Derive the decoding system operation configuration

Abstract

A device for decoding video data, the device comprising: a memory configured to store video data; and one or more processors implemented in a circuit and configured to: decode a value of a profile indicator syntax element in a bitstream including the video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; decode one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and decode the video data according to the decoding tool specific constraints and the category of the profile.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Application No. 16 / 924,941, filed on July 9, 2020, U.S. Provisional Application No. 62 / 872,637, filed on July 10, 2019, U.S. Provisional Application No. 62 / 912,526, filed on October 8, 2019, and U.S. Provisional Application No. 62 / 926,145, filed on October 25, 2019, the entire contents of each of which are hereby incorporated by reference. Technical Field

[0003] The present disclosure relates to video coding, including video encoding and video decoding. Background Art

[0004] Digital video capabilities may be incorporated into a variety of devices, including: digital televisions, digital live broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite wireless telephones, so-called "smart phones", video teleconferencing devices, video streaming devices, and the like. Digital video devices implement video coding techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264 / MPEG-4 Part 10, Advanced Video Coding (AVC), ITU-T H.265 / High Efficiency Video Coding (HEVC), and extensions of these standards. By implementing such video coding techniques, video devices may more efficiently send, receive, encode, decode, and / or store digital video information.

[0005] Video coding techniques include spatial (intra-picture) prediction and / or temporal (inter-picture) prediction to reduce or remove redundancy inherent in video sequences. For block-based video coding, a video slice (e.g., a video picture or a portion of a video picture) may be divided into video blocks, which may also be referred to as coding tree units (CTUs), coding units (CUs), and / or coding nodes. Video blocks in an intra-coded (I) slice of a picture are encoded using spatial prediction for reference samples in neighboring blocks in the same picture. Video blocks in an inter-coded (P or B) slice of a picture may use spatial prediction for reference samples in neighboring blocks in the same picture, or temporal prediction for reference samples in other reference pictures. Pictures may be referred to as frames, and reference pictures may be referred to as reference frames. Summary of the invention

[0006] In summary, the present disclosure describes techniques for deriving a decoding system operating configuration. Video decoding standards may have a variety of available "profiles," or sets of decoding tools. A sub-profile may include a subset of a set of decoding tools in a profile. The present disclosure describes techniques for decoding data (e.g., a profile indicator or a value of "profile_idc") that indicates which tools in a profile's available toolset are enabled and / or disabled. In this way, data associated with a disabled set of decoding tools for a bitstream does not need to be decoded, thereby improving video decoder performance and reducing the bitrate of a bitstream.

[0007] In one example, a method for decoding video data includes: decoding a value of a profile indicator syntax element in a bitstream including the video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; decoding one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and decoding the video data according to the decoding tool specific constraints and the category of the profile.

[0008] In another example, a device for decoding video data includes: a memory configured to store video data; and one or more processors implemented in a circuit and configured to: decode a value of a profile indicator syntax element in a bitstream including video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; decode one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and decode the video data according to the decoding tool specific constraints and the category of the profile.

[0009] In another example, a computer-readable storage medium stores instructions that cause a processor to: decode a value of a profile indicator syntax element in a bitstream including video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; decode one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and decode the video data according to the decoding tool specific constraints and the category of the profile.

[0010] In another example, a device for decoding video data includes: a unit for decoding a value of a profile indicator syntax element in a bitstream including the video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; a unit for decoding one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and a unit for decoding the video data according to the decoding tool specific constraints and the category of the profile.

[0011] The details of one or more examples are set forth in the accompanying drawings and the description below.Other features, objects, and advantages will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a block diagram illustrating an example video encoding and decoding system that may perform the techniques of this disclosure.

[0013] Figure 2A and Figure 2B is a conceptual diagram illustrating an example quadtree binary tree (QTBT) structure and a corresponding coding tree unit (CTU).

[0014] Figure 3 is a block diagram illustrating an example video encoder that may perform the techniques of this disclosure.

[0015] Figure 4 is a block diagram illustrating an example video decoder that may perform the techniques of this disclosure.

[0016] Figure 5 is a flowchart illustrating an example method for encoding a current block according to techniques of this disclosure.

[0017] Figure 6 is a flow chart illustrating an example method for decoding a current block, according to techniques of this disclosure.

[0018] Figure 7 is a flowchart illustrating an example method of encoding video data, in accordance with the techniques of this disclosure.

[0019] Figure 8 is a flow chart illustrating an example method of decoding video data, in accordance with the techniques of this disclosure. DETAILED DESCRIPTION

[0020] Typically, standardized video coding designs (e.g., H.264 / AVC or H.265 / HEVC) are defined as a family of standards that include a large number of different operating configurations (a collection of enabled tools), referred to as "profiles". A specific decoder decodes at least one, but not necessarily all, profiles. The decoder specification describes which profiles can be decoded. For example, a decoder that conforms to a particular profile is able to decode all bitstreams that conform to that profile. The conditions under which a decoder and bitstream conform to a profile are specified in the codec specification.

[0021] The video encoder may use the value of a syntax element (e.g., the profile_idc syntax element) to signal a profile identifier in a decoded bitstream. Example syntax and semantics are as follows:

[0022] seq_parameter_set_rbsp(){ Descriptor sps_seq_parameter_set_id ue(v) profile_idc u(7)

[0023] profile_idc indicates the profile to which the CVS conforms, as specified in Annex A of the ITU-T H.265 (HEVC) standard ("HEVC") and / or VVC. The bitstream shall not contain profile_idc values ​​other than those specified in Annex A of HEVC and / or VVC. Other values ​​of profile_idc are reserved for future use by ISO / IEC.

[0024] The capabilities of a video decoder that conforms to certain video coding designs (standardized by a Standard Development Organization (SDO)) may be specified in terms of the ability to decode video streams that conform to the profile (layer and level) constraints specified in the video coding specification. Specific values ​​for the syntax element profile_idc (layer or level) are generally specified in the text of this specification. Other values ​​of profile_idc (and level_idc) may be reserved for future use by ISO / IEC.

[0025] It is generally recommended that decoders conforming to a particular specification do not infer that reserved values ​​of profile_idc between the values ​​specified in the standards document indicate intermediate capabilities between specified profiles, as there is no restriction on the method chosen by ISO / IEC to use such future reserved values. However, a decoder may infer that reserved values ​​of level_idc associated with a particular value of tier_flag between the values ​​specified in the standards document indicate intermediate capabilities between specified levels of a tier.

[0026] The latter restriction is imposed to explicitly specify the conformance of a decoder to a particular operating configuration. In this approach, each new operating configuration (new profile), if identified as necessary, would be required to be published by the SDO that publishes that particular specification and would require the preservation of a new profile_idc value, which is a relatively lengthy process.

[0027] To avoid possible delays, industry (application) SDOs (e.g., DVB or ATSC) can define their own sub-profiles (subsets of certain profiles) that are required to be supported by the decoder operation in the application. However, this approach may lead to market fragmentation, as there may be various SDOs defining different sub-profiles, and hardware / software vendors providing encoders / decoders need to follow these SDOs and implement additional signaling logic to identify the application sub-profile outside of the video decoding specification logic.

[0028] The present disclosure describes techniques for specifying the decoding tools that a video decoder must support in order to successfully decode a video bitstream. In this way, a client device including a video decoder can determine which of a plurality of video bitstream sets to retrieve. Specifically, a client device can select a video bitstream encoded using a decoding tool implemented by a video decoder of the client device. If a plurality of such video bitstreams are available, the client device can also evaluate other selection criteria, such as bitrate, available bandwidth for retrieving the video bitstream, quality, format (e.g., whether the video bitstream supports single viewpoint, three-dimensional video data, multi-view video data, 360-degree video, spatial resolution, etc.) or other such characteristics.

[0029] In this way, the techniques of the present disclosure allow a client device to determine whether a video bitstream is decodable by a video decoder of the client device before retrieving a complete set of video data for the video bitstream. In this way, these techniques can improve the field of video decoding because these techniques allow a client device to quickly identify a decodable video bitstream while also avoiding bandwidth waste that might otherwise occur by retrieving a video bitstream that the video decoder cannot correctly decode. In addition, these techniques can improve latency associated with the retrieval of video data because a client device can quickly identify a video bitstream that can be correctly decoded by a video decoder of the client device.

[0030] Figure 1 1 is a block diagram illustrating an example video encoding and decoding system 100 that may perform techniques of the present disclosure. In general, the techniques of the present disclosure relate to decoding (encoding and / or decoding) video data. In general, video data includes any data used to process video. Thus, video data may include original, undecoded video, encoded video, decoded (e.g., reconstructed) video, and video metadata, such as signaling data.

[0031] like Figure 1As shown, in this example, system 100 includes a source device 102 that provides encoded video data to be decoded and displayed by a destination device 116. Specifically, source device 102 provides video data to destination device 116 via computer-readable medium 110. Source device 102 and destination device 116 may include any of a variety of devices, including desktop computers, notebook computers (i.e., laptop computers), tablet computers, set-top boxes, telephone handsets such as smartphones, televisions, cameras, display devices, digital media players, video game consoles, video streaming devices, etc. In some cases, source device 102 and destination device 116 may be equipped for wireless communication and may therefore be referred to as wireless communication devices.

[0032] exist Figure 1 In the example of , source device 102 includes video source 104, memory 106, video encoder 200 and output interface 108. Destination device 116 includes input interface 122, video decoder 300, memory 120 and display device 118. According to the present disclosure, the video encoder 200 of source device 102 and the video decoder 300 of destination device 116 can be configured to apply a technique of deriving (e.g., decoding data representation) a decoding system operation configuration. Therefore, source device 102 represents an example of a video encoding device, and destination device 116 represents an example of a video decoding device. In other examples, the source device and destination device may include other components or arrangements. For example, source device 102 may receive video data from an external video source such as an external camera. Similarly, destination device 116 may interface with an external display device instead of including an integrated display device.

[0033] Figure 1 The system 100 shown is only an example. In general, any digital video encoding and / or decoding device can perform techniques for deriving (e.g., decoded data represents) an encoding system operation configuration. The source device 102 and the destination device 116 are only examples of such decoding devices, wherein the source device 102 generates decoded video data to be transmitted to the target device 116. The present disclosure refers to a "decoding" device as a device that performs the decoding (encoding and / or decoding) of data. Therefore, the video encoder 200 and the video decoder 300 represent examples of decoding devices, specifically, video encoders and video decoders, respectively. In some examples, the devices 102 and 116 can be operated in a substantially symmetrical manner so that each device in the devices 102 and 116 includes a video encoding and decoding component. Therefore, the system 100 can support one-way or two-way video transmission between video devices 102 and 116, for example, for video streaming, video playback, video broadcasting, or video telephony.

[0034] Typically, the video source 104 represents a source of video data (i.e., original, undecoded video data), and provides a series of sequential pictures (also referred to as "frames") of the video data to the video encoder 200, which encodes the data of the pictures. The video source 104 of the source device 102 may include a video capture device (e.g., a video archive containing previously captured original video and / or a video feed interface) to receive video from a video content provider. As another alternative, the video source 104 may generate computer graphics-based data as source video, or a combination of real-time video, archived video, and computer-generated video. In each case, the video encoder 200 encodes captured, pre-captured, or computer-generated video data. The video encoder 200 may rearrange the images from the order in which they are received (sometimes referred to as "display order") to a decoding order for decoding. The video encoder 200 may generate a bitstream including encoded video data. Source device 102 may then output the encoded video data onto computer-readable medium 110 via output interface 108 for receipt and / or retrieval by, for example, input interface 122 of destination device 116 .

[0035] The memory 106 of the source device 102 and the memory 120 of the destination device 116 represent general purpose memory. In some examples, the memories 106, 120 can store raw video data, for example, raw video from the video source 104 and raw, decoded video data from the video decoder 300. Additionally or alternatively, the memories 106, 120 can store software instructions that can be executed by, for example, the video encoder 200 and the video decoder 300, respectively. Although shown separately from the video encoder 200 and the video decoder 300 in this example, it should be understood that the video encoder 200 and the video decoder 300 can also include internal memory to achieve functionally similar or equivalent purposes. In addition, the memories 106, 120 can store encoded video data, for example, encoded video data output from the video encoder 200 and input to the video decoder 300. In some examples, some portions of the memories 106, 120 can be allocated as one or more video buffers, for example, to store raw, decoded and / or encoded video data.

[0036] The computer-readable medium 110 may represent any type of medium or device capable of transmitting encoded video data from the source device 102 to the destination device 116. In one example, the computer-readable medium 110 represents a communication medium to enable the source device 102 to send the encoded video data directly to the destination device 116 in real time, for example, via a radio frequency network or a computer-based network. The output interface 108 may modulate a transmission signal including the encoded video data according to a communication standard (e.g., a wireless communication protocol), and the input interface 122 may demodulate the received transmission signal. The communication medium may include any wireless or wired communication medium, such as a radio frequency (RF) spectrum or one or more physical transmission lines. The communication medium may form part of a packet-based network, such as a local area network, a wide area network, or a global network such as the Internet. The communication medium may include a router, a switch, a base station, or any other device that facilitates communication from the source device 102 to the destination device 116.

[0037] In some examples, source device 102 may output the encoded data from output interface 108 to storage device 112. Similarly, destination device 116 may access the encoded data from storage device 112 via input interface 122. Storage device 112 may include any of a variety of distributed or locally accessed data storage media, such as a hard drive, Blu-ray disc, DVD, CD-ROM, flash memory, volatile or non-volatile memory, or any other suitable digital storage medium for storing encoded video data.

