is negative / positive, and / or whether both the top and bottom offsets are positive.

[0271] ii. For example, the value of the scaling window offset is limited based on the image size only when the value of the scaling window offset is positive or 0.

[0272] 1. For example, when scaling_win_left_offset and scaling_win_right_offset are not negative (or are positive), SubWidthC The value of (scaling_win_left_offset + scaling_win_right_offset) should be less than pic_width_in_luma_samples.

[0273] 2. For example, when scaling_win_top_offset and scaling_win_bottom_offset are not negative (or are positive), SubHeightC The value of (scaling_win_top_offset + scaling_win_bottom_offset) should be less than pic_height_in_luma_samples.

[0274] iii. For example, absolute offsets can be used to specify constraints.

[0275] 1. For example, SubWidthC The value of (abs(scaling_win_left_offset) + abs(scaling_win_right_offset)) should be less than X1. pic_width_in_luma_samples, where X1 is a positive integer, such as X1>= 1.

[0276] 2. For example, SubHeightC The value of (abs(scaling_win_top_offset) + abs(scaling_win_bottom_offset)) should be less than X2. pic_height_in_luma_samples, where X2 is a positive integer, such as X2 >= 1.

[0277] iv. Alternatively, when any scaling window offset value is negative, the offset value is not constrained to the image width / height (e.g., negative offsets are treated as 0-value offsets).

[0278] 1. For example, SubWidthC The value of (max(0, scaling_win_left_offset) + max(0, scaling_win_right_offset)) should be less than pic_width_in_luma_samples.

[0279] 2. For example, SubHeightC The value of (max(0, scaling_win_top_offset) + max(0, scaling_win_bottom_offset)) should be less than pic_height_in_luma_samples.

[0280] c. In one example, how bitstream consistency / constraints are performed between the reference image output width / height, the current image output width / height, the reference image width / height, the current image width / height, and the maximum image width / height (e.g., refPicOutputWidthL, refPicOutputHeightL, PicOutputWidthL, PicOutputHeightL, refPicWidthInLumaSamples, refPicHeightInLumaSamples, pic_width / height_in_luma_samples, pic_width / height_max_in_luma_samples) can depend on whether the scaling window offset value is negative.

[0281] d. In one example, how the width / height of the output image (e.g., PicOutputWidthL, PicOutputHeightL) is derived may depend on whether the scaling window offset is negative.

[0282] i. For example, when the scaling offset of the reference image is negative, it can be treated as a 0-value offset to calculate the width / height of the output image of the reference image.

[0283] ii. For example, the variable PicOutputWidthL can be derived as follows: PicOutputWidthL = pic_width_in_luma_samples - SubWidthC ( max(0, scaling_win_right_offset) + max(0, scaling_win_left_offset) ).

[0284] iii. For example, the variable PicOutputHeightL can be derived as follows: PicOutputHeightL = pic_height_in_luma_samples -SubWidthC ( max(0, scaling_win_bottom_offset) + max(0, scaling_win_top_offset) ).

[0285] e. In one example, how fractional sample interpolation is performed may depend on whether the value of the scaling window offset is negative.

[0286] i. For example, when the scaling window offset of the reference image is negative, it can be treated as a 0-value offset for motion compensation.

[0287] 1. For example, the variable fRefLeftOffset can be set to equal to ( ( SubWidthC max(0, scaling_win_left_offset) ) << 10 ), where scaling_win_left_offset is the scaling_win_left_offset of the reference image.

[0288] 2. For example, the variable fRefTopOffset can be set to equal to ((SubWidthC)). max(0, scaling_win_top_offset) ) << 10 ), where scaling_win_top_offset is the scaling_win_top_offset of the reference image.

[0289] ii. For example, when the scaling window offset of the current image is negative, it can be treated as a 0-value offset for fractional sample interpolation.

[0290] 1. For example, let (refxSb) L ,refySb L The luminance position is pointed to by the motion vector (refMvLX[0], refMvLX[1]) given in 1 / 16 sample units. The variable refxSb L and refySb L The following derivation can be made:

[0291] a. refxSb L = ( ( ( xSb - ( SubWidthC max(0, scaling_win_left_offset )) ) << 4 ) + refMvLX[ 0 ] ) scalingRatio[0]

[0292] b. refySb L = ( ( ( ySb - ( SubWidthC max(0, scaling_win_top_offset)) ) << 4 ) + refMvLX[ 1 ] ) scalingRatio[1]

[0293] 2. For example, let (refxSb) C,refySb C ) is the chromaticity position pointed to by the motion vector (refMvLX[0], refMvLX[1]) given in 1 / 32 sample units. Variable refxSb C and refySb C The derivation is as follows:

[0294] a. refxSb C = ( ( ( xSb - ( SubWidthC max(0, scaling_win_left_offset) ) ) / SubWidthC << 5 ) + refMvLX[ 0 ] ) scalingRatio[0] + addX

[0295] b. refySb C = ( ( ( ySb - ( SubWidthC max(0, scaling_win_top_offset)) ) / SubHeightC << 5 ) + refMvLX[ 1 ] ) scalingRatio[1] + addY

[0296] 21) Regarding the signaling for resolving the ninth problem (TSRC / DQ / SHD), one or more of the following solutions are proposed:

[0297] a. In one example, at the video unit level (such as at the sequence / picture group / picture / strip level), the signaling for the Symbolic Data Hiding (SDH) and Dependency Quantization (DQ) enable / disable flags can depend on whether Transform Skip Residual Coding (TSRC) is enabled.

[0298] i. For example, whether TSRC is enabled (e.g., sps / pps / ph / slice_ts_residual_coding_disabled_flag) can be signaled before the enable / disable flags of SDH / DQ at the same level (e.g., named sps / pps / ph / slice_dep_quant_enabled_flag, sps / pps / ph / slice_sign_data_hiding_enabled_flag).

[0299] ii. For example, signaling for SDH / DQ enable / disable flags at the SPS / PPS / PH / SH level (e.g., named sps / pps / ph / slice_dep_quant_enabled_flag, sps / pps / ph / slice_sign_data_hiding_enabled_flag) can be conditional on whether TSRC is disabled at the same or higher level (e.g., whether sps / pps / ph / slice_ts_residual_coding_disabled_flag is equal to 1).

[0300] iii. For example, the syntax signaling in SH (on top of JVET-Q2001-vE) can be changed as follows:

[0301]

[0302] iv. Additionally, if it does not exist, infer that sps / pps / ph / slice_dep_quant_enabled_flag is equal to some value (such as 0).

[0303] v. Additionally, if it does not exist, infer that sps / pps / ph / slice_sign_data_hiding_enabled_flag is equal to some value (such as 0).

[0304] b. In one example, whether TSRC is enabled can be signaled at the video unit level (such as at the sequence / picture group / picture / strip level).

[0305] i. For example, a signaling notification in SPS / PPS / PH / SH can be a flag named (sps / pps / ph / slice)_ts_residual_coding_enabled_flag.

[0306] ii. Alternatively, whether TSRC is disabled can be notified via signaling at the video unit level (such as at the sequence / picture group / picture / strip level).

[0307] iii. For example, a flag named (sps / pps / ph / slice)_ts_residual_coding_disabled_flag can be signaled in SPS / PPS / PH / SH.

[0308] c. In one example, based on whether transform skipping and DQ and SDH are enabled at the same or higher levels, a conditional signaling notification to the TSRC is given whether it is enabled.

[0309] i. For example, slice_ts_residual_coding_disabled_flag is conditionally signaled based on (sps_transform_skip_enabled_flag= 1 && ! slice_dep_quant_enabled_flag && ! slice_sign_data_hiding_enabled_flag).

[0310] ii. For example, based on (sps_transform_skip_enabled_flag= 1 && ! ph_dep_quant_enabled_flag && ! ph_sign_data_hiding_enabled_flag), ph_ts_residual_coding_disabled_flag is conditionally signaled.

[0311] iii. For example, based on (sps_transform_skip_enabled_flag = 1 && ! pps_dep_quant_enabled_flag && ! pps_sign_data_hiding_enabled_flag), pps_ts_residual_coding_disabled_flag is conditionally signaled.

[0312] iv. In the example above, sps_transform_skip_enabled_flag can be replaced by the SPS TSRC enable flag / SPS TSRC disable flag.

[0313] v. In the example above, sps_transform_skip_enabled_flag can be replaced by the PPS TS enable flag / PPS TSRC enable flag / PPS TSRC disable flag.

[0314] d. In one example, whether to apply SDH or DQ in a block may depend on whether TS and / or TSRS are used.

[0315] e. In one example, when TS and / or TSRS are used in a block, SDH and / or DQ are not applied. ii. In one example, when TS and / or TSRS are used in a block, the SE indicating whether SDH and / or DQ are used is not signaled and is inferred to be not used.

[0316] f. In one example, if TS and / or TSRS are used in a block, then constraints SDH and / or DQ cannot be used.

[0317] 22) It may be required that the scaling window offset (such as scaling_win_right_offset, scaling_win_left_offset, scaling_win_top_offset, scaling_win_bottom_offset) should be greater than (or not less than) an integer X, where X is negative.

