Method, computing system, device, and computer program for decoding video

Abstract

Various embodiments described in this disclosure include methods and systems for coding video. In one aspect, the method includes obtaining encoded video data comprising a plurality of blocks and parsing the encoded video data for each block of the plurality of blocks without reconstructing an entire motion vector predictor (MVP) list. The method also includes making a first determination to determine whether warped motion compensation is allowed for the block and whether warped motion compensation is enabled for a first spatial neighboring block, and determining whether to perform warped motion compensation on the block during a subsequent reconstruction operation based on the first determination. The method further includes designating the block for a warp magnification operation or a warp delta operation according to the determination to perform warped motion compensation on the block during a subsequent reconstruction operation.

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 427,061, filed November 21, 2022, entitled "Improvements on Warp Extend and Warp Delta Signaling," which is incorporated herein by reference in its entirety.

[0002] The disclosed embodiments relate generally to video coding, including, but not limited to, systems and methods for distortion expansion signaling and distortion delta signaling. [Background technology]

[0003] Digital video is supported by a variety of electronic devices, such as digital televisions, laptop and desktop computers, tablet computers, digital cameras, digital recording devices, digital media players, video game consoles, smartphones, video conferencing devices, and video streaming devices. The electronic devices transmit, receive, or otherwise communicate digital video data over communication networks and / or store the digital video data on storage devices. Because communication networks have limited bandwidth capacity and storage devices have limited memory resources, video coding may be used to compress the video data according to one or more video coding standards before the video data is communicated or stored.

[0004] Many video codec standards have been developed. Examples of video coding standards include AOMedia Video 1 (AV1), Versatile Video Coding (VVC), Joint Exploration test Model (JEM), High-Efficiency Video Coding (HEVC / H.265), Advanced Video Coding (AVC / H.264), and Moving Picture Expert Group (MPEG) coding. Generally, video coding uses prediction methods (e.g., inter-prediction, intra-prediction, etc.) that exploit the redundancy inherent in video data. The goal of video coding is to compress video data into a format that uses a low bitrate while avoiding or minimizing degradation of video quality.

[0005] HEVC (also known as H.265) is a video compression standard designed as part of the MPEG-H project. The H.265 / HEVC standard was published by ITU-T and ISO / IEC in 2013 (version 1), 2014 (version 2), 2015 (version 3), and 2016 (version 4). Versatile Video Coding (VVC) (also known as H.266) is a video compression standard intended as the successor to HEVC. The VVC / H.266 standard was published by ITU-T and ISO / IEC in 2020 (version 1) and 2022 (version 2). AV1 is an open video coding format designed to replace HEVC. The validated version 1.0.0 with errata 1 to the specification was released on January 8, 2019. Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, a video stream can be encoded into a bitstream, which involves compression and subsequent transmission to a decoder that can decode / decompress the video stream for viewing or further processing. Compression of the video stream can exploit spatial and temporal correlation in the video signal through spatial prediction and / or motion compensated prediction. Motion compensated prediction can include inter-prediction. Inter-prediction can use one or more motion vectors to generate a block to be coded using previously coded and decoded pixels. A decoder receiving the coded signal can recreate the block.

[0007] Not all motion across an image is translational. Therefore, translational motion patterns cannot accurately describe more complex motions such as rotation, zoom, and shear. To overcome this drawback, a warped motion mode using an affine model can be used. However, it is important to decide when (specifically, in which blocks) warped motion is allowed. [Means for solving the problem]

[0008] According to some embodiments, a method for decoding video is provided, the method including: (i) obtaining coded video data comprising a plurality of blocks; (ii) parsing the coded video data for each block of the plurality of blocks without reconstructing an entire motion vector predictor (MVP) list; (iii) making a first determination to determine whether warped motion compensation is allowed for the block and whether warped motion compensation is enabled for a first spatial neighboring block; (iv) determining whether to perform warped motion compensation for the block during a subsequent reconstruction operation based on the first determination; and (v) designating the block for a warp magnification operation or a warp delta operation in accordance with the determination to perform warped motion compensation for the block during a subsequent reconstruction operation.

[0009] According to some embodiments, a computing system, such as a streaming system, a server system, a personal computer system, or other electronic device, is provided. The computing system includes control circuitry and memory that stores one or more instruction sets. The one or more instruction sets include instructions for performing any of the methods described in this disclosure. In some embodiments, the computing system includes an encoder component and / or a decoder component.

[0010] According to some embodiments, a non-transitory computer-readable storage medium is provided that stores one or more instruction sets for execution by a computing system, the one or more instruction sets including instructions for performing any of the methods described in this disclosure.

[0011] Thus, devices and systems are disclosed along with methods for coding video that can complement or replace conventional methods, devices and systems for video coding.

[0012] The features and advantages described herein are not all-inclusive, and some additional features and advantages will be apparent to those skilled in the art, particularly in light of the drawings, specification, and claims provided in this disclosure. Furthermore, it should be noted that the language used in this specification has been selected primarily for readability and instructional purposes, and has not necessarily been selected to describe in detail or define the outer boundaries of the subject matter described in this disclosure.

[0013] In order to enable a more detailed understanding of the present disclosure, a more particular description may be made by reference to features of various embodiments, some of which are illustrated in the accompanying drawings. However, the accompanying drawings are merely illustrative of pertinent features of the present disclosure and should not be considered to be necessarily limiting, and other useful features may be permitted in the accompanying drawings used for explanation. This will be understood by those skilled in the art upon reading the present disclosure. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram illustrating an example of a communication system according to some embodiments. [Figure 2A] FIG. 2 is a block diagram illustrating example elements of an encoder component according to some embodiments. [Figure 2B] FIG. 2 is a block diagram illustrating example elements of a decoder component according to some embodiments. [Figure 3] FIG. 1 is a block diagram illustrating an example of a server system according to some embodiments. [Figure 4A] 1 illustrates an example coding tree structure according to some embodiments. [Figure 4B] 1 illustrates an example coding tree structure according to some embodiments. [Figure 4C] 1 illustrates an example coding tree structure according to some embodiments. [Figure 4D] 1 illustrates an example coding tree structure according to some embodiments. [Figure 5A]4 illustrates example motion samples used to derive model parameters for a block using motion prediction with local distortion, according to some embodiments. [Figure 5B] 10 illustrates motion vectors within a block using distortion expansion mode according to some embodiments. [Figure 5C] 1 illustrates a current block where two blocks are spatially neighbors, according to some embodiments. [Figure 5D] 1 illustrates a current block with four spatially neighboring blocks, according to some embodiments. [Figure 6] 1 is a flow diagram illustrating an example method for coding video according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0015] According to common practice, the various features illustrated in the figures are not necessarily drawn to scale and like reference numerals may be used to denote like features throughout the specification and figures.

[0016] This disclosure describes, among other things, when (for which blocks, as a specific example) to allow warped motion mode. Allowing warped motion mode (or warped Δ mode) and deriving the context for warped motion mode may require MVP candidates pointed to by an MVP index. However, if the parsing process requires MVP candidates pointed to by an MVP index, an entire MVP list (DRL list) needs to be constructed. Constructing the MVP list may significantly delay the parsing process. The methods and systems described in this application include determining when to allow warped motion mode and / or warped Δ mode without requiring the construction of an MVP list. For example, the determination may be based on one or more motion modes of one or more neighboring blocks.

[0017] System and Device Examples 1 is a block diagram illustrating a communication system 100 according to some embodiments. The communication system 100 includes a source device 102 and a plurality of electronic devices 120 (e.g., electronic devices 120-1 through 120-m) communicatively coupled to each other via one or more networks. In some embodiments, the communication system 100 is a streaming system, such as a streaming system used in conjunction with video-enabled applications, such as video conferencing applications, digital television applications, and media storage and / or distribution applications.

[0018] Source device 102 includes a video source 104 (e.g., a camera component or media storage) and an encoder component 106. In some embodiments, video source 104 is a digital camera (e.g., configured to create an uncompressed video sample stream). Encoder component 106 generates one or more encoded video bitstreams from the video stream. The video stream from video source 104 may be data-intensive compared to the encoded video bitstream 108 generated by encoder component 106. Because the encoded video bitstream 108 is data-intensive (less data) compared to the video stream from the video source, encoded video bitstream 108 requires less bandwidth to transmit and less storage space to store compared to the video stream from video source 104. In some embodiments, source device 102 does not include encoder component 106 (e.g., configured to transmit uncompressed video data to one or more networks 110).

[0019] The one or more networks 110 carry information between the source device 102, the server system 112, and / or the electronic device 120 and represent any number of networks, including, for example, wired (hardwired) and / or wireless communication networks. The one or more networks 110 may exchange data over circuit-switched and / or packet-switched channels. Exemplary networks include telecommunications networks, local area networks, wide area networks, and / or the Internet.

[0020] The one or more networks 110 include a server system 112 (e.g., a distributed / cloud computing system). In some embodiments, the server system 112 is or includes a streaming server (e.g., configured to store and / or distribute video content, such as an encoded video stream from the source device 102). The server system 112 includes a coder component 114 (e.g., configured to encode and / or decode video data). In some embodiments, the coder component 114 includes an encoder component and / or a decoder component. In various embodiments, the coder component 114 is instantiated as hardware, software, or a combination thereof. In some embodiments, the coder component 114 is configured to decode the encoded video bitstream 108 and re-encode the video data using various encoding standards and / or encoding methods to generate encoded video data 116. In some embodiments, the server system 112 is configured to generate multiple video formats and / or multiple video encodings from the encoded video bitstream 108.

[0021] In some embodiments, server system 112 functions as a Media-Aware Network Element (MANE). For example, server system 112 may be configured to prune encoded video bitstream 108 in order to tailor the potentially diverse bitstream to one or more of electronic devices 120. In some embodiments, a MANE separate from server system 112 is provided.