[0038] In some examples, source device 102 may output the encoded video data to file server 114 or another intermediate storage device that may store the encoded video data generated by source device 102. Destination device 116 may access the stored video data from file server 114 via streaming or downloading.

[0039] The file server 114 may be any type of server device capable of storing encoded video data and sending the encoded video data to the destination device 116. The file server 114 may represent a network server (e.g., for a website), a server configured to provide a file transfer protocol service (e.g., file transfer protocol (FTP) or file transfer over a unidirectional transport protocol (FLUTE)), a content delivery network (CDN) device, a hypertext transfer protocol (HTTP) server, a multimedia broadcast multicast service (MBMS) or an enhanced MBMS (eMBMS) server, and / or a network attached storage (NAS) device. The file server 114 may additionally or alternatively implement one or more HTTP streaming protocols, such as dynamic adaptive streaming over HTTP (DASH), HTTP real-time streaming (HLS), real-time streaming protocol (RTSP), HTTP dynamic streaming, and the like.

[0040] The destination device 116 may access the encoded video data from the file server 114 through any standard data connection including an Internet connection. This may include a wireless channel (e.g., a Wi-Fi connection), a wired connection (e.g., a digital subscriber line (DSL), a cable modem, etc.), or a combination of both suitable for accessing the encoded video data stored on the file server 114. The input interface 122 may be configured to operate according to any one or more of the various protocols discussed above for retrieving or receiving media data from the file server 114 or other such protocols for retrieving media data.

[0041] Output interface 108 and input interface 122 may represent wireless transmitters / receivers, modems, wired network components (e.g., Ethernet cards), wireless communication components that operate according to any of the various IEEE 802.11 standards, or other physical components. In examples where output interface 108 and input interface 122 include wireless components, output interface 108 and input interface 122 may be configured to transmit data (e.g., encoded video data) according to a cellular communication standard (e.g., 4G, 4G-LTE (Long Term Evolution), Advanced LTE, 5G, etc.). In some examples where output interface 108 includes a wireless transmitter, output interface 108 and input interface 122 may be configured to transmit data (e.g., encoded video data) according to other wireless standards (e.g., IEEE 802.11 specifications, IEEE 802.15 specifications (e.g., ZigBee 5G, etc.). TM ), Bluetooth TMStandards, etc.) to transmit data (e.g., encoded video data). In some examples, source device 102 and / or destination device 116 may include respective system-on-chip (SoC) devices. For example, source device 102 may include an SoC device to perform functions attributed to video encoder 200 and / or output interface 108, and destination device 116 may include an SoC device to perform functions attributed to video decoder 300 and / or input interface 122.

[0042] The techniques of the present disclosure may be applied to video decoding to support any of a variety of multimedia applications, such as over-the-air television broadcasts, cable television transmissions, satellite television transmissions, Internet streaming video transmissions, such as Dynamic Adaptive Streaming over HTTP (DASH), digital video encoded onto a data storage medium, decoding of digital video stored on a data storage medium, or other applications.

[0043] The input interface 122 of the destination device 116 receives an encoded video bitstream from the computer-readable medium 110 (e.g., storage device 112, file server 114, etc.). The encoded video bitstream may include signaling information defined by the video encoder 200, which is also used by the video decoder 300, such as syntax elements with values ​​describing characteristics and / or processing of video blocks or other coding units (e.g., slices, pictures, groups of pictures, sequences, etc.). The display device 118 displays decoded pictures of the decoded video data to a user. The display device 118 may represent any of a variety of display devices, such as a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display, an organic light emitting diode (OLED) display, or another type of display device.

[0044] Although not in Figure 1 , but in some examples, the video encoder 200 and the video decoder 300 may be integrated with an audio encoder and / or an audio decoder, respectively, and may include appropriate MUX-DEMUX units or other hardware and / or software for processing a multiplexed stream including both audio and video in a common data stream. If applicable, the MUX-DEMUX unit may conform to the ITU H.223 multiplexer protocol or other protocols, such as the User Datagram Protocol (UDP).

[0045] The video encoder 200 and the video decoder 300 can each be implemented as any of a variety of suitable encoder and / or decoder circuits, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), discrete logic units, software, hardware, firmware, or any combination thereof. When these techniques are partially implemented in software, the device may store instructions for the software in a suitable non-transitory computer-readable medium and use one or more processors to execute the instructions in hardware to perform the techniques of the present disclosure. Each of the video encoder 200 and the video decoder 300 may be included in one or more encoders or decoders, any of which may be integrated as part of a combined encoder / decoder (CODEC) in a corresponding device. A device including the video encoder 200 and / or the video decoder 300 may include an integrated circuit, a microprocessor, and / or a wireless communication device, such as a cellular phone.

[0046] The video encoder 200 and the video decoder 300 may operate in accordance with a video coding standard, such as ITU-T H.265, also known as High Efficiency Video Coding (HEVC), or an extension thereof, such as multi-view and / or scalable video coding extensions. Alternatively, the video encoder 200 and the video decoder 300 may operate in accordance with other proprietary or industry standards, such as Versatile Video Coding (VVC). The latest draft of the VVC standard is described in Bross et al., "Versatile Video Coding (Draft 5)", Joint Video Experts Group (JVET) of ITU-T SG 16WP 3 and ISO / IEC JTC 1 / SC 29 / WG 11, 14th Meeting, Geneva, CH, March 19-27, 2019, JVET-N1001-v3 (hereinafter referred to as "VVC Draft 5"). However, the technology of the present disclosure is not limited to any particular coding standard.

[0047] Typically, the video encoder 200 and the video decoder 300 can perform block-based decoding of the picture. The term "block" generally refers to a structure that includes data to be processed (e.g., to be encoded and / or decoded, or to be used in other ways during the encoding and / or decoding process). For example, a block may include a two-dimensional matrix of samples of luminance and / or chrominance data. Typically, the video encoder 200 and the video decoder 300 can decode video data represented in a YUV (e.g., Y, Cb, Cr) format. That is, the video encoder 200 and the video decoder 300 can decode luminance and chrominance components instead of decoding red, green and blue (RGB) data sampled from the picture, where the chrominance components may include red and blue chrominance components. In some examples, the video encoder 200 converts the received RGB format data into a YUV representation before encoding, and the video decoder 300 converts the YUV representation into an RGB format. Alternatively, a pre-processing and post-processing unit (not shown) can perform these conversions.

[0048] The present disclosure may generally refer to the decoding (e.g., encoding and decoding) of a picture to include the process of encoding or decoding the data of the picture. Similarly, the present disclosure may refer to the decoding of a block of a picture to include the process of encoding or decoding the data of the block, for example, prediction and / or residual decoding. The encoded video bitstream typically includes a series of values ​​of syntax elements that represent decoding decisions (e.g., decoding modes) and the division of the picture into blocks. Therefore, references to decoding a picture or a block should generally be understood as decoding the values ​​of the syntax elements that form the picture or block.

[0049] HEVC defines various blocks, including coding units (CUs), prediction units (PUs), and transform units (TUs). According to HEVC, a video decoder (e.g., video encoder 200) divides a coding tree unit (CTU) into CUs according to a quadtree structure. That is, the video decoder divides the CTU and CU into four equal, non-overlapping squares, and each node of the quadtree has zero or four child nodes. A node without child nodes may be referred to as a "leaf node", and the CU of such a leaf node may include one or more PUs and / or one or more TUs. The video decoder may further divide the PU and TU. For example, in HEVC, the residual quadtree (RQT) represents the division of the TU. In HEVC, PU represents inter-prediction data, and TU represents residual data. The intra-predicted CU includes intra-prediction information, such as intra-mode indication.

[0050] As another example, the video encoder 200 and the video decoder 300 may be configured to operate according to VVC. According to VVC, a video decoder (e.g., the video encoder 200) divides a picture into a plurality of coding tree units (CTUs). The video encoder 200 may divide the CTU according to a tree structure, such as a quadtree-binary tree (QTBT) structure or a multi-type tree (MTT) structure. The QTBT structure eliminates the concept of multiple partition types, such as the separation between CU, PU, ​​and TU of HEVC. The QTBT structure includes two levels: a first level divided according to quadtree partitions, and a second level divided according to binary tree partitions. The root node of the QTBT structure corresponds to the CTU. The leaf nodes of the binary tree correspond to coding units (CUs).

[0051] In the MTT partition structure, blocks can be partitioned using quadtree (QT) partitioning, binary tree (BT) partitioning, and one or more types of ternary tree (TT) partitioning. Ternary tree partitioning is a partitioning method that divides a block into three sub-blocks. In some examples, ternary tree partitioning divides a block into three sub-blocks without dividing the original block through the center. The partition types in MTT (e.g., QT, BT, and TT) can be symmetric or asymmetric.

[0052] In some examples, the video encoder 200 and the video decoder 300 may use a single QTBT or MTT structure to represent each of the luma and chroma components, while in other examples, the video encoder 200 and the video decoder 300 may use two or more QTBT or MTT structures, e.g., one QTBT / MTT structure for the luma component and another QTBT / MTT structure for the two chroma components (or two QTBT / MTT structures for corresponding chroma components).

[0053] The video encoder 200 and the video decoder 300 may be configured to use quadtree partitions for each HEVC, QTBT partition, MTT partition, or other partition structures. For illustrative purposes, a description of the technology of the present disclosure is given for QTBT partitions. However, it should be understood that the technology of the present disclosure may also be applied to a video decoder configured to use quadtree partitions or other types of partitions.

[0054] This disclosure may use "NxN" and "N times N" interchangeably to refer to the sampling dimensions of a block (e.g., a CU or other video block) in terms of the vertical and horizontal dimensions, for example, 16x16 samples or 16 times 16 samples. Typically, a 16x16 CU will have 16 samples in the vertical direction (y=16) and 16 samples in the horizontal direction (x=16). Similarly, an NxN CU typically has N samples in the vertical direction and N samples in the horizontal direction, where N represents a non-negative integer value. The samples in a CU may be arranged in rows and columns. In addition, a CU does not necessarily have the same number of samples in the horizontal direction as in the vertical direction. For example, a CU may contain N×M samples, where M is not necessarily equal to N.

[0055] The video encoder 200 encodes the video data of a CU representing prediction and / or residual information and other information. The prediction information indicates how the CU will be predicted in order to form a prediction block for the CU. The residual information typically represents the sample-by-sample difference between the CU samples before encoding and the prediction block.

[0056] Blocks (e.g., CTUs or CUs) may be grouped in a picture in various ways. As an example, a brick may refer to a rectangular area of ​​a CTU row within a particular tile in a picture. A tile may include a rectangular area of ​​a CTU within a particular tile column and a particular tile row in a picture. A tile column may refer to a rectangular area of ​​a CTU having a height equal to the picture height and a width specified by a syntax element (e.g., as specified in a picture parameter set). A tile row may refer to a rectangular area of ​​a CTU having a height specified by a syntax element (e.g., such as in a picture parameter set) and a width equal to the picture width.

[0057] In some examples, a tile may be divided into multiple bricks, each of which may include one or more CTU rows within the tile. A tile that is not divided into multiple bricks may also be referred to as a brick. A brick that is a true subset of a tile need not be referred to as a tile.

[0058] Tiles in a picture can also be arranged into slices. A slice can include an integer number of tiles of a picture, which can be exclusively contained in a single network abstraction layer (NAL) unit. In some examples, a slice includes a continuous sequence of complete tiles of multiple complete tiles or just one tile.

[0059] In order to predict a CU, the video encoder 200 may typically form a prediction block for the CU by inter-prediction or intra-prediction. Inter-prediction typically refers to predicting a CU based on data of a previously decoded picture, while intra-prediction typically refers to predicting a CU based on previously decoded data of the same picture. In order to perform inter-prediction, the video encoder 200 may use one or more motion vectors to generate a prediction block. The video encoder 200 may typically perform a motion search, for example, in terms of the difference between the CU and a reference block to identify a reference block that closely matches the CU. The video encoder 200 may calculate a difference metric using the sum of absolute differences (SAD), the sum of squared differences (SSD), the mean absolute difference (MAD), the mean squared difference (MSD), or other such differences to determine whether the reference block closely matches the current CU. In some examples, the video encoder 200 may use unidirectional prediction or bidirectional prediction to predict the current CU.

[0060] Some examples of VVC also provide an affine motion compensation mode, which can be considered an inter-prediction mode. In the affine motion compensation mode, the video encoder 200 can determine two or more motion vectors representing non-translational motion (e.g., zooming in or out, rotation, perspective motion, or other irregular motion types).

[0061] To perform intra prediction, the video encoder 200 can select an intra prediction mode to generate a prediction block. Some examples of VVC provide 67 intra prediction modes, including various directional modes as well as planar modes and DC modes. Typically, the video encoder 200 selects an intra prediction mode that describes samples adjacent to a current block (e.g., a block of a CU) from which samples of the current block are predicted. Assuming that the video encoder 200 decodes CTUs and CUs in a raster scan order (from left to right, from top to bottom), such samples can typically be above, above to the left, or to the left of the current block in the same picture as the current block.