[0318] a. In one example, X can depend on the image size.

[0319] 23) The variables PicOutputWidthL and PicOutputHeightL are derived as follows:

[0320] PicOutputWidthL = pic_width_in_luma_samples -SubWidthC ( scaling_win_right_offset + scaling_win_left_offset )

[0321] PicOutputHeightL = pic_height_in_luma_samples -SubWidthC ( scaling_win_bottom_offset + scaling_win_top_offset ).

[0322] Then one or more of the following restrictions can be applied:

[0323] a. ((aX1 PicOutputWidthL +bX1)>>cX1) <= ((dX1 X1 + eX1)>>fX1), where X1 is a non-negative integer.

[0324] b. ((aX0 PicOutputWidthL +bX0)>>cX0) >= ((dX0 X1 + eX0)>>fX0), where X0 is a non-negative integer.

[0325] c. ((aY1 PicOutputHeightL+bY1)>>cY1) <= (dY1 Y1+eY1)>>fY1, where Y1 is a non-negative integer.

[0326] d. ((aY0 PicOutputHeightL+bY0)>>cY0) <= (dY0 Y0+eY0)>>fY0, where Y0 is a non-negative integer.

[0327] e. ((aXY1 PicOutputWidthL PicOutputHeightL+bXY1)>>cXY1) <= (dXY1 XY1+eXY1)>>fXY1, where XY1 is a non-negative integer.

[0328] f. ((aXY0 PicOutputWidthL PicOutputHeightL+bXY0)>>cXY0) <= (dXY0 Y0+eXY0)>>fXY0, where XY0 is a non-negative integer.

[0329] g. In the above restrictions, aX1, bX1……eX1, fX1, aX0, bX0……eX0, fX0, aY1, bY1……eY1, fY1, aY0, bY0……eY0, fY0, aXY1, bXY1……eXY1, fXY1, aXY0, bXY0……eXY0, fXY0 are all integers. In one example, aX1 = aX0 = aY1 = aY0 = aXY1 = aXY0 = 1, bX1 = bX0 = bY1 = bY0 = bXY1 = bXY0 = 0, cX1 = cX0 = cY1 = cY0 = cXY1 = cXY0 = 0, dX1 = dX0 = dY1 = dY0 = dXY1 = dXY0 = 1, eX1 = eX0 = eY1 = eY0 = eXY1 = eXY0 = 0, fX1 = fX0 = fY1 = fY0 = fXY1 = fXY0 = 0.

[0330] h. In the above constraints, X1 and / or X0 may depend on pic_width_in_luma_samples.

[0331] i. In one example, X1 equals pic_width_in_luma_samples

[0332] ii. In one example, PicOutputWidthL <= pic_width_in_luma_samples K, where K is a positive integer, such as 2, 3, 4, 5, 6, 7, 8.

[0333] i. In the above constraints, Y1 and / or Y0 may depend on pic_height_in_luma_samples.

[0334] i. In one example, Y1 equals pic_height_in_luma_samples.

[0335] ii. In one example, PicOutputHeightL <= pic_height_in_luma_samples K, where K is a positive integer, such as 2, 3, 4, 5, 6, 7, 8.

[0336] 24) In one example, the maximum allowed value of five_minus_max_num_subblock_merge_cand can be equal to X, where X is less than 5. For example, X = 4.

[0337] a. For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. The value of `five_minus_max_num_subblock_merge_cand` should be in the range of 0 to 4 (inclusive). When it does not exist, the value of `five_minus_max_num_subblock_merge_cand` is inferred to be equal to 5.

[0338] 25) How to define the valid range of five_minus_max_num_subblock_merge_cand can depend on whether five_minus_max_num_subblock_merge exists.

[0339] a. For example, the valid range of five_minus_max_num_subblock_merge is defined only if five_minus_max_num_subblock_merge exists.

[0340] b. For example, the different valid ranges of five_minus_max_num_subblock_merge depend on whether five_minus_max_num_subblock_merge exists to define them.

[0341] c. For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. When `five_minus_max_num_subblock_merge_cand` exists, its value should be in the range of 0 to 5 – `sps_sbtmvp_enabled_flag` (inclusive). When it does not exist, the value of `five_minus_max_num_subblock_merge_cand` is inferred to be equal to 5.

[0342] d. For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. When it does not exist, the value of `five_minus_max_num_subblock_merge_cand` is inferred to be equal to 5. Otherwise (if `five_minus_max_num_subblock_merge_cand` exists), the value of `five_minus_max_num_subblock_merge_cand` should be in the range of 0 to 5 (inclusive). For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. When `five_minus_max_num_subblock_merge_cand` exists, the value of `five_minus_max_num_subblock_merge_cand` should be in the range of 0 to 5 – `sps_affine_enabled_flag` (inclusive). When it does not exist, the value of five_minus_max_num_subblock_merge_cand is inferred to be equal to 5.

[0343] e. For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. When it does not exist, the value of `five_minus_max_num_subblock_merge_cand` is inferred to be equal to 5. Otherwise (if `five_minus_max_num_subblock_merge_cand` exists), the value of `five_minus_max_num_subblock_merge_cand` should be in the range of 0 to 5 (inclusive).

[0344] f. For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. When `five_minus_max_num_subblock_merge_cand` exists, its value should be in the range of 0 to 4 (inclusive). When it does not exist, its value is inferred to be equal to 5.

[0345] g. For example, `five_minus_max_num_subblock_merge_cand` specifies 5 minus the maximum number of subblock-based merge motion vector prediction candidates supported in SPS. When it does not exist, the value of `five_minus_max_num_subblock_merge_cand` is inferred to be equal to 5. Otherwise (if `five_minus_max_num_subblock_merge_cand` exists), the value of `five_minus_max_num_subblock_merge_cand` should be in the range of 0 to 4 (inclusive).

[0346] 26) Regarding the CTU size of the co-positioned images for solving the tenth problem, one or more of the following solutions are proposed:

[0347] a. In one example, when the CTU / CTB size of the co-reference image is greater than (or less than or not equal to) the CTU / CTB size of the current image, it is required that any codec tool using motion information from different images (e.g., TMVP and / or SbTMVP) is not allowed / prohibited for the current strip / piece / piece group / sub-image / picture / video unit smaller than the current image.

[0348] b. In one example, when the CTU / CTB size of the interlayer reference picture is greater than (or less than or equal to) the CTU / CTB size of the current picture, it is required that any codec tools using motion information from different pictures (e.g., TMVP and / or SbTMVP) be prohibited / disabled for the current strip / piece / strip group / subpic / picture / video unit.

[0349] c. In the example above, the TMVP / SbTMVP usage instruction needs to be equal to 0 when any encoding / decoding tool that uses motion information from different images is prohibited / disabled.

[0350] i. In one example, ph_temporal_mvp_enabled_flag should be equal to 0.

[0351] d. In one example, whether or how signaling notification enables the use of codec tools that utilize motion information from different pictures (e.g., TMVP and / or SbTMVP) can depend on the CTU size of the reference picture in the reference picture list for the current video unit (e.g., strip / picture).

[0352] i. In one example, if all reference images have a different CTU size than the current video unit (e.g., smaller or larger), then the use of temporal motion vector prediction is disabled to ensure consistent bitstream performance.

[0353] ii. In one example, if all reference images have a different CTU size than the current video unit (e.g., smaller or larger), no signaling is given indicating the use of temporal motion vector prediction (e.g., ph_temporal_mvp_enabled_flag).

[0354] 1. Alternatively, it can be inferred that it is disabled.

[0355] 2. Alternatively, in addition, the signaling of the indices for the collocation reference images (e.g., sh_collocated_from_l0_flag, sh_collocated_ref_idx, ph_collocated_from_l0_flag, ph_collocated_ref_idx) will no longer be used.

[0356] e. In one example, any reference picture whose CTU / CTB size is greater than (or less than or equal to) the CTU / CTB size of the current picture is not allowed as a co-picture of the current strip / piece / strip group / subpicture / picture / video unit.

[0357] f. In one example, any picture whose CTU / CTB size is greater than (or less than or equal to) the CTU / CTB size of the current picture is not allowed to be labeled as a co-picture of the current strip / piece / strip group / subpicture / picture / video unit.

[0358] g. In one example, for a co-image to be used for the current picture / strip / piece / brick / sub-picture / video unit smaller than the picture, the CTU / CTB size of the co-image should be equal to the CTU / CTB size of the current picture / strip / piece / brick / sub-picture / video unit smaller than the picture.

[0359] i. In one example, the reference image is identified by sh_collocated_from_l0_flag and / or sh_collocated_ref_idx.

[0360] ii. In one example, the reference image is identified by ph_collocated_from_l0_flag and / or ph_collocated_ref_idx.

[0361] h. In one example, the above isopic image refers to the isopic image used for temporal motion vector prediction.

[0362] i. In one example, the above CTU / CTB size can be identified by an SPS syntax element that specifies the CTU size (e.g., sps_log2_ctu_size_minus5).

[0363] j. The above requirements can be expressed as bitstream constraints / consistency.

