Patent Application
20250024044
The present disclosure describes aspects generally related to video coding.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Image/video compression can help transmit image/video data across different devices, storage and networks with minimal quality degradation. In some examples, video codec technology can compress video based on spatial and temporal redundancy. In an example, a video codec can use techniques referred to as intra prediction that can compress an image based on spatial redundancy. For example, the intra prediction can use reference data from the current picture under reconstruction for sample prediction. In another example, a video codec can use techniques referred to as inter prediction that can compress an image based on temporal redundancy. For example, the inter prediction can predict samples in a current picture from a previously reconstructed picture with motion compensation. The motion compensation can be indicated by a motion vector (MV).
Aspects of the disclosure include bitstreams, methods, and apparatuses for video encoding/decoding. In some examples, an apparatus for video encoding/decoding includes processing circuitry.
Some aspects of the disclosure provide a method of video decoding. The method includes receiving a coded video bitstream that includes first coded information of a current block in a current picture. The first coded information indicates an inter prediction of the current block based on a reference block in a reference picture for the current block, and a potential application of a formular based inter prediction technique on the inter prediction of the current block. The formular based inter prediction technique generates a prediction sample of the current block based on a formular with one or more reconstructed samples in the reference block being input to the formular, the formular includes one or more parameters derived based on a current template of the current block and a reference template of the reference block. The method also includes determining first formular based inter prediction information for the potential application of the formular based inter prediction technique on the current block based on at least one of the first coded information of the current block and second coded information of a second block that is reconstructed before the current block. The first formular based inter prediction information includes at least one of a first control flag for the potential application, a first template type for deriving the one or more parameters, and a first formular type of the formular. The method also includes when the first control flag is true, applying the formular based inter prediction technique on the current block to generate at least a reconstructed sample of the current block.
According to an aspect of the disclosure, when the second coded information of the second block indicates that a second control flag of the second block for indicating the formular based inter prediction technique being applied on the second block is true, the method includes determining the first control flag of the current block based on a comparison of a value of the one or more parameters with a threshold value. In some examples, the method includes deriving the one or more parameters based on the current template of the current block and the reference template of the reference picture, determining that the first control flag is false when at least a first derived parameter value of a first parameter in the one or more parameters is larger than an upper threshold value of a first range for the first parameter or smaller than a lower threshold value of the first range for the first parameter, and determining that the first control flag is true when derived parameter values of the one or more parameters are within respective ranges of the one or more parameters.
In some examples, the method includes deriving the one or more parameters based on the current template of the current block and the reference template of the reference picture, determining that the first control flag is false when each of derived parameter values of the one or more parameters is larger than an upper threshold value of an associated range or smaller than a lower threshold value of the associated range, and determining that the first control flag is true when at least one of the derived parameter values of the one or more parameters is within the associated range.
In an example, the threshold value is a constant value. In another example, the threshold value is decoded from at least one of a sequence header, a slice header, a picture header, and a frame header in the coded video bitstream. In another example, the threshold value is determined based on at least one of a quantization parameter of the current block, a block size of current block, a shape of the current block, a temporal distance between the current block and the reference block.
In some embodiments, the method includes determining the first template type according to a default template type associated with a shape of the current block.
In some examples, the default template type is an above and left template type when the shape of the current block is a square, and an above template and a left template are available.
In some examples, the default template type is a left template type when the shape of the current block is a rectangle, a ratio of a height to a width of the current block is larger than a predefined threshold value and a left template is available.
In some examples, the default template type is an above template type when the shape of the current block is a rectangle, a ratio of a width to a height of the current block is larger than a predefined threshold value and an above template is available.
In some embodiments, the method includes determining the first template type according to a second template type of the second block when a second control flag of the second block is true. In an example, the method includes determining that the first template type of the current block is of a same type as the second template type of the second block when the first control flag of the current block is determined to be a same flag as the second control flag of the second block.
In some embodiments, the method includes determining that the first control flag of the current block is of a same flag as a second control flag of the second block regardless whether the second block uses the reference picture for inter prediction.
In some embodiments, the method includes storing the first formular based inter prediction information for the formular based inter prediction technique that has been applied on the current block in association with the current block, and reconstructing at least a third block in the current picture based on the first formular based inter prediction information.
In some examples, the first formular based inter prediction information comprises at least one of the first control flag of the current block, the first template type of the current block, the first formular type of the current block; and/or a transform type for residual data of the formular based inter prediction technique.
In some embodiments, the first formular based inter prediction information is stored in a unit of m×n samples, m and n are positive integer numbers.
Some aspects of the disclosure provide a method of video encoding. The method includes determining first formular based inter prediction information of a first prediction candidate using a formular based inter prediction technique on a current block in a current picture based on at least one of first coded information of the current block and second coded information of a second block that is coded before the current block. The formular based inter prediction technique generates a prediction sample of the current block based on a formular with one or more reconstructed samples of a reference block in a reference picture being input to the formular, the formular includes one or more parameters derived based on a current template of the current block and a reference template of the reference block, the first formular based inter prediction information includes at least one of a first control flag for the first prediction candidate, a first template type for deriving the one or more parameters, and a first formular type of the formular. When the first control flag is true, the method includes applying the formular based inter prediction technique on the current block to generate the first prediction candidate of the current block; and encoding the current block based on the first prediction candidate.
Aspects of the disclosure also provide an apparatus for video encoding or video decoding. The apparatus for video encoding/decoder including processing circuitry configured to implement any of the described methods for video encoding or video decoding.
Aspects of the disclosure also provide a non-transitory computer-readable medium storing instructions which, when executed by a computer, cause the computer to perform any of the described methods for video decoding/encoding.
Further features, the nature, and various advantages of the disclosed subject matter will be more apparent from the following detailed description and the accompanying drawings in which:
The video processing system (100) includes a capture subsystem (113), that can include a video source (101), for example a digital camera, creating for example a stream of video pictures (102) that are uncompressed. In an example, the stream of video pictures (102) includes samples that are taken by the digital camera. The stream of video pictures (102), depicted as a bold line to emphasize a high data volume when compared to encoded video data (104) (or coded video bitstreams), can be processed by an electronic device (120) that includes a video encoder (103) coupled to the video source (101). The video encoder (103) can include hardware, software, or a combination thereof to enable or implement aspects of the disclosed subject matter as described in more detail below. The encoded video data (104) (or encoded video bitstream), depicted as a thin line to emphasize the lower data volume when compared to the stream of video pictures (102), can be stored on a streaming server (105) for future use. One or more streaming client subsystems, such as client subsystems (106) and (108) in
It is noted that the electronic devices (120) and (130) can include other components (not shown). For example, the electronic device (120) can include a video decoder (not shown) and the electronic device (130) can include a video encoder (not shown) as well.
