WO2021061023A1 - Signalisation pour raffinement de vecteurs de mouvement - Google Patents

Signalisation pour raffinement de vecteurs de mouvement Download PDF

Info

Publication number
WO2021061023A1
WO2021061023A1 PCT/RU2020/050242 RU2020050242W WO2021061023A1 WO 2021061023 A1 WO2021061023 A1 WO 2021061023A1 RU 2020050242 W RU2020050242 W RU 2020050242W WO 2021061023 A1 WO2021061023 A1 WO 2021061023A1
Authority
WO
WIPO (PCT)
Prior art keywords
slice
picture
prediction
level
block
Prior art date
Application number
PCT/RU2020/050242
Other languages
English (en)
Inventor
Alexey Konstantinovich FILIPPOV
Huanbang CHEN
Vasily Alexeevich RUFITSKIY
Haitao Yang
Elena Alexandrovna ALSHINA
Original Assignee
Huawei Technologies Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co., Ltd. filed Critical Huawei Technologies Co., Ltd.
Publication of WO2021061023A1 publication Critical patent/WO2021061023A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/132—Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/186—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a colour or a chrominance component
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H04N19/523—Motion estimation or motion compensation with sub-pixel accuracy
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H04N19/577—Motion compensation with bidirectional frame interpolation, i.e. using B-pictures

Definitions

  • Embodiments of the present application generally relate to the field of video coding and more particularly to signaling of slice header syntax elements.
  • video data is generally compressed before being communicated across modem day telecommunications networks.
  • the size of a video could also be an issue when the video is stored on a storage device because memory resources may be limited.
  • Video compression devices often use software and/or hardware at the source to code the video data prior to transmission or storage, thereby decreasing the quantity of data needed to represent digital video images.
  • the compressed data is then received at the destination by a video decompression device that decodes the video data.
  • Embodiments provide methods for encoding and decoding a video sequence comprising coding of slice header syntax elements that depend on slice type.
  • Embodiments provide for an efficient encoding and/or decoding and corresponding signalling using motion refinement video coding tools such as BDOF or DMVR and signal related information in slice headers only for slices which allow or enable bidirectional inter-prediction, e.g. in bidirectional (B) prediction slices, also called B-slices.
  • motion refinement video coding tools such as BDOF or DMVR
  • signal related information in slice headers only for slices which allow or enable bidirectional inter-prediction, e.g. in bidirectional (B) prediction slices, also called B-slices.
  • a method of bi-directional inter-prediction of a coding block or coding unit comprises:
  • the slice level or picture level information is a sequence parameter set (SPS)-level BDOF flag.
  • SPS sequence parameter set
  • the slice level or picture level information is a sequence parameter set SPS-level DMVR flag (e.g., sps_dmvr_slice_present_flag).
  • a method for encoding a video sequence e.g. a coded video sequence, CVS
  • the method comprises:
  • a slice type or picture type of the video sequence to be encoded allows bi-directional inter-prediction tools to be used in the slice or picture (e.g. is a bi-directional inter-prediction slice or B-slice), - obtaining slice-level or picture-level information related to motion refinement video coding only if the slice type or picture type allows bi-directional prediction;
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • block-level information relates to the motion refinement video coding
  • the method further comprises the step of encoding the video by encoding at least one block predicted using motion refinement video coding tools for bi-directional prediction.
  • a method for decoding a video sequence e.g. a coded video sequence, CVS
  • the method comprises:
  • - obtaining (e.g. by parsing a bitstream, e.g. a slice header in the bitstream related to a current slice to be decoded) slice-level or picture-level information related to motion refinement video coding only if the slice type or picture type allows bi-directional inter-prediction;
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • block-level information relates to motion refinement video coding tools for bi-directional prediction; - performing bi-directional inter-prediction of each block by using motion refinement video coding according to the slice-level or picture-level and block-level information.
  • the method further comprises the step of decoding the block of the video sequence by decoding at least one block predicted using motion refinement video coding tools for bi-directional prediction.
  • the slice level or picture level information related to motion refinement video coding tools for bi-directional prediction (e.g. a flag slice disable bdof dmvr flag) is signaled for B-slices or B-pictures.
  • the slice level or picture level information related to motion refinement video coding tools for bi-directional prediction (e.g. a flag slice_disable_bdof_dmvr_flag) is inferred to be equal to values that disables said motion refinement video coding tools when it is not signaled for B-slices or B-pictures. That is, a value may be inferred as being default instead of being explicitly signalled, even for B-slices or pictures. This may further reduce signalling overhead and thus enhance coding efficiency.
  • the method comprises: obtaining sequence parameter set (SPS)-level information (e.g., sps_bdof_dmvr_slice_present_flag) related to the motion refinement video coding which indicates that signaling slice-level or picture level information for the motion refinement video coding is allowable.
  • SPS sequence parameter set
  • the motion refinement video coding comprise or are at least one of BDOF and DMVR.
  • the method comprises the following steps: obtaining a sequence parameter set (SPS)-level BDOF flag (e.g., sps_bdof_slice_present_flag) related to bi-directional optical flow prediction which ((SPS)- level BDOF flag) indicates that signalling of a slice-level or picture-level information related to motion refinement video coding is allowed; and
  • SPS sequence parameter set
  • level BDOF flag e.g., sps_bdof_slice_present_flag
  • the method comprises the following steps obtaining a sequence parameter set SPS-level DMVR flag (e.g., sps dm vr sl i ce present fl ag) related to decoder-side motion vector refinement which (SPS- level DMVR flag) indicates that signalling of a slice-level or picture-level information related to motion refinement video coding is allowed; and
  • a sequence parameter set SPS-level DMVR flag e.g., sps dm vr sl i ce present fl ag
  • the invention relates to an encoder comprising processing circuitry (e.g. a processor) configured for performing the method according to the first or second aspects or any of its embodiments.
  • processing circuitry e.g. a processor
  • the invention relates to a decoder comprising processing circuitry (e.g. a processor) configured for performing the method according to the first or third aspects or any of its embodiments.
  • processing circuitry e.g. a processor
  • the invention relates to an encoder, comprising one or more processors; and a non-transitory computer-readable storage medium coupled to the processors and storing programming for execution by the processors, wherein the programming, when executed by the processors, configures the encoder to carry out the method according to the first or second aspect or any of its embodiments.
  • the invention relates to a decoder, comprising one or more processors; and a non-transitory computer-readable storage medium coupled to the processors and storing programming for execution by the processors, wherein the programming, when executed by the processors, configures the encoder to carry out the method according to the first or third aspect or any of its embodiments.
  • the invention relates to a computer program product comprising a program code for performing the method according to any one of the first to third aspects or its embodiments.
  • the invention relates to a non-transitory computer-readable medium carrying a program code which, when executed by a computer device, causes the computer device to perform the method of any one of the first to third aspects or its embodiments.
  • the invention relates to apparatuses comprising respective means for performing all steps of methods according to the first to third aspects or any of its embodiments.
  • the present invention contributes to a balancing of processing load at the decoder side between the P-slices (having less signaling flags but more residual information) as compare to B-slices (having more flags to be signaled but less residual information).
  • B bidirectional prediction slices
  • FIG. IB is a block diagram showing another example of a video coding system configured to implement embodiments of the invention.
  • FIG. 2 is a block diagram showing an example of a video encoder configured to implement embodiments of the invention
  • FIG. 3 is a block diagram showing an example structure of a video decoder configured to implement embodiments of the invention
  • FIG. 4 is a block diagram illustrating an example of an encoding apparatus or a decoding apparatus
  • FIG. 5 is a block diagram illustrating another example of an encoding apparatus or a decoding apparatus
  • FIG. 6 is an illustration of the steps required at encoder side to obtain a set of transform blocks for used color components marked as a transform unit according to an embodiment of the invention
  • FIG. 7 is an illustration of an alternative way to resample residual blocks for obtaining a set of transform blocks for used color components marked as a transform unit according to an embodiment of the invention
  • FIG. 8 is a flowchart to illustrate the processing steps of the invention applied to a unit predicted using TPM at both decoder and encoder sides according to an embodiment of the invention
  • FIG. 9 is an illustration of a resampling process within a unit where the GMP technique is used according to an embodiment of the invention.
  • FIG. 10 is a flowchart to illustrate the processing steps of an embodiment of the invention at both decoder and encoder side if the resampling process is applied to a unit where the GMP technique is used;
  • FIG. 11 is a flowchart showing the signaling of the flag according to an embodiment of the invention.
  • FIG. 12 is a flowchart showing the signaling of the flag according to an embodiment of the invention.
  • FIG. 13 is an illustration of the smoothing process that uses one-dimensional padding of the samples adjacent to the near-boundary region
  • FIG. 15 is an illustration of obtaining the near-boundary region for the case of GMP using column-wise scan
  • FIG. 16 is an illustration of obtaining the near-boundary region for the case of GMP using a row-wise scan
  • FIG. 17 is an illustration of obtaining the near-boundary region for the case of GEO using a row-wise scan
  • FIG. 18 shows TPM and GEO modes
  • FIG. 19 shows parameters related to GEO
  • FIG. 20 illustrates a process of bi-directional optical flow (BDOF).
  • FIG. 21 illustrates a process of decoder side motion vector refinement (DMVR).
  • FIG. 22 is a high level scheme of a system for capturing, processing and displaying video.
  • FIG. 23 schematically illustrates a receiving and reproducing device for multiplexed video, audio and subtitle information.
  • a corresponding device may include one or a plurality of units, e.g. functional units, to perform the described one or plurality of method steps (e.g. one unit performing the one or plurality of steps, or a plurality of units each performing one or more of the plurality of steps), even if such one or more units are not explicitly described or illustrated in the figures.