[0364] 6. Examples

[0365] The following are some example embodiments of aspects of the invention summarized in Section 5 above, which can be applied to the VVC specification. Most of the relevant parts that have been added or supplemented are... bold, italic, underline The deleted parts are marked with [[]].

[0366] 6.1. First Embodiment

[0367] This embodiment applies to items 1, 1.a, 1.b, 1.c, 1.d, 3, 4.ai, 5, 6, 7, 8, 9, 9.a, 10, 11 and 12b.

[0368] 7.3.2.3 Sequence Parameter Set Syntax

[0369]

[0370] 7.4.3.3 Sequence Parameter Set (RBSP) Semantics ...

[0372]

[0373]

[0374] `res_change_in_clvs_allowed_flag` equal to 1 specifies that the image space resolution can be changed within the CLVS of the reference SPS. `res_change_in_clvs_allowed_flag` equal to 0 specifies that the image space resolution will not be changed within any CLVS of the reference SPS.

[0375] Equal to 1 The i-th subpic of each encoded / decoded image in CLVS is considered as a picture in the decoding process excluding loop filtering. A subpic_treated_as_pic_flag[i] equal to 0 indicates that the i-th subpic of each encoded / decoded image in CLVS is not considered as a picture in the decoding process excluding loop filtering. When it does not exist, the value of subpic_treated_as_pic_flag[i] is inferred to be equal to sps_independent_subpics_flag.

[0376]

[0377] – All images should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0378]

[0379] – All referenced SPSs should have the same sps_num_subpics_minus1 value, and for each j value in the range from 0 to sps_num_subpics_minus1 (inclusive), it should have subpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], subpic_width_minus1[j], subpic_height_minus1[j], and subpic_ctu_top_left_y[j], respectively. The same value as [[loop_filter_across_subpic_enabled_flag[j],]].

[0380] – For each value of j in the range from 0 to sps_num_subpics_minus1 (inclusive), All images should have the same value for SubpicIdVal[j]. ...

[0382] 7.4.3.4 Image Parameter Set (RBSP) Semantics ...

[0384] A value of 1 indicates that the scaling window offset parameter exists in PPS. A value of 0 indicates that the scaling window offset parameter does not exist in PPS. When [[res_change_in_clvs_allowed_flag ]] equals 0, the value of scaling_window_explicit_signalling_flag should be equal to 0.

[0385] , , and Specifies the offset applied to the image size for scaling ratio calculation. When not present, the values ​​of scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset are inferred to be equal to pps_conf_win_left_offset, pps_conf_win_right_offset, pps_conf_win_top_offset, and pps_conf_win_bottom_offset, respectively.

[0386] SubWidthC The value of (scaling_win_left_offset + scaling_win_right_offset) should be less than pic_width_in_luma_samples, and SubHeightC The value of (scaling_win_top_offset + scaling_win_bottom_offset) should be less than pic_height_in_luma_samples.

[0387]

[0388] The variables PicOutputWidthL and PicOutputHeightL are derived as follows:

[0389] PicOutputWidthL = pic_width_in_luma_samples -SubWidthC ( scaling_win_right_offset + scaling_win_left_offset ) (78)

[0390] PicOutputHeightL = pic_height_in_luma_samples -SubWidthC ( scaling_win_bottom_offset + scaling_win_top_offset ) (79)

[0391] Let refPicOutputWidthL and refPicOutputHeightL be the PicOutputWidthL and PicOutputHeightL of the reference image that references the current image of this PPS, respectively. Bitstream consistency is required if all of the following conditions are met:

[0392] –PicOutputWidthL 2 should be greater than or equal to refPicWidthInLumaSamples.

[0393] –PicOutputHeightL 2 should be greater than or equal to refPicHeightInLumaSamples.

[0394] –PicOutputWidthL should be less than or equal to refPicWidthInLumaSamples 8.

[0395] –PicOutputHeightL should be less than or equal to refPicHeightInLumaSamples 8.

[0396] –PicOutputWidthL pic_width_max_in_luma_samples should be greater than or equal to refPicOutputWidthL (pic_width_in_luma_samples - Max( 8, MinCbSizeY )).

[0397] –PicOutputHeightL pic_height_max_in_luma_samples should be greater than or equal to refPicOutputHeightL (pic_height_in_luma_samples - Max( 8, MinCbSizeY )). ...

[0399] 7.3.3.2 General Constraint Information Syntax

[0400]

[0401] 7.4.4.2 General Constraint Information Semantics ...

[0403]

[0404] A value of 1 indicates that `res_change_in_clvs_allowed_flag` should be equal to 0. A value of 0 for `no_res_change_in_clvs_constraint_flag` does not impose such a constraint. ...

[0406] 7.4.8.1 General Strip Header Semantics ...

[0408] Equal to 1 The slice_collocated_from_l0_flag, which is equal to 0, is used to specify that the slice_collocated_from_l0_flag ...

[0409] When slice_type equals B or P, ph_temporal_mvp_enabled_flag equals 1, and slice_collocated_from_l0_flag does not exist, the following applies:

[0410] – If rpl_info_in_ph_flag equals 1, then it is inferred that slice_collocated_from_l0_flag equals ph_collocated_from_l0_flag.

[0411] Otherwise (rpl_info_in_ph_flag equals 0 and slice_type equals P), the value of slice_collocated_from_l0_flag is inferred to be equal to 1.

[0412] Specify the reference index of the co-position image used for temporal motion vector prediction.

[0413] When slice_type equals P, when slice_type equals B and slice_collocated_from_l0_flag equals 1, slice_collocated_ref_idx refers to the entry in the reference image list 0, and the value of slice_collocated_ref_idx should be in the range of 0 to NumRefIdxActive[0]-1 (inclusive of 0 and NumRefIdxActive[0]-1).

[0414] When slice_type equals B and slice_collocated_from_l0_flag equals 0, slice_collocated_ref_idx refers to the entry in reference image list 1, and the value of slice_collocated_ref_idx should be in the range of 0 to NumRefIdxActive[1]-1 (inclusive of 0 and NumRefIdxActive[1]-1).

[0415] When slice_collocated_ref_idx does not exist, the following applies:

[0416] – If rpl_info_in_ph_flag equals 1, then it is inferred that the value of slice_collocated_ref_idx is equal to ph_collocated_ref_idx.

[0417] Otherwise (rpl_info_in_ph_flag equals 0), the value of slice_collocated_ref_idx is inferred to be equal to 0.

[0418] One requirement for bitstream consistency is that the image referenced by slice_collocated_ref_idx should be identical across all slices of the encoded and decoded image.

[0419] One requirement for bitstream consistency is that the values ​​of pic_width_in_luma_samples and pic_height_in_luma_samples of the reference image referenced by slice_collocated_ref_idx should be equal to the values ​​of pic_width_in_luma_samples and pic_height_in_luma_samples of the current image, respectively, and RprConstraintsActive[ slice_collocated_from_l0_flag ? 0 : 1 ][ slice_collocated_ref_idx ] should be equal to 0. ...

[0421] 8.5.3.2.2 Bilinear Interpolation Process for Brightness Samples ...

[0423] For i = 0..1, in full sample units (xInt) i yInt i The brightness position indicated is derived as follows:

[0424] –If subpic_treated_as_pic_flag[CurrSubpicIdx] equals 1, The following applies:

[0425] xInt i = Clip3( SubpicLeftBoundaryPos, SubpicRightBoundaryPos, xInt L +i )(640)

[0426] yInt i = Clip3( SubpicTopBoundaryPos, SubpicBotBoundaryPos, yInt L + i )(641)

[0427] Otherwise (subpic_treated_as_pic_flag[CurrSubpicIdx] equals 0) The following situations apply:

[0428] xInt i = Clip3( 0, picW - 1, refWraparoundEnabledFlag ? ClipH( (PpsRefWraparoundOffset ) MinCbSizeY, picW, (xInt) L + i ) ) : xInt L + i )(642)

[0429] yInt i = Clip3( 0, picH - 1, yInt L + i )(643) ...

[0431] 8.5.6.3.2 Brightness Sample Interpolation and Filtering Process ...

[0433] –If subpic_treated_as_pic_flag[CurrSubpicIdx] equals 1, The following applies:

[0434] xInt i = Clip3( SubpicLeftBoundaryPos, SubpicRightBoundaryPos, xInt i (959)

[0435] yInt i = Clip3( SubpicTopBoundaryPos, SubpicBotBoundaryPos, yInt i (960)

[0436] Otherwise (subpic_treated_as_pic_flag[CurrSubpicIdx] equals 0) The following situations apply:

[0437] xInt i = Clip3( 0, picW - 1, refWraparoundEnabledFlag ? ClipH( (PpsRefWraparoundOffset ) MinCbSizeY, picW, xInt i ) : xInti (961)

[0438] yInt i = Clip3( 0, picH - 1, yInt i (962) ...

[0440] 8.5.6.3.3 Process of obtaining integer samples of brightness ...