The receiver (231) may receive one or more coded video sequences, included in a bitstream for example, to be decoded by the video decoder (210). In an aspect, one coded video sequence is received at a time, where the decoding of each coded video sequence is independent from the decoding of other coded video sequences. The coded video sequence may be received from a channel (201), which may be a hardware/software link to a storage device which stores the encoded video data. The receiver (231) may receive the encoded video data with other data, for example, coded audio data and/or ancillary data streams, that may be forwarded to their respective using entities (not depicted). The receiver (231) may separate the coded video sequence from the other data. To combat network jitter, a buffer memory (215) may be coupled in between the receiver (231) and an entropy decoder/parser (220) (“parser (220)” henceforth). In certain applications, the buffer memory (215) is part of the video decoder (210). In others, it can be outside of the video decoder (210) (not depicted). In still others, there can be a buffer memory (not depicted) outside of the video decoder (210), for example to combat network jitter, and in addition another buffer memory (215) inside the video decoder (210), for example to handle playout timing. When the receiver (231) is receiving data from a store/forward device of sufficient bandwidth and controllability, or from an isosynchronous network, the buffer memory (215) may not be needed, or can be small. For use on best effort packet networks such as the Internet, the buffer memory (215) may be required, can be comparatively large and can be advantageously of adaptive size, and may at least partially be implemented in an operating system or similar elements (not depicted) outside of the video decoder (210).
The video decoder (210) may include the parser (220) to reconstruct symbols (221) from the coded video sequence. Categories of those symbols include information used to manage operation of the video decoder (210), and potentially information to control a rendering device such as a render device (212) (e.g., a display screen) that is not an integral part of the electronic device (230) but can be coupled to the electronic device (230), as shown in
The parser (220) may perform an entropy decoding/parsing operation on the video sequence received from the buffer memory (215), so as to create symbols (221).
Reconstruction of the symbols (221) can involve multiple different units depending on the type of the coded video picture or parts thereof (such as: inter and intra picture, inter and intra block), and other factors. Which units are involved, and how, can be controlled by subgroup control information parsed from the coded video sequence by the parser (220). The flow of such subgroup control information between the parser (220) and the multiple units below is not depicted for clarity.
Beyond the functional blocks already mentioned, the video decoder (210) can be conceptually subdivided into a number of functional units as described below. In a practical implementation operating under commercial constraints, many of these units interact closely with each other and can, at least partly, be integrated into each other. However, for the purpose of describing the disclosed subject matter, the conceptual subdivision into the functional units below is appropriate.
A first unit is the scaler/inverse transform unit (251). The scaler/inverse transform unit (251) receives a quantized transform coefficient as well as control information, including which transform to use, block size, quantization factor, quantization scaling matrices, etc. as symbol(s) (221) from the parser (220). The scaler/inverse transform unit (251) can output blocks comprising sample values, that can be input into aggregator (255).
In some cases, the output samples of the scaler/inverse transform unit (251) can pertain to an intra coded block. The intra coded block is a block that is not using predictive information from previously reconstructed pictures, but can use predictive information from previously reconstructed parts of the current picture. Such predictive information can be provided by an intra picture prediction unit (252). In some cases, the intra picture prediction unit (252) generates a block of the same size and shape of the block under reconstruction, using surrounding already reconstructed information fetched from the current picture buffer (258). The current picture buffer (258) buffers, for example, partly reconstructed current picture and/or fully reconstructed current picture. The aggregator (255), in some cases, adds, on a per sample basis, the prediction information the intra prediction unit (252) has generated to the output sample information as provided by the scaler/inverse transform unit (251).
In other cases, the output samples of the scaler/inverse transform unit (251) can pertain to an inter coded, and potentially motion compensated, block. In such a case, a motion compensation prediction unit (253) can access reference picture memory (257) to fetch samples used for prediction. After motion compensating the fetched samples in accordance with the symbols (221) pertaining to the block, these samples can be added by the aggregator (255) to the output of the scaler/inverse transform unit (251) (in this case called the residual samples or residual signal) so as to generate output sample information. The addresses within the reference picture memory (257) from where the motion compensation prediction unit (253) fetches prediction samples can be controlled by motion vectors, available to the motion compensation prediction unit (253) in the form of symbols (221) that can have, for example X, Y, and reference picture components. Motion compensation also can include interpolation of sample values as fetched from the reference picture memory (257) when sub-sample exact motion vectors are in use, motion vector prediction mechanisms, and so forth.
The output samples of the aggregator (255) can be subject to various loop filtering techniques in the loop filter unit (256). Video compression technologies can include in-loop filter technologies that are controlled by parameters included in the coded video sequence (also referred to as coded video bitstream) and made available to the loop filter unit (256) as symbols (221) from the parser (220). Video compression can also be responsive to meta-information obtained during the decoding of previous (in decoding order) parts of the coded picture or coded video sequence, as well as responsive to previously reconstructed and loop-filtered sample values.
The output of the loop filter unit (256) can be a sample stream that can be output to the render device (212) as well as stored in the reference picture memory (257) for use in future inter-picture prediction.
Certain coded pictures, once fully reconstructed, can be used as reference pictures for future prediction. For example, once a coded picture corresponding to a current picture is fully reconstructed and the coded picture has been identified as a reference picture (by, for example, the parser (220)), the current picture buffer (258) can become a part of the reference picture memory (257), and a fresh current picture buffer can be reallocated before commencing the reconstruction of the following coded picture.
The video decoder (210) may perform decoding operations according to a predetermined video compression technology or a standard, such as ITU-T Rec. H.265. The coded video sequence may conform to a syntax specified by the video compression technology or standard being used, in the sense that the coded video sequence adheres to both the syntax of the video compression technology or standard and the profiles as documented in the video compression technology or standard. Specifically, a profile can select certain tools as the only tools available for use under that profile from all the tools available in the video compression technology or standard. Also necessary for compliance can be that the complexity of the coded video sequence is within bounds as defined by the level of the video compression technology or standard. In some cases, levels restrict the maximum picture size, maximum frame rate, maximum reconstruction sample rate (measured in, for example megasamples per second), maximum reference picture size, and so on. Limits set by levels can, in some cases, be further restricted through Hypothetical Reference Decoder (HRD) specifications and metadata for HRD buffer management signaled in the coded video sequence.
In an aspect, the receiver (231) may receive additional (redundant) data with the encoded video. The additional data may be included as part of the coded video sequence(s). The additional data may be used by the video decoder (210) to properly decode the data and/or to more accurately reconstruct the original video data. Additional data can be in the form of, for example, temporal, spatial, or signal noise ratio (SNR) enhancement layers, redundant slices, redundant pictures, forward error correction codes, and so on.