  • a corresponding method may include one step to perform the functionality of the one or plurality of units (e.g.
  • Video coding typically refers to the processing of a sequence of pictures, which form the video or video sequence. Instead of the term “picture” the term “frame” or “image” may be used as synonyms in the field of video coding.
  • Video coding (or coding in general) comprises two parts video encoding and video decoding. Video encoding is performed at the source side, typically comprising processing (e.g. by compression) the original video pictures to reduce the amount of data required for representing the video pictures (for more efficient storage and/or transmission). Video decoding is performed at the destination side and typically comprises the inverse processing compared to the encoder to reconstruct the video pictures.
  • Embodiments referring to “coding” of video pictures shall be understood to relate to “encoding” or “decoding” of video pictures or respective video sequences.
  • the combination of the encoding part and the decoding part is also referred to as CODEC (Coding and Decoding).
  • the original video pictures can be reconstructed, i.e. the reconstructed video pictures have the same quality as the original video pictures (assuming no transmission loss or other data loss during storage or transmission).
  • further compression e.g. by quantization, is performed, to reduce the amount of data representing the video pictures, which cannot be completely reconstructed at the decoder, i.e. the quality of the reconstructed video pictures is lower or worse compared to the quality of the original video pictures.
  • Several video coding standards belong to the group of “lossy hybrid video codecs” (i.e. combine spatial and temporal prediction in the sample domain and 2D transform coding for applying quantization in the transform domain).
  • Each picture of a video sequence is typically partitioned into a set of non-overlapping blocks and the coding is typically performed on a block level.
  • the video is typically processed, i.e. encoded, on a block (video block) level, e.g. by using spatial (intra picture) prediction and/or temporal (inter picture) prediction to generate a prediction block, subtracting the prediction block from the current block (block currently processed/to be processed) to obtain a residual block, transforming the residual block and quantizing the residual block in the transform domain to reduce the amount of data to be transmitted (compression), whereas at the decoder the inverse processing compared to the encoder is applied to the encoded or compressed block to reconstruct the current block for representation.
  • the encoder duplicates the decoder processing loop such that both will generate identical predictions (e.g. intra- and inter predictions) and/or re-constructions for processing, i.e. coding, the subsequent blocks.
  • Fig. 1 A is a schematic block diagram illustrating an example coding system 10, e.g. a video coding system 10 (or short coding system 10) that may utilize techniques of this present application.
  • Video encoder 20 (or short encoder 20) and video decoder 30 (or short decoder 30) of video coding system 10 represent examples of devices that may be configured to perform techniques in accordance with various examples described in the present application.
  • the coding system 10 comprises a source device 12 configured to provide encoded picture data 21 e.g. to a destination device 14 for decoding the encoded picture data 13.
  • the source device 12 comprises an encoder 20, and may additionally, i.e. optionally, comprise a picture source 16, a pre-processor (or pre-processing unit) 18, e.g. a picture pre- processor 18, and a communication interface or communication unit 22.
  • the picture source 16 may comprise or be any kind of picture capturing device, for example a camera for capturing a real-world picture, and/or any kind of a picture generating device, for example a computer-graphics processor for generating a computer animated picture, or any kind of other device for obtaining and/or providing a real-world picture, a computer generated picture (e.g. a screen content, a virtual reality (VR) picture) and/or any combination thereof (e.g. an augmented reality (AR) picture).
  • the picture source may be any kind of memory or storage storing any of the aforementioned pictures.
  • the picture or picture data 17 may also be referred to as raw picture or raw picture data 17.
  • Pre-processor 18 is configured to receive the (raw) picture data 17 and to perform pre- processing on the picture data 17 to obtain a pre-processed picture 19 or pre-processed picture data 19.
  • Pre-processing performed by the pre-processor 18 may, e.g., comprise trimming, color format conversion (e.g. from RGB to YCbCr), color correction, or de- noting. It can be understood that the pre-processing unit 18 may be optional component.
  • the video encoder 20 is configured to receive the pre-processed picture data 19 and provide encoded picture data 21 (further details will be described below, e.g., based on Fig. 2).
  • Communication interface 22 of the source device 12 may be configured to receive the encoded picture data 21 and to transmit the encoded picture data 21 (or any further processed version thereof) over communication channel 13 to another device, e.g. the destination device 14 or any other device, for storage or direct reconstruction.
  • the destination device 14 comprises a decoder 30 (e.g. a video decoder 30), and may additionally, i.e. optionally, comprise a communication interface or communication unit 28, a post-processor 32 (or post-processing unit 32) and a display device 34.
  • a decoder 30 e.g. a video decoder 30
  • the communication interface 28 of the destination device 14 is configured receive the encoded picture data 21 (or any further processed version thereof), e.g. directly from the source device 12 or from any other source, e.g. a storage device, e.g. an encoded picture data storage device, and provide the encoded picture data 21 to the decoder 30.
  • a storage device e.g. an encoded picture data storage device
  • the communication interface 22 and the communication interface 28 may be configured to transmit or receive the encoded picture data 21 or encoded data 13 via a direct communication link between the source device 12 and the destination device 14, e.g. a direct wired or wireless connection, or via any kind of network, e.g. a wired or wireless network or any combination thereof, or any kind of private and public network, or any kind of combination thereof.
  • the communication interface 22 may be, e.g., configured to package the encoded picture data 21 into an appropriate format, e.g. packets, and/or process the encoded picture data using any kind of transmission encoding or processing for transmission over a communication link or communication network.
  • the communication interface 28, forming the counterpart of the communication interface 22, may be, e.g., configured to receive the transmitted data and process the transmission data using any kind of corresponding transmission decoding or processing and/or de-packaging to obtain the encoded picture data 21.
  • Both, communication interface 22 and communication interface 28 may be configured as unidirectional communication interfaces as indicated by the arrow for the communication channel 13 in Fig. 1 A pointing from the source device 12 to the destination device 14, or bi- directional communication interfaces, and may be configured, e.g. to send and receive messages, e.g. to set up a connection, to acknowledge and exchange any other information related to the communication link and/or data transmission, e.g. encoded picture data transmission.
  • the decoder 30 is configured to receive the encoded picture data 21 and provide decoded picture data 31 or a decoded picture 31 (further details will be described below, e.g., based on Fig. 3 or Fig. 5).
  • the post-processor 32 of destination device 14 is configured to post-process the decoded picture data 31 (also called reconstructed picture data), e.g. the decoded picture 31, to obtain post-processed picture data 33, e.g. a post-processed picture 33.
  • the post-processing performed by the post-processing unit 32 may comprise, e.g. color format conversion (e.g. from YCbCr to RGB), color correction, trimming, or re-sampling, or any other processing, e.g. for preparing the decoded picture data 31 for display, e.g. by display device 34.
  • the display device 34 of the destination device 14 is configured to receive the post-processed picture data 33 for displaying the picture, e.g. to a user or viewer.
  • the display device 34 may be or comprise any kind of display for representing the reconstructed picture, e.g. an integrated or external display or monitor.
  • the displays may, e.g. comprise liquid crystal displays (LCD), organic light emitting diodes (OLED) displays, plasma displays, projectors , micro LED displays, liquid crystal on silicon (LCoS), digital light processor (DLP) or any kind of other display.
  • Fig. 1 A depicts the source device 12 and the destination device 14 as separate devices
  • embodiments of devices may also comprise both or both functionalities, the source device 12 or corresponding functionality and the destination device 14 or corresponding functionality.
  • the source device 12 or corresponding functionality and the destination device 14 or corresponding functionality may be implemented using the same hardware and/or software or by separate hardware and/or software or any combination thereof.
  • the encoder 20 e.g. a video encoder 20
  • the decoder 30 e.g. a video decoder 30
  • both encoder 20 and decoder 30 may be implemented via processing circuitry as shown in Fig. IB, such as one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), discrete logic, hardware, video coding dedicated or any combinations thereof.
  • the encoder 20 may be implemented via processing circuitry 46 to embody the various modules as discussed with respect to encoder 20of FIG. 2 and/or any other encoder system or subsystem described herein.
  • the decoder 30 may be implemented via processing circuitry 46 to embody the various modules as discussed with respect to decoder 30 of FIG. 3 and/or any other decoder system or subsystem described herein.
  • the processing circuitry may be configured to perform the various operations as discussed later.
  • a device may store instructions for the software in a suitable, non-transitory computer-readable storage medium and may execute the instructions in hardware using one or more processors to perform the techniques of this disclosure.
  • Either of video encoder 20 and video decoder 30 may be integrated as part of a combined encoder/decoder (CODEC) in a single device, for example, as shown in Fig. IB.
  • CDEC combined encoder/decoder
  • Source device 12 and destination device 14 may comprise any of a wide range of devices, including any kind of handheld or stationary devices, e.g. notebook or laptop computers, mobile phones, smart phones, tablets or tablet computers, cameras, desktop computers, set- top boxes, televisions, display devices, digital media players, video gaming consoles, video streaming devices(such as content services servers or content delivery servers), broadcast receiver device, broadcast transmitter device, or the like and may use no or any kind of operating system.
  • the source device 12 and the destination device 14 may be equipped for wireless communication.
  • the source device 12 and the destination device 14 may be wireless communication devices.
  • video coding system 10 illustrated in Fig. 1 A is merely an example and the techniques of the present application may apply to video coding settings (e.g., video encoding or video decoding) that do not necessarily include any data communication between the encoding and decoding devices.
  • data is retrieved from a local memory, streamed over a network, or the like.