[0062] The video encoder 200 encodes data representing the prediction mode of the current block. For example, for inter-prediction mode, the video encoder 200 may encode data representing which of various available inter-prediction modes is used, as well as motion information of the corresponding mode. For unidirectional or bidirectional inter-prediction, for example, the video encoder 200 may encode motion vectors using advanced motion vector prediction (AMVP) or merge mode. The video encoder 200 may use a similar mode to encode motion vectors for affine motion compensation mode.

[0063] After prediction (e.g., intra-prediction or inter-prediction of a block), the video encoder 200 may calculate residual data for the block. The residual data (e.g., a residual block) represents the sample-by-sample difference between the block and a prediction block of the block formed using a corresponding prediction mode. The video encoder 200 may apply one or more transforms to the residual block to generate transformed data in a transform domain rather than a sampling domain. For example, the video encoder 200 may apply a discrete cosine transform (DCT), an integer transform, a wavelet transform, or a conceptually similar transform to the residual video data. In addition, the video encoder 200 may apply a secondary transform after the first transform, such as a mode-dependent non-separable secondary transform (MDNSST), a signal-dependent transform, a Karhunen-Loeve transform (KLT), and the like. The video encoder 200 generates transform coefficients after applying one or more transforms.

[0064] As described above, after performing any transforms to produce transform coefficients, the video encoder 200 may perform quantization of the transform coefficients. Quantization generally refers to the process of quantizing transform coefficients to potentially reduce the amount of data used to represent the coefficients, thereby providing further compression. By performing the quantization process, the video encoder 200 may reduce the bit depth associated with some or all of the coefficients. For example, the video encoder 200 may round an n-bit value to an m-bit value during quantization, where n is greater than m. In some examples, to perform quantization, the video encoder 200 may perform a bitwise right shift of the value to be quantized.

[0065] After quantization, the video encoder 200 can scan the transform coefficients to generate a one-dimensional vector from a two-dimensional matrix including the quantized transform coefficients. The scan can be designed to place coefficients with higher energy (and therefore lower frequency) at the front of the vector and transform coefficients with lower energy (and therefore higher frequency) at the back of the vector. In some examples, the video encoder 200 can scan the quantized transform coefficients using a predefined scan order to produce a serialization, and then entropy encode the quantized transform coefficients of the vector. In other examples, the video encoder 200 can perform adaptive scanning. After scanning the quantized transform coefficients to form a one-dimensional vector, the video encoder 200 can entropy encode the one-dimensional vector, for example, according to context adaptive binary arithmetic coding (CABAC). The video encoder 200 can also entropy encode the value of a syntax element, which describes metadata associated with the encoded video data for use by the video decoder 300 when decoding the video data.

[0066] To perform CABAC, the video encoder 200 may assign context within a context model to a symbol to be transmitted. The context may relate to, for example, whether neighboring values ​​of the symbol are zero values. The probability determination may be based on the context assigned to the symbol.

[0067] The video encoder 200 may also generate syntax data, such as block-based syntax data, picture-based syntax data, and sequence-based syntax data, to the video decoder 300, for example, in a picture header, a block header, a slice header, or other syntax data, such as a sequence parameter set (SPS), a picture parameter set (PPS), or a video parameter set (VPS). The video decoder 300 may similarly decode such syntax data to determine how to decode the corresponding video data.

[0068] In this way, the video encoder 200 can generate a bitstream including encoded video data, for example, a syntax element describing the division of a picture into blocks (eg, CUs) and prediction and / or residual information for the blocks. Finally, the video decoder 300 can receive the bitstream and decode the encoded video data.

[0069] In general, the video decoder 300 performs a process that is inverse to the process performed by the video encoder 200 to decode the encoded video data of the bitstream. For example, the video decoder 300 may use CABAC to decode the values ​​of the syntax elements of the bitstream in a manner substantially similar to (although inverse to) the CABAC encoding process of the video encoder 200. The syntax elements may define partition information of a picture as CTUs, and divide each CTU according to a corresponding partition structure (e.g., a QTBT structure) to define CUs of the CTU. The syntax elements may also define prediction and residual information for a block (e.g., a CU) of video data.

[0070] The residual information may be represented by, for example, quantized transform coefficients. The video decoder 300 may inverse quantize and inverse transform the quantized transform coefficients of the block to reproduce the residual block of the block. The video decoder 300 uses the prediction mode (intra-prediction or inter-prediction) and related prediction information (e.g., motion information for inter-prediction) conveyed by the signal to form a prediction block for the block. The video decoder 300 may then combine the prediction block and the residual block (sample by sample) to reproduce the original block. The video decoder 300 may perform additional processing, such as performing a deblocking process to reduce visual artifacts along the boundaries of the blocks.

[0071] According to the technology of the present disclosure, the video encoder 200 and the video decoder 300 may decode data representing the operational configuration of the decoding system, such as the value of a profile indicator (profile_idc). Specifically, profile_idc may have an associated maximum value within a range of possible values, and the video encoder 200 and the video decoder 300 may be configured to decode the values ​​within the range to indicate which of the decoding tool sets are enabled and disabled for a particular bitstream. That is, the video encoder 200 and the video decoder 300 may be configured with a defined operational configuration for a range of profile_idc values. The sub-profile of the corresponding profile (e.g., profile A) may be identified by a series of allowed sub-profiles. For example, a profile may be defined by a range of values ​​{1,255}, where the full operational range (tool set) is identified by a value of 255, and a value {1,254} will specify a sub-profile, implying that a limited range of tools in the profile are enabled (e.g., marking that some tools have been disabled and are therefore not used for the corresponding bitstream).

[0072] An example is shown below:

[0073] seq_parameter_set_rbsp(){ Descriptors sps_seq_parameter_set_id ue(v) profile_idc u(8)

[0074] In some examples, video encoder 200 and video decoder 300 may be configured with derivation logic that identifies the parameters of a sub-profile associated with a particular profile_idc value within a given range allowed by the profile.

[0075] For example, assume that a decoding design includes N tools, each of which is identified by one bit in the profile_idc value.

[0076] For example, for N=8, the following interpretation of profile_idc is possible:

[0077] ●Profile_idc=255 (binary representation is 111111111) specifies that all 8 tools (Tools {A, H}) are enabled.

[0078] ●Profile_idc=1 (00000001) specifies that only tool H is enabled.

[0079] ● Profile_idc=129 (10000001) specifies that only tools A and H are enabled.

[0080] More generally, in this example, the profile_idc value is a binary value with each bit corresponding to a coding tool. Each bit has a value indicating whether the corresponding coding tool is enabled or disabled. That is, when N tools are associated with each bit in the 8-bit representation of profile_idc, a value of 1 for the kth bit of profile_idc may specify that the profile may be associated with the tool being enabled, which is associated with the kth bit.

[0081] Alternatively, when N tools are associated with each bit in the 8-bit representation of profile_idc, a value of 0 in the k-th bit of profile_idc may specify that the profile may be associated with the tool associated with the k-th bit being disabled.

[0082] The enabling or disabling of one or more tools may be specified by one or more techniques as described above.

[0083] In some examples, a single bit in the profile_idc value may be used to combine and identify the tools, for example, for a coding design including N=8 tools, profile_idc may be represented by a 4-bit value, where the tools are paired for identification purposes. Therefore, for example:

[0084] ●Profile_idc=15(1111) specifies that all 8 tools are enabled.

[0085] ● Profile_idc=8(1000) specifies that only tools A and B are enabled.

[0086] Examples of various coding tools that can be enabled or disabled include use of binary ternary trees (BTT), partition unit coding order (SUCO), adaptive motion vector resolution (AMVR), merged motion vector difference (MMVD), affine mode, decoder side motion vector derivation (DMVR), adaptive loop filtering (ALF), advanced motion vector prediction (AMVP), intra block copy (IBC), and signaling of reference picture list (RPL) data in the picture header (PH) or slice header (SH).

[0087] In some examples, the kth bit in the K-bit representation of profile_idc can be associated with one or more tools, and the association of one or more tools is specified for the kth bit, where each k is in the range of 0 to K-1 (including 0 and K-1).

[0088] In some examples, a tool may be associated with more than one bit; constraints may be imposed to ensure that the flags do not specify contradictory specifications for the flags (i.e., not allowing one flag to indicate that a particular tool is enabled while another flag indicates that the particular tool is disabled).

[0089] For a tool, one or more tools may be designated as associated tools so that when the tool is enabled, the one or more associated tools may also be considered enabled. In some examples, for a tool, one or more tools may be designated as associated tools so that when the tool is disabled, the one or more associated tools may also be considered disabled. In some examples, a tool may be considered a parent tool (standalone tool) and one or more of its associated tools may be considered subordinate tools. Using one or more techniques of the present disclosure, profile_idc may be designated to apply only to one or more standalone tools.

[0090] The video decoder 300 may be implemented to conform to support all tools that define the highest possible profile_idc. However, in this embodiment, the video decoder 300 may refuse to decode a bitstream with a profile_idc within a given sub-range, which means that the video decoder 300 may be configured to refuse to decode a bitstream including certain combinations of decoding tools.

[0091] In some examples, certain constraints may be further imposed on other syntax values ​​of the bitstream. For example, in addition to the profile_idc value, the tool may have other enabling mechanisms signaled, such as enabling flags in the sequence parameter set (SPS), picture parameter set (PPS), slice / tile, or other level of the bitstream structure. In some examples, it may be stated that, depending on the profile_idc value, the syntax elements defining the operation of certain tools should be set to certain values, such as:

[0092] ● For Profile_idc=1 (00000001) it is specified that only tool H is enabled, therefore:

[0093] ○ All conforming bitstreams shall conform to the following constraints:

[0094] ■sps_enable_toolA is set to 0

[0095] ■sps_enable_toolB is set to 0

[0096] ■sps_enable_toolC is set to 0

[0097] ■sps_enable_toolD is set to 0

[0098] ■sps_enable_toolE is set to 0

[0099] ■sps_enable_toolF is set to 0

[0100] ■sps_enable_toolG is set to 0

[0101] ■sps_enable_toolH is set to 1

[0102] In some examples, the video encoder 200 and the video decoder 300 can include derivation logic for defining sub-profiles, for example, using a binary mask with binary multiplication and / or using bitwise shifting. In some examples, the derivation logic for certain profiles can apply an offset (e.g., increase or decrease a certain number) to specify a specific profile range, such as 128-256, where the offset is equal to 128.

[0103] In some examples, the profile IDC may have a binary (or exponential) structure that specifies enabled tools / tool ​​sets in a binary tree manner.

[0104] In some examples, the profile indication may belong to a set of possible values ​​specified in a video standard specification. For each possible value, a set of constraints and attributes may be defined. For each possible value C, a set of associated alternative values ​​(e.g., a sub-profile) may be specified that specifies an alternative profile indication for a bitstream. In some cases, the video decoder 300 may also decode all bitstreams that conform to any associated alternative value when conforming to profile C. The conditions associated with any alternative value may include conditions associated with value C and one or more additional constraints (e.g., if C indicates that all tools are enabled, then alternative value D may indicate that another tool H is disabled). Possible values ​​and alternative values ​​may be specified by one or more techniques, such as value ranges, values ​​followed by prefixes, strings, etc.

[0105] In some examples, an explicit profile_idc may not be specified, and the video encoder 200 and the video decoder 300 may derive a value for profile_idc from the profile_idc value (e.g., associated with the possible value C) and a set of syntax elements (e.g., associated with the constraint flags for each tool) to identify the profile / sub-profile to which the bitstream belongs. For each decoder that conforms to profile P, in addition to decoding bitstreams conforming to profile P, the decoder is also capable of decoding all bitstreams conforming to the sub-profiles of P. For each bitstream conforming to a sub-profile S of profile P, any decoder conforming to sub-profile S is capable of decoding the bitstream; any decoder conforming to P is capable of decoding the bitstream.

[0106] In some cases, sub-profiles can be considered hierarchical. For example, if P is a profile and S is a sub-profile of P, then S1 can be a sub-profile of S (and likewise, S1 is a sub-profile of P), obtained by further restrictions or conditions on top of S's conditions / restrictions.

[0107] One or more of the techniques discussed above may be applied to profiles or sub-profiles (including hierarchical) or related concepts.

[0108] In some examples, the additional profile information may be included in a SEI message or other part of the bitstream.The profile information may be considered to override the original profile indication in the bitstream.

[0109] In some examples, the profile indication override may also be accompanied by one or more alternative processes. For example, the profile indication in the bitstream may indicate that tool T may be used, and the profile override may indicate that the tool used to decode the bitstream may no longer be used. In addition, reference may be made to additional tool sets, or additional instructions, or additional references, or additional algorithms for alternative use. The use of such alternatives may not necessarily result in the original output, but may also specify and indicate / signal an indication of the specification of the alternative output in the bitstream through intra-bitstream signaling (SEI messages, etc.) or other means.

[0110] In some examples, the profile indicator (profile_idc) may not be used to indicate tool-specific enable / disable indications, as disclosed in some of the other aspects above. Instead, profile_idc may be used to specify certain categories of profiles (e.g., basic, primary, extended, constrained, etc.).

[0111] The video encoder 200 and the video decoder 300 may encode data representing an indication (e.g., a flag or other syntax element) of whether a profile constraint specific to a coding tool disclosed in some of the above-described techniques is indicated. For example, the video encoder 200 and the video decoder 300 may decode the constrained_tool_indication_flag in the bitstream to indicate that a coding tool-specific enable / disable indication may be signaled. In some examples, the indication may be a predefined value for some value of profile_idc. For example, for the main profile, the indication may be such that constrained_tool_indication_flag is equal to 0 and no constraints are applied to the tool; this may mean that all tools may be enabled for the bitstream. In some examples, the indication may be zero for a baseline profile indicating that all tools are disabled.