[0442] The brightness position indicated by the full sample units (xInt, yInt) is derived as follows:

[0443] –If subpic_treated_as_pic_flag[CurrSubpicIdx] equals 1, The following applies:

[0444] xInt = Clip3( SubpicLeftBoundaryPos, SubpicRightBoundaryPos, xInt L (968)

[0445] yInt = Clip3( SubpicTopBoundaryPos, SubpicBotBoundaryPos, yInt L (969)

[0446] -otherwise The following situations apply:

[0447] xInt = Clip3( 0, picW - 1, refWraparoundEnabledFlag ? ClipH( (PpsRefWraparoundOffset ) MinCbSizeY, picW, xInt L ) : xInt L (970)

[0448] yInt = Clip3( 0, picH - 1, yInt L (971) ...

[0450] 8.5.6.3.4 Colorimetric Sample Interpolation Process ...

[0452] –If subpic_treated_as_pic_flag[CurrSubpicIdx] equals 1, The following applies:

[0453] xInt i = Clip3( SubpicLeftBoundaryPos / SubWidthC, SubpicRightBoundaryPos / SubWidthC, xInt i (977)

[0454] yInt i = Clip3( SubpicTopBoundaryPos / SubHeightC,SubpicBotBoundaryPos / SubHeightC, yInt i (978)

[0455] Otherwise (subpic_treated_as_pic_flag[CurrSubpicIdx] equals 0) The following situations apply:

[0456] xInt i = Clip3( 0, picW C - 1, refWraparoundEnabledFlag ? ClipH(xOffset, picW C , xInt i ) : xInt C + i - 1 ) (979)

[0457] yInt i = Clip3( 0, picH C - 1, yInt i (980) ...

[0459] Alternatively, the highlighted part "and the sps_num_subpics_minus1 of the reference image refPicLX is greater than 0" can be replaced with "and if the reference image refPicLX is an ILRP with the same spatial resolution as the current image".

[0460] Alternatively, the highlighted section “sps_num_subpics_minus1 of reference image refPicLX is equal to 0” can be replaced with “or if the reference image refPicLX is an ILRP with a different spatial resolution than the current image”.

[0461] Alternatively, the requirement for co-located images can be expressed as, for example, that "one requirement for bitstream consistency is that the image referenced by slice_collocated_ref_idx should be identical across all slices of the encoded / decoded image." One requirement for "replacement" bitstream consistency is that the image referenced by slice_collocated_ref_idx should be identical across all slices of the encoded / decoded image. ".

[0462] Alternatively, the requirement for co-located images can be expressed as, for example, that "one requirement for bitstream consistency is that the image referenced by slice_collocated_ref_idx should be identical across all slices of the encoded / decoded image." One requirement for "replacement" bitstream consistency is that the image referenced by slice_collocated_ref_idx should be identical across all slices of the encoded / decoded image. ".

[0463] 6.2. Second Embodiment

[0464] In some alternative embodiments, the first embodiment has the following constraints:

[0465]

[0466] – All images should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0467]

[0468] – All referenced SPSs should have the same sps_num_subpics_minus1 value, and for each j value in the range from 0 to sps_num_subpics_minus1 (inclusive), it should have subpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], subpic_width_minus1[j], subpic_height_minus1[j], and subpic_ctu_top_left_y[j], respectively. The same value as [[loop_filter_across_subpic_enabled_flag[j],]].

[0469] – For each value of j in the range from 0 to sps_num_subpics_minus1 (inclusive), All images should have the same value for SubpicIdVal[j].

[0470] Replace with one of the following:

[0471] 1) When When subpic_treated_as_pic_flag[i] equals 1 All of the following conditions must be true for bitstream consistency to be required:

[0472] – All images should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0473]

[0474] – All referenced SPSs should have the same sps_num_subpics_minus1 value, and for each j value in the range from 0 to sps_num_subpics_minus1 (inclusive), it should have subpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], and subpic_width_minus1[j] respectively. andThe same value as `subpic_height_minus1[j][[and loop_filter_across_subpic_enabled_flag[j],]]`.

[0475] – For each value of j in the range from 0 to sps_num_subpics_minus1 (inclusive), All images should have the same value for SubpicIdVal[j].

[0476] 2) When When subpic_treated_as_pic_flag[i] equals 1 All of the following conditions must be true for bitstream consistency to be required:

[0477] – All images should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0478]

[0479] – All referenced SPSs should have the same sps_num_subpics_minus1 value, and for each j value in the range from 0 to sps_num_subpics_minus1 (inclusive), they should have the same values ​​for subpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], subpic_width_minus1[j], subpic_height_minus1[j], and loop_filter_across_subpic_enabled_flag[j].

[0480] – For each value of j in the range from 0 to sps_num_subpics_minus1 (inclusive), All images should have the same value for SubpicIdVal[j].

[0481] 3) When subpic_treated_as_pic_flag[i] equals 1, All of the following conditions must be true for bitstream consistency to be required:

[0482] – All images should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0483]

[0484] – All referenced SPSs should have the same sps_num_subpics_minus1 value, and for each j value in the range from 0 to sps_num_subpics_minus1 (inclusive), it should have subpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], subpic_width_minus1[j], subpic_height_minus1[j], and subpic_ctu_top_left_y[j], respectively. The same value as [[loop_filter_across_subpic_enabled_flag[j],]].

[0485] – For each value of j in the range from 0 to sps_num_subpics_minus1 (inclusive), All images should have the same value for SubpicIdVal[j].

[0486] 4) When When subpic_treated_as_pic_flag[i] equals 1 All of the following conditions must be true for bitstream consistency to be required:

[0487] – All images should have the same pic_width_in_luma_samples value and the same pic_height_in_luma_samples value.

[0488] –

[0489] – All referenced SPSs should have the same sps_num_subpics_minus1 value, and for each j value in the range from 0 to sps_num_subpics_minus1 (inclusive), it should have subpic_ctu_top_left_x[j], subpic_ctu_top_left_y[j], subpic_width_minus1[j], subpic_height_minus1[j], and subpic_ctu_top_left_y[j], respectively. The same value as loop_filter_across_subpic_enabled_flag[j].

[0490] – For each value of j in the range from 0 to sps_num_subpics_minus1 (inclusive), All images should have the same value for SubpicIdVal[j].

[0491] 6.3. Third Embodiment

[0492] This example highlights the following limitations regarding the maximum number of ALF and CC-ALF filters:

[0493] 1) Replace the constraint on the number of ALF APSs with a constraint on the number of filters. More specifically, it is proposed to add the following constraint:

[0494] The total number of adaptive loop filter categories for the luminance component, the total number of alternative filters for the chrominance component, and the total number of cross-component filters in all APS NAL units of the PU should be less than or equal to 200, 64, and 64, respectively.

[0495] 2) Based on item 1), the encoding and decoding of APS ID in the APS syntax is further changed from u(5) to u(v), with lengths of 9, 2 and 3 respectively, which are used for ALF, LMCS and scaling list APS respectively.

[0496] 3) Based on item 1), further change the encoding and decoding of the ALF APS index and the number of ALF APS in PH and SH from u(v) to ue(v).

[0497] 7.3.2.5 Adaptive Parameter Set (RBSP) Syntax

[0498]

[0499] 7.3.2.7 Image Header Structure Syntax

[0500]

[0501] 7.3.7.1 General Striped Header Syntax

[0502]

[0503] 7.4.3.5 Adaptive Parameter Set Semantics

[0504] Each APS RBSP should be available for the decoding process before being referenced, including in at least one AU whose TemporalId is less than or equal to the TemporalId of the encoded / decoded stripe NAL unit that references it or is provided by an external component.

[0505] All APS NAL units within the PU that have specific values ​​for adaptation_parameter_set_id and aps_params_type, regardless of whether they are prefix or suffix APS NAL units, should have the same content.

[0506] Provides an identifier for APS for reference by other syntax elements. The length of the syntax element adaptation_parameter_set_id, in bits, is aps_params_type = ALF_APS ? 9 : (aps_params_type == LMCS_APS ? 2 : 3 ).

[0507]

[0508] When aps_params_type equals LMCS_APS, the value of adaptation_parameter_set_id should be in the range of 0 to 3 (inclusive).

[0509] Let apsLayerId be the value of nuh_layer_id for a specific APS NAL cell, and vclLayerId be the value of nuh_layer_id for a specific VCL NAL cell. Unless apsLayerId is less than or equal to vclLayerId, and the layer whose nuh_layer_id is equal to apsLayerId is included in at least one OLS that includes a layer whose nuh_layer_id is equal to vclLayerId, a specific VCL NAL cell should not reference a specific APS NAL cell.

[0510] The type of APS parameter carried in APS is specified, as specified in Table 6.

[0511] …

[0512]

[0513] All APS NAL units with a specific value of aps_params_type share the same value space of adaptation_parameter_set_id, regardless of the nuh_layer_id value. APS NAL units with different aps_params_type values ​​use a separate value space for adaptation_parameter_set_id.

[0514] 7.4.3.7 Image Header Structure Semantics

[0515]

[0516]

[0517]

[0518]

[0519]

[0520] 7.4.8.1 General Strip Header Semantics

[0521] Specifies the number of ALF APSs referenced for the stripe. When slice_alf_enabled_flag equals 1 and slice_num_alf_aps_ids_luma does not exist, the value of slice_num_alf_aps_ids_luma is inferred to be equal to the value of ph_num_alf_aps_ids_luma.