  • a video encoding device may encode and store data to memory, and/or a video decoding device may retrieve and decode data from memory.
  • the encoding and decoding is performed by devices that do not communicate with one another, but simply encode data to memory and/or retrieve and decode data from memory.
  • HEVC High-Efficiency Video Coding
  • VVC Versatile Video coding
  • JCT-VC Joint Collaboration Team on Video Coding
  • VCEG ITU-T Video Coding Experts Group
  • MPEG ISO/IEC Motion Picture Experts Group
  • Fig. 2 shows a schematic block diagram of an example video encoder 20 that is configured to implement the techniques of the present application.
  • the video encoder 20 comprises an input 201 (or input interface 201), a residual calculation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, and inverse transform processing unit 212, a reconstruction unit 214, a loop filter unit 220, a decoded picture buffer (DPB) 230, a mode selection unit 260, an entropy encoding unit 270 and an output 272 (or output interface 272).
  • the mode selection unit 260 may include an inter prediction unit 244, an intra prediction unit 254 and a partitioning unit 262.
  • Inter prediction unit 244 may include a motion estimation unit and a motion compensation unit (not shown).
  • a video encoder 20 as shown in Fig. 2 may also be referred to as hybrid video encoder or a video encoder according to a hybrid video codec.
  • the residual calculation unit 204, the transform processing unit 206, the quantization unit 208, the mode selection unit 260 may be referred to as forming a forward signal path of the encoder 20, whereas the inverse quantization unit 210, the inverse transform processing unit 212, the reconstruction unit 214, the buffer 216, the loop filter 220, the decoded picture buffer (DPB) 230, the inter prediction unit 244 and the intra-prediction unit 254 may be referred to as forming a backward signal path of the video encoder 20, wherein the backward signal path of the video encoder 20 corresponds to the signal path of the decoder (see video decoder 30 in Fig. 3).
  • the inverse quantization unit 210, the inverse transform processing unit 212, the reconstruction unit 214, the loop filter 220, the decoded picture buffer (DPB) 230, the inter prediction unit 244 and the intra-prediction unit 254 are also referred to forming the “built-in decoder” of video encoder 20.
  • the encoder 20 may be configured to receive, e.g. via input 201, a picture 17 (or picture data 17), e.g. picture of a sequence of pictures forming a video or video sequence.
  • the received picture or picture data may also be a pre-processed picture 19 (or pre-processed picture data 19).
  • the picture 17 may also be referred to as current picture or picture to be coded (in particular in video coding to distinguish the current picture from other pictures, e.g. previously encoded and/or decoded pictures of the same video sequence, i.e. the video sequence which also comprises the current picture).
  • a (digital) picture is or can be regarded as a two-dimensional array or matrix of samples with intensity values.
  • a sample in the array may also be referred to as pixel (short form of picture element) or a pel.
  • the number of samples in horizontal and vertical direction (or axis) of the array or picture define the size and/or resolution of the picture.
  • typically three color components are employed, i.e. the picture may be represented or include three sample arrays.
  • RBG format or color space a picture comprises a corresponding red, green and blue sample array.
  • each pixel is typically represented in a luminance and chrominance format or color space, e.g.
  • YCbCr which comprises a luminance component indicated by Y (sometimes also L is used instead) and two chrominance components indicated by Cb and Cr.
  • the luminance (or short luma) component Y represents the brightness or grey level intensity (e.g. like in a grey-scale picture), while the two chrominance (or short chroma) components Cb and Cr represent the chromaticity or color information components.
  • a picture in YCbCr format comprises a luminance sample array of luminance sample values (Y), and two chrominance sample arrays of chrominance values (Cb and Cr).
  • Pictures in RGB format may be converted or transformed into YCbCr format and vice versa, the process is also known as color transformation or conversion.
  • a picture may comprise only a luminance sample array. Accordingly, a picture may be, for example, an array of luma samples in monochrome format or an array of luma samples and two corresponding arrays of chroma samples in 4:2:0, 4:2:2, and 4:4:4 colour format.
  • Embodiments of the video encoder 20 may comprise a picture partitioning unit (not depicted in Fig. 2) configured to partition the picture 17 into a plurality of (typically non-overlapping) picture blocks 203. These blocks may also be referred to as root blocks, macro blocks (H.264/AVC) or coding tree blocks (CTB) or coding tree units (CTU) (H.265/HEVC and VVC).
  • the picture partitioning unit may be configured to use the same block size for all pictures of a video sequence and the corresponding grid defining the block size, or to change the block size between pictures or subsets or groups of pictures, and partition each picture into the corresponding blocks.
  • the video encoder may be configured to receive directly a block 203 of the picture 17, e.g. one, several or all blocks forming the picture 17.
  • the picture block 203 may also be referred to as current picture block or picture block to be coded.
  • the picture block 203 again is or can be regarded as a two-dimensional array or matrix of samples with intensity values (sample values), although of smaller dimension than the picture 17.
  • the block 203 may comprise, e.g., one sample array (e.g. a luma array in case of a monochrome picture 17, or a luma or chroma array in case of a color picture) or three sample arrays (e.g. a luma and two chroma arrays in case of a color picture 17) or any other number and/or kind of arrays depending on the color format applied.
  • the number of samples in horizontal and vertical direction (or axis) of the block 203 define the size of block 203.
  • a block may, for example, an MxN (M-column by N-row) array of samples, or an MxN array of transform coefficients.
  • Embodiments of the video encoder 20 as shown in Fig. 2 may be configured to encode the picture 17 block by block, e.g. the encoding and prediction is performed per block 203.
  • Embodiments of the video encoder 20 as shown in Fig. 2 may be further configured to partition and/or encode the picture by using slices (also referred to as video slices), wherein a picture may be partitioned into or encoded using one or more slices (typically non- overlapping), and each slice may comprise one or more blocks (e.g. CTUs).
  • slices also referred to as video slices
  • each slice may comprise one or more blocks (e.g. CTUs).
  • Embodiments of the video encoder 20 as shown in Fig. 2 may be further configured to partition and/or encode the picture by using tile groups (also referred to as video tile groups) and/or tiles (also referred to as video tiles), wherein a picture may be partitioned into or encoded using one or more tile groups (typically non-overlapping), and each tile group may comprise, e.g. one or more blocks (e.g. CTUs) or one or more tiles, wherein each tile, e.g. may be of rectangular shape and may comprise one or more blocks (e.g. CTUs), e.g. complete or fractional blocks.
  • tile groups also referred to as video tile groups
  • tiles also referred to as video tiles
  • each tile group may comprise, e.g. one or more blocks (e.g. CTUs) or one or more tiles, wherein each tile, e.g. may be of rectangular shape and may comprise one or more blocks (e.g. CTUs), e.g. complete or fractional blocks.
  • the residual calculation unit 204 may be configured to calculate a residual block 205 (also referred to as residual 205) based on the picture block 203 and a prediction block 265 (further details about the prediction block 265 are provided later), e.g. by subtracting sample values of the prediction block 265 from sample values of the picture block 203, sample by sample (pixel by pixel) to obtain the residual block 205 in the sample domain.
  • a residual block 205 also referred to as residual 205
  • a prediction block 265 further details about the prediction block 265 are provided later
  • the transform processing unit 206 may be configured to apply a transform, e.g. a discrete cosine transform (DCT) or discrete sine transform (DST), on the sample values of the residual block 205 to obtain transform coefficients 207 in a transform domain.
  • a transform e.g. a discrete cosine transform (DCT) or discrete sine transform (DST)
  • DCT discrete cosine transform
  • DST discrete sine transform
  • the transform processing unit 206 may be configured to apply integer approximations of DCT/DST, such as the transforms specified for H.265/HEVC. Compared to an orthogonal DCT transform, such integer approximations are typically scaled by a certain factor. In order to preserve the norm of the residual block which is processed by forward and inverse transforms, additional scaling factors are applied as part of the transform process.
  • the scaling factors are typically chosen based on certain constraints like scaling factors being a power of two for shift operations, bit depth of the transform coefficients, tradeoff between accuracy and implementation costs, etc. Specific scaling factors are, for example, specified for the inverse transform, e.g. by inverse transform processing unit 212 (and the corresponding inverse transform, e.g. by inverse transform processing unit 312 at video decoder 30) and corresponding scaling factors for the forward transform, e.g. by transform processing unit 206, at an encoder 20 may be specified accordingly.
  • Embodiments of the video encoder 20 may be configured to output transform parameters, e.g. a type of transform or transforms, e.g. directly or encoded or compressed via the entropy encoding unit 270, so that, e.g., the video decoder 30 may receive and use the transform parameters for decoding.
  • transform parameters e.g. a type of transform or transforms, e.g. directly or encoded or compressed via the entropy encoding unit 270, so that, e.g., the video decoder 30 may receive and use the transform parameters for decoding.
  • the quantization unit 208 may be configured to quantize the transform coefficients 207 to obtain quantized coefficients 209, e.g. by applying scalar quantization or vector quantization.
  • the quantized coefficients 209 may also be referred to as quantized transform coefficients 209 or quantized residual coefficients 209.
  • the quantization process may reduce the bit depth associated with some or all of the transform coefficients 207. For example, an n-bit transform coefficient may be rounded down to an m-bit Transform coefficient during quantization, where n is greater than m.
  • the degree of quantization may be modified by adjusting a quantization parameter (QP). For example for scalar quantization, different scaling may be applied to achieve finer or coarser quantization. Smaller quantization step sizes correspond to finer quantization, whereas larger quantization step sizes correspond to coarser quantization.
  • the applicable quantization step size may be indicated by a quantization parameter (QP).