[0112] When a coding tool-specific profile constraint can be indicated according to the syntax element discussed above, the video encoder 200 and the video decoder 300 can decode the value of the syntax element (e.g., constrained_tool_val) to indicate the coding tool-specific constraint. For a coding tool, the video encoder 200 and the video decoder 300 can derive an indication of the constraint on the tool from constrained_tool_val. For example, the nth bit of constrained_tool_val can indicate whether the tool is enabled or disabled in the bitstream or profile.

[0113] In some examples, enabling or disabling tool categories may be derived from the profile category value (which in turn may be derived from the profile_idc value); within each profile category, further indications may be provided for tool-specific information. For example, the nth bit of profile_idc may be used to indicate whether a certain tool set is enabled or disabled. Tool-specific enable / disable information may be derived using constrained_tool_val. In some examples, the value range or allowed values ​​of constrained_tool_val may be restricted so as to include only indications for tools that belong to an enabled tool category.

[0114] For example, there may be 3 tool classes (Class A, B, and C), each with four tools (represented by four bits each). When all three classes are enabled, constrained_tool_val may contain 12 bits (4 bits for each of the 3 available classes), and the tool-specific enable / disable may be inferred from the techniques described above. When only two classes (e.g., Class A and Class C) are enabled, the constrained constrained_tool_val may be indicated with only 8 bits, where the first four bits may indicate a tool in Class A, and the remaining four bits may indicate a tool in Class C. Tools not specified in constrained_tool_val may be inferred to be disabled (or, in some alternatives, enabled).

[0115] The video encoder 200 and the video decoder 300 can also infer this information from the enablement / disablement of the tool category. The tool categories can be sorted in a predefined manner. The order in which the tools are indicated in constrained_tool_val can depend on the order of the tool categories. The number of bits or value range of constrained_tool_val can depend on the number of tool categories that are enabled / disabled, and which (which) specific tool categories are enabled / disabled. When there may be a dependency between two tools, it may be necessary that when indicating that one of the tools is enabled, the other tool should also be enabled. This can also be extended to profile categories or tool categories.

[0116] When tool-specific enable / disable information is specified, ToolVar may be a variable indicating that information. ToolVar may be defined / derived from profile_idc, constrained_tool_val, or other syntax elements (in some examples, ToolVar may be equal to profile_idc or constrained_tool_val, or in some examples, only certain bits of profile_idc or constrained_tool_Val may be used to derive ToolVar). The compliance of the bitstream and decoder to a particular profile or a particular profile with a particular ToolVar value may depend on the values ​​of profile_idc and ToolVar. Examples of decoder compliance are as follows:

[0117] A decoder conforming to the Main profile at a specific level (identified by a specific value of level_idc) with ToolVar equal to PIdc_Dec shall be able to decode all bitstreams for which all of the following conditions apply: The bitstream is indicated as conforming to the Main profile, where ToolVar is equal to PIdc_Bit, and PIdc_Dec|PIdc_Bit is equal to PIDc_Dec. The bitstream is indicated as conforming to a level lower than or equal to the specified level.

[0118] Alternatively, conformance can be defined as follows:

[0119] A decoder conforming to the Main profile at a specific level (identified by a specific value of level_idc) with ToolVar equal to PIdc_Dec shall be able to decode all bitstreams for which all of the following conditions apply: The bitstream is indicated as conforming to the Main profile, where ToolVar is equal to PIdc_Bit, and PIdc_Dec & PIdc_Bit are equal to PIdc_Bit. The bitstream is indicated as conforming to a level lower than or equal to the specified level.

[0120] An example of the syntax of a sequence parameter set (SPS) raw byte sequence payload (RBSP) consistent with the techniques of the present disclosure is shown in Table 1 below:

[0121] Table 1

[0122] seq_parameter_set_rbsp(){ Descriptors sps_seq_parameter_set_id ue(v) profile_idc u(8) level_idc u(8) toolset_idc u(32)

[0123] The semantics of the "toolset_idc" syntax element shown in Table 1 can be defined as follows:

[0124] toolset_idc indicates the set of constraints to which the CVS conforms, as specified in Annex A of HEVC and / or VVC. The bitstream shall not contain toolset_idc values ​​other than those specified in Annex A. Other values ​​of toolset_idc are reserved for future use by ISO / IEC.

[0125] In addition, the video encoder 200 and the video decoder 300 may comply with the VVC discussed above. VVC may reference the following as Annex A, as described above, consistent with the technology of the present disclosure:

[0126] Profiles, Levels, and Toolsets

[0127] (This annex forms an integral part of this International Standard.)

[0128] A.1 Overview of profiles, levels and toolsets

[0129] Profiles, levels, and toolsets specify restrictions on a bitstream, thereby limiting the capabilities required to decode the bitstream. Profiles, levels, and toolsets can also be used to indicate interoperability points between various decoder implementations.

[0130] NOTE 1—This document does not include separate selectable "options" at the decoder level, as this would increase interoperability difficulties.

[0131] Each profile specifies a subset of algorithm features and restrictions that all decoders conforming to that profile should support.

[0132] NOTE 2—An encoder is not required to use any specific subset of features supported in a profile.

[0133] Each level specifies a set of restrictions on the values ​​that the syntax elements of this document may take. The same set of level definitions is used for all profiles, but individual implementations may support different levels for each supported profile. For any given profile, a level typically corresponds to a specific decoder processing load and memory capabilities.

[0134] The profile specified in clause A.3 is also referred to as the profile specified in Annex A.

[0135] A.1.1 Main Profile

[0136] Conformance of the bitstream to the Main profile is indicated by profile_idc equal to 1.

[0137] A bitstream conforming to the Main profile shall comply with the following constraints:

[0138] — The syntax element toolset_idc shall be in the range 1 to x1FFFFF, inclusive.

[0139] —The tool flag values ​​in the active SPS shall conform to the constraints specified in Table A.9-76.

[0140] — An active SPS shall have chroma_format_idc equal to 0 or 1 only.

[0141] — Active SPS should have bit_depth_luma_minus8 equal to 2 only.

[0142] — The active SPS should have bit_depth_chroma_minus8 equal to 2 only.

[0143] – The level constraints specified in clause A.4 for the Main profile shall be met.

[0144] A decoder conforming to the Main profile at a specific level (identified by a specific value of level_idc) with toolset_idc equal to TIdc_dec (in the range 1 to x1FFFFF, inclusive) shall be able to decode all bitstreams for which all of the following conditions apply:

[0145] —The bitstream is indicated as conforming to the Main profile, where toolset_idc is equal to TIdc_Bit, and TIdc_Dec|TIdc_Bit is equal to TIdc_Dec.

[0146] —The bitstream is indicated as conforming to a level lower than or equal to the specified level.

[0147] A.2 Toolset

[0148] A bitstream conforming to the Main profile shall obey the constraints specified in Table A.1 for the SPS flag values:

[0149] Table A.9-76.5 Conformity requirements for tool marking values ​​in SPS

[0150]

[0151]

[0152] The present disclosure may generally refer to "signaling" certain information, such as syntax elements. The term "signaling" may generally refer to the communication of values ​​of syntax elements and / or other data used to decode encoded video data. That is, the video encoder 200 may signal the values ​​of syntax elements in a bitstream, and the video decoder 300 may parse the bitstream to extract the signal values. Generally, signaling refers to generating values ​​in the bitstream, although it should be understood that the video decoder 300 will also parse the bitstream to extract and interpret the signal values. As described above, the source device 102 may transmit the bitstream to the destination device 116 in substantially real time or in non-real time, such as may occur when storing syntax elements to the storage device 112 for later retrieval by the destination device 116.

[0153] Figure 2A and Figure 2B is a conceptual diagram showing an example quadtree binary tree (QTBT) structure 130 and a corresponding coding tree unit (CTU) 132. Solid lines represent quadtree partitioning and dashed lines represent binary tree partitioning. In each split (i.e., non-leaf) node of the binary tree, a flag bit is signaled to indicate which split type (i.e., horizontal or vertical) is used, in which case 0 indicates horizontal splitting and 1 indicates vertical splitting. For quadtree splitting, since the quadtree node splits a block horizontally and vertically into 4 sub-blocks of equal size, there is no need to indicate the split type. Therefore, the video encoder 200 can encode syntax elements (e.g., split information) at the regional tree level (i.e., solid line) of the QTBT structure 130 and syntax elements (e.g., split information) at the prediction tree level (i.e., dashed line) of the QTBT structure 130, and the video decoder 300 can decode the above syntax elements. The video encoder 200 may encode video data (eg, prediction and transform data) of a CU represented by a terminal leaf node of the QTBT structure 130 , and the video decoder 300 may decode the data.

[0154] generally, Figure 2B The CTU 132 may be associated with parameters defining the size of blocks corresponding to nodes of the QTBT structure 130 at the first and second levels. These parameters may include a CTU size (representing the size of the CTU 132 in a sample), a minimum quadtree size (MinQTSize, representing the minimum allowed quadtree leaf node size), a maximum binary tree size (MaxBTSize, representing the maximum allowed binary tree root node size), a maximum binary tree depth (MaxBTDepth, representing the maximum allowed maximum binary tree depth), and a minimum binary tree size (MinBTSize, representing the minimum allowed binary tree leaf node size).

[0155] The root node of the QTBT structure corresponding to the CTU may have four child nodes at the first level of the QTBT structure, and each child node may be divided according to the quadtree partitioning. That is, the nodes of the first level are leaf nodes (without child nodes) or have four child nodes. The example of the QTBT structure 130 represents such a node, including a parent node and a child node with a solid line branch. If the node of the first level is not larger than the maximum allowed binary tree root node size (MaxBTSize), the nodes may be further divided by the corresponding binary tree. The binary tree splitting of a node may be iterated until the node generated by the split reaches the minimum allowed binary tree leaf node size (MinBTSize) or the maximum allowed binary tree depth (MaxBTDepth). The example of the QTBT structure 130 represents such a node as having a dotted line for branching. The binary tree leaf node is called a coding unit (CU), which is used for prediction (e.g., intra-picture prediction or inter-picture prediction) and transformation without any further partitioning. As discussed above, a CU may also be referred to as a "video block" or "block".

[0156] In one example of a QTBT partition structure, the CTU size is set to 128x128 (luminance sample and two corresponding 64x64 chroma samples), MinQTSize is set to 16x16, MaxBTSize is set to 64x64, MinBTSize (for width and height) is set to 4, and MaxBTDepth is set to 4. Quadtree partitioning is first applied to the CTU to generate quadtree leaf nodes. The size of the quadtree leaf node can range from 16x16 (ie, MinQTSize) to 128x128 (ie, CTU size). If the leaf quadtree node is 128x128, it will not be further split by the binary tree because the size exceeds MaxBTSize (ie, 64x64 in this example). Otherwise, the binary tree will further divide the leaf quadtree node. Therefore, the quadtree leaf node is also the root node of the binary tree, and the depth of the binary tree is 0. When the binary tree depth reaches MaxBTDepth (4 in this example), further splitting is not allowed. When the binary tree node width is equal to MinBTSize (4 in this example), it means that no further horizontal splitting is allowed. Similarly, a binary tree node with a height equal to MinBTSize means that no further vertical splitting is allowed for the binary tree node. As described above, the leaf nodes of the binary tree are called CUs and are further processed according to prediction and transformation without further division.

[0157] Figure 3 is a block diagram illustrating an example video encoder 200 that may perform the techniques of this disclosure. Figure 3For purposes of explanation, and should not be considered limiting of the techniques broadly illustrated and described in this disclosure. For purposes of illustration, this disclosure describes the video encoder 200 in the context of video coding standards such as the HEVC video coding standard under development and the H.266 video coding standard. However, the techniques of this disclosure are not limited to these video coding standards and are generally applicable to video encoding and decoding.

[0158] exist Figure 3 In the example of , the video encoder 200 includes a video data memory 230, a mode selection unit 202, a residual generation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a filter unit 216, a decoded picture buffer (DPB) 218, and an entropy coding unit 220. Any one or all of the video data memory 230, the mode selection unit 202, the residual generation unit 204, the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210, the inverse transform processing unit 212, the reconstruction unit 214, the filter unit 216, the DPB 218, and the entropy coding unit 220 may be implemented in one or more processors or in processing circuits. In addition, the video encoder 200 may include additional or alternative processors or processing circuits to perform these and other functions.

[0159] Video data memory 230 may store video data to be encoded by components of video encoder 200. Video encoder 200 may receive video data from, for example, video source 104 ( Figure 1 ) receives video data stored in video data memory 230. DPB218 can be used as a reference picture memory, which stores reference video data for use when the video encoder 200 predicts subsequent video data. Video data memory 230 and DPB 218 can be formed by any of a variety of memory devices, such as dynamic random access memory (DRAM), including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM) or other types of storage devices. Video data memory 230 and DPB 218 can be provided by the same memory device or a separate memory device. In various examples, video data memory 230 can be on the chip with other components of video encoder 200, as shown, or off-chip relative to those components.