The video encoder (303) may receive video samples from a video source (301) (that is not part of the electronic device (320) in the
The video source (301) may provide the source video sequence to be coded by the video encoder (303) in the form of a digital video sample stream that can be of any suitable bit depth (for example: 8 bit, 10 bit, 12 bit, . . . ), any colorspace (for example, BT.601 Y CrCB, RGB, . . . ), and any suitable sampling structure (for example Y CrCb 4:2:0, Y CrCb 4:4:4). In a media serving system, the video source (301) may be a storage device storing previously prepared video. In a videoconferencing system, the video source (301) may be a camera that captures local image information as a video sequence. Video data may be provided as a plurality of individual pictures that impart motion when viewed in sequence. The pictures themselves may be organized as a spatial array of pixels, wherein each pixel can comprise one or more samples depending on the sampling structure, color space, etc. in use. The description below focuses on samples.
According to an aspect, the video encoder (303) may code and compress the pictures of the source video sequence into a coded video sequence (343) in real time or under any other time constraints as required. Enforcing appropriate coding speed is one function of a controller (350). In some aspects, the controller (350) controls other functional units as described below and is functionally coupled to the other functional units. The coupling is not depicted for clarity. Parameters set by the controller (350) can include rate control related parameters (picture skip, quantizer, lambda value of rate-distortion optimization techniques, . . . ), picture size, group of pictures (GOP) layout, maximum motion vector search range, and so forth. The controller (350) can be configured to have other suitable functions that pertain to the video encoder (303) optimized for a certain system design.
In some aspects, the video encoder (303) is configured to operate in a coding loop. As an oversimplified description, in an example, the coding loop can include a source coder (330) (e.g., responsible for creating symbols, such as a symbol stream, based on an input picture to be coded, and a reference picture(s)), and a (local) decoder (333) embedded in the video encoder (303). The decoder (333) reconstructs the symbols to create the sample data in a similar manner as a (remote) decoder also would create. The reconstructed sample stream (sample data) is input to the reference picture memory (334). As the decoding of a symbol stream leads to bit-exact results independent of decoder location (local or remote), the content in the reference picture memory (334) is also bit exact between the local encoder and remote encoder. In other words, the prediction part of an encoder “sees” as reference picture samples exactly the same sample values as a decoder would “see” when using prediction during decoding. This fundamental principle of reference picture synchronicity (and resulting drift, if synchronicity cannot be maintained, for example because of channel errors) is used in some related arts as well.
The operation of the “local” decoder (333) can be the same as a “remote” decoder, such as the video decoder (210), which has already been described in detail above in conjunction with
In an aspect, a decoder technology except the parsing/entropy decoding that is present in a decoder is present, in an identical or a substantially identical functional form, in a corresponding encoder. Accordingly, the disclosed subject matter focuses on decoder operation. The description of encoder technologies can be abbreviated as they are the inverse of the comprehensively described decoder technologies. In certain areas a more detail description is provided below.
During operation, in some examples, the source coder (330) may perform motion compensated predictive coding, which codes an input picture predictively with reference to one or more previously coded picture from the video sequence that were designated as “reference pictures.” In this manner, the coding engine (332) codes differences between pixel blocks of an input picture and pixel blocks of reference picture(s) that may be selected as prediction reference(s) to the input picture.
The local video decoder (333) may decode coded video data of pictures that may be designated as reference pictures, based on symbols created by the source coder (330). Operations of the coding engine (332) may advantageously be lossy processes. When the coded video data may be decoded at a video decoder (not shown in
The predictor (335) may perform prediction searches for the coding engine (332). That is, for a new picture to be coded, the predictor (335) may search the reference picture memory (334) for sample data (as candidate reference pixel blocks) or certain metadata such as reference picture motion vectors, block shapes, and so on, that may serve as an appropriate prediction reference for the new pictures. The predictor (335) may operate on a sample block-by-pixel block basis to find appropriate prediction references. In some cases, as determined by search results obtained by the predictor (335), an input picture may have prediction references drawn from multiple reference pictures stored in the reference picture memory (334).
The controller (350) may manage coding operations of the source coder (330), including, for example, setting of parameters and subgroup parameters used for encoding the video data.
Output of all aforementioned functional units may be subjected to entropy coding in the entropy coder (345). The entropy coder (345) translates the symbols as generated by the various functional units into a coded video sequence, by applying lossless compression to the symbols according to technologies such as Huffman coding, variable length coding, arithmetic coding, and so forth.
The transmitter (340) may buffer the coded video sequence(s) as created by the entropy coder (345) to prepare for transmission via a communication channel (360), which may be a hardware/software link to a storage device which would store the encoded video data. The transmitter (340) may merge coded video data from the video encoder (303) with other data to be transmitted, for example, coded audio data and/or ancillary data streams (sources not shown).
The controller (350) may manage operation of the video encoder (303). During coding, the controller (350) may assign to each coded picture a certain coded picture type, which may affect the coding techniques that may be applied to the respective picture. For example, pictures often may be assigned as one of the following picture types:
An Intra Picture (I picture) may be coded and decoded without using any other picture in the sequence as a source of prediction. Some video codecs allow for different types of intra pictures, including, for example Independent Decoder Refresh (“IDR”) Pictures.
A predictive picture (P picture) may be coded and decoded using intra prediction or inter prediction using a motion vector and reference index to predict the sample values of each block.
A bi-directionally predictive picture (B Picture) may be coded and decoded using intra prediction or inter prediction using 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 for the reconstruction of a single block.
Source pictures commonly may be subdivided spatially into a plurality of sample blocks (for example, blocks of 4×4, 8×8, 4×8, or 16×16 samples each) and coded on a block-by-block basis. Blocks may be coded predictively with reference to other (already coded) blocks as determined by the coding assignment applied to the blocks' respective pictures. For example, blocks of I pictures may be coded non-predictively or they may be coded predictively with reference to already coded blocks of the same picture (spatial prediction or intra prediction). Pixel blocks of P pictures may be coded predictively, via spatial prediction or via temporal prediction with reference to one previously coded reference picture. Blocks of B pictures may be coded predictively, via spatial prediction or via temporal prediction with reference to one or two previously coded reference pictures.
The video encoder (303) may perform coding operations according to a predetermined video coding technology or standard, such as ITU-T Rec. H.265. In its operation, the video encoder (303) may perform various compression operations, including predictive coding operations that exploit temporal and spatial redundancies in the input video sequence. The coded video data, therefore, may conform to a syntax specified by the video coding technology or standard being used.
In an aspect, the transmitter (340) may transmit additional data with the encoded video. The source coder (330) may include such data as part of the coded video sequence. Additional data may comprise temporal/spatial/SNR enhancement layers, other forms of redundant data such as redundant pictures and slices, SEI messages, VUI parameter set fragments, and so on.
A video may be captured as a plurality of source pictures (video pictures) in a temporal sequence. Intra-picture prediction (often abbreviated to intra prediction) makes use of spatial correlation in a given picture, and inter-picture prediction makes uses of the (temporal or other) correlation between the pictures. In an example, a specific picture under encoding/decoding, which is referred to as a current picture, is partitioned into blocks. When 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 that is referred to as a motion vector. The motion vector points to the reference block in the reference picture, and can have a third dimension identifying the reference picture, in case multiple reference pictures are in use.