[0522] [i] specifies the adaptation_parameter_set_id of the i-th ALF APS referenced by the luminance component of the specified strip. The TemporalId of the APS NAL cell with aps_params_type equal to ALF_APS and adaptation_parameter_set_id equal to slice_alf_aps_id_luma[i] should be less than or equal to the TemporalId of the encoded / decoded strip NAL cell. When slice_alf_enabled_flag is equal to 1 and slice_alf_aps_id_luma[i] does not exist, the value of slice_alf_aps_id_luma[i] is inferred to be equal to the value of ph_alf_aps_id_luma[i].

[0523] Specifies the adaptation_parameter_set_id of the ALF APS referenced for the chroma components of the specified stripe. The TemporalId of the APS NAL unit having aps_params_type equal to ALF_APS and adaptation_parameter_set_id equal to slice_alf_aps_id_chroma should be less than or equal to the TemporalId of the encoded / decoded stripe NAL unit. When slice_alf_enabled_flag equals 1 and slice_alf_aps_id_chroma does not exist, the value of slice_alf_aps_id_chroma is inferred to be equal to the value of ph_alf_aps_id_chroma.

[0524] The adaptation_parameter_set_id is used to reference the Cb color component of the specified strip.

[0525] The TemporalId of an APS NAL cell with an aps_params_type equal to ALF_APS and an adaptation_parameter_set_id equal to slice_cc_alf_cb_aps_id should be less than or equal to the TemporalId of the encoded / decoded slice NAL cell. When slice_cc_alf_cb_enabled_flag is equal to 1 and slice_cc_alf_cb_aps_id does not exist, the value of slice_cc_alf_cb_aps_id is inferred to be equal to the value of ph_cc_alf_cb_aps_id.

[0526] The value of alf_cc_cb_filter_signal_flag for the APS NAL cell whose aps_params_type is equal to ALF_APS and whose adaptation_parameter_set_id is equal to slice_cc_alf_cb_aps_id should be equal to 1.

[0527] Specifies the `adaptation_parameter_set_id` as the reference for the Cr color component of the specified stripe. The TemporalId of the APS NAL unit, which has `aps_params_type` equal to `ALF_APS` and `adaptation_parameter_set_id` equal to `slice_cc_alf_cr_aps_id`, should be less than or equal to the TemporalId of the encoded / decoded stripe NAL unit. When `slice_cc_alf_cr_enabled_flag` equals 1 and `slice_cc_alf_cr_aps_id` does not exist, the value of `slice_cc_alf_cr_aps_id` is inferred to be equal to the value of `ph_cc_alf_cr_aps_id`.

[0528] The value of alf_cc_cr_filter_signal_flag for the APS NAL cell whose aps_params_type is equal to ALF_APS and whose adaptation_parameter_set_id is equal to slice_cc_alf_cr_aps_id should be equal to 1.

[0529] In the example above, the following can be used instead:

[0530] Provides an identifier for APS for reference by other syntax elements. The length of the syntax element adaptation_parameter_set_id, in bits, is aps_params_type = ALF_APS ? M : (aps_params_type == LMCS_APS ? 2 : 3) where M is equal to a value not less than 3 (e.g., 4, 5, 6, 7, 8, 9).

[0531] The values ​​“200, 64, 64” can be replaced by other non-zero integer values.

[0532] The value “327” can be replaced by other non-zero integer values.

[0533] 6.4. Fourth Embodiment

[0534] In this embodiment, some examples are provided on how to constrain co-position reference images.

[0535] Equal to 1 The co-location image used for temporal motion vector prediction is derived from reference image list 0. A value of 0 for sh_collocated_from_l0_flag indicates that the co-location image used for temporal motion vector prediction is derived from reference image list 1.

[0536] When sh_slice_type equals B or P, ph_temporal_mvp_enabled_flag equals 1, and sh_collocated_from_l0_flag does not exist, the following applies:

[0537] – If sh_slice_type equals B, then it is inferred that sh_collocated_from_l0_flag equals ph_collocated_from_l0_flag.

[0538] Otherwise (sh_slice_type equals P), the value of sh_collocated_from_l0_flag is inferred to be equal to 1.

[0539] Specify the reference index of the co-position image used for temporal motion vector prediction.

[0540] When sh_slice_type equals P or when sh_slice_type equals B and sh_collocated_from_l0_flag equals 1, sh_collocated_ref_idx refers to the entry in reference image list 0, and the value of sh_collocated_ref_idx should be in the range of 0 to NumRefIdxActive[0]-1 (inclusive of 0 and NumRefIdxActive[0]-1).

[0541] When sh_slice_type equals B and sh_collocated_from_l0_flag equals 0, sh_collocated_ref_idx refers to the entry in reference image list 1, and the value of sh_collocated_ref_idx should be in the range of 0 to NumRefIdxActive[1]-1 (inclusive of 0 and NumRefIdxActive[1]-1).

[0542] When sh_collocated_ref_idx does not exist, the following applies:

[0543] – If pps_rpl_info_in_ph_flag equals 1, then it is inferred that the value of sh_collocated_ref_idx is equal to ph_collocated_ref_idx.

[0544] Otherwise (pps_rpl_info_in_ph_flag equals 0), the value of sh_collocated_ref_idx is inferred to be equal to 0.

[0545] One requirement for bitstream consistency is that the image referenced by sh_collocated_ref_idx should be identical across all stripes of the encoded and decoded image, and RprConstraintsActive[ sh_collocated_from_l0_flag ? 0 : 1 ][ sh_collocated_ref_idx ] should equal 0.

[0546] Note – The above constraints require that the corresponding image has the same spatial resolution and the same scaling window offset as the current image. .

[0547] Figure 5This is a block diagram illustrating an example video processing system 1900, in which various techniques disclosed herein can be implemented. Various implementations may include some or all of the components of system 1900. System 1900 may include an input terminal 1902 for receiving video content. The video content may be received in a raw or uncompressed format (e.g., 8 or 10-bit multi-component pixel values), or in a compressed or encoded format. Input terminal 1902 may represent a network interface, a peripheral bus interface, or a storage interface. Examples of network interfaces include wired interfaces such as Ethernet, Passive Optical Network (PON), and wireless interfaces such as Wi-Fi or cellular interfaces.

[0548] System 1900 may include codec component 1904, which may implement the various codec or encoding methods described in this document. Codec component 1904 may reduce the average bit rate of the video from input 1902 to the output of codec component 1904 to produce a codec representation of the video. Therefore, codec techniques are sometimes referred to as video compression or video codec techniques. As indicated by component 1906, the output of codec component 1904 may be stored or transmitted via connected communication. Component 1908 may use the stored or transmitted bitstream (or codec) representation of the video received at input 1902 to generate pixel values ​​or displayable video sent to display interface 1910. The process of generating user-visible video from the bitstream representation is sometimes referred to as video decompression. Furthermore, although some video processing operations are referred to as “codec” operations or tools, it should be understood that codec tools or operations are used at the encoder, and corresponding decoding tools or operations, the opposite of the codec result, will be performed by the decoder.

[0549] Examples of peripheral bus interfaces or display interfaces may include Universal Serial Bus (USB), High Definition Multimedia Interface (HDMI), or DisplayPort. Examples of storage interfaces include SATA (Serial Advanced Technology Accessory), PCI, IDE, etc. The technologies described in this document can be implemented in a variety of electronic devices, such as mobile phones, laptops, smartphones, or other devices capable of performing digital data processing and / or video display.

[0550] Figure 6This is a block diagram of a video processing apparatus 3600. Apparatus 3600 can be used to implement one or more methods described herein. Apparatus 3600 can be embodied in smartphones, tablets, computers, Internet of Things (IoT) receivers, etc. Apparatus 3600 may include one or more processors 3602, one or more memories 3604, and video processing hardware 3606. Processor 3602 can be configured to implement one or more methods described in this document. Memory 3604 can be used to store data and code for implementing the methods and techniques described herein. Video processing hardware 3606 can be used to implement some of the techniques described in this document in hardware circuitry.

[0551] Figure 8 This is a block diagram of an example video encoding / decoding system 100 that implements the technology of the present invention.

[0552] like Figure 8 As shown, the video encoding / decoding system 100 may include a source device 110 and a destination device 120. The source device 110 generates encoded video data; the source device 110 may be referred to as a video encoding device. The destination device 120 can decode the encoded video data generated by the source device 110; the destination device 120 may be referred to as a video decoding device.

[0553] The source device 110 may include a video source 112, a video encoder 114, and an input / output (I / O) interface 116.

[0554] Video source 112 may include sources such as video capture devices, interfaces for receiving video data from video content providers, and / or computer graphics systems for generating video data, or combinations of these sources. Video data may include one or more images. Video encoder 114 encodes the video data from video source 112 to generate a bitstream. The bitstream may include a sequence of bits forming a encoded representation of the video data. The bitstream may include encoded images and associated data. An encoded image is an encoded representation of an image. Associated data may include sequence parameter sets, image parameter sets, and other syntax structures. I / O interface 116 may include a modulator / demodulator (modem) and / or a transmitter. Encoded video data may be transmitted directly to destination device 120 via network 130a through I / O interface 116. Encoded video data may also be stored in storage media / server 130b for access by destination device 120.