  • the quantization parameter may for example be an index to a predefined set of applicable quantization step sizes.
  • small quantization parameters may correspond to fine quantization (small quantization step sizes) and large quantization parameters may correspond to coarse quantization (large quantization step sizes) or vice versa.
  • the quantization may include division by a quantization step size and a corresponding and/or the inverse dequantization, e.g. by inverse quantization unit 210, may include multiplication by the quantization step size.
  • Embodiments according to some standards, e.g. HEVC may be configured to use a quantization parameter to determine the quantization step size.
  • the quantization step size may be calculated based on a quantization parameter using a fixed point approximation of an equation including division.
  • Additional scaling factors may be introduced for quantization and dequantization to restore the norm of the residual block, which might get modified because of the scaling used in the fixed point approximation of the equation for quantization step size and quantization parameter.
  • the scaling of the inverse transform and dequantization might be combined.
  • customized quantization tables may be used and signaled from an encoder to a decoder, e.g. in a bitstream.
  • the quantization is a lossy operation, wherein the loss increases with increasing quantization step sizes.
  • Embodiments of the video encoder 20 may be configured to output quantization parameters (QP), e.g. directly or encoded via the entropy encoding unit 270, so that, e.g., the video decoder 30 may receive and apply the quantization parameters for decoding.
  • QP quantization parameters
  • the inverse quantization unit 210 is configured to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain dequantized coefficients 211, e.g. by applying the inverse of the quantization scheme applied by the quantization unit 208 based on or using the same quantization step size as the quantization unit 208.
  • the dequantized coefficients 211 may also be referred to as dequantized residual coefficients 211 and correspond - although typically not identical to the transform coefficients due to the loss by quantization - to the transform coefficients 207.
  • the inverse transform processing unit 212 is configured to apply the inverse transform of the transform applied by the transform processing unit 206, e.g. an inverse discrete cosine transform (DCT) or inverse discrete sine transform (DST) or other inverse transforms, to obtain a reconstructed residual block 213 (or corresponding dequantized coefficients 213) in the sample domain.
  • the reconstructed residual block 213 may also be referred to as transform block 213.
  • the reconstruction unit 214 (e.g. adder or summer 214) is configured to add the transform block 213 (i.e. reconstructed residual block 213) to the prediction block 265 to obtain a reconstructed block 215 in the sample domain, e.g. by adding - sample by sample - the sample values of the reconstructed residual block 213 and the sample values of the prediction block 265.
  • the loop filter unit 220 (or short “loop filter” 220), is configured to filter the reconstructed block 215 to obtain a filtered block 221, or in general, to filter reconstructed samples to obtain filtered samples.
  • the loop filter unit is, e.g., configured to smooth pixel transitions, or otherwise improve the video quality.
  • the loop filter unit 220 may comprise one or more loop filters such as a de-blocking filter, a sample-adaptive offset (SAO) filter or one or more other filters, e.g. a bilateral filter, an adaptive loop filter (ALF), a sharpening, a smoothing filters or a collaborative filters, or any combination thereof.
  • the loop filter unit 220 is shown in FIG. 2 as being an in loop filter, in other configurations, the loop filter unit 220 may be implemented as a post loop filter.
  • the filtered block 221 may also be referred to as filtered reconstructed block 221.
  • Embodiments of the video encoder 20 may be configured to output loop filter parameters (such as sample adaptive offset information), e.g. directly or encoded via the entropy encoding unit 270, so that, e.g., a decoder 30 may receive and apply the same loop filter parameters or respective loop filters for decoding.
  • loop filter parameters such as sample adaptive offset information
  • the decoded picture buffer (DPB) 230 may be a memory that stores reference pictures, or in general reference picture data, for encoding video data by video encoder 20.
  • the DPB 230 may be formed by any of a variety of memory devices, such as dynamic random access memory (DRAM), including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM), or other types of memory devices.
  • DRAM dynamic random access memory
  • SDRAM synchronous DRAM
  • MRAM magnetoresistive RAM
  • RRAM resistive RAM
  • the decoded picture buffer (DPB) 230 may be configured to store one or more filtered blocks 221.
  • the decoded picture buffer 230 may be further configured to store other previously filtered blocks, e.g. previously reconstructed and filtered blocks 221, of the same current picture or of different pictures, e.g.
  • the decoded picture buffer (DPB) 230 may be also configured to store one or more unfiltered reconstructed blocks 215, or in general unfiltered reconstructed samples, e.g. if the reconstructed block 215 is not filtered by loop filter unit 220, or any other further processed version of the reconstructed blocks or samples.
  • the mode selection unit 260 comprises partitioning unit 262, inter-prediction unit 244 and intra-prediction unit 254, and is configured to receive or obtain original picture data, e.g. an original block 203 (current block 203 of the current picture 17), and reconstructed picture data, e.g. filtered and/or unfiltered reconstructed samples or blocks of the same (current) picture and/or from one or a plurality of previously decoded pictures, e.g. from decoded picture buffer 230 or other buffers (e.g. line buffer, not shown).
  • the reconstructed picture data is used as reference picture data for prediction, e.g. inter-prediction or intra-prediction, to obtain a prediction block 265 or predictor 265.
  • Embodiments of the mode selection unit 260 may be configured to select the partitioning and the prediction mode (e.g. from those supported by or available for mode selection unit 260), which provide the best match or in other words the minimum residual (minimum residual means better compression for transmission or storage), or a minimum signaling overhead (minimum signaling overhead means better compression for transmission or storage), or which considers or balances both.
  • the mode selection unit 260 may be configured to determine the partitioning and prediction mode based on rate distortion optimization (RDO), i.e. select the prediction mode which provides a minimum rate distortion.
  • RDO rate distortion optimization
  • Terms like “best”, “minimum”, “optimum” etc. in this context do not necessarily refer to an overall “best”, “minimum”, “optimum”, etc. but may also refer to the fulfillment of a termination or selection criterion like a value exceeding or falling below a threshold or other constraints leading potentially to a “sub-optimum selection” but reducing complexity and processing time.
  • partitioning e.g. by partitioning unit 260
  • prediction processing by inter-prediction unit 244 and intra-prediction unit 254
  • the partitioning unit 262 may partition (or split) a current block 203 into smaller partitions, e.g. smaller blocks of square or rectangular size. These smaller blocks (which may also be referred to as sub-blocks) may be further partitioned into even smaller partitions.
  • This is also referred to tree-partitioning or hierarchical tree-partitioning, wherein a root block, e.g. at root tree-level 0 (hierarchy-level 0, depth 0), may be recursively partitioned, e.g. partitioned into two or more blocks of a next lower tree-level, e.g.
  • nodes at tree-level 1 (hierarchy-level 1, depth 1), wherein these blocks may be again partitioned into two or more blocks of a next lower level, e.g. tree-level 2 (hierarchy-level 2, depth 2), etc. until the partitioning is terminated, e.g. because a termination criterion is fulfilled, e.g. a maximum tree depth or minimum block size is reached.
  • Blocks which are not further partitioned are also referred to as leaf-blocks or leaf nodes of the tree.
  • a tree using partitioning into two partitions is referred to as binary-tree (BT)
  • BT binary-tree
  • TT ternary- tree
  • QT quad-tree
  • the term “block” as used herein may be a portion, in particular a square or rectangular portion, of a picture.
  • the block may be or correspond to a coding tree unit (CTU), a coding unit (CU), prediction unit (PU), and transform unit (TU) and/or to the corresponding blocks, e.g. a coding tree block (CTB), a coding block (CB), a transform block (TB) or prediction block (PB).
  • CTU coding tree unit
  • CU coding unit
  • PU prediction unit
  • TU transform unit
  • a coding tree block CB
  • CB coding block
  • TB transform block
  • PB prediction block
  • a coding tree unit may be or comprise a CTB of luma samples, two corresponding CTBs of chroma samples of a picture that has three sample arrays, or a CTB of samples of a monochrome picture or a picture that is coded using three separate colour planes and syntax structures used to code the samples.
  • a coding tree block may be an NxN block of samples for some value of N such that the division of a component into CTBs is a partitioning.
  • a coding unit may be or comprise a coding block of luma samples, two corresponding coding blocks of chroma samples of a picture that has three sample arrays, or a coding block of samples of a monochrome picture or a picture that is coded using three separate colour planes and syntax structures used to code the samples.
  • a coding block may be an MxN block of samples for some values of M and N such that the division of a CTB into coding blocks is a partitioning.
  • a coding tree unit may be split into CUs by using a quad-tree structure denoted as coding tree.
  • the decision whether to code a picture area using inter-picture (temporal) or intra-picture (spatial) prediction is made at the CU level.
  • Each CU can be further split into one, two or four PUs according to the PU splitting type. Inside one PU, the same prediction process is applied and the relevant information is transmitted to the decoder on a PU basis.
  • a CU can be partitioned into transform units (TUs) according to another quadtree structure similar to the coding tree for the CU.
  • a combined Quad-tree and binary tree (QTBT) partitioning is for example used to partition a coding block.
  • a CU can have either a square or rectangular shape.
  • a coding tree unit (CTU) is first partitioned by a quadtree structure.
  • the quadtree leaf nodes are further partitioned by a binary tree or ternary (or triple) tree structure.
  • the partitioning tree leaf nodes are called coding units (CUs), and that segmentation is used for prediction and transform processing without any further partitioning.
  • CUs coding units
  • multiple partition for example, triple tree partition may be used together with the QTBT block structure.
  • the mode selection unit 260 of video encoder 20 may be configured to perform any combination of the partitioning techniques described herein.