In some aspects, a bi-prediction technique can be used in the inter-picture prediction. According to the bi-prediction technique, two reference pictures, such as a first reference picture and a second reference picture that are both prior in decoding order to the current picture in the video (but may be in the past and future, respectively, in display order) are used. A block in the current picture can be coded by a first motion vector that points to a first reference block in the first reference picture, and a second motion vector that points to a second reference block in the second reference picture. The block can be predicted by a combination of the first reference block and the second reference block.
Further, a merge mode technique can be used in the inter-picture prediction to improve coding efficiency.
According to some aspects of the disclosure, predictions, such as inter-picture predictions and intra-picture predictions, are performed in the unit of blocks. For example, according to the HEVC standard, a picture in a sequence of video pictures is partitioned into coding tree units (CTU) for compression, the CTUs in a picture have the same size, such as 64×64 pixels, 32×32 pixels, or 16×16 pixels. In general, a CTU includes three coding tree blocks (CTBs), which are one luma CTB and two chroma CTBs. Each CTU can be recursively quadtree split into one or multiple coding units (CUs). For example, a CTU of 64×64 pixels can be split into one CU of 64×64 pixels, or 4 CUs of 32×32 pixels, or 16 CUs of 16×16 pixels. In an example, each CU is analyzed to determine a prediction type for the CU, such as an inter prediction type or an intra prediction type. The CU is split into one or more prediction units (PUs) depending on the temporal and/or spatial predictability. Generally, each PU includes a luma prediction block (PB), and two chroma PBs. In an aspect, a prediction operation in coding (encoding/decoding) is performed in the unit of a prediction block. Using a luma prediction block as an example of a prediction block, the prediction block includes a matrix of values (e.g., luma values) for pixels, such as 8×8 pixels, 16×16 pixels, 8×16 pixels, 16×8 pixels, and the like.
It is noted that the video encoders (103) and (303), and the video decoders (110) and (210) can be implemented using any suitable technique. In an aspect, the video encoders (103) and (303) and the video decoders (110) and (210) can be implemented using one or more integrated circuits. In another aspect, the video encoders (103) and (303), and the video decoders (110) and (210) can be implemented using one or more processors that execute software instructions.
The present disclosure provides techniques for derivation and propagation of coded information in inter prediction coding.
Various inter prediction modes can be used in video coding. For example, in VVC, for an inter-predicted CU, motion parameters can include MV(s), one or more reference picture indices, a reference picture list usage index, and additional information for certain coding features to be used for inter-predicted sample generation. A motion parameter can be signaled explicitly or implicitly. When a CU is coded with a skip mode, the CU can be associated with a PU and can have no significant residual coefficients, no coded motion vector delta or MV difference (e.g., MVD) or a reference picture index. A merge mode can be specified where the motion parameters for the current CU are obtained from neighboring CU(s), including spatial and/or temporal candidates, and optionally additional information such as introduced in VVC. The merge mode can be applied to an inter-predicted CU, not only for skip mode. In an example, an alternative to the merge mode is the explicit transmission of motion parameters, where MV(s), a corresponding reference picture index for each reference picture list and a reference picture list usage flag and other information are signaled explicitly per CU.
In an embodiment, such as in VVC, VVC Test model (VTM) reference software includes one or more refined inter prediction coding tools that include: an extended merge prediction, a merge motion vector difference (MMVD) mode, an adaptive motion vector prediction (AMVP) mode with symmetric MVD signaling, an affine motion compensated prediction, a subblock-based temporal motion vector prediction (SbTMVP), an adaptive motion vector resolution (AMVR), a motion field storage ( 1/16th luma sample MV storage and 8×8 motion field compression), a bi-prediction with CU-level weights (BCW), a bi-directional optical flow (BDOF), a prediction refinement using optical flow (PROF), a decoder side motion vector refinement (DMVR), a combined inter and intra prediction (CIIP), a geometric partitioning mode (GPM), and the like. Inter predictions and related methods are described in details below.
Extended merge prediction can be used in some examples. In an example, such as in VTM4, a merge candidate list is constructed by including the following five types of candidates in order: spatial motion vector predictor(s) (MVP(s)) from spatial neighboring CU(s), temporal MVP(s) from collocated CU(s), history-based MVP(s) (HMVP(s)) from a first-in-first-out (FIFO) table, pairwise average MVP(s), and zero MV(s).
A size of the merge candidate list can be signaled in a slice header. In an example, the maximum allowed size of the merge candidate list is 6 in VTM4. For each CU coded in the merge mode, an index (e.g., a merge index) of a best merge candidate can be encoded using truncated unary binarization (TU). The first bin of the merge index can be coded with context (e.g., context-adaptive binary arithmetic coding (CABAC)) and a bypass coding can be used for other bins.
Some examples of a generation process of each category of merge candidates are provided below. In an embodiment, spatial candidate(s) are derived as follows. The derivation of spatial merge candidates in VVC can be identical to that in HEVC. In an example, a maximum of four merge candidates are selected among candidates located in positions depicted in
To reduce computational complexity, not all possible candidate pairs are considered in the mentioned redundancy check. Instead, only pairs linked with an arrow in
In an embodiment, temporal candidate(s) are derived as follows. In an example, only one temporal merge candidate is added to the candidate list.
According to some aspects of the disclosure, formular based prediction methods can be used in inter prediction or intra prediction. For inter prediction, a formular based prediction method can use a formular to generate samples of the current block in a current picture based on reference samples of a reference block in a reference picture. For intra prediction, a formular based prediction method can use a formular to generate a first color component of the current block based a second color component of the current block. In some examples, parameters in a formular for a formular based prediction method can be derived based on a template of the current block.
In some examples, local illumination compensation (LIC) is used as an inter prediction technique to model local illumination variation between a current block and a prediction block (also referred to as reference block) of the current block by using a linear function. The prediction block is in a reference picture, and can be pointed by motion vector (MV). The parameters of a linear formular can include a scale a and an offset B, and the linear formular can be represented by ax p[x, y] +ß to compensate illumination changes, where p[x, y] denotes a reference sample at a location [x, y] in the reference block (also referred to as prediction block), the reference block is pointed to by MV from the current block. In some examples, the scale a and the offset β can be derived based on a template of the current block and a corresponding reference template of the reference block by using the least square method, thus no signaling overhead is required, except that an LIC flag may be signaled to indicate the use of LIC. The scale a and the offset B that are derived based on the template of the current block can be referred to as template based parameter set.