[0022] Electronic device 120-1 includes a decoder component 122 and a display 124. In some embodiments, decoder component 122 is configured to decode encoded video data 116 to generate an output video stream that can be rendered on a display or other type of rendering device. In some embodiments, one or more of electronic devices 120 do not include a display component (e.g., are communicatively coupled to an external display device and / or include media storage). In some embodiments, electronic device 120 is a streaming client. In some embodiments, electronic device 120 is configured to access server system 112 to obtain encoded video data 116.

[0023] The source device and / or the electronic devices 120 are sometimes referred to as “terminal devices” or “user devices.” In some embodiments, one or more of the source device 102 and / or the electronic devices 120 are instances of a server system, a personal computer, a portable device (e.g., a smartphone, tablet, or laptop), a wearable device, a videoconferencing device, and / or other types of electronic devices.

[0024] As an example of the operation of communication system 100, source device 102 transmits encoded video bitstream 108 to server system 112. For example, source device 102 may code a stream of pictures captured by the source device. Server system 112 may receive the encoded video bitstream 108 and decode and / or encode the encoded video bitstream 108 using coder component 114. For example, server system 112 may apply more optimal coding to the video data for network transmission and / or storage. Server system 112 may transmit encoded video data 116 (e.g., one or more coded video bitstreams) to one or more electronic devices 120. Each electronic device 120 may decode the encoded video data 116 to recover video pictures and display them accordingly.

[0025] In some embodiments, the transmission described above is a one-way data transmission. One-way data transmission is sometimes used, such as in media serving applications. In some embodiments, the transmission described above is a two-way data transmission. Two-way data transmission is sometimes used, such as in video conferencing applications. In some embodiments, the coded video bitstream 108 and / or coded video data 116 are encoded and / or decoded according to any of the video coding / compression standards described in this disclosure, such as HEVC, VVC, and / or AV1.

[0026] FIG. 2A is a block diagram illustrating example elements of an encoder component 106 according to some embodiments. The encoder component 106 receives a source video sequence from a video source 104. In some embodiments, the encoder component includes a receiver (e.g., transceiver) component configured to receive the source video sequence. In some embodiments, the encoder component 106 receives a video sequence from a video source at another location (e.g., a video source that is a component of a different device than the encoder component 106). The video source 104 can provide the source video sequence in the form of a digital video sample stream, which can be in any suitable bit depth (e.g., 8-bit, 10-bit, or 12-bit), any suitable color space (e.g., BT.601 Y CrCb or RGB), and any suitable sampling structure (e.g., Y CrCb 4:2:0 or Y CrCb 4:4:4). In some embodiments, the video source 104 is a storage device that stores pre-captured / prepared video. In some embodiments, the video source 104 is a camera that captures on-site image information as a video sequence. The video data may be provided as multiple individual pictures that, when viewed sequentially, achieve motion. The picture itself is organized as a spatial array of pixels, each of which may contain one or more samples depending on the sampling structure, color space, etc. used. The relationship between pixels and samples is readily understood by those skilled in the art. The following discussion will focus on samples.

[0027] The encoder component 106 is configured to code and / or compress pictures of a source video sequence into a coded video sequence 216 in real time, or subject to other time constraints necessitated by the application. Enforcing an appropriate coding rate is one of the functions of the controller 204. In some embodiments, the controller 204 controls and is operatively connected to other functionalities described below. Parameters set by the controller 204 may include rate control-related parameters (e.g., picture skip, quantizer, and / or λ value for rate-distortion optimization techniques), picture size, group of pictures (GOP) layout, maximum motion vector search range, etc. Those skilled in the art can readily identify other functions of the controller 204, such as those for the encoder component 106, that are optimized for a particular system design.

[0028] In some embodiments, the encoder component 106 is configured to operate in a coding loop. As a simplified example, the coding loop includes a source coder 202 (e.g., responsible for creating symbols, such as a symbol stream, based on an input picture to be coded and one or more reference pictures) and a decoder 210 (located here, not elsewhere). The decoder 210 reconstructs the symbols to create sample data, similar to a decoder (located elsewhere) (assuming the compression between the symbols and the coded video bitstream is lossless). The reconstructed sample stream (sample data) is input to a reference picture memory 208. Because decoding the symbol stream results in bit-accurate results regardless of the decoder's location (located here or elsewhere), the contents of the reference picture memory 208 are also bit-accurate compared to an encoder located here versus an encoder located elsewhere. In this way, the predictive portion of the encoder interprets the same sample values ​​as reference picture samples as if the decoder were to use prediction during decoding. The principles of such reference picture synchronicity (and the resulting drift when synchronicity cannot be maintained due to, for example, channel errors) are known to those skilled in the art.

[0029] The operation of decoder 210 may be the same as the operation of an in-place decoder, such as decoder component 122, described in detail below in conjunction with Figure 2B. However, somewhat with reference to Figure 2B, because symbols are valid and the decoding of symbols into an encoded / coded video sequence by entropy coder 214 and parser 254 may be lossless, the entropy decoding portion of decoder component 122, including buffer memory 252 and parser 254, may not be fully implemented in in-place decoder 210.

[0030] At this point, it can be said that any decoder technology other than parsing / entropy decoding present in a decoder must also necessarily be present in the corresponding encoder in substantially the same functional form. For this reason, the disclosed subject matter focuses on the operation of the decoder. The description of the encoder technology can be omitted, as it is the reverse of the decoder technology described overall. Only certain parts require more detailed description, which will be described below.

[0031] As part of its operation, source coder 202 may perform motion-compensated predictive coding, which involves coding an input frame by predicting with reference to one or more previously coded frames from the video sequence designated as reference frames. In this manner, coding engine 212 codes differences between pixel blocks of the input frame and pixel blocks of one or more reference frames that can be selected as one or more prediction references for the input frame. For example, controller 204 may manage the coding operations of source coder 202, including setting parameters and subgroup parameters used to encode the video data.

[0032] The decoder 210 decodes the coded video data of frames that can be designated as reference frames based on symbols created by the source coder 202. The operation of the coding engine 212 may be advantageously a lossy process. When the coded video data is decoded by some video decoder (not shown in FIG. 2A ), the reconstructed video sequence may be a copy of the source video sequence with some errors. The decoder 210 may repeat the decoding process that may be performed by a video decoder at another location on the reference frames, causing the reconstructed reference frames to be stored in the reference picture memory 208. In this manner, the encoder component 106 stores copies of reconstructed reference frames that have common content with the reconstructed reference frames that would be obtained by a video decoder at another location (without transmission errors).

[0033] The predictor 206 may perform a predictive search for the coding engine 212. That is, for a new frame to be coded, the predictor 206 may search the reference picture memory 208 to obtain sample data (as candidate reference pixel blocks) and specific metadata, such as reference picture motion vectors, block shapes, etc., that can serve as suitable predictive references for the new picture. The predictor 206 may operate by using one sample block per pixel block to detect suitable predictive references. In some examples, as determined by the search results obtained by the predictor 206, the input picture may include predictive references obtained from multiple reference pictures stored in the reference picture memory 208.

[0034] The output of all the above functional units may undergo entropy coding in entropy coder 214. Entropy coder 214 converts the symbols produced by the various functional units into a coded video sequence by losslessly compressing the symbols according to techniques known to those skilled in the art (e.g., Huffman coding, variable length coding and / or arithmetic coding).

[0035] In some embodiments, the output of the entropy coder 214 is coupled to a transmitter. The transmitter may be configured to buffer one or more coded video sequences created by the entropy coder 214 for transmission over a communication channel 218, and may be hardware / software coupled to a storage device that stores the coded video data. The transmitter may also be configured to integrate other data to be transmitted, such as coded audio data and / or ancillary data streams (sources not shown), with the coded video data obtained from the source coder 202. In some embodiments, the transmitter may transmit ancillary data along with the coded video. The source coder 202 may include such data as part of the coded video sequence. The ancillary data may comprise temporal / spatial / SNR enhancement layers, other forms of redundant data such as redundant pictures or slices, Supplementary Enhancement Information (SEI) messages, Visual Usability Information (VUI) parameter set fragments, etc.

[0036] The controller 204 may manage the operation of the encoder component 106. During coding, the controller 204 may assign a specific coded picture type to each coded picture, which may affect the coding technique applied to the respective picture. For example, a picture may be assigned as an Intra Picture (I-picture), a Predictive Picture (P-picture), or a Bi-directionally Predictive Picture (B-picture). An Intra Picture can be coded and decoded without using any other frames in the sequence as a basis for prediction. Some video codecs allow various types of intra pictures, including, for example, Independent Decoder Refresh (IDR) pictures. Those skilled in the art will recognize these variations of I-pictures and their corresponding applications and features, and therefore will not be repeated in this description. A Predictive Picture can be coded and decoded using intra prediction or inter prediction, using at most one motion vector and reference index to predict sample values ​​for each block. Bidirectionally predictive pictures use intra or inter prediction and can be coded and decoded using up to two motion vectors and reference indices to predict the sample values ​​of each block. Similarly, multiple-predictive pictures can use more than two reference pictures and associated metadata to reconstruct a block.

[0037] In general, a source picture can be spatially subdivided into multiple sample blocks (e.g., blocks of 4x4, 8x8, 4x8, or 16x16 samples each), and the blocks can be coded one by one. Blocks can be coded predictively with reference to other (already coded) blocks, as determined by the coding assignment applied to the picture corresponding to each block. For example, blocks of an I-picture can be coded without prediction, or with prediction with reference to previously coded blocks of the same picture (spatial prediction, or intra-prediction). Pixel blocks of a P-picture can be coded without prediction with spatial prediction or with temporal prediction with reference to one previously coded reference picture. Blocks of a B-picture can be coded without prediction with spatial prediction or with temporal prediction with reference to one or two previously coded reference pictures.