  • the video encoder 20 is configured to determine or select the best or an optimum prediction mode from a set of (e.g. pre-determined) prediction modes.
  • the set of prediction modes may comprise, e.g., intra-prediction modes and/or inter-prediction modes.
  • Intra-Prediction e.g., intra-prediction modes and/or inter-prediction modes.
  • the intra prediction unit 254 (or in general the mode selection unit 260) is further configured to output intra-prediction parameters (or in general information indicative of the selected intra prediction mode for the block) to the entropy encoding unit 270 in form of syntax elements 266 for inclusion into the encoded picture data 21, so that, e.g., the video decoder 30 may receive and use the prediction parameters for decoding.
  • the set of (or possible) inter-prediction modes depends on the available reference pictures (i.e. previous at least partially decoded pictures, e.g. stored in DBP 230) and other inter- prediction parameters, e.g. whether the whole reference picture or only a part, e.g. a search window area around the area of the current block, of the reference picture is used for searching for a best matching reference block, and/or e.g. whether pixel interpolation is applied, e.g. half/semi-pel and/or quarter-pel interpolation, or not.
  • the available reference pictures i.e. previous at least partially decoded pictures, e.g. stored in DBP 230
  • other inter- prediction parameters e.g. whether the whole reference picture or only a part, e.g. a search window area around the area of the current block, of the reference picture is used for searching for a best matching reference block, and/or e.g. whether pixel interpolation is applied, e.g.
  • skip mode and/or direct mode may be applied.
  • the inter prediction unit 244 may include a motion estimation (ME) unit and a motion compensation (MC) unit (both not shown in Fig.2).
  • the motion estimation unit may be configured to receive or obtain the picture block 203 (current picture block 203 of the current picture 17) and a decoded picture 231, or at least one or a plurality of previously reconstructed blocks, e.g. reconstructed blocks of one or a plurality of other/different previously decoded pictures 231, for motion estimation.
  • a video sequence may comprise the current picture and the previously decoded pictures 231, or in other words, the current picture and the previously decoded pictures 231 may be part of or form a sequence of pictures forming a video sequence.
  • the encoder 20 may, e.g., be configured to select a reference block from a plurality of reference blocks of the same or different pictures of the plurality of other pictures and provide a reference picture (or reference picture index) and/or an offset (spatial offset) between the position (x, y coordinates) of the reference block and the position of the current block as inter prediction parameters to the motion estimation unit.
  • This offset is also called motion vector (MV).
  • the motion compensation unit is configured to obtain, e.g. receive, an inter prediction parameter and to perform inter prediction based on or using the inter prediction parameter to obtain an inter prediction block 265.
  • Motion compensation performed by the motion compensation unit, may involve fetching or generating the prediction block based on the motion/block vector determined by motion estimation, possibly performing interpolations to sub-pixel precision. Interpolation filtering may generate additional pixel samples from known pixel samples, thus potentially increasing the number of candidate prediction blocks that may be used to code a picture block.
  • the motion compensation unit may locate the prediction block to which the motion vector points in one of the reference picture lists.
  • the motion compensation unit may also generate syntax elements associated with the blocks and video slices for use by video decoder 30 in decoding the picture blocks of the video slice.
  • syntax elements associated with the blocks and video slices for use by video decoder 30 in decoding the picture blocks of the video slice.
  • tile groups and/or tiles and respective syntax elements may be generated or used.
  • the present invention broadly relates to motion refinement video coding tools for inter prediction and enhancing coding efficiency by reducing signalling overhead for motion refinement tools.
  • the entropy encoding unit 270 is configured to apply, for example, an entropy encoding algorithm or scheme (e.g. a variable length coding (VLC) scheme, an context adaptive VLC scheme (CAVLC), an arithmetic coding scheme, a binarization, a context adaptive binary arithmetic coding (CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), probability interval partitioning entropy (PIPE) coding or another entropy encoding methodology or technique) or bypass (no compression) on the quantized coefficients 209, inter prediction parameters, intra prediction parameters, loop filter parameters and/or other syntax elements to obtain encoded picture data 21 which can be output via the output 272, e.g.
  • an entropy encoding algorithm or scheme e.g. a variable length coding (VLC) scheme, an context adaptive VLC scheme (CAVLC), an arithmetic coding scheme, a binarization, a context adaptive binary a
  • an encoded bitstream 21 in the form of an encoded bitstream 21, so that, e.g., the video decoder 30 may receive and use the parameters for decoding, .
  • the encoded bitstream 21 may be transmitted to video decoder 30, or stored in a memory for later transmission or retrieval by video decoder 30.
  • Other structural variations of the video encoder 20 can be used to encode the video stream.
  • a non-transform based encoder 20 can quantize the residual signal directly without the transform processing unit 206 for certain blocks or frames.
  • an encoder 20 can have the quantization unit 208 and the inverse quantization unit 210 combined into a single unit. Decoder and Decoding Method
  • Fig. 3 shows an example of a video decoder 30 that is configured to implement the techniques of this present application.
  • the video decoder 30 is configured to receive encoded picture data 21 (e.g. encoded bitstream 21), e.g. encoded by encoder 20, to obtain a decoded picture 331.
  • the encoded picture data or bitstream comprises information for decoding the encoded picture data, e.g. data that represents picture blocks of an encoded video slice (and/or tile groups or tiles) and associated syntax elements.
  • the decoder 30 comprises an entropy decoding unit 304, an inverse quantization unit 310, an inverse transform processing unit 312, a reconstruction unit 314 (e.g. a summer 314), a loop filter 320, a decoded picture buffer (DBP) 330, a mode application unit 360, an inter prediction unit 344 and an intra prediction unit 354.
  • Inter prediction unit 344 may be or include a motion compensation unit.
  • Video decoder 30 may, in some examples, perform a decoding pass generally reciprocal to the encoding pass described with respect to video encoder 100 from FIG. 2.
  • the inverse quantization unit 210 may be identical in function to the inverse quantization unit 110
  • the inverse transform processing unit 312 may be identical in function to the inverse transform processing unit 212
  • the reconstruction unit 314 may be identical in function to reconstruction unit 214
  • the loop filter 320 may be identical in function to the loop filter 220
  • the decoded picture buffer 330 may be identical in function to the decoded picture buffer 230. Therefore, the explanations provided for the respective units and functions of the video 20 encoder apply correspondingly to the respective units and functions of the video decoder 30.
  • the entropy decoding unit 304 is configured to parse the bitstream 21 (or in general encoded picture data 21) and perform, for example, entropy decoding to the encoded picture data 21 to obtain, e.g., quantized coefficients 309 and/or decoded coding parameters (not shown in Fig. 3), e.g. any or all of inter prediction parameters (e.g. reference picture index and motion vector), intra prediction parameter (e.g. intra prediction mode or index), transform parameters, quantization parameters, loop filter parameters, and/or other syntax elements.
  • Entropy decoding unit 304 maybe configured to apply the decoding algorithms or schemes corresponding to the encoding schemes as described with regard to the entropy encoding unit 270 of the encoder 20.
  • Entropy decoding unit 304 may be further configured to provide inter prediction parameters, intra prediction parameter and/or other syntax elements to the mode application unit 360 and other parameters to other units of the decoder 30.
  • Video decoder 30 may receive the syntax elements at the video slice level and/or the video block level. In addition or as an alternative to slices and respective syntax elements, tile groups and/or tiles and respective syntax elements may be received and/or used.
  • the inverse quantization unit 310 may be configured to receive quantization parameters (QP) (or in general information related to the inverse quantization) and quantized coefficients from the encoded picture data 21 (e.g. by parsing and/or decoding, e.g. by entropy decoding unit 304) and to apply based on the quantization parameters an inverse quantization on the decoded quantized coefficients 309 to obtain dequantized coefficients 311, which may also be referred to as transform coefficients 311.
  • the inverse quantization process may include use of a quantization parameter determined by video encoder 20 for each video block in the video slice (or tile or tile group) to determine a degree of quantization and, likewise, a degree of inverse quantization that should be applied.
  • Inverse transform processing unit 312 may be configured to receive dequantized coefficients 311, also referred to as transform coefficients 311, and to apply a transform to the dequantized coefficients 311 in order to obtain reconstructed residual blocks 213 in the sample domain.
  • the reconstructed residual blocks 213 may also be referred to as transform blocks 313.
  • the transform may be an inverse transform, e.g., an inverse DCT, an inverse DST, an inverse integer transform, or a conceptually similar inverse transform process.
  • the inverse transform processing unit 312 may be further configured to receive transform parameters or corresponding information from the encoded picture data 21 (e.g. by parsing and/or decoding, e.g. by entropy decoding unit 304) to determine the transform to be applied to the dequantized coefficients 311.
  • the reconstruction unit 314 (e.g. adder or summer 314) may be configured to add the reconstructed residual block 313, to the prediction block 365 to obtain a reconstructed block 315 in the sample domain, e.g. by adding the sample values of the reconstructed residual block 313 and the sample values of the prediction block 365. Filtering
  • the loop filter unit 320 (either in the coding loop or after the coding loop) is configured to filter the reconstructed block 315 to obtain a filtered block 321, e.g. to smooth pixel transitions, or otherwise improve the video quality.
  • the loop filter unit 320 may comprise one or more loop filters such as a de-blocking filter, a sample-adaptive offset (SAO) filter or one or more other filters, e.g. a bilateral filter, an adaptive loop filter (ALF), a sharpening, a smoothing filters or a collaborative filters, or any combination thereof.
  • the loop filter unit 320 is shown in FIG. 3 as being an in loop filter, in other configurations, the loop filter unit 320 may be implemented as a post loop filter.