[0160] In the present disclosure, unless specifically described as such, references to the video data memory 230 should not be interpreted as limited to memory inside the video encoder 200; or unless specifically described as such, references to the video data memory 230 should not be interpreted as limited to memory outside the video encoder 200. Rather, references to the video data memory 230 should be understood as a reference memory that stores video data received by the video encoder 200 for encoding (e.g., video data for a current block to be encoded). Figure 1 The memory 106 may also provide temporary storage for the outputs of the various units of the video encoder 200 .

[0161] Shows Figure 3 The various units of the video encoder 200 are described to help understand the operations performed by the video encoder 200. These units can be implemented as fixed-function circuits, programmable circuits, or a combination thereof. Fixed-function circuits refer to circuits that provide specific functions and are pre-set on the operations that can be performed. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functions in the operations that can be performed. For example, a programmable circuit can execute software or firmware that causes the programmable circuit to operate in a manner defined by the instructions of the software or firmware. Fixed-function circuits can execute software instructions (for example, to receive parameters or output parameters), but the type of operation performed by the fixed-function circuit is generally immutable. In some examples, one or more of these units can be different circuit blocks (fixed function or programmable), and in some examples, these one or more units can be integrated circuits.

[0162] The video encoder 200 may include an arithmetic logic unit (ALU), an elementary function unit (EFU), a digital circuit, an analog circuit, and / or a programmable core formed from programmable circuits. In an example where the operation of the video encoder 200 is performed using software executed by programmable circuits, the memory 106 ( Figure 1 ) may store object code for software received and executed by the video encoder 200, or another memory (not shown) within the video encoder 200 may store these instructions.

[0163] The video data memory 230 is configured to store received video data. The video encoder 200 may retrieve a picture of video data from the video data memory 230 and provide the video data to the residual generation unit 204 and the mode selection unit 202. The video data in the video data memory 230 may be original video data to be encoded.

[0164] The mode selection unit 202 includes a motion estimation unit 222, a motion compensation unit 224, and an intra prediction unit 226. The mode selection unit 202 may include additional functional units to perform video prediction according to other prediction modes. As an example, the mode selection unit 202 may include a palette unit, an intra-block copy unit (which may be part of the motion estimation unit 222 and / or the motion compensation unit 224), an affine unit, a linear model (LM) unit, and the like.

[0165] The mode selection unit 202 generally coordinates multiple encoding passes to test combinations of encoding parameters and the resulting rate-distortion values ​​for these combinations. The encoding parameters may include the division of a CTU into CUs, a prediction mode for a CU, a transform type for residual data of a CU, a quantization parameter for residual data of a CU, etc. The mode selection unit 202 may ultimately select a combination of encoding parameters that has a better rate-distortion value than other tested combinations.

[0166] According to the technology of the present disclosure, the mode selection unit 202 can also be configured to enable or disable various decoding tools. For example, the mode selection unit 202 can determine a set of decoding tools that can be used for the entire video presentation. Within the set of decoding tools that can be enabled, the mode selection unit 202 can determine that certain decoding tools do not need to be enabled for a specific decoding sequence. In addition, all decoding tools that can be enabled can be within a specific profile indicated by a profile indicator (profile_idc).

[0167] Examples of various coding tools that can be enabled or disabled include use of binary ternary trees (BTT), partition unit coding order (SUCO), adaptive motion vector resolution (AMVR), merged motion vector difference (MMVD), affine mode, decoder side motion vector derivation (DMVR), adaptive loop filtering (ALF), advanced motion vector prediction (AMVP), intra block copy (IBC), and signaling of reference picture list (RPL) data in the picture header (PH) or slice header (SH).

[0168] The mode selection unit 202 may receive input from an administrator or other user specifying that certain decoding tools can be enabled and other decoding tools are to be disabled. Within the set of decoding tools that can be enabled, the mode selection unit 202 may test decoding of a sequence of pictures with and without those decoding tools. If the test run indicates that one or more of the decoding tools are not needed for the sequence, the mode selection unit 202 may disable those decoding tools. If one or more of the decoding tools are needed (e.g., use of the decoding tools results in lower rate-distortion values ​​than disabling the tools), the mode selection unit 202 may enable the decoding tools.

[0169] The mode selection unit 202 may encode a sequence parameter set (SPS) for a sequence of pictures. The SPS may include a profile indicator (profile_idc), and one or more values ​​representing specific constraints for decoding tools, which are separate from the profile indicator. The specific constraints for decoding tools may indicate a set of decoding tools that may be enabled or disabled for a single sequence. Each SPS in a common video program may have the same profile indicator value and specific constraints for decoding tools. However, for a particular sequence of pictures, the mode selection unit 202 may disable one or more decoding tools that may be disabled according to the specific constraints for decoding tools. For each disabled decoding tool, the mode selection unit 202 may avoid encoding further data for the decoding tool (e.g., initialization data for the decoding tool that will be required using the decoding tool) because those decoding tools are disabled. In this way, the size of the SPS for a sequence of pictures for which one or more decoding tools are disabled may be reduced compared to an SPS for a sequence of pictures for which all (or more) decoding tools are enabled.

[0170] In one example, the mode selection unit 202 may encode the coding tool specific constraints as one or more values ​​of a toolset indicator (toolset_idc) syntax element, as shown in Table 1 above. For example, the value of toolset_idc may act as a bit array, where each bit corresponds to a different coding tool. A binary one of a coding tool may indicate that the coding tool may be enabled for a sequence of pictures, while a binary zero of a coding tool may indicate that the coding tool is disabled. The mode selection unit 202 may encode data indicating whether the coding tool is actually enabled for each coding tool that may be enabled, and if so, any data for initializing or otherwise using the coding tool. The mode selection unit 202 may include the data in an SPS, a picture parameter set (PPS) that references the SPS, a picture header (PH) of a picture included in a sequence represented by the SPS, a slice header (SH) of a picture, or a block header of a slice or a block of a picture. Likewise, the mode selection unit 202 may control various elements of the video encoder 200 to use enabled coding tools and avoid using disabled coding tools during encoding of video data, as described below.

[0171] The video encoder 200 may divide the picture retrieved from the video data memory 230 into a series of CTUs and encapsulate one or more CTUs in a slice. The mode selection unit 202 may divide the CTUs of the picture according to a tree structure (e.g., the QTBT structure or quadtree structure of HEVC described above). As described above, the video encoder 200 may form one or more CUs by dividing the CTUs according to the tree structure. Such CUs may also be generally referred to as "video blocks" or "blocks".

[0172] In general, the mode selection unit 202 also controls its components (e.g., the motion estimation unit 222, the motion compensation unit 224, and the intra prediction unit 226) to generate a prediction block for the current block (e.g., the current CU, or in HEVC, the overlapping portion of the PU and TU). For inter prediction of the current block, the motion estimation unit 222 may perform a motion search to identify one or more closely matching reference blocks in one or more reference pictures (e.g., one or more previously encoded pictures stored in the DPB 218). Specifically, the motion estimation unit 222 may calculate values ​​representing the degree of similarity of the potential reference blocks to the current block, for example, based on the sum of absolute differences (SAD), the sum of squared differences (SSD), the mean absolute difference (MAD), the mean squared difference (MSD), etc. The motion estimation unit 222 may generally perform these calculations using the sample-by-sample differences between the current block and the reference block under consideration. The motion estimation unit 222 may identify the reference block having the lowest value resulting from these calculations, which indicates the reference block that most closely matches the current block.

[0173] The motion estimation unit 222 may form one or more motion vectors (MVs) that define the position of a reference block in a reference picture relative to a current block in a current picture. The motion estimation unit 222 may then provide the motion vectors to the motion compensation unit 224. For example, for unidirectional inter prediction, the motion estimation unit 222 may provide a single motion vector, while for bidirectional inter prediction, the motion estimation unit 222 may provide two motion vectors. The motion compensation unit 224 may then use the motion vectors to generate a prediction block. For example, the motion compensation unit 224 may use the motion vectors to retrieve data for the reference block. As another example, if the motion vector has fractional sample precision, the motion compensation unit 224 may interpolate the values ​​of the prediction block according to one or more interpolation filters. In addition, for bidirectional inter prediction, the motion compensation unit 224 may retrieve data for two reference blocks identified by corresponding motion vectors (e.g., by sample-by-sample averaging or weighted averaging) and combine the retrieved data.

[0174] As another example, for intra prediction or intra prediction decoding, the intra prediction unit 226 can generate a prediction block based on samples adjacent to the current block. For example, for directional mode, the intra prediction unit 226 can generally combine the values ​​of adjacent samples in a mathematical manner and fill these calculated values ​​along a defined direction on the current block to generate a prediction block. As another example, for DC mode, the intra prediction unit 226 can calculate the average value of adjacent samples to the current block and generate a prediction block to include the resulting average value for each sample of the prediction block.

[0175] The mode selection unit 202 provides the prediction block to the residual generation unit 204. The residual generation unit 204 receives the original undecoded version of the current block from the video data memory 230 and receives the prediction block from the mode selection unit 202. The residual generation unit 204 calculates the sample-by-sample difference between the current block and the prediction block. The resulting sample-by-sample difference defines a residual block for the current block. In some examples, the residual generation unit 204 may also determine the difference between the sample values ​​in the residual block to generate the residual block using residual differential pulse code modulation (RDPCM). In some examples, the residual generation unit 204 may be formed using one or more subtractor circuits that perform binary subtraction.

[0176] In the example where the mode selection unit 202 divides the CU into PUs, each PU may be associated with a luma prediction unit and a corresponding chroma prediction unit. The video encoder 200 and the video decoder 300 may support PUs of various sizes. As described above, the size of the CU may refer to the size of the luma coding block of the CU, and the size of the PU may refer to the size of the luma prediction unit of the PU. Assuming that the size of a particular CU is 2Nx2N, the video encoder 200 may support PU sizes of 2Nx2N or NxN for intra prediction, and symmetric PU sizes of 2Nx2N, 2NxN, Nx2N, NxN or the like for inter prediction. The video encoder 200 and the video decoder 300 may also support asymmetric partitioning of PU sizes of 2NxnU, 2NxnD, nLx2N, and nRx2N for inter prediction.

[0177] In an example where the mode selection unit does not further split the CU into PUs, each CU may be associated with a luma coding block and a corresponding chroma coding block. As described above, the size of a CU may refer to the size of the luma coding block of the CU. The video encoder 200 and the video decoder 120 may support CU sizes of 2N×2N, 2N×N, or N×2N.

[0178] For other video coding techniques (e.g., intra-block copy mode coding, affine mode coding, and linear model (LM) mode coding (if enabled), to name a few), the mode selection unit 202 generates a prediction block for the current block being encoded via various units associated with the coding technique. In some examples (e.g., palette mode coding), the mode selection unit 202 may not generate a prediction block, but instead generate syntax elements indicating how to reconstruct the block based on the selected palette. In such a mode, the mode selection unit 202 may provide these syntax elements to the entropy coding unit 220 for encoding.

[0179] As described above, the residual generation unit 204 receives video data of a current block and a corresponding prediction block. The residual generation unit 204 then generates a residual block for the current block. To generate the residual block, the residual generation unit 204 calculates the sample-by-sample difference between the prediction block and the current block.

[0180] The transform processing unit 206 applies one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a "transform coefficient block"). The transform processing unit 206 may apply various transforms to the residual block to form a transform coefficient block. For example, the transform processing unit 206 may apply a discrete cosine transform (DCT), a directional transform, a Karhunen-Loeve transform (KLT), or a conceptually similar transform to the residual block. In some examples, the transform processing unit 206 may perform multiple transforms on the residual block, such as a primary transform and a secondary transform, such as a rotation transform. In some examples, the transform processing unit 206 does not apply a transform to the residual block.

[0181] The quantization unit 208 may quantize the transform coefficients in the transform coefficient block to produce a quantized transform coefficient block. The quantization unit 208 may quantize the transform coefficients of the transform coefficient block according to a quantization parameter (QP) value associated with the current block. The video encoder 200 (e.g., via the mode selection unit 202) may adjust the degree of quantization applied to the transform coefficient block associated with the current block by adjusting the QP value associated with the CU. Quantization may result in a loss of information, and therefore, the precision of the quantized transform coefficients may be lower than the precision of the original transform coefficients generated by the transform processing unit 206.

[0182] The inverse quantization unit 210 and the inverse transform processing unit 212 may apply inverse quantization and inverse transform to the quantized transform coefficient block, respectively, to reconstruct a residual block from the transform coefficient block. The reconstruction unit 214 may generate a reconstructed block corresponding to the current block (although possibly with some degree of distortion) based on the reconstructed residual block and the prediction block generated by the mode selection unit 202. For example, the reconstruction unit 214 may add samples of the reconstructed residual block to corresponding samples from the prediction block generated by the mode selection unit 202 to generate a reconstructed block.

[0183] Filter unit 216 may perform one or more filtering operations on the reconstructed block. For example, filter unit 216 may perform a deblocking operation to reduce blocking artifacts along the edges of the CU. In some examples, the operations of filter unit 216 may be skipped.

[0184] The video encoder 200 stores the reconstructed blocks in the DPB 218. For example, in an example where the operation of the filter unit 216 is not required, the reconstruction unit 214 can store the reconstructed blocks to the DPB 218. In an example where the operation of the filter unit 216 is required, the filter unit 216 can store the filtered reconstructed blocks to the DPB 218. The motion estimation unit 222 and the motion compensation unit 224 can retrieve reference images from the DPB 218 formed by the reconstructed (and possibly filtered) blocks to the inter-prediction blocks of the subsequently encoded images. In addition, the intra-prediction unit 226 can use the reconstructed blocks in the DPB 218 of the current picture to perform intra-prediction on other blocks in the current picture.