[0038] A video may be captured in time order as multiple source pictures (video pictures). Intra-picture prediction (often abbreviated as intra-prediction) exploits spatial correlation within a given picture, while inter-picture prediction exploits correlation (temporal or other) between pictures. In one example, a particular picture being coded / decoded, called the current picture, is divided into blocks. If a block in the current picture is similar to a reference block in a previously coded and still buffered reference picture in the video, the block in the current picture can be coded by a vector called a motion vector. The motion vector points toward the reference block in the reference picture and may have a third dimension to identify the reference picture when multiple reference pictures are used.

[0039] Encoder component 106 may perform coding operations according to a pre-defined video coding technique or standard, such as any of those described in this disclosure. In doing so, encoder component 106 may perform various compression operations, including predictive coding operations that exploit temporal and spatial redundancy in the input video sequence. Thus, the coded video data may conform to a syntax defined by the video coding technique or standard being used.

[0040] 2B is a block diagram illustrating example elements of a decoder component 122 according to some embodiments. The decoder component 122 of FIG. 2B is coupled to a channel 218 and a display 124. In some embodiments, the decoder component 122 includes a transmitter coupled to a loop filter unit 256 and configured to transmit data to the display 124 (e.g., via a wired or wireless connection).

[0041] In some embodiments, decoder component 122 includes a receiver coupled to channel 218 and configured to receive data from channel 218 (e.g., via a wired or wireless connection). The receiver may be configured to receive one or more coded video sequences that are decoded by decoder component 122. In some embodiments, the decoding of each coded video sequence is independent of the other coded video sequences. Each coded video sequence may be received from channel 218, which may be hardware / software coupled to a storage device that stores the coded video data. The receiver may receive the coded video data along with other data, such as coded audio data and / or ancillary data streams, and may forward the other data to a corresponding destination (not shown). The receiver may separate the coded video sequence from the other data. In some embodiments, the receiver receives ancillary (redundant) data along with the coded video. The ancillary data may be included as part of the coded video sequence. The ancillary data may be used by decoder component 122 to decode the data and / or more accurately reconstruct the original video data. For example, the side data may take the form of a temporal, spatial or SNR enhancement layer, a redundant slice, a redundant picture, a forward error correction code, and the like.

[0042] According to some embodiments, decoder component 122 includes a buffer memory 252, a parser 254 (sometimes referred to as an entropy decoder), a scaler / inverse transform unit 258, an intra-picture predictor 262, a motion compensated predictor 260, an aggregator 268, a loop filter unit 256, a reference picture memory 266, and a current picture memory 264. In some embodiments, decoder component 122 is implemented as an integrated circuit, a series of integrated circuits, and / or other electronic circuitry. In some embodiments, decoder component 122 is implemented at least partially in software.

[0043] A buffer memory 252 is connected between the channel 218 and the parser 254 (e.g., to account for network jitter). In some embodiments, the buffer memory 252 is separate from the decoder component 122. In some embodiments, a separate buffer memory is provided between the output of the channel 218 and the decoder component 122. In some embodiments, in addition to the buffer memory 252 within the decoder component 122 (e.g., configured to handle playout timing), a separate buffer memory is provided outside the decoder component 122 (e.g., to account for network jitter). When receiving data from a store-and-forward device or an isochronous network with sufficient bandwidth and controllability, the buffer memory 252 may not be required, or the buffer memory 252 may be small. When used with a best-effort packet network such as the Internet, the buffer memory 252 may be required, and may be relatively large and advantageously an optimally sized memory, and may be implemented at least in part by an operating system or similar element (not shown) outside the decoder component 122.

[0044] Parser 254 is configured to reconstruct symbols 270 from the coded video sequence. The symbols may include, for example, information used to manage the operation of decoder component 122 and / or information for controlling a rendering device such as display 124. The control information for one or more rendering devices may take the form of, for example, Supplementary Enhancement Information (SEI) messages or Video Usability Information (VUI) parameter set fragments (not shown). Parser 254 parses (entropy decodes) the coded video sequence. The coding of the coded video sequence may conform to video coding techniques and standards and may follow principles well known to those skilled in the art, including variable length coding, Huffman coding, context-sensitive or non-context-sensitive arithmetic coding, etc. Parser 254 may extract from the coded video sequence a set of subgroup parameters for at least one subgroup of pixels present in the video decoder based on at least one parameter corresponding to the group. The subgroups may include a Group of Pictures (GOP), a picture, a tile, a slice, a macroblock, a Coding Unit (CU), a block, a Transform Unit (TU), a Prediction Unit (PU), etc. Parser 254 may also extract information from the coded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, etc.

[0045] The reconstruction of symbols 270 may involve multiple different parts depending on the type of coded video picture or part thereof (e.g., inter-picture and intra-picture, inter-block and intra-block) and other factors. Which parts are involved and how they are involved may be controlled by part group control information parsed from the coded video sequence by parser 254. For clarity, the flow of such part group control information between parser 254 and multiple parts described below is not shown.

[0046] Further to the functional blocks already described, decoder component 122 may be conceptually subdivided into a number of functional sections, as described below. In an actual implementation operating within commercial constraints, many of these sections may interact closely with one another and may be at least partially integrated with one another. However, for purposes of describing the disclosed subject matter, the conceptual subdivision into functional sections described below will remain.

[0047] The scaler / inverse transform unit 258 receives the quantized transform coefficients and control information (such as the transform used, block size, quantization factor, and / or quantization scaling matrix) as one or more symbols 270 from the parser 254. The scaler / inverse transform unit 258 can output blocks containing sample values ​​that can be input to the aggregater 268.

[0048] In some examples, the output samples of the scaler / inverse transform unit 258 are suitable for intra-coded blocks, i.e., blocks that do not use predictive information from a previously reconstructed picture but can use predictive information from a previously reconstructed portion of the current picture. Such predictive information can be provided by the intra prediction unit 262, which may generate blocks of the same size and shape as the block being reconstructed using surrounding already reconstructed information obtained from the current (partially reconstructed) picture obtained from the current picture memory 264. The aggregator 268 may add, for each sample, the predictive information generated by the intra prediction unit 262 to the output sample information provided by the scaler / inverse transform unit 258.

[0049] In other examples, the output samples of the scaler / inverse transform unit 258 are suitable for inter-coded blocks, and possibly motion-compensated blocks. In such examples, the motion-compensated predictor 260 may access the reference picture memory 266 to obtain samples used for prediction. The obtained samples may be motion-compensated according to symbols 270 related to the block, and then added to the output of the scaler / inverse transform unit 258 (referred to as residual samples or residual signals in this example) by an aggregator 268 to generate output sample information. The addresses in the reference picture memory 266 from which the motion-compensated predictor 260 obtains prediction samples may be controlled by motion vectors. The motion vectors may be available to the motion-compensated predictor 260 in the form of symbols 270, which may have, for example, X, Y, and reference picture components. Motion compensation may also include interpolation of sample values ​​obtained from the reference picture memory 266 when sub-sample accurate motion vectors are used, motion vector prediction mechanisms, etc.

[0050] The output samples of the aggregator 268 may be subjected to various loop filtering techniques in the loop filter unit 256. The video compression techniques may include in-loop filtering techniques that are controlled by parameters included in the coded video bitstream and made available to the loop filter unit 256 as symbols 270 from the parser 254, but may also correspond to meta-information obtained when decoding previous (decoding order) portions of the coded picture or coded video sequence, and may also correspond to previously reconstructed loop-filtered sample values.

[0051] The output of the loop filter unit 256 can be a sample stream that can be output to a drawing device such as the display 124, as well as stored in a reference picture memory 266 for use in later inter-picture prediction.

[0052] Some coded pictures, once fully reconstructed, can be used as reference pictures for later prediction. Once a coded picture is fully reconstructed and the coded picture is identified as a reference picture (e.g., by parser 254), the current reference picture can become part of reference picture memory 266, and a new current picture memory can be reallocated before starting reconstruction of the next coded picture.

[0053] Decoder component 122 may perform decoding operations according to a predetermined video compression technique, which may be described in a document of a standard, such as any of those described in this disclosure. A coded video sequence is said to comply with the syntax defined by the video compression technique or standard used in the sense that the coded video sequence adheres to the syntax of the video compression technique or standard as defined in the video compression technique document or standard, and in particular as defined in its profile document. Compliance with some video compression techniques or standards also means that the complexity of the coded video sequence is within the limits defined by the level of the video compression technique or standard. In some examples, the level imposes limits on the maximum picture size, maximum frame rate, maximum reconstruction sample rate (e.g., measured in millions of samples per second), maximum reference picture size, etc. The limits imposed by the level may, in some examples, be further restricted by a Hypothetical Reference Decoder (HRD) specification and metadata for HRD buffer management signaled in the coded video sequence.

[0054] 3 is a block diagram illustrating a server system 112 according to some embodiments. The server system 112 includes a control circuit 302, one or more network interfaces 304, a memory 314, a user interface 306, and one or more communication buses 312 interconnecting these components. In some embodiments, the control circuit 302 includes one or more processors (e.g., a CPU, a GPU, and / or a DPU). In some embodiments, the control circuit includes one or more field programmable gate arrays (FPGAs), hardware accelerators, and / or one or more integrated circuits (e.g., application specific integrated circuits).

[0055] One or more network interfaces 304 may be configured to interface with one or more communications networks (e.g., wireless, wired, and / or optical networks). The communications networks may be local networks, wide area networks, metropolitan networks, vehicular networks, industrial networks, real-time networks, delay-tolerant networks, etc. Examples of communications networks include local area networks such as Ethernet, cellular networks (including WLAN, GSM, 3G, 4G, 5G, LTE, etc.), television wired or wireless wide area digital networks (including cable television, satellite television, and terrestrial broadcast television), vehicular and industrial networks (including CANBus), etc. Such communications may be unidirectional, receive-only (e.g., television broadcast), unidirectional transmit-only (e.g., from a CANbus to a specific CANbus device), or bidirectional (e.g., communications to another computer system using a local or wide area digital network). Such communications may include communications to one or more cloud computing networks.