[0555] Destination device 120 may include I / O interface 126, video decoder 124 and display device 122.

[0556] I / O interface 126 may include a receiver and / or a modem. I / O interface 126 may acquire 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, which is configured to interface with an external display device.

[0557] The video encoder 114 and the video decoder 124 can operate according to video compression standards, such as the High Efficiency Video Codec (HEVC) standard, the Multi-Functional Video Codec (VVM) standard, and other current and / or further standards.

[0558] Figure 9 This is a block diagram illustrating an example of a video encoder 200, which may be... Figure 8 The video encoder 114 in the system 100 shown.

[0559] The video encoder 200 can be configured to perform any or all of the techniques of this invention. Figure 9 In the example, the video encoder 200 includes multiple functional components. The techniques described in this invention can be shared among the various components of the video encoder 200. In some examples, the processor can be configured to perform any or all of the techniques described in this disclosure.

[0560] The functional components of the video encoder 200 may include a segmentation unit 201, a prediction unit 202, 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. The prediction unit 202 may include a mode selection unit 203, a motion estimation unit 204, a motion compensation unit 205, and an intra-frame prediction unit 206.

[0561] In other examples, the video encoder 200 may include more, fewer, or different functional components. In one example, the prediction unit 202 may include an intra-block copy (IBC) unit. The IBC unit can perform prediction in IBC mode, where at least one reference picture is the picture containing the current video block.

[0562] Furthermore, some components, such as the motion estimation unit 204 and the motion compensation unit 205, can be highly integrated, but for illustrative purposes, in Figure 9 The examples are shown separately.

[0563] The segmentation unit 201 can segment an image into one or more video blocks. The video encoder 200 and the video decoder 300 can support various video block sizes.

[0564] The mode selection unit 203 can select one of the encoding / decoding modes (e.g., intra-frame or inter-frame) based on the error result, and provide the resulting intra-frame or inter-frame encoded / decoded block to the residual generation unit 207 to generate residual block data, and to the reconstruction unit 212 to reconstruct the encoded block for use as a reference picture. In some examples, the mode selection unit 203 can select a combined intra-frame and inter-frame prediction (CIIP) mode, where the prediction is based on the inter-frame prediction signal and the intra-frame prediction signal. In the case of inter-frame prediction, the mode selection unit 203 can also select the resolution of the motion vector for the block (e.g., sub-pixel or integer pixel precision).

[0565] To perform inter-frame prediction on the current video block, motion estimation unit 204 can 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 can determine the predicted video block for the current video block based on motion information from images other than those associated with the current video block from buffer 213 and decoded samples.

[0566] For example, depending on whether the current video block is in an I-band, P-band, or B-band, the motion estimation unit 204 and the motion compensation unit 205 can perform different operations on the current video block.

[0567] In some examples, motion estimation unit 204 can perform unidirectional prediction on the current video block, and can search for a reference video block for the current video block in the reference images of list 0 or list 1. Then, motion estimation unit 204 can generate a reference index and a motion vector, whereby the reference index indicates the reference image containing the reference video block in list 0 or list 1, and the motion vector indicates the spatial displacement between the current video block and the reference video block. Motion estimation unit 204 can output the reference index, prediction direction indicator, and motion vector as motion information for the current video block. Motion compensation unit 205 can generate a predicted video block for the current block based on the reference video block indicated by the motion information of the current video block.

[0568] In other examples, motion estimation unit 204 can perform bidirectional prediction on the current video block. Motion estimation unit 204 can search for a reference video block for the current video block in the reference images in list 0, and can also search for another reference video block for the current video block in the reference images in list 1. Then, motion estimation unit 204 can generate a reference index and a motion vector. The reference index indicates the reference images containing the reference video blocks in lists 0 and 1, and the motion vector indicates the spatial displacement between the reference video blocks and the current video block. Motion estimation unit 204 can output the reference index and motion vector of the current video block as motion information for the current video block. Motion compensation unit 205 can generate a predicted video block for the current video block based on the reference video blocks indicated by the motion information of the current video block.

[0569] In some examples, the motion estimation unit 204 can output a complete set of motion information for the decoder's decoding processing.

[0570] In some examples, motion estimation unit 204 may not output the complete set of motion information for the current video. Instead, motion estimation unit 204 may signal the motion information of the current video block by referencing the 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 neighboring video blocks.

[0571] In one example, the motion estimation unit 204 may indicate a value in the syntax structure associated with the current video block that indicates to the video decoder 300 that the current video block has the same motion information as another video block.

[0572] In another example, motion estimation unit 204 can identify another video block and motion vector difference (MVD) in the syntax structure associated with the current video block. The motion vector difference indicates the difference between the motion vector of the current video block and the motion vector of the indicated video block. Video decoder 300 can use the motion vector of the indicated video block and the motion vector difference to determine the motion vector of the current video block.

[0573] As discussed above, the video encoder 200 can predictively signal motion vectors. Two examples of predictive signaling techniques that can be implemented by the video encoder 200 include Advanced Motion Vector Prediction (AMVP) and Merge Pattern Signaling.

[0574] Intra-prediction unit 206 can perform intra-prediction on the current video block. When intra-prediction unit 206 performs intra-prediction on the current video block, it can generate prediction data for the current video block based on decoded samples of other video blocks in the same frame. The prediction data for the current video block may include the predicted video block and various syntax elements.

[0575] The residual generation unit 207 can generate residual data for the current video block by subtracting (e.g., indicated by a negative sign) the predicted video block from the current video block. The residual data for the current video block can include residual video blocks corresponding to different sample components of the samples in the current video block.

[0576] In other examples, such as in skip mode, the current video block may not have residual data for the current video block, and the residual generation unit 207 may not perform the subtraction operation.

[0577] The transform processing unit 208 can generate one or more transform coefficient video blocks of the current video block by applying one or more transforms to the residual video block associated with the current video block.

[0578] After the transform processing unit 208 generates a transform coefficient video block associated with the current video block, the quantization unit 209 can 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.

[0579] Inverse quantization unit 210 and inverse transform unit 211 can apply inverse quantization and inverse transform to the transform coefficient video block, respectively, to reconstruct the residual video block from the transform coefficient video block. Reconstruction unit 212 can add the reconstructed residual video block to the corresponding sample from one or more predicted video blocks generated by prediction unit 202 to generate a reconstructed video block associated with the current block, which is stored in buffer 213.

[0580] After the video block is reconstructed by the reconstruction unit 212, a loop filtering operation can be performed to reduce video block artifacts in the video block.

[0581] The entropy encoding unit 214 can receive data from other functional components of the video encoder 200. When the entropy encoding unit 214 receives data, it can perform one or more entropy encoding operations to generate entropy-encoded data and output a bitstream including the entropy-encoded data.

[0582] Figure 10 This is a block diagram illustrating an example of a video decoder 300, which may be... Figure 8 The video decoder 114 in the system 100 shown.

[0583] The video decoder 300 can be configured to perform any or all of the techniques of this invention. Figure 10In the example, the video decoder 300 includes multiple functional components. The techniques described in this disclosure can be shared among the various components of the video decoder 300. In some examples, the processor can be configured to perform any or all of the techniques described in this disclosure.

[0584] exist Figure 10 In the example, the video decoder 300 includes an entropy decoding unit 301, a motion compensation unit 302, an intra-frame prediction unit 303, an inverse quantization unit 304, an inverse transform unit 305, a reconstruction unit 306, and a buffer 307. In some examples, the video decoder 300 can perform functions typically associated with the video encoder 200. Figure 9 The decoding sequence is the inverse of the encoding sequence described.

[0585] Entropy decoding unit 301 can retrieve encoded bitstreams. The encoded bitstreams may include entropy-encoded video data (e.g., encoded video data blocks). Entropy decoding unit 301 can decode the entropy-encoded video data, and using the entropy-decoded video data, motion compensation unit 302 can determine motion information, including motion vectors, motion vector precision, reference image list index, and other motion information. For example, motion compensation unit 302 can determine such information by executing AMVP and Merge modes.

[0586] The motion compensation unit 302 can generate motion compensation blocks, possibly performing interpolation based on an interpolation filter. The syntax elements can include identifiers of the interpolation filters to be used with sub-pixel precision.

[0587] The motion compensation unit 302 can use an interpolation filter, such as that used by the video encoder 200 during the encoding of a video block, to calculate the interpolation values ​​of sub-integer pixels of the reference block. The motion compensation unit 302 can determine the interpolation filter used by the video encoder 200 based on the received syntax information, and use the interpolation filter to generate the prediction block.

[0588] The motion compensation unit 302 may use some syntax information to determine the size of the blocks of frames and / or stripes used to encode the encoded video sequence, segmentation information describing how each macroblock of the picture of the encoded video sequence is segmented, a mode indicating how each segment is encoded, one or more reference frames (and a list of reference frames) for each inter-frame encoded block, and other information used to decode the encoded video sequence.