  • decoded video blocks 321 of a picture are then stored in decoded picture buffer 330, which stores the decoded pictures 331 as reference pictures for subsequent motion compensation for other pictures and/or for output respectively display.
  • the decoder 30 is configured to output the decoded picture 311, e.g. via output 312, for presentation or viewing to a user.
  • the inter prediction unit 344 may be identical to the inter prediction unit 244 (in particular to the motion compensation unit) and the intra prediction unit 354 may be identical to the inter prediction unit 254 in function, and performs split or partitioning decisions and prediction based on the partitioning and/or prediction parameters or respective information received from the encoded picture data 21 (e.g. by parsing and/or decoding, e.g. by entropy decoding unit 304).
  • Mode application unit 360 may be configured to perform the prediction (intra or inter prediction) per block based on reconstructed pictures, blocks or respective samples (filtered or unfiltered) to obtain the prediction block 365.
  • Video decoder 30 may construct the reference frame lists, List 0 and List 1, using default construction techniques based on reference pictures stored in DPB 330.
  • the same or similar may be applied for or by embodiments using tile groups (e.g. video tile groups) and/or tiles (e.g. video tiles) in addition or alternatively to slices (e.g. video slices), e.g. a video may be coded using I, P or B tile groups and /or tiles.
  • Mode application unit 360 is configured to determine the prediction information for a video block of the current video slice by parsing the motion vectors or related information and other syntax elements, and uses the prediction information to produce the prediction blocks for the current video block being decoded. For example, the mode application unit 360 uses some of the received syntax elements to determine a prediction mode (e.g., intra or inter prediction) used to code the video blocks of the video slice, an inter prediction slice type (e.g., B slice, P slice, or GPB slice), construction information for one or more of the reference picture lists for the slice, motion vectors for each inter encoded video block of the slice, inter prediction status for each inter coded video block of the slice, and other information to decode the video blocks in the current video slice.
  • a prediction mode e.g., intra or inter prediction
  • an inter prediction slice type e.g., B slice, P slice, or GPB slice
  • construction information for one or more of the reference picture lists for the slice motion vectors for each inter encoded video block of the slice, inter prediction status for each
  • tile groups e.g. video tile groups
  • tiles e.g. video tiles
  • slices e.g. video slices
  • Embodiments of the video decoder 30 as shown in Fig. 3 may be configured to partition and/or decode the picture by using slices (also referred to as video slices), wherein a picture may be partitioned into or decoded using one or more slices (typically non-overlapping), and each slice may comprise one or more blocks (e.g. CTUs).
  • slices also referred to as video slices
  • each slice may comprise one or more blocks (e.g. CTUs).
  • Embodiments of the video decoder 30 as shown in Fig. 3 may be configured to partition and/or decode the picture by using tile groups (also referred to as video tile groups) and/or tiles (also referred to as video tiles), wherein a picture may be partitioned into or decoded using one or more tile groups (typically non-overlapping), and each tile group may comprise, e.g. one or more blocks (e.g. CTEis) or one or more tiles, wherein each tile, e.g. may be of rectangular shape and may comprise one or more blocks (e.g. CTUs), e.g. complete or fractional blocks.
  • tile groups also referred to as video tile groups
  • tiles also referred to as video tiles
  • each tile group may comprise, e.g. one or more blocks (e.g. CTEis) or one or more tiles, wherein each tile, e.g. may be of rectangular shape and may comprise one or more blocks (e.g. CTUs), e.g. complete or fractional blocks.
  • the decoder 30 can be used to decode the encoded picture data 21.
  • the decoder 30 can produce the output video stream without the loop filtering unit 320.
  • a non-transform based decoder 30 can inverse-quantize the residual signal directly without the inverse-transform processing unit 312 for certain blocks or frames.
  • the video decoder 30 can have the inverse-quantization unit 310 and the inverse-transform processing unit 312 combined into a single unit.
  • a processing result of a current step may be further processed and then output to the next step.
  • a further operation such as Clip or shift, may be performed on the processing result of the interpolation filtering, motion vector derivation or loop filtering.
  • the value of motion vector is constrained to a predefined range according to its representing bit. If the representing bit of motion vector is bitDepth, then the range is -2 A (bitDepth-l) ⁇ 2 A (bitDepth-l)-l, where “ A ” means exponentiation.
  • bitDepth is set equal to 16
  • the range is -32768 ⁇ 32767
  • bitDepth is set equal to 18
  • the range is -131072-131071.
  • the value ofthe derived motion vector e.g. the MVs of four 4x4 sub-blocks within one 8x8 block
  • the max difference between integer parts of the four 4x4 sub-block MVs is no more than N pixels, such as no more than 1 pixel.
  • N pixels such as no more than 1 pixel.
  • mvx is a horizontal component of a motion vector of an image block or a sub-block
  • mvy is a vertical component of a motion vector of an image block or a sub-block
  • ux and uy indicates an intermediate value
  • FIG. 4 is a schematic diagram of a video coding device 400 according to an embodiment of the disclosure.
  • the video coding device 400 is suitable for implementing the disclosed embodiments as described herein.
  • the video coding device 400 may be a decoder such as video decoder 30 of FIG. 1 A or an encoder such as video encoder 20 of FIG. 1A.
  • the video coding device 400 comprises ingress ports 410 (or input ports 410) and receiver units (Rx) 420 for receiving data; a processor, logic unit, or central processing unit (CPU)
  • the video coding device 400 may also comprise optical-to-electrical (OE) components and electrical-to-optical (EO) components coupled to the ingress ports 410, the receiver units 420, the transmitter units 440, and the egress ports 450 for egress or ingress of optical or electrical signals.
  • OE optical-to-electrical
  • EO electrical-to-optical
  • the processor 430 is implemented by hardware and software.
  • the processor 430 may be implemented as one or more CPU chips, cores (e.g., as a multi-core processor), FPGAs, ASICs, and DSPs.
  • the processor 430 is in communication with the ingress ports 410, receiver units 420, transmitter units 440, egress ports 450, and memory 460.
  • the processor 430 comprises a coding module 470.
  • the coding module 470 implements the disclosed embodiments described above. For instance, the coding module 470 implements, processes, prepares, or provides the various coding operations. The inclusion of the coding module 470 therefore provides a substantial improvement to the functionality of the video coding device 400 and effects a transformation of the video coding device 400 to a different state.
  • the coding module 470 is implemented as instructions stored in the memory 460 and executed by the processor 430.
  • the memory 460 may comprise one or more disks, tape drives, and solid-state drives and may be used as an over-flow data storage device, to store programs when such programs are selected for execution, and to store instructions and data that are read during program execution.
  • the memory 460 may be, for example, volatile and/or non-volatile and may be a read-only memory (ROM), random access memory (RAM), ternary content-addressable memory (TCAM), and/or static random-access memory (SRAM).
  • Fig. 5 is a simplified block diagram of an apparatus 500 that may be used as either or both of the source device 12 and the destination device 14 from Fig. 1 according to an exemplary embodiment.
  • a processor 502 in the apparatus 500 can be a central processing unit.
  • the processor 502 can be any other type of device, or multiple devices, capable of manipulating or processing information now-existing or hereafter developed.
  • the disclosed implementations can be practiced with a single processor as shown, e.g., the processor 502, advantages in speed and efficiency can be achieved using more than one processor.
  • a memory 504 in the apparatus 500 can be a read only memory (ROM) device or a random access memory (RAM) device in an implementation. Any other suitable type of storage device can be used as the memory 504.
  • the memory 504 can include code and data 506 that is accessed by the processor 502 using a bus 512.
  • the memory 504 can further include an operating system 508 and application programs 510, the application programs 510 including at least one program that permits the processor 502 to perform the methods described here.
  • the application programs 510 can include applications 1 through N, which further include a video coding application that performs the methods described here.
  • the apparatus 500 can also include one or more output devices, such as a display 518.
  • the display 518 may be, in one example, a touch sensitive display that combines a display with a touch sensitive element that is operable to sense touch inputs.
  • the display 518 can be coupled to the processor 502 via the bus 512.
  • the bus 512 of the apparatus 500 can be composed of multiple buses.
  • the secondary storage 514 can be directly coupled to the other components of the apparatus 500 or can be accessed via a network and can comprise a single integrated unit such as a memory card or multiple units such as multiple memory cards.
  • the apparatus 500 can thus be implemented in a wide variety of configurations.
  • Triangular partitioning mode (TPM) and geometric motion partitioning (GMP) are partitioning techniques that enable non-horizontal and non-vertical boundaries between prediction partitions, as exemplarily shown in Fig. 6, where prediction unit PU1 601 and prediction unit PU1 602 are combined in region 603 using a weighted averaging procedure of subsets of their samples related to different color components.
  • TMP enables boundaries between prediction partitions only along rectangular block diagonals, whereas boundaries according to GMP may be located at arbitrary positions as Fig. 9 illustrates.
  • integer numbers within squares denote weights Wpm applied to luma component of prediction unit PU1.
  • weights Wpm applied to luma component of prediction unit PU2 are calculated as follows:
  • Weights applied to chroma components of corresponding prediction units may differ from weights applied to luma components of corresponding prediction units.
  • MergeTriangleFlag is a flag that identifies whether TPM is selected or not (“0” means that TPM is not selected; otherwise, TPM is chosen); merge triangle split dir is a split direction flag for TPM (“0” means the split direction from top-left corner to the below-right corner; otherwise, the split direction is from top-right corner to the below-left corner i.e. in Fig. 6 the flag is 0); merge_triangle_idx0 and merge_ti _ rangle idxl are indices of merge candidates 0 and 1 used for TPM.