[0056] The user interface 306 includes one or more output devices 308 and / or one or more input devices 310. The one or more input devices 310 may include one or more of a keyboard, a mouse, a trackpad, a touch screen, a data glove, a joystick, a microphone, a scanner, a camera, etc. The one or more output devices 308 may include one or more of an audio output device (e.g., a speaker), a visual output device (e.g., a display or monitor), etc.

[0057] Memory 314 may include high-speed random-access memory (such as DRAM, SRAM, DDR RAM, and / or other random-access solid-state memory devices) and / or non-volatile memory (such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, and / or other non-volatile solid-state storage devices). Alternatively, memory 314 includes one or more storage devices located remotely from control circuitry 302. Memory 314 includes a non-transitory computer-readable storage medium, or alternatively, a non-volatile solid-state memory device in memory 314 includes the non-transitory computer-readable storage medium. In some embodiments, memory 314, or the non-transitory computer-readable storage medium of memory 314, stores the following programs, modules, instructions, and data structures, or a subset or superset thereof: • an operating system 316 that handles various basic system services and includes procedures for performing hardware-dependent tasks; a network communications module 318 used to connect the server system 112 to other computing devices via one or more network interfaces 304 (e.g., via wired and / or wireless connections); A coding module 320 for performing various functions related to encoding and / or decoding data, such as video data. In some embodiments, the coding module 320 is an instance of the coder component 114. The coding module 320 may include, but is not limited to, one or more of the following: A decoding module 322 that performs various functions related to decoding the encoded data, such as those described above with respect to the decoder component 122. An encoding module 340 that performs various functions related to encoding data, such as those described above with respect to the encoder component 106. A picture memory 352 that stores pictures and picture data and is used, for example, with the coding module 320. In some embodiments, the picture memory 352 includes one or more of the reference picture memory 208, the buffer memory 252, the current picture memory 264, and the reference picture memory 266.

[0058] In some embodiments, the decoding module 322 includes a parsing module 324 (e.g., configured to perform various functions described above with respect to the parser 254), a transform module 326 (e.g., configured to perform various functions described above with respect to the scalar / inverse transform unit 258), a prediction module 328 (e.g., configured to perform various functions described above with respect to the motion compensation prediction unit 260 and / or the intra-picture prediction unit 262), and a filter module 330 (e.g., configured to perform various functions described above with respect to the loop filter unit 256).

[0059] In some embodiments, the encoding module 340 includes a code module 342 (e.g., configured to perform various functions described above with respect to the source coder 202, the coding engine 212, and / or the entropy coder 214) and a prediction module 344 (e.g., configured to perform various functions described above with respect to the predictor 206). In some embodiments, the decoding module 322 and / or the encoding module 340 include a subset of the modules shown in Figure 3. For example, a prediction module shared by both the decoding module 322 and the encoding module 340 is used.

[0060] Each of the above-identified modules stored in memory 314 corresponds to an instruction set for performing functions described in this disclosure. The above-identified modules (e.g., instruction sets) need not be implemented as separate software programs, procedures, or modules; thus, various subsets of these modules may be combined or otherwise rearranged in various embodiments. For example, coding module 320 may suitably not include separate decoding and encoding modules, but rather use the same set of modules that perform both sets of functions. In some embodiments, memory 314 stores a subset of the above-identified modules and data structures. In some embodiments, memory 314 stores additional modules and data structures not described above, such as an audio processing module.

[0061] In some embodiments, server system 112 includes web servers, Hypertext Transfer Protocol (HTTP) servers, File Transfer Protocol (FTP) servers, and web pages and applications implemented using Common Gateway Interface (CGI) scripts, PHP Hyper-text Preprocessor (PHP), Active Server Pages (ASP), HyperText Markup Language (HTML), Extensible Markup Language (XML), Java, JavaScript, Asynchronous JavaScript and XML (AJAX), XHP, Javelin, Wireless Universal Resource File (WURFL), etc.

[0062] While Figure 3 illustrates a server system 112 according to some embodiments, Figure 3 is intended more as a functional description of various features that may be present in one or more server systems than as a structural overview of the embodiments described in this disclosure. In practice, those skilled in the art will recognize that items shown separately can be combined and some items can be separated. For example, some items shown separately in Figure 3 can be implemented on a single server, and some items can be implemented on more than one server. The actual number of servers used to implement server system 112 and how functionality is allocated among the servers will vary from implementation to implementation and will otherwise depend in part on the amount of data traffic the server system handles during peak and average usage periods.

[0063] Example Coding Approach 4A-4D show example coding tree structures according to some embodiments. As shown in the first coding tree structure (400) in FIG. 4A, some coding schemes (e.g., VP9) use a four-way partitioning tree starting at the 64x64 level and going down to the 4x4 level, with some additional restrictions on 8x8 blocks. In FIG. 4A, the partitioning portion, designated R, is recursive in that the same partitioning tree is repeated at lower scales until the lowest 4x4 level is reached.

[0064] As shown in the second coding tree structure (402) of FIG. 4B, some coding techniques (e.g., AV1) expand the partition tree to a 10-way structure, increasing the maximum size (e.g., referred to as a superblock in the VP9 or AV1 nomenclature) starting at 128x128. The second coding tree structure includes a 4:1 or 1:4 rectangular partition not found in the first coding tree structure. The partition type with three subdivisions in the second level of FIG. 4B is called a T-type partition. The rectangular partition in this tree structure cannot be further subdivided. In addition to the coding block size, a coding tree depth can be defined, indicating the depth of the partition from the root node. For example, the coding tree depth of the root node (e.g., 128x128) is set to 0, and the coding tree depth increases by 1 after the tree block is further partitioned.

[0065] For example, instead of forcing a fixed size transform unit like VP9, ​​AV1 allows a luma coding block to be split into transform units of multiple sizes. This split can be expressed by a recursive split down a maximum of two levels. To incorporate AV1's extended coding block split, transform sizes from 4x4 to 64x64 square, 2:1 or 1:2, and 4:1 or 1:4 are supported. For chroma blocks, only the largest possible transform unit is allowed.

[0066] For example, a quadtree structure, represented like a coding tree, may be used to divide CTUs into CUs by adapting to various local characteristics, as in HEVC. In some embodiments, the decision of whether to code a picture area using inter-picture (temporal) prediction or intra-picture (spatial) prediction is made at the CU level. Each CU may be further divided into one PU, two PUs, or four PUs according to the PU partition type. The same prediction process is applied within a PU, and related information is sent to the decoder on a PU-by-PU basis. After obtaining a residual block by applying a prediction process based on the PU partition type, the CU may be divided into TUs according to another quadtree structure similar to the quadtree structure of the CU's coding tree. One important feature of the HEVC structure is that there are multiple partitioning concepts, including CUs, PUs, and TUs. In HEVC, a CU or TU can only be square, while a PU can be either square or rectangular in the case of an inter-predicted block. In HEVC, a coding block may be further divided into four square small blocks, and a transform is performed on each small block (TU). Each TU can be recursively further divided (using quadtree partitioning) into smaller TUs, which are called residual quadtrees (RQTs). At picture boundaries, such as in HEVC, implicit quadtree partitioning may be used so that blocks continue to be quadtree partitioned until their size aligns with the picture boundary.

[0067] A quadtree with nested multi-type trees, such as those found in VVC, using binary and ternary tree segmentation structures, can replace the concept of multiple types of partitioning units with another concept, thereby removing the barrier between the concepts of CU, PU, ​​and TU when, for example, the concepts are not necessary for CUs whose size is too large for the maximum transform length, and supporting greater flexibility in the partitioning shape of CUs. In the coding tree structure, CUs can have either square or rectangular shapes. ACTUs are first partitioned using a four-element tree (also called a quadtree) structure. The leaf nodes of the four-element tree can be further partitioned using a multi-type tree structure. As shown in the third coding tree structure (404) in Figure 4C, the multi-type tree structure includes four partition types. For example, the multi-type tree structure includes a vertical binary division (SPLIT_BT_VER), a horizontal binary division (SPLIT_BT_HOR), a vertical third division (SPLIT_TT_VER), and a horizontal third division (SPLIT_TT_HOR). The leaf nodes of the multi-type tree are called CUs, and this segmentation is used for prediction and transformation processes without any further division, unless the CU is too large for the maximum transform length. This means that in most cases, the CU, PU, ​​and TU have the same block size in a quadtree with a nested multi-type tree coding block structure. An exception occurs when the maximum supported transform length is smaller than the width or height of the color components of the CU. An example of the block division of one CTU (406) is shown in Figure 4D, which shows an example of a quadtree with a nested multi-type tree coding block structure.

[0068] The maximum supported luma transform size may be 64x64, and the maximum supported chroma transform size may be 32x32 as in VVC. If the width or height of the CB is larger than the maximum transform width or maximum transform height, the CB is automatically split horizontally and / or vertically to meet the transform size limitation in that direction.

[0069] The coding tree scheme supports a feature similar to VTM7, where luma and chroma have separate block tree structures. In some cases, for P and B slices, the luma CTB and chroma CTB in one CTU share the same coding tree structure. In contrast, for I slices, luma and chroma can have separate block tree structures. When the separate block tree mode is applied, the luma CTB is divided into CUs by one coding tree structure, and the chroma CTB is divided into chroma CUs by another coding tree structure. This means that a CU in an I slice may contain or consist of a coding block for the luma component or coding blocks for two chroma components, and a CU in a P or B slice may always contain or consist of coding blocks for all three color components, except when the video is monochrome.

[0070] To support extended coding block partitioning, multiple transform sizes (e.g., from 4 points to 64 points in each dimension) and transform shapes (e.g., square, or rectangle with width / height ratios of 2:1 or 1:2, and 4:1 or 1:4) may be used, as in AV1.