[0589] Intra-prediction unit 303 can use, for example, an intra-prediction mode received in the bitstream to form prediction blocks from spatially adjacent blocks. Inverse quantization unit 303 inverse quantizes (e.g., dequantizes) the quantized video block coefficients provided in the bitstream and decoded by entropy decoding unit 301. Inverse transform unit 303 applies an inverse transform.

[0590] The reconstruction unit 306 can add the residual block to the corresponding predicted block generated by the motion compensation unit 202 or the intra-frame prediction unit 303 to form a decoded block. If necessary, a deblocking filter can also be applied to filter the decoded block to remove block artifacts. The decoded video block is then stored in a buffer 307, which provides a reference block for subsequent motion compensation / intra-frame prediction and also generates decoded video for presentation on a display device.

[0591] The following is a list of preferred embodiments.

[0592] The following scheme illustrates example embodiments of the techniques discussed in the previous section (e.g., item 1).

[0593] 1. A video processing method (e.g., Figure 7 The method 700 shown includes: performing (702) a conversion between videos comprising one or more video images, wherein the encoded / decoded representation conforms to a format rule; wherein the format rule specifies that two or more syntax fields in the sequence parameter set control the reference image resolution (RPR) variation in the video.

[0594] 2. According to the method of Scheme 1, wherein a first syntax field among two or more syntax fields indicates whether RPR is used for one or more images, and a second syntax field among two or more syntax fields indicates whether the image resolution is allowed to be changed at the sequence level in the encoded / decoded representation.

[0595] The following scheme illustrates example embodiments of the techniques discussed in the previous section (e.g., item 2).

[0596] 3. A video processing method, comprising: performing a conversion between videos comprising one or more video images, wherein the encoded / decoded representation conforms to a format rule; wherein the format rule specifies that a single syntax field in a sequence parameter set controls the reference image resolution (RPR) variation in the video; and wherein the format rule specifies that, regardless of the value of the single syntax field, resampling of the inter-layer reference images is permitted for use in the conversion.

[0597] The following schemes illustrate example embodiments of the techniques discussed in the previous section (e.g., items 3, 5, 6, 7, 9, and 10).

[0598] 4. A video processing method comprising: performing a conversion between a video comprising one or more layers, the one or more layers comprising one or more images, the one or more images comprising one or more sub-images, wherein the encoded and decoded representation conforms to a format rule; wherein the format rule specifies a first constraint on cross-layer alignment or a second constraint on a combination of scalability of sub-images and inter-layer images.

[0599] 5. According to the method of Scheme 4, the first constraint defines cross-layer alignment constraints on the current layer and all higher layers that depend on the current layer, but does not impose alignment constraints on the lower layers of the current layer and all higher layers that do not depend on the current layer.

[0600] 6. According to the method of scheme 4, the second constraint imposes cross-layer alignment restrictions on all layers in each dependency tree of a specific layer.

[0601] 7. According to the method of scheme 4, the second constraint constrains the value of subpic_treated_as_pic_flag[i] based on the cross-layer alignment constraint.

[0602] 8. According to the method of scheme 4, the second constraint constrains the value of loop_filter_across_subpic_enabled_flag[i] based on the cross-layer alignment constraint.

[0603] 9. The method according to any one of schemes 4 to 8, wherein the first constraint and / or the second constraint are specified for the target set of access units.

[0604] 10. According to the method of Scheme 4, wherein the second constraint constrains the value of each of the scaling window parameters scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset and scaling_win_bottom_offset according to the cross-layer alignment constraint.

[0605] The following scheme illustrates example embodiments of the techniques discussed in the previous section (e.g., item 11).

[0606] 11. A video processing method comprising: performing a conversion between a video comprising one or more layers, the one or more layers comprising one or more video images, the one or more video images comprising one or more sub-images, wherein the conversion conforms to a format rule specifying that inter-layer reference images or long-term reference images are not permitted as co-images of the current image used for the conversion.

[0607] The following scheme illustrates example embodiments of the techniques discussed in the previous section (e.g., item 12).

[0608] 12. A video processing method comprising: performing a conversion between a video comprising a plurality of images and a codec representation of the video, wherein the conversion conforms to a rule specifying that the value of each of scaling_win_left_offset, scaling_win_right_offset, scaling_win_top_offset, and scaling_win_bottom_offset is identical for any two images within the same codec video sequence or a codec video sequence having the same pic_width_in_luma_samples and pic_height_in_luma_samples values.

[0609] The following scheme illustrates example embodiments of the techniques discussed in the previous section (e.g., item 13).

[0610] 13. A video processing method, comprising: performing a conversion between a video comprising multiple images and a encoded / decoded representation of the video, wherein the conversion conforms to a rule specifying that inter-layer prediction is allowed only when the current image is an intra-frame random access point image, provided that the image resolution or scaling window differs for the current image and other images in the same access unit.

[0611] The following scheme illustrates example embodiments of the techniques discussed in the previous section (e.g., item 20).

[0612] 14. A video processing method, comprising: converting a video block of a current image of a video to a encoded and decoded representation of the video; determining whether a rule is applied based on a comparison of a first size of the video block with a second size of the video block in a co-located video image or an inter-layer image; and performing the conversion based on the determination.

[0613] 15. According to the method of scheme 14, wherein the rule specifies that when the first size is larger than the second size, the use of motion information from different pictures is prohibited for the transformation in the current picture.

[0614] 16. According to the method of scheme 14, wherein the rule specifies that when the first size is larger than the second size, the use of motion information from different pictures is prohibited for the transformation in the current picture.

[0615] In the above scheme, a video block can correspond to a codec tree unit or a codec tree block.

[0616] 17. The method according to any one of schemes 1 to 16, wherein the conversion includes encoding the video into a encoded / decoded representation.

[0617] 18. The method according to any one of schemes 1 to 16, wherein the conversion includes decoding the encoded / decoded representation to generate the pixel values ​​of the video.

[0618] 19. A video decoding apparatus comprising a processor configured to perform the methods described in one or more of embodiments 1 to 18.

[0619] 20. A video encoding apparatus comprising a processor configured to perform the methods described in one or more of embodiments 1 to 18.

[0620] 21. A computer program product in which computer code is stored, which, when executed by a processor, causes the processor to perform the method described in any one of schemes 1 to 18.

[0621] 22. A method, apparatus or system described in this document.

[0622] Figure 13 This is a flowchart representation of a method 1300 for video processing according to the present technology. Method 1300 includes, at operation 1310, performing a conversion between video units of a current frame of the video and the bitstream of the video according to a rule. The rule specifies that, for a given frame that can be used as a reference frame for its motion information for the conversion, the given frame has the same codec tree unit size or the same codec tree block size as the current frame.

[0623] In some embodiments, the rule specifies that codec tools using motion information are disabled in response to a given image having different codec tree unit sizes or different codec tree block sizes. In some embodiments, a video unit comprises a stripe. In some embodiments, motion information is used for temporal motion vector prediction. In some embodiments, motion information is used for sub-block-based temporal motion vector prediction.

[0624] In some embodiments, the given image is a collocation image. In some embodiments, the collocation image is identified by a collocation image list and an index, the index specifying a reference index for the collocation image used for temporal motion vector prediction. In some embodiments, the collocation image list is determined by a first syntax flag, which specifies whether the collocation image used for temporal motion vector prediction is derived from reference image list 0 or reference image list 1. In some embodiments, the first syntax flag is represented as sh_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx. In some embodiments, the codec tree unit size of the collocation image is represented by a variable in the sequence parameter set, the variable specifying the size of each codec tree unit. In some embodiments, the variable is represented as sps_log2_ctu_size_minus5.

[0625] In some embodiments, the given image is an interlayer image. In some embodiments, a second syntax flag in the image header specifies that the use of motion information is disabled. In some embodiments, the second syntax flag is represented as ph_temporal_mvp_enabled_flag.

[0626] In some embodiments, whether and how a codec tool using motion information is used for conversion is determined by the codec tree unit size of reference images in one or more reference image lists based on video units. In some embodiments, the codec tool is disabled in response to all reference images having a different codec tree unit size or a different codec tree block size than the current image.

[0627] In some embodiments, the conversion includes encoding the video into a bitstream. In some embodiments, the conversion includes decoding the video from the bitstream.

[0628] In the scheme described herein, the encoder can conform to the format rules by generating an encoded / decoded representation. In the scheme described herein, the decoder can use the format rules to parse the syntax elements in the encoded / decoded representation, determining the presence or absence of syntax elements according to the format rules, in order to generate the decoded video.

[0629] In this document, the term "video processing" can refer to video encoding, video decoding, video compression, or video decompression. For example, a video compression algorithm can be applied during the conversion from the pixel representation of a video to the corresponding bitstream representation, and vice versa. For example, as defined by the syntax, the bitstream representation of the current video block can correspond to bits that are in the same position or scattered at different positions within the bitstream. For example, a macroblock can be encoded based on the error residual values ​​after transformation and encoding / decoding, and also using bits from the header and other fields in the bitstream. Furthermore, during the conversion, the decoder can, based on this determination, parse the bitstream knowing whether some fields may or may not be present, as described in the above scheme. Similarly, the encoder can determine whether certain syntax fields are included or excluded, and generate the encoded / decoded representation accordingly by including or excluding syntax fields from the encoded / decoded representation.