[0185] In general, the entropy coding unit 220 may entropy encode syntax elements received from other functional components of the video encoder 200. For example, the entropy coding unit 220 may entropy encode the quantized transform coefficient blocks from the quantization unit 208. As another example, the entropy coding unit 220 may entropy encode the prediction syntax elements (e.g., motion information for inter-prediction or intra-mode information for intra-prediction) from the mode selection unit 202. The entropy coding unit 220 may perform one or more entropy coding operations on syntax elements as another example of video data to generate entropy coded data. For example, the entropy coding unit 220 may perform a context adaptive variable length coding (CAVLC) operation, a CABAC operation, a variable to variable (V2V) length coding operation, a syntax-based context adaptive binary arithmetic coding (SBAC) operation, a probability interval partitioning entropy (PIPE) coding operation, an exponential Golomb coding operation, or another entropy coding operation on the data. In some examples, the entropy coding unit 220 may operate in a bypass mode where the syntax elements are not entropy coded.

[0186] The video encoder 200 may output a bitstream including entropy encoding syntax elements required to reconstruct a block of a slice or picture. In particular, the entropy encoding unit 220 may output a bitstream.

[0187] The above operations are described for blocks. Such descriptions should be understood as operations for luma coding blocks and / or chroma coding blocks. As described above, in some examples, the luma coding blocks and chroma coding blocks are the luma and chroma components of a CU. In some examples, the luma coding blocks and chroma coding blocks are the luma and chroma components of a PU.

[0188] In some examples, the operations performed for the luma coding block do not need to be repeated for the chroma coding block. As an example, the operations for identifying the motion vector (MV) and reference picture for the luma coding block do not need to be repeated to identify the MV and reference picture for the chroma block. Instead, the MV for the luma coding block can be adjusted to determine the MV for the chroma block, and the reference picture can be the same. As another example, the intra prediction process can be the same for the luma coding block and the chroma coding block.

[0189] The video encoder 200 represents an example of a device configured to encode video data, comprising: a memory configured to store video data; and one or more processors implemented in circuits and configured to: encode a value of a profile indicator syntax element in a bitstream comprising video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; encode one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and encode the video data according to the decoding tool specific constraints and the category of the profile.

[0190] Figure 4 is a block diagram illustrating an example video decoder 300 that can perform the techniques of this disclosure. Figure 4 For purposes of explanation, and not to limit the techniques extensively illustrated and described in this disclosure. For purposes of illustration, this disclosure describes a video decoder 300 based on techniques of VVC and HEVC. However, the techniques of this disclosure may be performed by video decoding devices configured for other video decoding standards.

[0191] exist Figure 4 In the example of , the video decoder 300 includes a coded picture buffer (CPB) memory 320, an entropy decoding unit 302, a prediction processing unit 304, an inverse quantization unit 306, an inverse transform processing unit 308, a reconstruction unit 310, a filter unit 312, and a decoded picture buffer (DPB) 314. Any or all of the CPB memory 320, the entropy decoding unit 302, the prediction processing unit 304, the inverse quantization unit 306, the inverse transform processing unit 308, the reconstruction unit 310, the filter unit 312, and the DPB 314 can be implemented in one or more processors or in processing circuits. In addition, the video decoder 300 may include additional or alternative processors or processing circuits to perform these and other functions.

[0192] The prediction processing unit 304 includes a motion compensation unit 316 and an intra prediction unit 318. The prediction processing unit 304 may include additional units to perform predictions according to other prediction modes. As an example, the prediction processing unit 304 may include a palette unit, an intra-block copy unit (which may form part of the motion compensation unit 316), an affine unit, a linear model (LM) unit, etc. In other examples, the video decoder 300 may include more, fewer, or different functional components.

[0193] CPB memory 320 may store video data (e.g., encoded video bitstreams) to be decoded by components of video decoder 300. The video bitstream may be obtained, for example, from computer readable medium 110 ( Figure 1 ) obtains video data stored in CPB memory 320. CPB memory 320 may include a CPB that stores coded video data (e.g., syntax elements) from a coded video bitstream. Moreover, CPB memory 320 may store video data other than syntax elements of decoded pictures, such as temporary data representing outputs from various units of video decoder 300. DPB 314 typically stores decoded pictures, and video decoder 300 may output and / or use decoded pictures as reference video data when decoding subsequent data or pictures of the coded video bitstream. CPB memory 320 and DPB 314 may be formed by any of a variety of memory devices, such as dynamic random access memory (DRAM), including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM) or other types of memory devices. CPB memory 320 and DPB 314 may be provided by the same memory device or a separate memory device. In various examples, CPB memory 320 may be on-chip with other components of video decoder 300, or off-chip relative to those components.

[0194] Additionally or alternatively, in some examples, video decoder 300 may retrieve the video from memory 120 ( Figure 1 ) retrieves the decoded video data. That is, memory 120 may store data as discussed above with respect to CPB memory 320. Likewise, when some or all of the functionality of video decoder 300 is implemented in software to be executed by processing circuitry of video decoder 300, memory 120 may store instructions to be executed by video decoder 300.

[0195] Shows Figure 4 The various units are described to help understand the operations performed by the video decoder 300. These units may be implemented as fixed function circuits, programmable circuits, or a combination thereof. Figure 3Similarly, a fixed-function circuit refers to a circuit that provides a specific function and is pre-set in the operations that can be performed. A programmable circuit refers to a circuit that can be programmed to perform a variety of tasks and provides flexible functions in the operations that can be performed. For example, a programmable circuit can execute software or firmware that causes the programmable circuit to operate in a manner defined by the instructions of the software or firmware. A fixed-function circuit can execute software instructions (e.g., to receive parameters or output parameters), but the type of operation performed by the fixed-function circuit is generally immutable. In some examples, one or more of these units can be different circuit blocks (fixed-function or programmable), and in some examples, these one or more units can be integrated circuits.

[0196] The video decoder 300 may include an ALU, an EFU, a digital circuit, an analog circuit, and / or a programmable core formed by a programmable circuit. In an example where the operation of the video decoder 300 is performed by software executed on the programmable circuit, an on-chip or off-chip memory may store instructions (e.g., object code) of the software received and executed by the video decoder 300.

[0197] According to the technology of the present disclosure, the entropy decoding unit 302 can decode a sequence parameter set (SPS) for a picture sequence. The SPS may include a profile indicator (profile_idc) indicating the profile to which the video bitstream including the picture sequence conforms. The SPS may also include a set of one or more values ​​representing a specific constraint for a decoding tool for a picture sequence, wherein the specific constraint for the decoding tool may indicate whether the corresponding decoding tool can be enabled for the picture sequence. The entropy decoding unit 302 may also decode data indicating whether the decoding tool is actually enabled for each decoding tool that can be enabled, and any initialization information or other data required for using the decoding tool for the picture sequence. The entropy decoding unit 302 may also determine that the SPS will not include data for disabled decoding tools, and therefore may determine whether the bits of the video bitstream correspond to the data of these decoding tools or to other data based on whether the decoding tools can be enabled. Therefore, the entropy decoding unit 302 may adjust the parsing decisions made during the parsing and decoding of the video bitstream based on whether certain decoding tools can be enabled.

[0198] The entropy decoding unit 302 may also provide parameters for enabled coding tools to other components of the video decoder 300. For example, the entropy decoding unit 302 may provide data indicating whether certain coding tools are enabled and any initialization information or other data required to use the enabled coding tools to other components of the video decoder 300.

[0199] Examples of various coding tools that can be enabled or disabled include use of binary ternary trees (BTT), partition unit coding order (SUCO), adaptive motion vector resolution (AMVR), merged motion vector difference (MMVD), affine mode, decoder side motion vector derivation (DMVR), adaptive loop filtering (ALF), advanced motion vector prediction (AMVP), intra block copy (IBC), and signaling of reference picture list (RPL) data in the picture header (PH) or slice header (SH).

[0200] Thus, for example, entropy decoding unit 302 may provide an indication to motion compensation unit 316 whether MMVD is enabled. If MMVD is enabled, motion compensation unit 316 may determine whether motion information for a particular block of video data is encoded using conventional merge mode, advanced motion vector prediction (AMVP), or MMVD, and if MMVD, reproduce the motion vector of the block using MMVD. As another example, if DMVR is enabled, entropy decoding unit 302 may provide an indication that DMVR is enabled, and motion compensation unit 316 may perform DMVR for certain blocks for which DMVR is to be used to reproduce motion information. As yet another example, if IBC is enabled, entropy decoding unit 302 may provide an indication that IBC is enabled to prediction processing unit 304, and motion compensation unit 316 may perform IBC for certain blocks accordingly.

[0201] The entropy decoding unit 302 may receive the encoded video data from the CPB and entropy decode the video data to reproduce the syntax elements. The prediction processing unit 304, the inverse quantization unit 306, the inverse transform processing unit 308, the reconstruction unit 310, and the filter unit 312 may generate decoded video data based on the syntax elements extracted from the bitstream.

[0202] Typically, the video decoder 300 reconstructs a picture block by block. The video decoder 300 may perform a reconstruction operation on each block individually (where a block currently being reconstructed (ie, decoded) may be referred to as a "current block").

[0203] The entropy decoding unit 302 may entropy decode syntax elements defining quantized transform coefficients of the quantized transform coefficient block and transform information (e.g., a quantization parameter (QP) and / or a transform mode indication). The inverse quantization unit 306 may use the QP associated with the quantized transform coefficient block to determine a quantization degree, and likewise, determine an inverse quantization degree for application by the inverse quantization unit 306. The inverse quantization unit 306 may, for example, perform a bitwise left shift operation to inverse quantize the quantized transform coefficients. The inverse quantization unit 306 may thereby form a transform coefficient block including the transform coefficients.

[0204] After the inverse quantization unit 306 forms the transform coefficient block, the inverse transform processing unit 308 may apply one or more inverse transforms to the transform coefficient block to generate a residual block associated with the current block. For example, the inverse transform processing unit 308 may apply an inverse DCT, an inverse integer transform, an inverse Karhunen-Loeve transform (KLT), an inverse rotational transform, an inverse directional transform, or another inverse transform to the coefficient block.

[0205] In addition, prediction processing unit 304 generates a prediction block based on the prediction information syntax element entropy decoded by entropy decoding unit 302. For example, if the prediction information syntax element indicates that the current block is inter-predicted, motion compensation unit 316 can generate a prediction block. In this case, the prediction information syntax element can indicate a reference picture in DPB 314 from which to retrieve the reference block, and a motion vector that identifies the position of the reference block in the reference picture relative to the position of the current block in the current picture. Motion compensation unit 316 can generally perform an inter-prediction process in a manner substantially similar to that described for motion compensation unit 224 ( Figure 3 ).

[0206] As another example, if the prediction information syntax element indicates that the current block is intra-predicted, the intra-prediction unit 318 can generate a prediction block according to the intra-prediction mode indicated by the prediction information syntax element. Again, the intra-prediction unit 318 can generally be used in conjunction with the intra-prediction unit 226 ( Figure 3 ) The intra prediction process is performed in a manner substantially similar to that described in the prior art. The intra prediction unit 318 may retrieve data of neighboring samples of the current block from the DPB 314.

[0207] The reconstruction unit 310 may reconstruct the current block using the prediction block and the residual block. For example, the reconstruction unit 310 may add samples of the residual block to corresponding samples of the prediction block to reconstruct the current block.

[0208] The filter unit 312 may perform one or more filtering operations on the reconstructed block. For example, the filter unit 312 may perform a deblocking operation to reduce blocking artifacts along the edges of the reconstructed block. The operations of the filter unit 312 may not necessarily be performed in all examples.

[0209] The video decoder 300 may store the reconstructed blocks in the DPB 314. As discussed above, the DPB 314 may provide reference information to the prediction processing unit 304, such as samples of the current picture for intra prediction and previously decoded pictures for subsequent motion compensation. In addition, the video decoder 300 may output decoded pictures from the DPB 314 for subsequent display on a display device (e.g., Figure 1 The image is presented on a display device 118).

[0210] In this way, the video decoder 300 represents an example of a video decoding device, which includes: a memory, the memory being configured to store video data; and one or more processors, which are implemented in circuits and are configured to: decode the value of a profile indicator syntax element in a bitstream including the video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; decode one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and decode the video data according to the decoding tool specific constraints and the category of the profile.

[0211] Figure 5 1 is a flowchart illustrating an example method for encoding a current block according to the techniques of the present disclosure. The current block may include a current CU. Although for the video encoder 200 ( Figure 1 and Figure 3 ), but it should be understood that other devices may be configured to perform the same Figure 5 Similar approach.