[0071] In some embodiments, for each coding block of an interframe, if the mode of the current block is an inter-coding mode rather than a skip mode, a separate flag is signaled to indicate whether a single reference mode or a mixed reference mode is used for the current block. In the single reference mode, a predictive block may be generated by one motion vector. In the mixed reference mode, a predictive block is generated by a weighted average of two predictive blocks derived from two motion vectors. The modes that can be signaled in the single reference case are detailed in Table 1 below.

[0072] [Table 1]

[0073] The modes that can be signaled in case of mixed references are detailed in Table 2 below.

[0074] [Table 2]

[0075] Some standards, such as AV1, allow for a motion vector precision (or accuracy) of 1 / 8 pixel. Syntax may be used to signal the motion vector differential in reference frame list 0 (L0) or reference frame list 1 (L1) as follows: For example, the syntax mv_joint specifies which components of the motion vector differential are non-zero. A syntax mv_joint value of 0 indicates the absence of non-zero MVD along either the horizontal or vertical direction; a value of 1 indicates the presence of non-zero MVD along only the horizontal direction; a value of 2 indicates the presence of non-zero MVD along only the vertical direction; and a value of 3 indicates the presence of non-zero MVD along both the horizontal and vertical directions. The syntax mv_sign indicates whether the motion vector differential is positive or negative. The syntax mv_class indicates the class of the motion vector differential. As shown in Table 3 below, a higher class indicates a larger magnitude of the motion vector differential. The syntax mv_bit specifies the integer part of the offset between the motion vector differential and the magnitude of the beginning of each MV class. The syntax mv_fr indicates the first two fractional bits of the motion vector differential. The syntax mv_hp indicates the third fractional bit of the motion vector differential.

[0076] [Table 3]

[0077] For NEW_NEARMV and NEAR_NEWMV modes (shown in Table 2 above), the MVD precision depends on the associated class and the MVD size. For example, fractional MVDs are only allowed if the MVD size is one pixel or less. In addition, only one MVD value is allowed if the associated MV class value is MV_CLASS_1 or greater, and the MVD value for each MV class is derived as 4, 8, 16, 32, or 64 for MV class 1 (MV_CLASS_1), 2 (MV_CLASS_2), 3 (MV_CLASS_3), 4 (MV_CLASS_4), or 5 (MV_CLASS_5). The allowed MVD values ​​for each MV class are shown in Table 6 below.

[0078] [Table 4]

[0079] In some embodiments, one context is used to signal mv_joint or mv_class if the current block is coded using NEW_NEARMV or NEAR_NEWMV mode, and another context is used to signal mv_joint or mv_class if the current block is not coded using NEW_NEARMV or NEAR_NEWMV mode.

[0080] An inter-coding mode JOINT_NEWMV may be applied, which indicates whether the MVDs of two reference lists are jointly signaled. When the inter-prediction mode is equivalent to the JOINT_NEWMV mode, the MVDs of reference L0 and reference L1 are jointly signaled. Therefore, only one MVD (referred to as joint_mvd) may be signaled to the decoder, and the ΔMVs of reference L0 and reference L1 may be derived from joint_mvd. The JOINT_NEWMV mode is signaled together with the NEAR_NEARMV mode, NEAR_NEWMV mode, NEW_NEARMV mode, NEW_NEWMV mode, and GLOBAL_GLOBALMV mode.

[0081] When JOINT_NEWMV mode is signaled and the picture order count (POC) distances between two reference frames and the current frame are different, the size of the MVD of reference L0 or reference L1 is changed based on the POC distance. For example, the distance between reference frame L0 and the current frame is denoted as td0, and the distance between reference frame L1 and the current frame is denoted as td1. If td0 is greater than or equal to td1, joint_mvd is directly used for reference L0, and the mvd of reference L1 is derived from joint_mvd according to the following Equation 1:

number

number

[0082] The inter-coding mode AMVDMV may be added to the single reference example. When the AMVDMV mode is selected, this indicates that adaptive MVD resolution (AMVD) is applied to the signal MVD. A flag, e.g., amvd_flag, may be added in the JOINT_NEWMV mode to indicate whether AMVD is applied to the joint MVD coding mode. When adaptive MVD resolution is applied to the joint MVD coding mode (referred to as joint AMVD coding), the MVDs of two reference frames are signaled together, and the precision of the MVD is implicitly determined by the MVD size. The MVDs of two (or more) reference frames are signaled together, and MVD coding is applied.

[0083] AMVR, as originally proposed in CWG-C012, supports a total of seven MV precisions (8, 4, 2, 1, 1 / 2, 1 / 4, 1 / 8). For each prediction block, the AVM encoder explores all supported precision values ​​and signals the highest precision to the decoder. To reduce encoder runtime, two precision sets are supported. Each precision set contains four default precisions. The precision set is adaptively selected at the frame level based on the maximum precision value for the frame. Similar to AV1, the maximum precision is signaled in the frame header. Table 5 summarizes the supported precision values ​​based on the frame-level maximum precision.

[0084] [Table 5]

[0085] In the AV1-like AOM Video Model (AVM), there is a frame-level flag that indicates whether the MV of a frame has a precision of 1 pixel or less. AMVR is valid only if the value of the cur_frame_force_integer_mv flag is 0. In AMVR, if the block precision is less than the maximum precision, the motion model and interpolation filter are not signaled. If the block precision is less than the maximum precision, the motion mode is inferred as translational motion and the interpolation filter is inferred as a regular interpolation filter. Similarly, if the block precision is either 4 pixels or 8 pixels, the inter-intra mode is not signaled and is inferred as 0.

[0086] Motion compensation usually assumes a translational motion model between the reference block and the target block, whereas an affine motion model is used for distorted motion. The affine motion model can be expressed by Equation 3 below:

number

[0087] In global distortion motion compensation, global motion information is signaled for each inter-reference frame, and the global motion information includes a global motion type and some motion parameters. The global motion types and the number of associated parameters are shown in Table 6.

[0088] [Table 6]

[0089] After signaling the reference frame index, if global motion is selected, the global motion type and parameters associated with the given reference frame are used for the current coding block.

[0090] In local warped motion compensation, local warped motion is allowed for inter-coded blocks if the following conditions are met: First, the current block must use single reference prediction; the coding block must have a width or height of 8 or more; and finally, at least one of the adjacent neighboring blocks must use the same reference frame as the current block.

[0091] When localized distorted motion is used for the current block, the affine model parameters are estimated by minimizing the mean square of the difference between the reference and modeled mappings based on the MVs of the current block and its adjacent neighboring blocks. To estimate the localized distorted motion parameters, if the neighboring blocks use the same reference frame as the current block, a pair of mapping samples is obtained between the center sample in the neighboring block and the corresponding sample in the reference frame. Then, three additional samples are created by shifting the center position by 1 / 4 sample in one or both dimensions. These additional samples can also be considered as a pair of mapping samples to ensure the stability of the model parameter estimation process.

[0092] The MVs of neighboring blocks used to derive the motion parameters are called motion samples. The motion samples are selected from neighboring blocks that use the same reference frame as the current block. Note that the distorted motion prediction mode is only valid for blocks that use a single reference frame.

[0093] 5A shows an example of motion samples used to derive model parameters for a block using motion prediction with local distortion, according to some embodiments. As shown in FIG. 5A, the motion vectors of neighboring blocks B0, B1, and B2 are referred to as MV0, MV1, and MV2, respectively. A current block is predicted using uni-prediction with reference frame Ref0. For example, neighboring block B0 is predicted using hybrid prediction with reference frames Ref0 and Ref1, neighboring block B1 is predicted using uni-prediction with reference frame Ref0, and neighboring block B2 is predicted using hybrid prediction with reference frames Ref0 and Ref2. The motion vector MV0 of B0 is Ref0 , B1 MV1 Ref0 and B2 MV2 Ref0 may be used as the motion sample for deriving the affine motion parameters of the current block.

[0094] In addition to translational motion, AVM also supports warped motion compensation. Two types of warped motion models are supported: global warping model and local warping model. For example, the global warping model is associated with each reference frame, and each of the four non-translation parameters is coded with 12-bit precision, and the translation motion vector is coded with 15-bit precision. A coding block may choose to use it directly (in the case of the reference frame index). The global warping model captures frame-level scaling and rotation. Thus, the global warping model originally focuses on rigid motion across a frame. A coding block-level local warping model is also supported. In the local warping mode (also known as WARPED_CAUSAL), the warping parameters of the current block are derived by fitting the model to nearby motion vectors using the least-squares method.

[0095] In the warped motion mode WARP_EXTEND, the motion of neighboring blocks is smoothly extended into the current block while using some warp parameter modifications. This allows complex warped motion to be represented across multiple blocks while minimizing block artifacts. To achieve this, the WARP_EXTEND mode applied to the NEWMV block constructs a new warp model based on two constraints: the per-pixel motion vectors generated by the new warp model must be contiguous with the per-pixel motion vectors of neighboring blocks, and the central pixel of the current block must have a per-pixel motion vector that matches the signaled motion vector of the entire block. Figure 5B illustrates intrablock motion vectors using the warp extension mode according to some embodiments. For example, if the neighboring block to the left of the current block is a warped block, as shown in Figure 5B, a model that fits the motion vectors shown in Figure 5B is used as the warp model.

[0096] The two constraints for constructing the new distortion model suggest some equations involving the distortion parameters of the neighboring blocks and the current block. Once suggested, these equations can be solved to calculate the distortion model of the current block. For example, if the distortion models of the neighboring blocks are expressed as (A,...,F) and the new distortion model is expressed as (A',...,F'), the first constraint at each point along the common edge is as follows:

number

[0097] Note that the y values ​​of the points along the edge are different, but the x values ​​of all points are the same, i.e. the y coefficients must be the same for both (e.g. B'=B and D'=D), while the x coefficients give us an equation for the other coefficients, as defined in Equation 5 below. B'=B D'=D A'x+E'=Ax+E C'x+F'=Cx+F Equation 5 - Coefficient of x for distortion modeling In Equation 5, x is the horizontal position of a vertical column of pixels and is therefore effectively a constant.