In some examples, LIC is used for uni-prediction inter CUs. In some examples, intra neighbor samples (neighboring samples that are predicted using intra prediction) of the current block can be used in LIC parameter derivation. In some examples, LIC is disabled for blocks with less than 32 luma samples. In some examples, for non subblock modes (e.g., non affine modes), LIC parameter derivation is performed based on the template block samples of the current CU, instead of partial template block samples for the first top-left 16×16 unit. In some examples, LIC parameter derivation is performed based on partial template block samples, such as the partial template block samples for the first top-left 16×16 unit. In some examples, template samples of the reference block are determined by using motion compensation (MC) with the MV of the block without rounding it to integer-pel precision.
In some examples, cross component prediction can be used as an intra prediction technique. The cross-component prediction can include a first technique referred to as cross component linear model (CCLM), a second technique referred to as multi-model linear model (MMLM), a third technique referred to as convolutional cross-component model (CCCM), and a fourth technique referred to as gradient linear model (GLM).
For example, the first technique CCLM is used to reduce the cross-component redundancy. In the CCLM, the chroma samples are predicted based on the reconstructed luma samples of the same CU by using a linear model (also referred to as linear formular), such as using Eq. (1):
where predC(i, j) represents the predicted chroma samples in a CU and recL′ (i, j) represents the downsampled reconstructed luma samples of the same CU. The CCLM linear model includes parameters (a and b) that can be derived, in an example, with at most four neighbouring chroma samples and their corresponding down-sampled luma samples. In an example, the at most four neighbouring chroma samples and their corresponding down-sampled luma samples are referred to as templates of the CU.
In some examples, based on the location of the neighboring chroma samples, CCLM can include different modes that is referred to as LM_T (LM top mode or above mode LM_A), LM_L (LM left mode) and LM_LT (LM left top mode or left above mode LM_LA or just LM mode). For example, the dimensions of the current chroma block are W×H, then W′ and H′ can be set for various modes in CCLM. When LM mode (also referred to as LM_LT or LM_LA) is applied, W′=W, H′=H; when LM-A mode is applied, W′=W+H; when LM-L mode is applied, H′=H+W.
It is noted that MMLM, CCCM and GLM also use functions for prediction. Parameters of the functions can be derived based on templates.
It is noted that following description uses inter prediction to illustrate techniques to derive coded information for formular based prediction methods, and the techniques can be suitably used to derive coded information for intra prediction.
Some aspects of the disclosure provide techniques for derivation and propagation of coded information in inter prediction coding. For example, encoder/decoder can determine formular based inter prediction information for a potential application of the formular based inter prediction technique on a current block based on at least one of coded information of the current block and coded information of a second block that is reconstructed before the current block. The formular based inter prediction information includes at least one of a control flag for the potential application, a template type for deriving the one or more parameters, and a formular type of the formular.
According to some aspects of the disclosure, some inter prediction techniques are designed to minimize the distortion between the current block and its prediction block in the corresponding reference picture. For example, an inter prediction technique (also referred to as a first method of inter prediction method, formular based inter prediction technique, function based inter prediction technique, or model based inter prediction technique) can apply a formular, such as a non-linear formular, a linear formular and the like, using an original prediction block in the reference picture as input of the formular to generate a current block in a current picture. For example, an inter prediction technique can generate a prediction of a sample in a current block based on a formular with one or more predicted samples in a reference picture as inputs. The formular can include linear terms or non-linear terms, and can include one or more parameters that can be derived. It is noted that LIC is one of such inter prediction techniques.
In some examples, the formular is a linear formular, and can be represented by Σi=0n(αi×p(xi, yi))+β, where n is a non-negative integer number, and p(xi, yi) is a predicted sample at a location (xi, yi) in the reference picture, the predicted sample is pointed based on an MV associated with the current block. Further, a group of predicted samples that are represented by p(xi, yi), where i=0, . . . , n, can be a group of predicted samples around a corresponding sample in the reference sample that are point by the MV based on a current sample to be predicted. In some examples, the parameter at and B can be derived based on a template of the current block (also referred to as current block template) and a template of a prediction block (also referred to as prediction block template) for the current block (e.g., by using the least square method) by minimizing the difference between current block template and its prediction block template. The template of the current block is composed of the spatial neighboring reconstructed samples of the current block, the template of the prediction block is composed of the spatial neighboring reconstructed samples of the prediction block.
In some examples, multiple candidate template types can also be supported, and one candidate template type is selected to derive the parameters of the linear formular. A syntax can be signaled in the bitstream (e.g., at the block level) to indicate which candidate template type is selected.
In some examples, a control flag can be signaled in the bitstream (e.g., at the block level) in association with a formular based inter prediction technique to indicate whether the formular based inter prediction technique is applied on the current block or not. Alternatively, the value of the control flag can also be inherited from the other coded block. More specifically, a first control flag of the formular based inter prediction technique associated with the current block is inherited from a second control flag of the formular based inter prediction technique associated with another one or multiples coded blocks. Moreover, the control flag can be derived at the coding block level to adaptively determine whether the formular based inter prediction technique is applied or not.
In some examples, a first control flag of a formular based inter prediction technique associated with the current block is inherited from a second control flag of the formular based inter prediction technique associated with another one or multiples coded blocks. In some examples, the coded information of the formular based inter prediction technique can be derived from adjacent coded block, non-adjacent coded block, or the coded blocks which store the coded information within the buffer.
It is noted that, in the present disclosure, without limitation of the generality, in an example, the term parameter refers to the parameters αi and β used to determine the linear formular for deriving the prediction block. The term template type refers to different template shapes, such as but no limited to one of the template types shown in
Some aspects of the present disclosure provide techniques to derive the information for applying the formular based inter prediction technique on a current block, such as the control flag, the template type, the formular type, and the like of the formular based inter prediction technique for the current block, using coded information, such as coded information of current block and/or coded information of other coded block(s).
According to an aspect of the disclosure, when the control flag associated with the other coded block (e.g., adjacent neighboring block, non adjacent neighboring block, temporal collocated block, and the like) is true, the control flag of the current block is derived based on a comparison between the values of derived parameters (e.g., parameters αi and β) and the predefined threshold values.
In some embodiments, when one of the parameters is larger than and (or) smaller than the corresponding threshold value, the control flag is false; otherwise, the control flag is true. In some examples, the other coded block (e.g., a coded block in a buffer that is coded using a formular based inter prediction technique) has a control flag of a true value, and when at least one of the parameters of a formular for applying the formular based inter prediction technique on the current block (e.g., derived based on a template) has a value that is beyond a range, such as larger than a upper threshold value, or smaller than a lower threshold value, the control flag is false; otherwise, all of the parameters of a formular for applying the formular based inter prediction technique on the current block are in a predefined range, the control flag for applying the formular based inter prediction technique is true.
In some embodiments, when all parameters are larger than and (or) smaller than each corresponding threshold values, the control flag is false; otherwise, the control flag is true. In some examples, the other coded block (e.g., a coded block in a buffer that is coded using a formular based inter prediction technique) has a control flag of a true value, and when each parameter of the parameters of a formular for applying the formular based inter prediction technique on the current block (e.g., derived based on a template) has a value that is beyond a specific range for the parameter), such as larger than a upper threshold value for the parameter, or smaller than a lower threshold value for the parameter, the control flag is false; otherwise, at least one parameter is in the specific range for the parameter, the control flag is true.