[0212] In this example, the video encoder 200 initially determines the enabled and disabled coding tools of the profile of the video coding standard (350). The video encoder 200 then encodes the value of the profile_idc value indicating which of these coding tools are enabled and disabled (352), for example, as described above. The video encoder 200 may then predict the current block using the enabled coding tools instead of the disabled coding tools (354). For example, the video encoder 200 may form a prediction block for the current block. The video encoder 200 may then calculate a residual block for the current block (356). To calculate the residual block, the video encoder 200 may calculate the difference between the original uncoded block and the prediction block for the current block. The video encoder 200 may then transform and quantize the coefficients of the residual block (358). Next, the video encoder 200 may scan the quantized transform coefficients of the residual block (360). During or after the scan, the video encoder 200 may entropy encode the coefficients (362). For example, video encoder 200 may encode the coefficients using CAVLC or CABAC. Video encoder 200 may then output entropy coded data (364) for the block. It should be understood that Figure 5 The various steps of the decoding process described in will only include encoding using enabled decoding tools and not encoding using disabled decoding tools.

[0213] In this way, Figure 5The method represents an example of a method, which includes: determining a maximum value of a possible value range of a profile indicator syntax element, the profile indicator syntax element representing a set of decoding tools used to decode video data of a bitstream; decoding a value of the profile indicator syntax element in the bitstream, the value being less than the maximum value; determining one or more decoding tools in the decoding tools that are not used to decode the video data of the bitstream, the one or more decoding tools in the decoding tools being represented by the value of the profile indicator syntax element; and decoding the video data using the remaining decoding tools in the decoding tool set, excluding the one or more decoding tools in the decoding tools represented by the value of the profile indicator syntax element.

[0214] Figure 6 1 is a flowchart illustrating an example method for decoding a current block according to the techniques of the present disclosure. The current block may include a current CU. Although for the video decoder 300 ( Figure 1 and Figure 4 ), but it should be understood that other devices may be configured to perform the same Figure 6 Similar approach.

[0215] In this example, the video decoder 300 may initially decode the value of the profile_idc syntax element indicating enabled and disabled coding tools (370). The video decoder 300 may then use the value of the profile_idc syntax element to determine which coding tools are enabled and disabled (372). The video decoder 300 may then receive entropy coded data for the current block, e.g., entropy coded prediction information and entropy coded data for coefficients of a residual block corresponding to the current block (374). The video decoder 300 may entropy decode the entropy coded data to determine prediction information for the current block and reproduce coefficients of the residual block (376). The video decoder 300 may predict the current block (378), e.g., using an intra-prediction or inter-prediction mode indicated by the prediction information for the current block, to calculate a prediction block for the current block. The video decoder 300 may then inverse scan the reproduced coefficients (380) to create a block of quantized transform coefficients. The video decoder 300 may then inverse quantize and inverse transform the coefficients to produce a residual block (382). The video decoder 300 may finally decode the current block by combining the prediction block and the residual block (384). It should be understood that Figure 6 The various steps of the decoding process described in will only include encoding using enabled decoding tools instead of using disabled decoding tools. Similarly, the video decoder 300 will avoid decoding data of syntax elements corresponding to disabled decoding tools.

[0216] In this way, Figure 6The method represents an example of a method, which includes: determining a maximum value of a possible value range of a profile indicator syntax element, the profile indicator syntax element representing a set of decoding tools used to decode video data of a bitstream; decoding a value of the profile indicator syntax element in the bitstream, the value being less than the maximum value; determining one or more decoding tools in the decoding tools that are not used to decode the video data of the bitstream, the one or more decoding tools in the decoding tools being represented by the value of the profile indicator syntax element; and decoding the video data using the remaining decoding tools in the decoding tool set, excluding the one or more decoding tools in the decoding tools represented by the value of the profile indicator syntax element.

[0217] Figure 7 2 is a flowchart illustrating an example method of encoding video data according to the techniques of the present disclosure. Figure 1 and Figure 3 ), but it should be understood that other devices may be configured to perform the same Figure 7 Similar approach.

[0218] Initially, the video encoder 200 can determine which decoding tools to enable and disable (400). For example, as described above, the mode selection unit 202 can receive configuration data from an administrator or other user that indicates certain decoding tools to be completely disabled for the entire video program. Also, among those decoding tools that can be enabled, the mode selection unit 202 can perform multiple test encoding runs with the decoding tools enabled or disabled and measure the rate-distortion metric for each run. When a decoding tool does not improve the rate-distortion metric, the mode selection unit 202 can disable the decoding tool.

[0219] The video encoder 200 may encode (402) an SPS including a profile indicator (profile_idc) indicating the category of the profile to which the bitstream conforms. Within a given profile, various decoding tools may be available. However, according to the technology of the present disclosure, certain decoding tools may be disabled for the entire video program, so that a video decoder that supports enabled decoding tools while also technically conforming to the profile may be developed. Therefore, the video encoder 200 may encode (404) data indicating which decoding tools within the profile may be enabled, and therefore which decoding tools within the profile may not be enabled. That is, the video encoder 200 may encode the value of a decoding tool-specific constraint indicating whether the decoding tool may be enabled or not enabled for at least a subset of the bitstream. The profile indicator and the data indicating the decoding tool-specific constraint (i.e., the decoding tool that may be enabled) may remain the same in all SPSs of the video program. Within a given sequence of pictures, the video encoder 200 may encode (406) data indicating whether the decoding tool is actually enabled or disabled.

[0220] The video encoder 200 can then encode each picture of the picture sequence. Typically, encoding of a picture includes dividing the picture into blocks and encoding each block separately. For example, the video encoder 200 can use enabled decoding tools to predict the current block (408). As an example, the video encoder 200 can determine whether to use conventional intra prediction or conventional inter prediction to predict the block. For decoding tools such as intra-block copy, motion vector difference merging (MMVD), affine mode, DMVR, etc., the video encoder 200 can also select from these modes if these modes are enabled as described above. The video encoder 200 can ultimately use the prediction mode and prediction information (e.g., motion information or other information indicating how to generate the prediction block) to generate a prediction block.

[0221] The video encoder 200 may then calculate a residual block for the current block (410). Specifically, the video encoder 200 may calculate a sample-by-sample difference between the current block and the predicted block to generate a residual block. The video encoder 200 may further transform and quantize the residual block using enabled coding tools (412). For example, if enabled, the video encoder 200 may select from discrete cosine transform (DCT), discrete sine transform (DST), Karhunen-Loeve transform (KLT), quadratic transform, rotation transform, etc. to transform the block from a spatial (or pixel) domain to a transform (or frequency) domain.

[0222] Video encoder 200 may then scan the coefficients of the resulting transform block (414). During the scan, or after the scan, video encoder 200 may entropy encode the coefficients and other values ​​of the syntax elements using enabled coding tools (416). Video encoder 200 may also output entropy encoded data for the coefficients and other values ​​(e.g., prediction information) (418).

[0223] In this way, Figure 7 The method represents an example of a method for encoding video data, the method comprising: encoding a value of a profile indicator syntax element in a bitstream including the video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; encoding one or more values ​​representing one or more decoding tool specific constraints separately from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and encoding the video data according to the decoding tool specific constraints and the category of the profile.

[0224] Figure 8 is a flowchart illustrating an example method of decoding video data according to the techniques of the present disclosure. Figure 1 and Figure 4 ), but it should be understood that other devices may be configured to perform the same Figure 8 Similar approach.

[0225] The video decoder 300 may initially entropy decode a profile indicator (profile_idc) value of a sequence parameter set (SPS) that indicates a category of a profile to which the video bitstream conforms (430). The video decoder 300 may also entropy decode data indicating coding tools that may be enabled (432), such as coding tool-specific constraints indicating whether coding tools corresponding to the coding tool-specific constraints may be enabled for at least a subset of the bitstream. The video decoder 300 may also decode data indicating which coding tools that could be enabled are actually enabled or disabled (434), and use the data to determine which coding tools are enabled or disabled (436).

[0226] The video decoder 300 can then decode the pictures of the video data sequence according to the enabled and disabled decoding tools and the profile to which the video bitstream conforms. For example, the video decoder 300 can decode and reproduce the pictures block by block. Therefore, the video decoder 300 can initially receive entropy coded data for a current block (374). The data can include prediction information (e.g., intra prediction or motion information), as well as quantized transform coefficients for the current block.

[0227] The video decoder 300 may use enabled decoding tools to entropy decode the entropy coded data to determine prediction information and reproduce the quantized transform coefficients (376). The video decoder 300 may use enabled decoding tools to form a prediction block for the current block (378). The video decoder 300 may also inverse scan the reproduced coefficients to form a quantized transform block (380). The video decoder 300 may use enabled decoding tools (e.g., secondary transform, rotation transform, DCT, DST, KLT, etc.) to inverse quantize and inverse transform the coefficients to produce a residual block for the current block (382). The video decoder 300 may then combine the prediction block and the residual block sample by sample to reproduce the current block (384). Although Figure 8 Not shown, but if ALF is enabled, the video decoder 300 may also use ALF to filter blocks of a picture, for example, to reduce blocking artifacts.

[0228] In this way, Figure 8 The method represents an example of a method for decoding video data, the method comprising: decoding a value of a profile indicator syntax element in a bitstream including the video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; decoding one or more values ​​representing one or more decoding tool specific constraints separate from the profile indicator syntax element, each of the decoding tool specific constraints indicating whether a decoding tool corresponding to the decoding tool specific constraint can be enabled for at least a subset of the bitstream; and decoding the video data according to the decoding tool specific constraints and the category of the profile.

[0229] Some of the techniques of this application are summarized in the following examples:

[0230] Example 1: A method for decoding video data, the method comprising: determining a maximum value of a possible value range of a profile indicator syntax element, the profile indicator syntax element representing a set of decoding tools used to decode video data of a bitstream; decoding a value of the profile indicator syntax element in the bitstream, the value being less than the maximum value; determining one or more decoding tools among the decoding tools that are not used to decode the video data of the bitstream, the one or more decoding tools among the decoding tools being represented by the value of the profile indicator syntax element; and decoding the video data using the remaining decoding tools in the decoding tool set, excluding the one or more decoding tools among the decoding tools represented by the value of the profile indicator syntax element.

[0231] Example 2: The method of Example 1, wherein coding the value of the profile indicator syntax element comprises coding the value in a sequence parameter set (SPS) of the bitstream.

[0232] Example 3: A method according to any of Examples 1 and 2, wherein the value of the profile indicator syntax element comprises a binary value, each bit in the binary value indicating whether one or more corresponding decoding tools in the decoding tools are enabled or disabled.

[0233] Example 4: The method of Example 3, wherein at least one of the bits of the binary value indicates whether a plurality of corresponding decoding tools in the set of decoding tools are enabled or disabled.

[0234] Example 5: A method according to any of Examples 1-3, wherein the value of the profile indicator syntax element includes a binary value, each bit in the binary value indicates whether a corresponding one of the decoding tools is enabled or disabled.

[0235] Example 6: The method according to any of Examples 1-5 further includes: determining whether the bitstream can be decoded using the value of the profile indicator syntax element.

[0236] Example 7: A method according to any of Examples 1-6, wherein determining the one or more decoding tools that are not used in the decoding tools includes: applying a binary mask to the value of the profile indicator syntax element.

[0237] Example 8: A method according to any of Examples 1-7, wherein determining the one or more decoding tools that are not used in the decoding tools includes: applying a bitwise shift operation to the value of the profile indicator syntax element.

[0238] Example 9: A method according to any of Examples 1-8, wherein determining the one or more decoding tools that are not used in the decoding tools includes: applying an offset to the value of the profile indicator syntax element.

[0239] Example 10: The method of any of Examples 1-9, wherein the value of the profile indicator syntax element comprises a binary or exponential structure.

[0240] Example 11: A method according to any of Examples 1-10, wherein decoding the video data includes: decoding the video data, wherein decoding the value of the profile indicator syntax element includes: decoding the value of the profile indicator syntax element, and wherein determining the one or more decoding tools that are not used includes: determining the one or more decoding tools that are not used based on the value of the profile indicator syntax element.

[0241] Example 12: A method according to any of Examples 1-11, wherein decoding the video data includes: encoding the video data, and wherein decoding the value of the profile indicator syntax element includes: determining the value indicating that the one or more decoding tools are not used; and encoding the value of the profile indicator syntax element.

[0242] Example 13: A method for decoding video data, the method comprising: decoding the value of a profile indicator syntax element in a bitstream, the value of the profile indicator indicating the category of a profile to which the bitstream conforms; decoding data of a syntax element separate from the profile indicator syntax element that represents one or more decoding tool-specific constraints; and decoding the video data according to the tool-specific constraints.

[0243] Example 14: The method of Example 13, further comprising decoding a value of a syntax element indicating that a tool-specific enable / disable indication is signaled in the bitstream.

[0244] Example 15: The method of Example 14, wherein the syntax element indicating that the coding tool specific enable / disable indication is signaled comprises a constrained_tool_indication_flag.

[0245] Example 16: A method according to any of Examples 14 and 15, wherein the value of the syntax element representing the coding tool-specific enable / disable indication transmitted by the signal has a value predefined according to the value of the profile indicator syntax element.

[0246] Example 17: A method according to any of Examples 14-16, wherein the value of the syntax element representing the tool-specific enable / disable indication transmitted by the signal indicates that: when the value of the profile indicator syntax element indicates that the bitstream conforms to the baseline profile, all tools corresponding to the tool-specific constraints are disabled.

[0247] Example 18: The method of any of Examples 13-17, wherein the syntax element representing the one or more tool-specific constraints comprises a constrained_tool_val syntax element.

[0248] Example 19: A method according to any of Examples 13-18, wherein the syntax element representing the one or more tool-specific constraints includes a plurality of bits, each of the bits having a binary value representing whether the corresponding decoding tool is enabled or disabled.