[0098] The second constraint stipulates that the motion vector at the center of the block must be equal to the one signaled using the NEWMV mechanism. This results in two more equations, resulting in a system of six equations in six variables with a unique solution. These equations can be solved efficiently in both software and hardware. The solution can be solved using basic addition, subtraction, multiplication, and division by powers of two. Therefore, the complexity of this mode is less than that of the local distortion mode using least squares.

[0099] Note that there may be multiple neighboring blocks from which to extend. Therefore, there must be a method to select which block to extend from. A similar problem is faced in motion vector prediction. Specifically, there may be several possible motion vectors derived from nearby blocks, and one will be selected as the basis for NEWMV coding. The solution to this problem can be extended to accommodate the requirements of WARP_EXTEND. This is done by tracking the origin of each motion vector prediction. WARP_EXTEND is then enabled only if the selected motion vector prediction comes from the nearest block. This block is then used as the only "neighboring block" for the rest of the algorithm.

[0100] Note that the warp model of the neighboring block may be very good as is, and no further modification is necessary. To make this cheap to code, WARP_EXTEND can be used for the NEARMV block. The selection of the neighboring block is the same as for NEWMV, except that the selection in NEWMV requires that the neighboring block is a warped block (not simply translated by a translation motion). However, if this is the case and WARP_EXTEND is selected, the warp model parameters of the neighboring block are copied to the current block.

[0101] In some embodiments, the motion mode WARP_DELTA may be used. In this mode, the distortion model of a block is coded as a Δ derived from a predicted distortion model, similar to how motion vectors are coded as a Δ derived from a predicted motion vector. The prediction may be derived either from a global motion model (if present) or from neighboring blocks.

[0102] Constraints may be applied to avoid coding the same predicted distortion model in multiple ways. For example, when the mode is NEARMV or NEWMV, the same neighborhood selection logic as described for WARP_EXTEND is used. If this results in a neighboring block being distorted, the model of that neighboring block (without the rest of the WARP_EXTEND logic being applied) is used as the prediction. Otherwise, the global distortion model is used as the base. Other constraints may also be applied. This example is not intended to limit the scope of the embodiments. Then, Δ for each of the non-translation parameters may be coded. Finally, the translation part of the model is adjusted so that the pixel-wise motion vector of the block's center matches the overall motion vector of the block.

[0103] This tool (WARP_DELTA) uses more bits to encode than the other warp modes because it involves explicitly coding the delta for each warp parameter. Therefore, WARP_DELTA can be disabled for blocks smaller than 16x16. However, the decoding logic is very simple, and therefore it can represent complex motion that cannot be represented by the other warp modes.

[0104] FIG. 5C illustrates a current block with two spatially neighboring blocks, according to some embodiments. FIG. 5D illustrates a current block with four spatially neighboring blocks, according to some embodiments. In some embodiments, the distortion expansion mode is not always allowed at the syntax level. To check whether the distortion expansion mode is allowed for the current block, a dynamic reference list (MVP) list may need to be constructed. The MVP candidate indicated by the MVP index is checked. For example, the candidate may be denoted as S. In this example, the position of S is checked, and if S does not come from the upper left spatially neighboring block (block 2 in FIG. 5C) or the upper left spatially neighboring block (block 1 in FIG. 5C), distortion expansion is not allowed. Otherwise (if S is located at 1 or 2), the mode (current block) is checked. If the current block is NEWMV, distortion expansion is allowed; otherwise (for example, if the current block is NEARMV), the motion mode of S is checked. If S is a distortion (eg, normal distortion, magnification distortion, or Δ distortion), then distortion magnification is allowed; otherwise, distortion magnification is not allowed.

[0105] Similar to the warp extension mode, in some embodiments, the warp Δ mode is also not always allowed. The allowance of the warp Δ mode also depends on the MVP candidate. For example, the MVP candidate (S) pointed to by the MVP index is checked. If the current block uses NEWMV, the warp Δ mode is allowed. Otherwise, if the current block uses NEWMV, it is determined whether S comes from a spatially neighboring block (e.g., it is determined that S does not come from TMPV, scaled SMVP, or Ref MV bank, etc.). In this example, if S is spatial and S is a warp mode (e.g., normal warp, extension warp, or Δ warp), the warp Δ mode is allowed; otherwise, the warp Δ mode is not allowed.

[0106] In some embodiments, two contexts are required to code and / or parse the warp extension mode. For example, the first context is derived based on the motion mode of the MVP candidate (S) pointed to by the MVP index. If the mode of the current block is NEWMV, the first context is equal to 0. If the current block is NEWMV and S is a warp mode, the first context is equal to 1. If the current block is NEWMV and S is a global motion, the first context is equal to 2. If the current block is NEWMV and S is a translation motion, the first context is equal to 3. As an example, the second context depends on the boundary size of the current block adjacent to S.

[0107] The allowance of the distortion expansion mode and distortion delta mode, and the context derivation of the distortion expansion mode, each require MVP candidates pointed to by MVP indexes. This approach significantly delays the parsing process due to the need to construct the entire MVP list (DRL list) in the parsing process.

[0108] 6 is a flow diagram illustrating a method 600 for decoding video according to some embodiments. Method 600 may be performed in a computing system (e.g., server system 112, source device 102, or electronic device 120) having control circuitry and memory for storing instructions executed by the control circuitry. In some embodiments, method 600 is performed by executing instructions stored in a memory (e.g., memory 314) of the computing system. As used in this disclosure, the term block may be interpreted as a prediction block, a coding block, or a coding unit (CU).

[0109] The system obtains video data including a plurality of blocks (602). For each block of the plurality of blocks, the system parses the encoded video data (604) without reconstructing the entire motion vector predictor (MVP) list. The system makes a first determination (606) to determine whether warped motion compensation is allowed for the block and whether warped motion compensation is enabled for a first spatial neighbor. Based on the first determination, the system determines (608) whether to perform warped motion compensation for the block during a subsequent reconstruction operation. The system designates (610) the block for a warp magnification operation or a warp delta operation according to the determination to perform warped motion compensation for the block during a subsequent reconstruction operation.

[0110] In some embodiments, warp magnification mode or warp delta mode is allowed when normal warp mode is allowed (eg, there is no need to build an MVP list during the parsing stage).

[0111] In some embodiments, whether the warp extension mode or warp Δ mode is allowed depends on the availability and mode or motion mode of spatially neighboring blocks and the mode of the current block. In some embodiments, the number of neighboring blocks to be scanned and the locations of the neighboring blocks are predetermined. In one example, spatially neighboring blocks are scanned, and the warp extension mode or warp Δ mode is allowed if one or more of the neighboring blocks are available and located in the same tile as the current block. In another example, spatially neighboring blocks are scanned, and the warp extension mode or warp Δ mode is allowed if one or more of the neighboring blocks are available, located in the same tile as the current block, and in an inter mode (e.g., a mode other than intra mode). In another example, spatially neighboring blocks are scanned, and the warp extension mode or warp Δ mode is allowed if one or more of the neighboring blocks are available, located in the same tile as the current block, coded in an inter mode (e.g., a mode other than intra mode), and in a warp mode. In another example, spatially neighboring blocks are scanned, and the current block mode is further checked if one or more neighboring blocks are available, located in the same tile as the current block, and coded in inter mode (e.g., a mode other than intra mode). If the current block is in NEWMV mode, the warp extension mode or warp Δ mode is allowed; otherwise, if the current block is in NEWMV mode and one of the spatially neighboring blocks is in warp mode, the warp extension mode or warp Δ mode of the current block is allowed. In another example, if the current block is in NEWMV mode, the warp extension mode or warp Δ mode is allowed; otherwise, the availability of spatially neighboring blocks is checked as described in the above example. In another example, whether the warp extension mode is allowed and whether warp Δ is allowed are determined by two different processes.In another example, scanning for neighboring blocks involves only two neighboring blocks above and to the left of the current block, i.e., only the spatially neighboring blocks located at (-1,0) and (0,-1) as shown in Figure 5C. In another example, scanning for neighboring blocks involves only four neighboring blocks above and to the left of the current block, i.e., only the spatially neighboring blocks located at (-1,0), (0,-1), (height -1,-1), and (-1, width -1) as shown in Figure 5D. In another example, when scanning for neighboring blocks, the positions of the neighboring blocks may depend on the block shape and / or aspect ratio and / or block size.

[0112] In some embodiments, one context is used during coding / parsing of distortion expansion mode. In some embodiments, this context is derived depending on the block size. For example, there are a total of 22 possible block sizes, with contexts ranging from 0 to 21.

[0113] In some embodiments, one context is used when coding / parsing the warp extension mode. In some embodiments, the context depends on the state and / or mode of spatially neighboring blocks. In some embodiments, the number of neighboring blocks scanned and the scanning order are predetermined. In one example, the context depends on the number of neighboring blocks using a warp mode. In another example, the context depends on the number of neighboring blocks using global motion. In another example, the context depends on the number of neighboring blocks using translation motion. In another example, the context depends on the number of neighboring blocks using a warp mode, global motion, and / or translation motion that have the same reference picture as the current block and use warp mode, global motion, and / or translation motion. In another example, two or more contexts are used when coding and / or parsing the warp extension mode. In some embodiments, a particular context depends on the state and / or mode of a spatially neighboring block (e.g., block 2 in FIG. 5C ) at a predetermined location. In another example, as shown in FIG. 5C , a first context is derived from the state of block 1. For example, if the current block uses NEAR MVS mode, the context value is equal to 0. If block 1 is not available, is not in the same tile, is not coded using inter mode, or does not have the same reference frame as the current block, the context value is equal to 1. If block 1 uses warp mode, the context value is equal to 2. If block 1 uses global motion, the context value is equal to 3. If block 1 uses translation motion, the context value is equal to 4. In some embodiments, the same rules apply to the second context value derived based on the state of block 2.