  • the merge candidates are motion vectors associated with the prediction units PU1 and PU2 in the list of reference motion vectors (reference picture list). Table 1.
  • TPM is described in the following proposal: R-L. Liao and C.S. Lim “CE10.3.1.b: Triangular prediction unit mode,” contribution JVET-L0124 to the 12 th JVET meeting, Macao, China, October 2018.
  • GMP is explained in the following paper: M. Blaser,
  • Prediction errors are localized only in near-boundary region that covers the boundary between partitions that use a more compact representation. Transform and quantization are performed only for this near-boundary region.
  • a near-boundary region is defined by start and end side positions, wherein the first of the side positions is located on a first side of the block, a side of the block is top, left, right or bottom; and the second side position is located on the second side of the block, and wherein the first side of the block is not the same as the second side of the block.
  • the first position is on the left side of the block, at the boundary between regions 602 and 603 in the left hand drawing (corresponding to the boundary between a left hand pixel marked as “0” and a left hand pixel marked with “1” in the upper right hand drawing) and the second position is on the right side of the block, at the boundary between regions 603 and 601 in the left hand drawing (corresponding to the boundary between a right hand pixel marked “7” and a right hand pixel marked “8” in the upper right hand drawing.
  • the near-boundary region could be defined by a curve that connects the first and the second positions and includes the near-boundary region of the samples with the distance to the curve not exceeding a distance threshold. This threshold is set to 2.
  • rows of a subsampled block are obtained by selecting a set of samples from a range of rows of a block of residual signal, wherein the start position for the first row of the range is specified as the first side position and the end position is specified for the last row of the range as the end position, and wherein a sampling position is specified for each of the rows between the first row and the last row of the range so that the sampling position is a monotonic function of the row position within a block, and wherein the set of samples comprises the samples for which the distance to the sampling position of the row is not greater than the distance threshold.
  • the distance threshold is smaller than corresponding block side length, i.e. it could be set to half of the height or half of the width of the block.
  • Embodiments of this application disclose a mechanism of resampling a block to obtain this near-boundary region that is processed as a transform block / transform unit.
  • Prediction unit PU1 601 and prediction unit PU2 602 are combined using TPM technique to get a predictor, wherein a prediction error is calculated for these units.
  • a residue block contains 2 zero-residue regions 611 and 612, and region 613 is resampled into a transform block (TB) 623, that the TB623 represents residues for a color component of a transform unit (TU).
  • regions 611 and 612 residues are assumed to be zero, whereas residual should be non zero in region 613.
  • region 613 covers the area where weights at least for one prediction unit PU1 or PU2 are non- zero.
  • residue signal from region 613 can be resampled into transform block 623 by reading samples from memory row-wise or column-wise.
  • non-zero residuals showed in region 701 covers a part of the area where weights at least for one prediction unit PU1 or PU2 are non-zero.
  • regions 702 and 703 residues are assumed to be quantized out to zero. So, transform block 704 that represents residues for a color component of a transform unit (TU) is the result of resampling region 701.
  • processing steps for the TPM case are presented as 2 flow-charts for decoder and encoder, respectively.
  • step 801 residual data are decoded, inverse quantization and inverse transform (if any) are performed to obtain transform blocks (TBs) of a TU.
  • inverse resampling 802 restores residues within each transform block (TB) of a TU placing samples of a transform blocks at corresponding positions within a residue block.
  • Fig. 6 Similarly, this correspondence is also shown in Fig. 7. Regions 611 and 612 in Fig. 6 or regions 702 and 703 in Fig. 7 are filled in by zero.
  • Step 803 corresponds to PU reconstruction using the restored residues and TPM predictor.
  • the order of actions shown in Fig. 8 for TPM is as follows.
  • prediction process is fulfilled to get a predictor for a unit, residues are obtained according to the predictor.
  • samples corresponds to region 613 in Fig. 6 or region 701 in Fig. 7 are fetched from memory either row-wise or column-wise to get transform blocks of a TU. Forward transform, quantization and residual coding are performed as in step 813.
  • regions 902, 904, 912 and 914 residues are assumed to be zero.
  • the boundary between regions 902 and 904 is shown by line 903, whereas the boundary between regions 912 and 914 is shown by line 913.
  • the near-boundary regions 901 or 911 cover the area between regions 902 and 904 as well as 912 and 914 in different ways as Fig. 9 illustrates, respectively.
  • regions 901 or 911 are resampled into transform blocks of different shapes 905 and 915, respectively.
  • step 1001 residual are decoded, inverse quantization and inverse transform (if any) are performed to obtain transform blocks of a TU. Then, inverse resampling 1002 should restore residues within each transform block of a TU, placing samples of a transform blocks at corresponding positions within a residue blocks.
  • Fig. 9 Regions 902, 904, 912 and 914 in Fig. 9 are filled in by zero.
  • Final step 1003 corresponds to PU reconstruction using the restored residues and GMP predictor.
  • step 1011 prediction process is fulfilled to get a predictor for a unit and then residues are obtained.
  • step 1012 samples corresponds to regions 901 and 911 in Fig. 9 are fetched from memory either row-wise or column-wise to get transform blocks of a TU.
  • forward transform, quantization and residual coding are performed as in step 1013.
  • the proposed mechanism adds one more state that should be signal.
  • Fig. 11 we disclose a signaling mechanism for the proposed method exemplarily applied to TPM.
  • steps 1101 and 1102 the value of the flags MergeTriagleFlag and cbf are checked. If the values of both MergeTriagleFlag and cbf flags is set to 1, then the flag ShapeAdaptiveResamplingFlag should be checked.
  • the encoder side its value can be iterated in Rate-Distortion Optimization procedure. So, its set value should be read from memory.
  • a value of ShapeAdaptiveResamplingFlag should be parsed from a bit-stream.
  • ShapeAdaptiveResamplingFlag 1
  • cbf Coded Block Flag
  • cu cbf for an entire coding unit (CU)
  • tu cbf luma tu cbf cb
  • tu cbf cr are CBFs for luma, Cb, and Cr components of TU, respectively.
  • the abbreviation cbf in step 1102 may denote any of this flag. Of course, the meaning of this flag is different in each case. If cu cbf is checked, then the proposed resampling is applied to each color component. Otherwise, it is used only for a concrete color component (luma, Cb, or Cr).
  • the height of a region to be resampled and, therefore, the height of a TB can be different.
  • the height of region 613 in Fig. 6 differs the height of region 701 in Fig. 7.
  • the height of a region to be resampled and, therefore, the height of a TB should be adjustable.
  • the 1 st mechanism to adjust the height of a region to be resampled and, therefore, the height of a TB is to derive it using an entire block shape and size.
  • the 2 nd mechanism to adjust the height of a region to be resampled and, therefore, the height of a TB is to signal it in a bit-stream as shown in Fig. 12.
  • Steps 1201-1203 are same as steps 1101-1103 in Fig. 11.
  • the value of ShapeAdaptiveResamplingFlag is checked whether it equals 1 or not.
  • ShapeAdaptiveResamplingFlag 1
  • the syntax element ShapeAdaptiveResampling should be read from memory (at the encoder side) or parsed from a bit-stream (at the decoder side) at step 1205.
  • Different codes can be used to encode or decode the syntax element ShapeAdaptiveResampling. For example, if it is necessary to choose only between 2 values of the heights of a region to be resampled and, therefore, the height of a TB, 1 bin flag can be used. If more options (3 or more variants of the height) are available, unary truncated code, fixed-length code, exponential Golomb-Rice code, etc. might be used as codes.
  • Fetch sample p[x][y] locates within region 1301 immediately on block boundaries and marked by white circles in Fig. 13;
  • the proposed deblocking filter is directional.
  • the propagation directions are marked by arrows 1304 and 1305 in Fig. 13.
  • FIG. 14 Another mechanism to deblock boundaries between regions 1401 and 1402 as well as 1401 and 1403 is presented in Fig. 14.
  • Spatial filter of (2 N +l)x(2 M +l) size (where N andMare non-zero integer values) are applied on the boundaries between regions 1401 and 1402 as well as 1401 and 1403 so that the spatial filter is fed by a group of samples that contains at least one sample belonging to region 1401 and at least one sample belonging to region 1402 or 1403.
  • regions where spatial filter is applied have sizes of of 3x3 and are denoted by 1404 and 1405 have size.
  • This spatial filter should relate to the type of low-pass smoothing filters. If a 3x3 Gaussian filter is used, its coefficients can be as follows:
  • a near boundary region is defined by the partitioning process of GMP that subdivides a PU onto two regions using a straight line. This line has an intersection with the PU boundary in two points corresponding to two integer positions.
  • partitioning There are 6 cases of partitioning, four of these cases split PU into one triangle and 1 pentagon area, and the rest two cases split PU into two trapeze areas.
  • these two positions are located on top and bottom side, or on the left and right sides of the PU.
  • ⁇ xs,y s ⁇ and ⁇ x E ,y E ⁇ denote start and end positions, shown in Fig 15 and Fig 16 respectively, for a colomn-wise and a row- wise scans.
  • S TB denotes height TB (Fig 15) or width TB (Fig 16) of the subsampled block and is further referred to as a subsampling width Sw.
  • samples of the subsampled block B(x, y) are obtained from PU samples p(x,y) as follows:
  • samples of the subsampled block B(x,y ) are obtained from PU samples p(x,y) as follows:
  • selection of the scan depends on whether a horizontal or vertical component of the start and end positions are closer to the corner that is aligned with the resulting triangle.