[0249] Example 20: The method according to any of Examples 13-19 further includes: using the value of the profile indicator syntax element or at least one of the data of the syntax element representing the one or more tool-specific constraints to derive the value of a tool variable indicating whether the decoding tool is enabled or disabled.

[0250] Example 21: A method according to any of Examples 13-20, wherein the decoding includes decoding.

[0251] Example 22: A method according to any of Examples 13-21, wherein decoding includes encoding.

[0252] Example 23: An apparatus for decoding video data, the apparatus comprising one or more units for performing the method according to any of Examples 1-22.

[0253] Example 24: The apparatus of Example 23, wherein the one or more units comprise one or more processors.

[0254] Example 25: The device of Example 23 further comprises a display configured to display the video data.

[0255] Example 26: The device of Example 23, wherein the device comprises one or more of: a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box.

[0256] Example 27: The apparatus of Example 23, further comprising a memory configured to store the video data.

[0257] Example 28: The apparatus of Example 23, further comprising a camera configured to capture the video data.

[0258] Example 29: The device of Example 23, wherein the device comprises at least one of: an integrated circuit; a microprocessor; or a wireless communication device.

[0259] Example 30: A computer-readable storage medium having instructions stored thereon, which, when executed, cause a processor to perform the method according to any of Examples 1-22.

[0260] Example 31: A device for decoding video data, the device comprising: a unit for determining a maximum value of a possible range of values ​​of a profile indicator syntax element, the profile indicator syntax element representing a set of decoding tools used to decode video data of a bitstream; a unit for decoding a value of the profile indicator syntax element in the bitstream, the value being less than the maximum value; a unit for determining one or more of the decoding tools that are not used to decode the video data of the bitstream, the one or more of the decoding tools being represented by the value of the profile indicator syntax element; and a unit for decoding the video data using the remaining decoding tools in the decoding tool set, excluding the one or more of the decoding tools represented by the value of the profile indicator syntax element.

[0261] Example 32: A device for decoding video data, the device comprising: a unit for decoding the value of a profile indicator syntax element in a bitstream, the value of the profile indicator indicating the category of a profile to which the bitstream conforms; a unit for decoding data of a syntax element representing one or more decoding tool-specific constraints, separate from the profile indicator syntax element; and a unit for decoding the video data according to the tool-specific constraints.

[0262] It should be appreciated that, according to examples, certain actions or events of any of the techniques described herein may be performed in a different order, may be added, combined, or omitted altogether (e.g., not all described actions are necessary for implementation of the techniques). In addition, in some examples, actions or events may be performed concurrently (e.g., through multithreading, interrupt processing, or multiple processors) rather than sequentially.

[0263] In one or more examples, the described functions can be implemented with hardware, software, firmware, or any combination thereof. If implemented with software, these functions can be stored on a computer-readable medium as one or more instructions or codes, or sent via a computer-readable medium, and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium such as a data storage medium, or a communication medium (which includes, for example, any medium that facilitates the transfer of a computer program from one location to another location according to a communication protocol). In this way, a computer-readable medium may generally correspond to (1) a non-temporary tangible computer-readable storage medium or (2) a communication medium (such as a signal or carrier wave). A data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures for the implementation of the technology described in the present disclosure. A computer program product may include a computer-readable medium.

[0264] By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program codes in the form of instructions or data structures and can be accessed by a computer. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if instructions are sent from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other temporary media, but are directed to non-temporary, tangible storage media. As used herein, disks and discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and blue-ray discs, wherein disks usually copy data magnetically, while optical discs use lasers to optically copy data. Combinations of the above should also be included within the scope of computer-readable media.

[0265] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Therefore, as used herein, the terms "processor" and "processing circuit" may refer to any of the aforementioned structures or any other structures suitable for the implementation of the techniques described herein. In addition, in some aspects, the functions described herein may be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated into a combined codec. In addition, these techniques may be fully implemented in one or more circuits or logic units.

[0266] The techniques of the present disclosure may be implemented in a variety of devices or apparatuses, including wireless handheld devices, integrated circuits (ICs), or a set of ICs (e.g., chipsets). Various components, modules, or units are described in the present disclosure to emphasize the functional aspects of devices configured to perform the disclosed techniques, but are not necessarily required to be implemented by different hardware units. Rather, as described above, the various units may be combined in a codec hardware unit, or provided by a collection of interoperable hardware units, including one or more processors as described above in combination with appropriate software and / or firmware.

[0267] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

1. A method for decoding video data, the method comprising: decoding a value of a profile indicator syntax element in a bitstream comprising video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; Decoding a single value representing a plurality of coding tool specific constraints separate from the profile indicator syntax element, the single value being represented by a plurality of bits, each bit of the plurality of bits corresponding to one of the plurality of coding tool specific constraints, each of the plurality of coding tool specific constraints being used to indicate, according to a value of a bit of the plurality of bits for a corresponding one of the plurality of coding tool specific constraints, whether a coding tool corresponding to the coding tool specific constraint can be enabled for at least a subset of the bitstream; as well as The video data is coded according to the coding tool specific constraints and the category of the profile.

2. The method according to claim 1, further comprising: A value of a syntax element representing a coding tool specific enable / disable indication signaled in the bitstream is decoded.

3. The method according to claim 2, wherein: The syntax element indicating that the coding tool specific enable / disable indication is signaled includes a constrained_tool_indication_flag.

4. The method according to claim 2, wherein: The value of the syntax element indicating that the coding tool specific enable / disable indication is signaled has a value predefined according to the value of the profile indicator syntax element.

5. The method according to claim 2, wherein: The value of the syntax element indicating whether the coding tool specific enable / disable indication is signaled indicates that when the value of the profile indicator syntax element indicates that the bitstream conforms to a baseline profile, all tools corresponding to the coding tool specific constraints are disabled.

6. The method according to claim 2, further comprising: For each of the coding tools that can be enabled as indicated by the coding tool specific constraint, a value of a syntax element representing the coding tool specific enable / disable indication is decoded, while a value of a syntax element representing the coding tool specific enable / disable indication for coding tools that cannot be enabled as indicated by the coding tool specific constraint is not decoded.

7. The method according to claim 6, wherein: The syntax elements representing the coding tool specific enable / disable indication include a corresponding constrained_tool_val syntax element.

8. The method according to claim 1, further comprising: Using at least one of the value of the profile indicator syntax element or the single value representing the plurality of coding tool specific constraints, a value of a coding tool variable representing whether one of the coding tools is enabled or disabled is derived.

9. The method according to claim 1, wherein: Decoding the single value representing the plurality of coding tool specific constraints includes decoding a single value of a toolset indicator representing a set of constraints to which the bitstream complies.

10. The method according to claim 1, wherein: Decoding the video data includes: decoding the video data.

11. The method according to claim 1, wherein: Decoding the video data includes encoding the video data.

12. A device for decoding video data, the device comprising: a memory configured to store video data; as well as One or more processors implemented in circuitry and configured to: decoding a value of a profile indicator syntax element in a bitstream comprising video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; Decoding a single value representing a plurality of coding tool specific constraints separate from the profile indicator syntax element, the single value being represented by a plurality of bits, each bit of the plurality of bits corresponding to one of the plurality of coding tool specific constraints, each of the plurality of coding tool specific constraints being used to indicate, according to a value of a bit of the plurality of bits for a corresponding one of the plurality of coding tool specific constraints, whether a coding tool corresponding to the coding tool specific constraint can be enabled for at least a subset of the bitstream; as well as The video data is coded according to the coding tool specific constraints and the category of the profile.

13. The device according to claim 12, wherein: The one or more processors are further configured to decode a value of a syntax element representing a coding tool specific enable / disable indication signaled in the bitstream.

14. The device according to claim 13, wherein: The syntax element indicating that the coding tool specific enable / disable indication is signaled includes a constrained_tool_indication_flag.

15. The apparatus according to claim 13, wherein: The value of the syntax element indicating that the coding tool specific enable / disable indication is signaled has a value predefined according to the value of the profile indicator syntax element.

16. The apparatus according to claim 13, wherein: The value of the syntax element indicating whether the coding tool specific enable / disable indication is signaled indicates that when the value of the profile indicator syntax element indicates that the bitstream conforms to a baseline profile, all tools corresponding to the coding tool specific constraints are disabled.

17. The apparatus according to claim 13, wherein: The one or more processors are configured to, for each of the coding tools that can be enabled as indicated by the coding tool specific constraints, decode a value of a syntax element representing the coding tool specific enable / disable indication, and not decode a value of a syntax element representing the coding tool specific enable / disable indication for coding tools that cannot be enabled as indicated by the coding tool specific constraints.

18. The apparatus according to claim 17, wherein: The syntax elements representing the coding tool specific enable / disable indication include a corresponding constrained_tool_val syntax element.

19. The apparatus according to claim 12, wherein: The one or more processors are further configured to derive a value of a coding tool variable representing whether one of the coding tools is enabled or disabled using at least one of the value of the profile indicator syntax element or the single value representing the plurality of coding tool specific constraints.

20. The apparatus of claim 12, wherein: To decode the single value representing the plurality of decoding tool specific constraints, the one or more processors are configured to decode a single value of a toolset indicator representing a set of constraints to which the bitstream complies.

21. The apparatus of claim 12, wherein: The apparatus comprises a video decoder, and wherein the one or more processors are configured to decode the video data.

22. The apparatus of claim 12, wherein: The apparatus comprises a video encoder, and wherein the one or more processors are configured to encode the video data.

23. The device of claim 12, further comprising a display configured to display the video data.

24. The apparatus of claim 12, wherein: The device includes one or more of the following: a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box.

25. The apparatus of claim 12, wherein: The device comprises at least one of the following: integrated circuit; microprocessor; or Wireless communication equipment.

26. A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause a processor to: decoding a value of a profile indicator syntax element in a bitstream comprising video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; Decoding a single value representing a plurality of coding tool specific constraints separate from the profile indicator syntax element, the single value being represented by a plurality of bits, each bit of the plurality of bits corresponding to one of the plurality of coding tool specific constraints, each of the plurality of coding tool specific constraints being used to indicate, according to a value of a bit of the plurality of bits for a corresponding one of the plurality of coding tool specific constraints, whether a coding tool corresponding to the coding tool specific constraint can be enabled for at least a subset of the bitstream; and The video data is coded according to the coding tool specific constraints and the category of the profile.

27. The non-transitory computer-readable storage medium of claim 26, further comprising instructions that cause the processor to decode a value of a syntax element representing a coding tool-specific enable / disable indication signaled in the bitstream.

28. The non-transitory computer-readable storage medium of claim 27, wherein: The syntax element indicating that the coding tool specific enable / disable indication is signaled includes a constrained_tool_indication_flag.

29. The non-transitory computer-readable storage medium of claim 27, wherein: The value of the syntax element indicating that the coding tool specific enable / disable indication is signaled has a value predefined according to the value of the profile indicator syntax element.

30. The non-transitory computer-readable storage medium of claim 27, wherein: The value of the syntax element indicating whether the coding tool specific enable / disable indication is signaled indicates that when the value of the profile indicator syntax element indicates that the bitstream conforms to a baseline profile, all tools corresponding to the coding tool specific constraints are disabled.

31. The non-transitory computer-readable storage medium of claim 27, further comprising instructions for causing the processor to perform the following operations: for each of the decoding tools that can be enabled as indicated by the decoding tool specific constraints, decode the value of the syntax element representing the decoding tool specific enable / disable indication, and do not decode the value of the syntax element representing the decoding tool specific enable / disable indication for the decoding tools that cannot be enabled as indicated by the decoding tool specific constraints.

32. The non-transitory computer-readable storage medium of claim 31, wherein: The syntax elements representing the coding tool specific enable / disable indication include a corresponding constrained_tool_val syntax element.

33. The non-transitory computer-readable storage medium of claim 26, further comprising instructions for causing the processor to perform the following operations: using the value of the profile indicator syntax element or at least one of the single values ​​representing the multiple decoding tool specific constraints, deriving a value of a decoding tool variable indicating whether one of the decoding tools is enabled or disabled.

34. The non-transitory computer-readable storage medium of claim 26, wherein: The instructions that cause the processor to decode the single value representing the plurality of coding tool specific constraints include instructions that cause the processor to decode a single value of a toolset indicator representing a set of constraints to which the bitstream complies.

35. The non-transitory computer-readable storage medium of claim 26, wherein: The instructions for causing the processor to decode the video data include instructions for causing the processor to decode the video data.

36. The non-transitory computer-readable storage medium of claim 26, wherein: The instructions for causing the processor to decode the video data include instructions for causing the processor to encode the video data.

37. A device for decoding video data, the device comprising: means for decoding a value of a profile indicator syntax element in a bitstream comprising video data, the value of the profile indicator indicating a category of a profile to which the bitstream conforms; means for decoding a single value representing a plurality of coding tool specific constraints separate from the profile indicator syntax element, the single value being represented by a plurality of bits, each bit of the plurality of bits corresponding to one of the plurality of coding tool specific constraints, each of the plurality of coding tool specific constraints being configured to indicate, based on a value of a bit of the plurality of bits for a corresponding one of the plurality of coding tool specific constraints, whether a coding tool corresponding to the coding tool specific constraint can be enabled for at least a subset of the bitstream; as well as Means for coding the video data according to the coding tool specific constraints and the category of the profile.

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