[0114] 6 depicts some logical steps in a particular order, the order of non-order-dependent steps may be changed, and other steps may be combined or eliminated. Some reordering and other groupings not specifically mentioned will be apparent to those skilled in the art, and thus the ordering and grouping depicted in this disclosure is not intended to be limiting. Furthermore, it should be understood that the various steps may be implemented in hardware, firmware, software, or any combination thereof.

[0115] As described above, the present system needs to track the MVP list (DRL list) to obtain candidates to determine whether a distortion expansion / distortion Δ mode is allowed for a given block. Information from the MVP list is also required for any derivation of context. The need to build an MVP list during the parsing process slows the parsing process and / or requires more computational resources. The embodiments described in this disclosure include methods and processes for determining whether a distortion expansion / distortion Δ is allowed for a given block without needing to build an MVP list.

[0116] Attention is now directed to several embodiments.

[0117] (A1) In one aspect, some embodiments include a method of decoding video (e.g., method 600). In some embodiments, the method is performed by a computing system (e.g., server system 112) having memory and control circuitry. In some embodiments, the method is performed by a coding module (e.g., coding module 320). In some embodiments, the method is performed by a parser (e.g., parser 254). The method includes: (i) obtaining coded video data comprising a plurality of blocks; (ii) parsing the coded video data for each block of the plurality of blocks without reconstructing an entire motion vector predictor (MVP) list; (iii) making a first determination to determine whether warped motion compensation is allowed for the block and whether warped motion compensation is enabled for a first spatial neighboring block; (iv) determining whether to perform warped motion compensation on the block during a subsequent reconstruction operation based on the first determination; and (v) designating the block for a warp extension operation or a warp delta operation according to the determination to perform warped motion compensation on the block during a subsequent reconstruction operation.

[0118] In some embodiments, the method includes: (i) obtaining encoded video data comprising a plurality of blocks; and (ii) parsing the encoded video data, the parsing comprising, for each block of the plurality of blocks, (a) determining whether to perform warped motion compensation on the block during a subsequent reconstruction operation; and (b) designating the block in accordance with the determination, the designating including: (1) designating the block for a warp extension operation or a warp Δ operation in accordance with a determination that warp motion compensation is allowed for the block; or (2) designating the block for a warp extension operation or a warp Δ operation in accordance with a determination that warp motion compensation is enabled for a block that is a first spatial neighbor.

[0119] (A2) In some embodiments of A1, the designating step further includes the step of designating the block for a warp magnification operation or a warp Δ operation in accordance with a determination that warp motion compensation is not allowed for the block and is not allowed for a block that is a first spatial neighbor.

[0120] (A3) In some embodiments of A1 or A2, the parsing step does not include identifying motion vector predictor (MVP) candidates or constructing an MVP index. An MVP index is sometimes referred to as a dynamic reference list (DRL) index. An MVP candidate block is a candidate block pointed to by an MVP index.

[0121] (A4) In some embodiments of any of A1 to A3, the warp magnification operation includes magnifying the motion of neighboring blocks.

[0122] (A5) In some embodiments of A4, amplifying the motion of neighboring blocks includes modifying one or more motion parameters.

[0123] (A6) In some embodiments of any of A1 to A5, the warp Δ operation includes applying Δ to the predicted warp model.

[0124] (A7) In some embodiments of A6, the predicted distortion model is a spatially neighboring block distortion model or a global distortion model.

[0125] (A8) In some embodiments of any of A1 to A7, determining whether to perform warped motion compensation for the block includes scanning one or more spatially neighboring blocks, including the first spatially neighboring block.

[0126] (A9) In some embodiments of A8, the one or more spatially neighboring blocks are scanned in an order based on one or more characteristics of the blocks and / or one or more characteristics of the one or more spatially neighboring blocks, for example, the characteristics include block size, aspect ratio, and / or block shape.

[0127] (A10) In some embodiments of A8 or A9, the one or more spatially neighboring blocks are scanned in a predetermined order. For example, the top-most neighboring block to the left of the block is analyzed first, followed by the left-most neighboring block above the block. As another example, the bottom-most neighboring block to the left of the block is analyzed first, followed by the right-most neighboring block above the block, followed by the top-most neighboring block to the left of the block, followed by the left-most neighboring block above the block.

[0128] (A11) In some embodiments of A10, scanning one or more spatially neighboring blocks includes scanning up to a predetermined number of spatially neighboring blocks. In some embodiments, the predetermined number of spatially neighboring blocks is a subset of all spatially neighboring blocks of the block.

[0129] (A12) In some embodiments of any of A1-A11, determining whether to perform warped motion compensation for the block includes identifying whether the block is designated for nearby motion vector (NEARMV) mode or new motion vector (NEWMV) mode.

[0130] (A13) In some embodiments of A12, the designating step further includes designating the block for a warp magnification operation or a warp delta operation in accordance with a determination that the block is designated for a NEWMV mode. In some embodiments, the designating step further includes designating the block as ineligible for a warp magnification operation or a warp delta operation in accordance with a determination that the block is designated for a NEWMV mode.

[0131] (A14) In some embodiments of A12 or A13, the designating step further includes designating the block for a warp up-scale operation or a warp Δ operation in accordance with determining that the block is designated for NEAR MVS mode and determining that motion compensation with warp is enabled for the spatially neighboring blocks. In some embodiments, the designating step further includes designating the block as ineligible for a warp up-scale operation or a warp Δ operation in accordance with determining that the block is designated for NEAR MVS mode and determining that motion compensation with warp is not enabled for each spatially neighboring block in the predetermined set of spatially neighboring blocks.

[0132] (A15) In some embodiments of any of A1 to A14, the designating step further includes designating the block for the warp magnification operation or the warp delta operation in accordance with a determination that the spatially neighboring blocks are available and that the spatially neighboring blocks are in the same tile as the block. In some embodiments, the designating step further includes designating the block as ineligible for the warp magnification operation or the warp delta operation in accordance with a determination that each spatially neighboring block in the predetermined set of spatially neighboring blocks is not available or is not in the same tile as the block.

[0133] (A16) In some embodiments of any of A1-A15, the designating step further includes designating the block for a warp magnification operation or a warp Δ operation in accordance with a determination that the spatial neighbor blocks are available, a determination that the spatial neighbor blocks are in the same tile as the block, and a determination that the spatial neighbor blocks are designated as inter-coded. In some embodiments, the designating step further includes designating the block as ineligible for a warp magnification operation or a warp Δ operation in accordance with a determination that each spatial neighbor block in the predetermined set of spatial neighbor blocks is designated as intra-coded.

[0134] (A17) In some embodiments of any of A1 to A16, the designating step further includes designating the block for a warp magnification or warp Δ operation in accordance with a determination that the spatial neighbor blocks are available, a determination that the spatial neighbor blocks are in the same tile as the block, a determination that the spatial neighbor blocks are designated as intercoded, and a determination that warp motion compensation is enabled for the spatial neighbor blocks. In some embodiments, the designating step further includes designating the block as ineligible for a warp magnification or warp Δ operation in accordance with a determination that warp motion compensation is not enabled (disabled) for each spatial neighbor block in the predetermined set of spatial neighbor blocks.

[0135] (A18) In some embodiments of any of A1 to A17, the designating step further includes (i) designating the block for a warp magnification or warp Δ operation in accordance with a determination that the block is designated for a new motion vector mode, or (ii) designating the block for a warp magnification or warp Δ operation in accordance with a determination that the block is designated for a nearby motion vector mode and a determination that spatially neighboring blocks are available. In some embodiments, the designating step further includes designating the block as ineligible for a warp magnification or warp Δ operation in accordance with a determination that the block is designated for a nearby motion vector mode and a determination that each spatially neighboring block in the predetermined set of spatially neighboring blocks is unavailable or is not in the same tile as the block.

[0136] (A19) In some embodiments of any of A1 to A18, the parsing step further comprises determining a block distortion magnification context for a block of the plurality of blocks.

[0137] (A20) In some embodiments of A19, the distortion magnification context is determined based on the block size of the block.

[0138] (A21) In some embodiments of A19 or A20, the distortion magnification context is determined based on a scan of one or more spatially neighboring blocks. In some embodiments, the scan of the one or more spatially neighboring blocks includes scanning up to a predetermined number of spatially neighboring blocks in a predetermined order.

[0139] (A22) In some embodiments of any of A19 to A21, the warp expansion context is determined based on the number of blocks that are spatially neighbors designated for warped motion compensation.

[0140] (A23) In some embodiments of any of A19 to A22, the distortion expansion context is determined based on the number of spatially neighboring blocks that use global motion (e.g., spatially neighboring blocks that are specified to use a global motion model).

[0141] (A24) In some embodiments of any of A19 to A23, the distortion expansion context is determined based on the number of blocks that are spatially neighbors that use translational motion (e.g., blocks that are spatially neighbors that are specified to use a translational motion model).

[0142] (A25) In some embodiments of any of A19 to A23, the warp expansion context is determined based on the number of spatially neighboring blocks that have the same reference picture as the block and use one of the warp modes, global motion or translation motion.

[0143] (A26) In some embodiments of any of A19 to A25, the distortion magnification context is determined based on the state and / or mode of a block that is a predetermined spatial neighbor. In some embodiments, the block that is a predetermined spatial neighbor is a left-most neighbor block above the block (e.g., block 2 in FIG. 5C ). In some embodiments, the block that is a predetermined spatial neighbor is a top-most neighbor block to the left of the block (e.g., block 1 in FIG. 5C ).