In some embodiments, the threshold value(s) can be predefined constant values. In some examples, the constant value(s) can be signaled in the coded video bitstream, such as but not limited to sequence header, slice header, picture header, frame header, and the like.
In some embodiments, the threshold value(s) can be determined by other coded information, including, but not limited to: a function of quantization parameter, coding block (e.g., current block) size/shape, temporal distance between prediction block and current block.
According to an aspect of the disclosure, a specific template type can be assigned to be a default template type of the current block. The specific template type can be but not limited to be one the template types shown in
In some embodiments, the above and left template Tα+l, such as the above and left template (820) in
In some embodiments, the left template Tl, such as the left template (840) in
In some embodiments, the top template Ta, such as the above template (830) in
According to an aspect of the disclosure, the template type of the formular based inter prediction technique can be derived based on the selected template type of the other coded block (such as an adjacent neighboring block, a non adjacent neighboring block, a temporal collocated block, and the like) when the control flag of the other coded block is true.
In some embodiments, the template type of the current block is inherited from the selected template type of the formular based inter prediction technique applied on the other coded block when the control flag of the formular based inter prediction technique to applied on the current block is derived from (the same) the other coded block.
According to an aspect of the disclosure, when the control flag associated with the other coded block is true, regardless whether the other coded block is coded using the same reference picture with the current block or not, the control flag can be inherited. In other words, the coded information of the other coded block can be partially merged, e.g., reference picture is still signaled, but the control flag is inherited, or vice versa.
Some aspects of the disclosure also provide techniques to store the information of the formular based inter prediction techniques applied on the coded block, and the stored information can be used for coding/decoding subsequent blocks in coding/decoding. The stored information includes but not limited to the control flag, template type, the formular type and the like. In an example, a buffer that buffers neighboring samples of the current block also include the information of the formular based inter prediction techniques for the neighboring samples. In another example, a line buffer that buffers some samples in above CTUs also include the information of the formular based inter prediction techniques of those samples in the above CTUs.
In some embodiments, the signaled and/or the derived template type of the formular based inter prediction technique can be stored for the subsequent blocks in coding or decoding.
In some embodiments, the derived control flag of the formular based inter prediction technique of the current block can be stored for the subsequent blocks in coding or decoding.
In some embodiments, the derived transform type for residual signal associated with the formular based inter prediction technique applied on the current block can be stored for the subsequent blocks in coding or decoding.
In some embodiments, the information of the formular based inter prediction technique is stored in m×n unit, where m and n are non-zero positive integer number. In an example, the information of the formular based inter prediction technique is stored in 4×4 unit (e.g., once every 4×4 samples). In another example, the information of the formular based inter prediction technique is stored in 8×8 unit (e.g., once every 8×8 samples).
At (S910), a coded video bitstream that includes first coded information of a current block in a current picture is received. The first coded information indicates an inter prediction of the current block based on a reference block in a reference picture for the current block, and also indicates a potential application of a formular based inter prediction technique on the inter prediction of the current block. The formular based inter prediction technique generates a prediction sample of the current block based on a formular with one or more reconstructed samples in the reference block being input to the formular. The formular includes one or more parameters derived based on a current template of the current block and a reference template of the reference block. The second block can be an adjacent neighboring block of the current block, can be a non-adjacent neighboring block of the current block, and can be a collocated block of the current block in a different picture.
At (S920), first formular based inter prediction information for the potential application of the formular based inter prediction technique on the current block is determined based on at least one of the first coded information of the current block and second coded information of a second block that is reconstructed before the current block. The first formular based inter prediction information includes at least one of a first control flag, a first template type, and a first formular type for the potential application of the formular based inter prediction technique.
At (S930), when the first control flag is true, the formular based inter prediction technique is applied on the current block to generate at least a reconstructed sample of the current block.
According to an aspect of the disclosure, when the second coded information of the second block indicates that a second control flag of the second block for indicating the formular based inter prediction technique being applied on the second block is true, the first control flag of the current block is determined based on a comparison of a value of the one or more parameters with a threshold value.
In some examples, the one or more parameters are derived based on the current template of the current block and the reference template of the reference picture. The first control flag is determined to be false when at least a first derived parameter value of a first parameter in the one or more parameters is not in a first range that is defined for the first parameter, such as larger than an upper threshold value of the first range for the first parameter or smaller than a lower threshold value of the first range for the first parameter. The first control flag is determined to be true when derived parameter values of the one or more parameters are within respective ranges of the one or more parameters.
In some embodiments, the one or more parameters are derived based on the current template of the current block and the reference template of the reference picture. The first control flag is derived to be false when each of derived parameter values of the one or more parameters is not in an associated range that is defined for the parameter, such as larger than an upper threshold value of the associated range or smaller than a lower threshold value of the associated range. The first control flag is determined to be true when at least one of the derived parameter values of the one or more parameters is within the associated range.
In some examples, the threshold value(s) is (are) a constant value(s) or the threshold value(s) is (are) decoded from at least one of a sequence header, a slice header, a picture header, and a frame header in the coded video bitstream.
In some examples, the threshold value is determined based on at least one of a quantization parameter of the current block, a block size of current block, a shape of the current block, a temporal distance between the current block and the reference block.
In some embodiments, the first template type is determined according to a default template type associated with a shape of the current block. In some examples, the default template type is an above and left template type (e.g., the above and left template type (820) in
In some examples, the default template type is a left template type (e.g., the left template type (840) in
In some examples, the default template type is an above template type (e.g., the above template type (830) in
In some embodiments, the first template type is determined according to a second template type of the second block when a second control flag of the second block is true.
In some embodiments, the first template type of the current block is of a same type as the second template type of the second block when the first control flag of the current block is determined to be a same flag as the second control flag of the second block.
In some embodiments, the first control flag of the current block is determined of a same flag as a second control flag of the second block regardless whether the second block uses the same reference picture as the first block for inter prediction.
In some embodiments, the first formular based inter prediction information for the formular based inter prediction technique that has been applied on the current block is stored in association with the current block. The stored information can be used for reconstruction of subsequent blocks. For example, at least a third block in the current picture is reconstructed based on the first formular based inter prediction information. In an example, formular based inter prediction information for the third block is determined according to the first formular based inter prediction information.
It is noted that the first formular based inter prediction information comprises at least one of the first control flag of the current block, the first template type of the current block, the first formular type of the current block; and/or a transform type for residual data of the formular based inter prediction technique.
In some examples, the first formular based inter prediction information is stored in a unit of m×n samples, m and n are positive integer numbers.
Then, the process proceeds to (S999) and terminates.