[0630] The disclosed and other schemes, examples, embodiments, modules, and functional operations described in this document can be implemented in digital electronic circuits, in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, and in combinations of one or more of them. The disclosed embodiments and other embodiments can be implemented as one or more computer program products, such as one or more modules of computer program instructions encoded in a computer-readable medium for execution by or control of the operation of a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a storage device, a combination of materials that implement machine-readable propagating signals, and combinations of one or more of them. The term "data processing apparatus" includes all means, devices, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus may include code that creates an execution environment for the computer program in question, for example, code constituting processor firmware, a protocol stack, a database management system, an operating system, or combinations of one or more of them. Propagating signals are artificially generated signals, such as machine-generated electrical, optical, or electromagnetic signals, which are generated to encode information for transmission to a suitable receiver device.

[0631] Computer programs (also known as programs, software, software applications, scripts, or code) can be written in any programming language, including compiled or interpreted languages, and can be deployed in any form, including as standalone programs or as modules, components, subroutines, or other units suited to a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored as a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple collaborative files (e.g., a file storing one or more modules, subroutines, or code sections). Computer programs can be deployed to execute on a single computer or on multiple computers located in one place or distributed across multiple locations and interconnected via a communication network.

[0632] The processes and logic flows described herein can be executed by one or more programmable processors that execute one or more computer programs to perform functions by manipulating input data and generating outputs. The processes and logic flows can also be executed by special-purpose logic circuitry, and the devices can be implemented as special-purpose logic circuitry, such as FPGAs (Field-Programmable Gate Arrays) or ASICs (Application-Specific Integrated Circuits).

[0633] For example, processors suitable for executing computer programs include general-purpose and special-purpose microprocessors, as well as any one or more processors in any kind of digital computer. Typically, the processor receives instructions and data from read-only memory or random access memory, or both. The basic components of a computer are a processor for executing instructions and one or more storage devices for storing instructions and data. Typically, a computer will also include, or be operatively coupled to, one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, to receive data from or transfer data to such mass storage devices, both. However, a computer does not need to have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor storage devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM discs. The processor and memory may be supplemented or incorporated therein by dedicated logic circuitry.

[0634] While this patent document contains numerous details, these details should not be construed as limiting the scope of any subject matter or claimed content, but rather as descriptions of features characteristic of specific embodiments of a particular art. Certain features described in this patent document within the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually in any suitable sub-combination in multiple embodiments. Furthermore, although features may be described above as functioning in certain combinations, and even initially claimed in this way, in some cases, one or more features from a claimed combination may be removed from that combination, and the claimed combination may be for sub-combinations or variations thereof.

[0635] Similarly, although operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed in the specific order or sequence shown, or requiring all illustrated operations to obtain the desired result. Furthermore, the separation of various system components in the embodiments described in this patent document should not be construed as requiring such separation in all embodiments.

[0636] Only some implementation methods and examples are described, and other implementation methods, enhancements and variations may be made based on the content described and shown in this patent document.

Claims

1. A method for processing video data, comprising: According to the rules, a conversion is performed between the video unit of the current image of the video and the bitstream of the video. The rule stipulates that, for a given image available as a peer reference image, the given image has the same codec tree unit size or the same codec tree block size as the current image, and the motion information of the peer reference image is used for the transformation. The rule stipulates that, in response to a given image having different codec tree unit sizes or different codec tree block sizes, the codec tool using the motion information is disabled, and wherein the codec tool is a temporal motion vector prediction codec tool or a sub-block-based temporal motion vector prediction codec tool. Wherein, when the fourth syntax flag in the image header indicates that the motion information is disabled, the first syntax flag indicating whether the collocation reference image is derived from reference image list 0 or reference image list 1, and the reference index of the collocation reference image are omitted in the bitstream, wherein the first syntax flag is represented as sh_collocated_from_l0_flag or ph_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx or ph_collocated_ref_idx.

2. The method according to claim 1, wherein, The video unit is a strip.

3. The method according to claim 1 or 2, wherein, The corresponding reference image is identified by a list of corresponding reference images and an index, wherein the index specifies the reference index of the corresponding reference image.

4. The method according to claim 3, wherein, The list of corresponding reference images is determined by a first syntax flag, which specifies whether the corresponding reference images are derived from reference image list 0 or reference image list 1.

5. The method according to claim 4, wherein, The first syntax flag is represented as sh_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx.

6. The method according to claim 5, wherein, The value of the second syntax element specifying the size of each coding tree unit of the co-referenced image referenced by the reference index is equal to the value of the third syntax element specifying the size of each coding tree unit of the current image.

7. The method according to claim 6, wherein, The second syntax element and the third syntax element are included in the sequence parameter set, and both the second syntax element and the third syntax element are represented as sps_log2_ctu_size_minus5.

8. The method according to claim 1, wherein, The fourth syntax flag is represented as ph_temporal_mvp_enabled_flag.

9. The method according to claim 1, wherein, The conversion includes encoding the video into the bitstream.

10. The method according to claim 1, wherein, The conversion includes decoding the video from the bitstream.

11. An apparatus for processing video data, comprising a processor and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to: According to the rules, a conversion is performed between the video unit of the current image of the video and the bitstream of the video. in, The rule stipulates that, for a given image available as a co-location reference image, the given image has the same codec tree unit size or the same codec tree block size as the current image, and the motion information of the co-location reference image is used for the transformation. The rule stipulates that, in response to a given image having different codec tree unit sizes or different codec tree block sizes, the codec tool using the motion information is disabled, and wherein the codec tool is a temporal motion vector prediction codec tool or a sub-block-based temporal motion vector prediction codec tool. Wherein, when the fourth syntax flag in the image header indicates that the motion information is disabled, the first syntax flag indicating whether the collocation reference image is derived from reference image list 0 or reference image list 1, and the reference index of the collocation reference image are omitted in the bitstream, wherein the first syntax flag is represented as sh_collocated_from_l0_flag or ph_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx or ph_collocated_ref_idx.

12. A non-transitory computer-readable storage medium for storing instructions, said instructions causing a processor to: According to the rules, a conversion is performed between the video unit of the current image of the video and the bitstream of the video. in, The rule stipulates that, for a given image available as a co-location reference image, the given image has the same codec tree unit size or the same codec tree block size as the current image, and the motion information of the co-location reference image is used for the transformation. The rule stipulates that, in response to a given image having different codec tree unit sizes or different codec tree block sizes, the codec tool using the motion information is disabled, and wherein the codec tool is a temporal motion vector prediction codec tool or a sub-block-based temporal motion vector prediction codec tool. Wherein, when the fourth syntax flag in the image header indicates that the motion information is disabled, the first syntax flag indicating whether the collocation reference image is derived from reference image list 0 or reference image list 1, and the reference index of the collocation reference image are omitted in the bitstream, wherein the first syntax flag is represented as sh_collocated_from_l0_flag or ph_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx or ph_collocated_ref_idx.

13. A method for storing a bitstream of video, comprising: The bitstream of the video is generated from the video units of the current image of the video according to the rules; The bitstream is stored in a non-transitory computer-readable recording medium. The rule stipulates that, for a given image available as a peer reference image, the given image has the same codec tree unit size or the same codec tree block size as the current image, and the motion information of the peer reference image is used to generate the bitstream of the video. The rule stipulates that, in response to a given image having different codec tree unit sizes or different codec tree block sizes, the codec tool using the motion information is disabled, and wherein the codec tool is a temporal motion vector prediction codec tool or a sub-block-based temporal motion vector prediction codec tool. Wherein, when the fourth syntax flag in the image header indicates that the motion information is disabled, the first syntax flag indicating whether the collocation reference image is derived from reference image list 0 or reference image list 1, and the reference index of the collocation reference image are omitted in the bitstream, wherein the first syntax flag is represented as sh_collocated_from_l0_flag or ph_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx or ph_collocated_ref_idx.

14. A non-transitory computer-readable recording medium storing a bitstream of video, further storing a computer program thereon, characterized in that, The computer program is executed by the processor to achieve the following: The bitstream of the video is generated from the video units of the current image of the video according to the rules; The rule stipulates that, for a given image available as a peer reference image, the given image has the same codec tree unit size or the same codec tree block size as the current image, and the motion information of the peer reference image is used to generate the bitstream of the video. The rule stipulates that, in response to a given image having different codec tree unit sizes or different codec tree block sizes, the codec tool using the motion information is disabled, and wherein the codec tool is a temporal motion vector prediction codec tool or a sub-block-based temporal motion vector prediction codec tool. Wherein, when the fourth syntax flag in the image header indicates that the motion information is disabled, the first syntax flag indicating whether the collocation reference image is derived from reference image list 0 or reference image list 1, and the reference index of the collocation reference image are omitted in the bitstream, wherein the first syntax flag is represented as sh_collocated_from_l0_flag or ph_collocated_from_l0_flag, and the reference index is represented as sh_collocated_ref_idx or ph_collocated_ref_idx.

Images