[0144] (A27) In some embodiments of any of A19 to A26, the distortion magnification context includes a first context determined based on blocks that are first spatially neighbors and a second context determined based on blocks that are second spatially neighbors.

[0145] (A28) In some embodiments of any of A19 to A27, (i) a first value is assigned to the warp magnification context in accordance with a determination that the block is designated for a nearby motion vector mode; (ii) a second value is assigned to the warp magnification context in accordance with a determination that the predetermined spatial neighboring block is not available, is not in the same tile as the block, is not designated as intercoded, or does not have the same reference frame as the block; (iii) a third value is assigned to the warp magnification context in accordance with a determination that the predetermined spatial neighboring block uses global motion; (iv) a fourth value is assigned to the warp magnification context in accordance with a determination that the predetermined spatial neighboring block uses global motion; and (v) a fifth value is assigned to the warp magnification context in accordance with a determination that the predetermined spatial neighboring block uses translation motion.

[0146] The methods described in this disclosure may be used individually or combined in any order. Each of the methods may be performed by processing circuitry (e.g., one or more processors or one or more integrated circuits). In some embodiments, the processing circuitry executes a program stored on a non-transitory computer-readable medium.

[0147] In another aspect, some embodiments include a computing system (e.g., server system 112) including control circuitry (e.g., control circuitry 302) and memory (e.g., memory 314) coupled to the control circuitry, wherein the memory stores one or more instruction sets configured to be executed by the control circuitry, the one or more instruction sets including instructions for performing any of the methods described in this disclosure (e.g., A1-A28 above).

[0148] In yet another aspect, some embodiments include a non-transitory computer-readable storage medium storing one or more instruction sets for execution by control circuitry of a computing system, the one or more instruction sets including instructions for performing any of the methods described herein (e.g., A1-A28 above).

[0149] Although the terms "first," "second," etc. may be used in this disclosure to describe various elements, it is understood that these elements are not necessarily limited by these terms; they are merely used to distinguish one element from another.

[0150] The terms used in this disclosure are for the purpose of describing particular embodiments only and are not intended to impose limitations on the claims. When used in the description of embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It is also understood that the term "and / or," as used in this disclosure, refers to and includes any and all possible combinations of one or more of the associated listed items. It is further understood that the terms "comprises" and / or "comprising," as used herein, indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0151] As used in this disclosure, the term "if" can be interpreted to mean "when" a stated precondition is true, "when" a stated precondition is true, "in response to determining" that a stated precondition is true, "according to determining" that a stated precondition is true, or "in response to detecting" that a stated precondition is true, depending on the context. Similarly, the phrase "if it is determined that [a stated precondition is true]" or "if [a stated precondition is true]" or "when [a stated precondition is true]" can be interpreted to mean "upon determining" that a stated precondition is true, or "in response to determining" that a stated precondition is true, or "upon determining" that a stated precondition is true, or "upon detecting" that a stated precondition is true, or "in response to detecting" that a stated precondition is true, depending on the context.

[0152] The foregoing description has been provided for illustrative purposes with respect to specific embodiments. However, the above illustrative description is not intended to be exhaustive or to limit the disclosed claims to the precise form consistent with the present invention. Many modifications and variations are possible in light of the above teachings. The embodiments have been chosen and described to best explain the principles of operation and practical applications so that others skilled in the art can understand them. [Explanation of symbols]

[0153] 1 block 2 blocks 3 blocks 4 blocks 100 Communication Systems 102 Source Devices 104 Video Sources 106 Encoder Components 108 Video Bitstream 110 Network 112 Server System 114 Coda Constituents 116 Video Data 120 Electronic Devices 122 Decoder Components 124 display 202 Source Coder 204 Controller 206 Predictor 208 Reference Picture Memory 210 decoder 212 Coding Engine 214 Entropy Coder 216 video sequences 218 Communication Channels 252 buffer memory 254 Parser 256 Loop filter section 258 Inverse Conversion Unit 260 Compensation Prediction Unit 262 Intra-picture prediction unit 264 Current Picture Memory 266 Reference Picture Memory 268 Collector 270 symbols 302 Control circuit 304 Network Interface 306 User Interface 308 Output Devices 310 Input Devices 312 communication bus 314 memory 316 Operating Systems 318 Network Communication Module 320 Coding Module 322 Decryption Module 324 Perspective Module 326 Conversion Module 328 Prediction Module 330 Filter Module 340 Encoding Module 342 Code Module 344 Prediction Module 352 Picture Memory 600 ways B0 Block B1 Block B2 Block

Claims

1. 1. A method of decoding video executed on a computing system having a memory and one or more processors, comprising: obtaining encoded video data comprising a plurality of blocks; parsing the coded video data for each block of the plurality of blocks without reconstructing an entire motion vector predictor (MVP) list; making a first determination of whether the block is allowed for motion compensation with warp and whether motion compensation with warp is enabled for blocks that are in a first spatial neighborhood; determining whether to perform warped motion compensation for the block during a subsequent reconstruction operation based on the first determination; designating the block for a warp magnification operation or a warp delta operation in accordance with a determination that warp motion compensation will be performed on the block during the subsequent reconstruction operation; A method comprising:

2. The method of claim 1 , wherein the parsing step does not include identifying motion vector predictor candidates or constructing an MVP index.

3. 2. The method of claim 1, wherein determining whether to perform warped motion compensation for the block comprises scanning one or more spatially neighboring blocks, including the first spatially neighboring block.

4. 4. The method of claim 3, wherein the one or more spatially neighboring blocks are scanned in an order based on one or more characteristics of the block and / or one or more characteristics of the one or more spatially neighboring blocks.

5. The method of claim 3 , wherein the one or more spatially neighboring blocks are scanned in a predetermined order.

6. 6. The method of claim 5, wherein scanning one or more spatially neighboring blocks comprises scanning up to a predetermined number of spatially neighboring blocks.

7. 2. The method of claim 1, wherein determining whether to perform warped motion compensation for the block comprises identifying whether the block is designated for a nearby motion vector (NEARMV) mode or a new motion vector (NEWMV) mode.

8. 8. The method of claim 7, wherein the designating step further comprises designating the block for a warp magnification operation or a warp delta operation in accordance with determining that the block is designated for the NEWMV mode.

9. The step of specifying determining that the block is designated for the NEARMV mode; determining that warped motion compensation is enabled for blocks that are spatially neighbors; The method of claim 7 , further comprising designating the block for a warp magnification or warp delta operation according to:

10. The step of specifying determining that a block is available that is a spatial neighbor; determining that the spatially neighboring blocks are in the same tile as the block; The method of claim 1 , further comprising designating the block for a warp magnification or warp delta operation according to:

11. The step of specifying determining that a block is available that is a spatial neighbor; determining that the spatially neighboring blocks are in the same tile as the block; determining that the blocks that are spatial neighbors are designated as being inter-coded; The method of claim 1 , further comprising designating the block for a warp magnification or warp delta operation according to:

12. The step of specifying determining that a block is available that is a spatial neighbor; determining that the spatially neighboring blocks are in the same tile as the block; determining that the spatially neighboring blocks are designated as being inter-coded; determining that warped motion compensation is enabled for the spatially neighboring blocks; The method of claim 1 , further comprising designating the block for a warp magnification or warp delta operation according to:

13. The step of specifying designating the block for a warp magnification operation or a warp delta operation in accordance with determining that the block is designated for a new motion vector mode; or designating the block for a warp magnification operation or a warp delta operation in accordance with determining that the block is designated for a nearby motion vector mode and determining that a block that is a spatial neighbor is available. The method of claim 1 further comprising:

14. The method of claim 1 , wherein the parsing step further comprises determining, for a block of the plurality of blocks, a distortion magnification context for the block.

15. a control circuit; Memory and one or more sets of instructions stored in the memory and configured to be executed by the control circuitry, instructions for obtaining encoded video data comprising a plurality of blocks; instructions for parsing the encoded video data for each block of the plurality of blocks without rebuilding an entire motion vector predictor (MVP) list; instructions for making a first determination of whether motion compensation with warp is allowed for the block and whether motion compensation with warp is enabled for blocks that are in a first spatial neighborhood; instructions for determining, based on the first determination, whether to perform warped motion compensation for the block during a subsequent reconstruction operation; instructions for designating the block for a warp magnification operation or a warp delta operation in accordance with a determination that warp motion compensation will be performed on the block during the subsequent reconstruction operation; one or more instruction sets comprising: A computing system comprising:

16. The computing system of claim 15 , wherein the warp magnification operation comprises magnifying motion of neighboring blocks.

17. 16. The computing system of claim 15, wherein determining whether to perform warped motion compensation for the block comprises scanning one or more spatially neighboring blocks, including the first spatially neighboring block.

18. 1. A non-transitory computer-readable storage medium storing one or more sets of instructions configured to be executed by a computing device having control circuitry and memory, the one or more sets of instructions comprising: instructions for obtaining encoded video data comprising a plurality of blocks; instructions for parsing the encoded video data for each block of the plurality of blocks without rebuilding an entire motion vector predictor (MVP) list; instructions for making a first determination of whether motion compensation with warp is allowed for the block and whether motion compensation with warp is enabled for blocks that are in a first spatial neighborhood; instructions for determining, based on the first determination, whether to perform warped motion compensation for the block during a subsequent reconstruction operation; instructions for designating the block for a warp magnification operation or a warp delta operation in accordance with a determination that warp motion compensation will be performed on the block during the subsequent reconstruction operation; 1. A non-transitory computer-readable storage medium comprising:

19. 20. The non-transitory computer-readable storage medium of claim 18, wherein the warp magnification operation comprises magnifying motion of neighboring blocks.

20. 20. The non-transitory computer-readable storage medium of claim 18, wherein determining whether to perform warped motion compensation for the block comprises scanning one or more spatially neighboring blocks, including the first spatially neighboring block.

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