The process (900) can be suitably adapted. Step(s) in the process (900) can be modified and/or omitted. Additional step(s) can be added. Any suitable order of implementation can be used.
At (S1010), first formular based inter prediction information of a first prediction candidate using a formular based inter prediction technique on a current block in a current picture is determined based on at least one of first coded information of the current block and second coded information of a second block that is coded before the current block. The formular based inter prediction technique generates a prediction sample of the current block based on a formular with one or more reconstructed samples of a reference block in a reference picture being input to the formular, the formular includes one or more parameters derived based on a current template of the current block and a reference template of the reference block. The first formular based inter prediction information includes at least one of a first control flag, a first template type, and a first formular type for the formular based inter prediction technique. The second block can be an adjacent neighboring block of the current block, can be a non-adjacent neighboring block of the current block, and can be a collocated block of the current block in a different picture.
At (S1020), when the first control flag is true, the formular based inter prediction technique is applied on the current block to generate the first prediction candidate of the current block.
At (S1030), the current block is encoded based on the first prediction candidate. In some examples, a plurality of prediction candidates including the first prediction candidate can be generated. Cost values can be calculated respectively for the plurality of prediction candidates. For example, a first cost value is calculated and is associated with the first prediction candidate. Then, one of the prediction candidates can be selected based on the cost values associated with the prediction candidates. In an example, whether to apply the formular based inter prediction technique on the current block is determined based on at least a first cost value associated with the first prediction candidate. When the first prediction candidate has the lowest cost value, the first prediction candidate is selected, and the current block is further encoded according to the first prediction candidate.
It is noted that in some examples, the first prediction candidate is among a plurality of candidates, the encoder can calculate cost values associated with the plurality of candidates, and select one of the candidates based on the cost values. Then, the current block is encoded according to the selected candidate.
According to an aspect of the disclosure, when the second coded information of the second block indicates that a second control flag of the second block for indicating the formular based inter prediction technique being applied on the second block is true, the first control flag of the current block is determined based on a comparison of a value of the one or more parameters with a threshold value.
In some examples, the one or more parameters are derived based on the current template of the current block and the reference template of the reference picture. The first control flag is determined to be false when at least a first derived parameter value of a first parameter in the one or more parameters is not in a first range that is defined for the first parameter, such as larger than an upper threshold value of the first range for the first parameter or smaller than a lower threshold value of the first range for the first parameter. The first control flag is determined to be true when derived parameter values of the one or more parameters are within respective ranges of the one or more parameters.
In some embodiments, the one or more parameters are derived based on the current template of the current block and the reference template of the reference picture. The first control flag is derived to be false when each of derived parameter values of the one or more parameters is not in an associated range that is defined for the parameter, such as larger than an upper threshold value of the associated range or smaller than a lower threshold value of the associated range. The first control flag is determined to be true when at least one of the derived parameter values of the one or more parameters is within the associated range.
In some examples, the threshold value(s) is (are) a constant value(s) or the threshold value(s) is (are) encoded in at least one of a sequence header, a slice header, a picture header, and a frame header in the coded video bitstream.
In some examples, the threshold value is determined based on at least one of a quantization parameter of the current block, a block size of current block, a shape of the current block, a temporal distance between the current block and the reference block.
In some embodiments, the first template type is determined according to a default template type associated with a shape of the current block. In some examples, the default template type is an above and left template type (e.g., the above and left template type (820) in
In some examples, the default template type is a left template type (e.g., the left template type (840) in
In some examples, the default template type is an above template type (e.g., the above template type (830) in
In some embodiments, the first template type is determined according to a second template type of the second block when a second control flag of the second block is true.
In some embodiments, the first template type of the current block is of a same type as the second template type of the second block when the first control flag of the current block is determined to be a same flag as the second control flag of the second block.
In some embodiments, the first control flag of the current block is determined of a same flag as a second control flag of the second block regardless whether the second block uses the same reference picture as the first block for inter prediction.
In some embodiments, the first formular based inter prediction information for the formular based inter prediction technique that has been applied on the current block is stored in association with the current block. The stored information can be used for the encoding of subsequent blocks. For example, at least a third block in the current picture is encoded based on the first formular based inter prediction information. In an example, formular based inter prediction information for the third block is determined according to the first formular based inter prediction information.
It is noted that the first formular based inter prediction information includes at least one of the first control flag of the current block, the first template type of the current block, the first formular type of the current block; and/or a transform type for residual data of the formular based inter prediction technique.
In some examples, the first formular based inter prediction information is stored in a unit of m×n samples, m and n are positive integer numbers.
Then, the process proceeds to (S1099) and terminates.
The process (1000) can be suitably adapted. Step(s) in the process (1000) can be modified and/or omitted. Additional step(s) can be added. Any suitable order of implementation can be used.
According to an aspect of the disclosure, a method of processing visual media data is provided. In the method, a bitstream of visual media data is processed according to a format rule. For example, the bitstream may be a bitstream that is decoded/encoded in any of the decoding and/or encoding methods described herein. The format rule may specify one or more constraints of the bitstream and/or one or more processes to be performed by the decoder and/or encoder.
In an example, the bitstream includes coded information of one or more pictures including a current block in a current picture. The format rule specifies that the bitstream that includes first coded information of the current block in the current picture is received. The first coded information indicates an inter prediction of the current block based on a reference block in a reference picture for the current block, and also indicates a potential application of a formular based inter prediction technique on the inter prediction of the current block. The formular based inter prediction technique generates a prediction sample of the current block based on a formular with one or more reconstructed samples in the reference block being input to the formular. The formular includes one or more parameters derived based on a current template of the current block and a reference template of the reference block. Further, the format rule specifies that first formular based inter prediction information for the potential application of the formular based inter prediction technique on the current block is determined based on at least one of the first coded information of the current block and second coded information of a second block that is in the current picture and reconstructed before the current block. The first formular based inter prediction information includes at least one of a first control flag, a first template type, and a first formular type for the potential application of the formular based inter prediction technique. Further, the format rule specifies that when the first control flag is true, the formular based inter prediction technique is applied on the current block to generate at least a reconstructed sample of the current block.
The techniques described above, can be implemented as computer software using computer-readable instructions and physically stored in one or more computer-readable media. For example,
The computer software can be coded using any suitable machine code or computer language, that may be subject to assembly, compilation, linking, or like mechanisms to create code comprising instructions that can be executed directly, or through interpretation, micro-code execution, and the like, by one or more computer central processing units (CPUs), Graphics Processing Units (GPUs), and the like.
The instructions can be executed on various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, internet of things devices, and the like.
The components shown in
Computer system (1100) may include certain human interface input devices. Such a human interface input device may be responsive to input by one or more human users through, for example, tactile input (such as: keystrokes, swipes, data glove movements), audio input (such as: voice, clapping), visual input (such as: gestures), olfactory input (not depicted). The human interface devices can also be used to capture certain media not necessarily directly related to conscious input by a human, such as audio (such as: speech, music, ambient sound), images (such as: scanned images, photographic images obtain from a still image camera), video (such as two-dimensional video, three-dimensional video including stereoscopic video).
Input human interface devices may include one or more of (only one of each depicted): keyboard (1101), mouse (1102), trackpad (1103), touch screen (1110), data-glove (not shown), joystick (1105), microphone (1106), scanner (1107), camera (1108).
Computer system (1100) may also include certain human interface output devices. Such human interface output devices may be stimulating the senses of one or more human users through, for example, tactile output, sound, light, and smell/taste. Such human interface output devices may include tactile output devices (for example tactile feedback by the touch-screen (1110), data-glove (not shown), or joystick (1105), but there can also be tactile feedback devices that do not serve as input devices), audio output devices (such as: speakers (1109), headphones (not depicted)), visual output devices (such as screens (1110) to include CRT screens, LCD screens, plasma screens, OLED screens, each with or without touch-screen input capability, each with or without tactile feedback capability-some of which may be capable to output two dimensional visual output or more than three dimensional output through means such as stereographic output; virtual-reality glasses (not depicted), holographic displays and smoke tanks (not depicted)), and printers (not depicted).
Computer system (1100) can also include human accessible storage devices and their associated media such as optical media including CD/DVD ROM/RW (1120) with CD/DVD or the like media (1121), thumb-drive (1122), removable hard drive or solid state drive (1123), legacy magnetic media such as tape and floppy disc (not depicted), specialized ROM/ASIC/PLD based devices such as security dongles (not depicted), and the like.
Those skilled in the art should also understand that term “computer readable media” as used in connection with the presently disclosed subject matter does not encompass transmission media, carrier waves, or other transitory signals.
Computer system (1100) can also include an interface (1154) to one or more communication networks (1155). Networks can for example be wireless, wireline, optical. Networks can further be local, wide-area, metropolitan, vehicular and industrial, real-time, delay-tolerant, and so on. Examples of networks include local area networks such as Ethernet, wireless LANs, cellular networks to include GSM, 3G, 4G, 5G, LTE and the like, TV wireline or wireless wide area digital networks to include cable TV, satellite TV, and terrestrial broadcast TV, vehicular and industrial to include CANBus, and so forth. Certain networks commonly require external network interface adapters that attached to certain general purpose data ports or peripheral buses (1149) (such as, for example USB ports of the computer system (1100)); others are commonly integrated into the core of the computer system (1100) by attachment to a system bus as described below (for example Ethernet interface into a PC computer system or cellular network interface into a smartphone computer system). Using any of these networks, computer system (1100) can communicate with other entities. Such communication can be uni-directional, receive only (for example, broadcast TV), uni-directional send-only (for example CANbus to certain CANbus devices), or bi-directional, for example to other computer systems using local or wide area digital networks. Certain protocols and protocol stacks can be used on each of those networks and network interfaces as described above.
Aforementioned human interface devices, human-accessible storage devices, and network interfaces can be attached to a core (1140) of the computer system (1100).
The core (1140) can include one or more Central Processing Units (CPU) (1141), Graphics Processing Units (GPU) (1142), specialized programmable processing units in the form of Field Programmable Gate Areas (FPGA) (1143), hardware accelerators for certain tasks (1144), graphics adapters (1150), and so forth. These devices, along with Read-only memory (ROM) (1145), Random-access memory (1146), internal mass storage such as internal non-user accessible hard drives, SSDs, and the like (1147), may be connected through a system bus (1148). In some computer systems, the system bus (1148) can be accessible in the form of one or more physical plugs to enable extensions by additional CPUs, GPU, and the like. The peripheral devices can be attached either directly to the core's system bus (1148), or through a peripheral bus (1149). In an example, the screen (1110) can be connected to the graphics adapter (1150). Architectures for a peripheral bus include PCI, USB, and the like.
CPUs (1141), GPUs (1142), FPGAs (1143), and accelerators (1144) can execute certain instructions that, in combination, can make up the aforementioned computer code. That computer code can be stored in ROM (1145) or RAM (1146). Transitional data can also be stored in RAM (1146), whereas permanent data can be stored for example, in the internal mass storage (1147). Fast storage and retrieve to any of the memory devices can be enabled through the use of cache memory, that can be closely associated with one or more CPU (1141), GPU (1142), mass storage (1147), ROM (1145), RAM (1146), and the like.
The computer readable media can have computer code thereon for performing various computer-implemented operations. The media and computer code can be those specially designed and constructed for the purposes of the present disclosure, or they can be of the kind well known and available to those having skill in the computer software arts.
As an example and not by way of limitation, the computer system having architecture (1100), and specifically the core (1140) can provide functionality as a result of processor(s) (including CPUs, GPUs, FPGA, accelerators, and the like) executing software embodied in one or more tangible, computer-readable media. Such computer-readable media can be media associated with user-accessible mass storage as introduced above, as well as certain storage of the core (1140) that are of non-transitory nature, such as core-internal mass storage (1147) or ROM (1145). The software implementing various aspects of the present disclosure can be stored in such devices and executed by core (1140). A computer-readable medium can include one or more memory devices or chips, according to particular needs. The software can cause the core (1140) and specifically the processors therein (including CPU, GPU, FPGA, and the like) to execute particular processes or particular parts of particular processes described herein, including defining data structures stored in RAM (1146) and modifying such data structures according to the processes defined by the software. In addition or as an alternative, the computer system can provide functionality as a result of logic hardwired or otherwise embodied in a circuit (for example: accelerator (1144)), which can operate in place of or together with software to execute particular processes or particular parts of particular processes described herein. Reference to software can encompass logic, and vice versa, where appropriate. Reference to a computer-readable media can encompass a circuit (such as an integrated circuit (IC)) storing software for execution, a circuit embodying logic for execution, or both, where appropriate. The present disclosure encompasses any suitable combination of hardware and software.
The use of “at least one of” or “one of” in the disclosure is intended to include any one or a combination of the recited elements. For example, references to at least one of A, B, or C; at least one of A, B, and C; at least one of A, B, and/or C; and at least one of A to C are intended to include only A, only B, only C or any combination thereof. References to one of A or B and one of A and B are intended to include A or B or (A and B). The use of “one of” does not preclude any combination of the recited elements when applicable, such as when the elements are not mutually exclusive.
While this disclosure has described several examples of aspects, there are alterations, permutations, and various substitute equivalents, which fall within the scope of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise numerous systems and methods which, although not explicitly shown or described herein, embody the principles of the disclosure and are thus within the spirit and scope thereof.
The present application claims the benefit of priority to U.S. Provisional Application No. 63/526,155, “On Derivation and Propagation Of Coded Information Of Inter Prediction” filed on Jul. 11, 2023, which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63526155 | Jul 2023 | US |