  • x s — x E is quantized to the closest power-of-two value and a column-wise scan is applied.
  • S w is selected in such a way that the resulting near-boundary region is inside the PU.
  • Geometrical partitioning Another mechanism of non-rectangular partitioning known as Geometrical partitioning (GEO) was disclosed in contribution JVET-O0489 “Non-CE4: Geometrical partitioning for inter blocks” by S. Esenlik, H. Gao, A. Filippov, V. Rufitskiy, A.M. Kotra, B. Wang, Z. Zhao, E. Alshina, M. Blaser, J. Sauer) to the 16 th JVET meeting, Gothenburg, Sweden, July 2019.
  • GEO is very similar to GMP using a subset of GMP’s features and capabilities.
  • Fig. 17 illustrates how shape-adaptive resampling can be applied to a block where GEO is used.
  • Fig. 17 illustrates how shape-adaptive resampling can be applied to a block where GEO is used.
  • modes 1810 and 1820 correspond to TPM with different values of a split flag (split direction flag).
  • Subblocks 1811 and 1812 as well as subblocks 1821 and 1822 denote both prediction blocks for triangular partitioning modes 1810 and 1820, respectively.
  • Partitioning modes 1830, 1840, 1850, 1860, 1870, 1880, and 1890 are beyond the capabilities of the VTM-6.0 software and VVC specification draft version 6. These modes are generated by GEO. Each of them requires two prediction blocks such as 1831 and 1832 for partitioning mode 1830.
  • a prediction block defines an inter-predictor that can be taken only out of a set of merge candidates also known as merge candidate list. In fact, mechanisms of constructing the merge candidate list are shared by (i.e. is the same for) both TPM and GEO. Note that the maximum number of triangular merge mode candidates, MaxNumTriangleMergeCand, is derived as follows:
  • MaxNumTriangleMergeCand MaxNumMergeCand - max_num_merge_cand_minus_max_num_triangle_cand.
  • MaxNumTriangleMergeCand When max_num_merge_cand_minus_max_num_triangle_cand is present in a slice header, the value of MaxNumTriangleMergeCand shall be in the range of 2 to MaxNumMergeCand, inclusive.
  • MaxNumTriangleMergeCand When max_num_merge_cand_minus_max_num_triangle_cand is not present, and (sps triangle enabled flag is equal to 0 or MaxNumMergeCand is less than 2), MaxNumTriangleMergeCand is set equal to 0. When MaxNumTriangleMergeCand is equal to 0, triangle merge mode is not allowed for the current slice. sps_triangle_enabled_flag specifies whether triangular shape based motion compensation (also known as TPM or triangular prediction mode) can be used for inter prediction.
  • TPM triangular shape based motion compensation
  • sps_triangle_enabled_flag 0 specifies that the syntax shall be constrained such that no triangular shape based motion compensation is used in the coded video sequence (CVS), and merge triangle split dir, merge triangle idxO, and merge triangle idxl are not present in coding unit syntax of the CVS.
  • sps_triangle_enabled_flag 1 specifies that triangular shape based motion compensation can be used in the CVS.
  • MaxNumMergeCand 6 - six_minus_max_num_merge_cand.
  • MaxNumMergeCand shall be in the range of 1 to 6, inclusive.
  • the value of six_minus_max_num_merge_cand is inferred to be equal to pps_six_minus_max_num_merge_cand_plusl - 1.
  • six minus max num merge cand specifies the maximum number of merging MVP candidates supported in the slice subtracted from 6.
  • pps_six_minus_max_num_merge_cand_plusl 0 specifies that six_minus_max_num_merge_cand is present in a slice header of slices referring to the PPS.
  • pps_six_minus_max_num_merge_cand_plusl is greater than 0 specifies that six_minus_max_num_merge_cand is not present in the slice header of slices referring to the picture parameter set (PPS).
  • PPS picture parameter set
  • the value of pps_six_minus_max_num_merge_cand_plusl shall be in the range of 0 to 6, inclusive.
  • GEO Global_merge_idxO and geo_merge_idxl define what MVP information is set to subblocks
  • geo_partition_idx indicates a selected partition mode (among, e.g., 64, 80, 140, etc. possibilities subject to GEO implementation) and is coded using truncated binary binarization and bypass coding.
  • geo_partition_idx is used as an index to the lookup table that stores values of a and p parameter pairs that are respectively denoted by 1921 and 1922 in Fig. 19.
  • the partitions of the GEO mode do not include partitions that can be obtained by TPM of binary splitting.
  • TPM and GEO divide a block into 2 subblocks that MVP candidate indices geo_merge_idx0 and geo_merge_idxl are assigned to.
  • Current implementations signal non-rectangular subblock partitioning and prediction related information for B and P slices, which increases signaling overhead.
  • TPM and GEO are not applicable for P-slices so that undesired signalling overhead is created.
  • Table 3 Merge data syntax
  • Embodiments of the invention signal any information related to TPM, GEO and similar video coding tools, e.g. any other non-rectangular partitioning or prediction based video coding tools, only for B-slices as, for example, shown in Table 4.
  • Table 4. The proposed general slice header syntax for TPM
  • bi-directional optical flow also known as BIO
  • BIO is a sample-wise motion refinement on the top of block-wise motion compensation for “true” bi-directional prediction, which means, one of the two reference pictures is prior to the current picture in display order and the other is after the current picture 2020 in display order (Fig. 20).
  • BDOF is built on the assumption of the continuous optical flow across the time domain in the local vicinity. It is only applied to the luma component.
  • the motion vector field (v x , v y ) is determined by minimizing the difference D between the values in corresponding points of the two reference pictures:
  • D is defined as follows: where 1° and I 1 are the luma sample values from reference picture 0 and 1 (denoted as 2010 and 2030 in Fig. 20), respectively, after block motion compensation t o and t 1 denote the distances to the reference picture 0 and 1 from the current picture. 1) represent the horizontal and vertical gradients at location (i, j) , which represents all the points in a 3 x 3 square window W centered on the currently predicted point (i, j). BDOF requires the decoder side to perform more complex operations than the traditional motion compensation. It was reported that 13 multiplications / samples are required for performing BDOF operation.
  • decoder side motion vector (MV) refinement applies to bi-predictive merge candidates.
  • the initial MV pair (MV0 and MV1) taken from reference pictures 2110 and 2130, respectively, is suggested by the selected merge candidate.
  • a pair of prediction blocks is generated by using the initial MV pair from the merge candidate.
  • Atemplate block is generated by averaging these two prediction blocks.
  • template matching costs between the generated template block and the reference block indicated by each of the eight neighboring positions around the original MV are checked. The position with a minimum cost is indicated as MV’0 (MV’ 1). This updated MV pair will be used to generate the final prediction signal.
  • Embodiments of the invention signal any information related to BDOF, DMVR and similar video coding tools, e.g. any other motion refinement video coding tools for bi-directional prediction, only for B-slices as, for example, shown in Table 5.
  • sps bdof dmvr slice present flag 1 specifies that slice disable bdof dmvr flag is present in slice headers referring to the SPS.
  • sps bdof dmvr slice present flag 0 specifies that slice disable bdof dmvr flag is not present in slice headers referring to the SPS.
  • the value of sps bdof dmvr slice present flag is inferred to be equal to 0.
  • slice disable bdof dmvr flag 1 specifies that neither of bi-directional optical flow inter prediction and decoder motion vector refinement based inter bi-prediction is enabled in the current slice.
  • slice disable bdof dmvr flag 0 specifies that bi-directional optical flow inter prediction or decoder motion vector refinement based inter bi-prediction may or may not be enabled in the current slice.
  • slice disable bdof dmvr flag is not present, the value of slice disable bdof dmvr flag is inferred to be 0.
  • Table 6 and Table 7 the embodiments related to TPM, BDOF and DMVR syntax are presented. Table 6. The disclosed general slice header syntax for TPM, BDOF and DMVR
  • semantics of the DMVR and BDOF related flags may be defined as follows.
  • sps bdof dmvr slice present flag 1 specifies that slice disable bdof dmvr flag is present in slice headers referring to the SPS.
  • sps bdof dmvr slice present flag 0 specifies that slice disable bdof dmvr flag is not present in slice headers referring to the SPS.
  • the value of sps bdof dmvr slice present flag is inferred to be equal to 0.
  • slice disable bdof dmvr flag 1 specifies that neither of bi-directional optical flow inter prediction and decoder motion vector refinement based inter bi-prediction is enabled in the current slice.
  • slice disable bdof dmvr flag 0 specifies that bi-directional optical flow inter prediction or decoder motion vector refinement based inter bi-prediction may or may not be enabled in the current slice.
  • slice disable bdof dmvr flag When slice type is not equal to B, the value of slice disable bdof dmvr flag is inferred to be 1. Otherwise, when slice disable bdof dmvr flag is not present, the value of slice disable bdof dmvr flag is inferred to be 0.
  • VVC Video Coding
  • a picture header is indicated as a special-type of a network access layer (NAL) unit.
  • NAL network access layer
  • nuhjayerjd When nal_unit_type is equal to PH_NUT, the value of nuhjayerjd shall be equal to the value of nuhjayerjd of the VCL NAL units of the layer access unit containing the picture header NAL unit.
  • PH NUT denotes a “Picture header” type of a NAL unit.
  • Access unit may comprise several NAL units that are signaled in accordance with the coding order.
  • This coding order may be determined, e.g. as follows:
  • This clause specifies the order of NAL units and coded pictures and their association to layer access units and access units for CVSs that conform to one or more of the profiles specified in Annex A and that are decoded using the decoding process specified in clauses 2 through 10.
  • a layer access unit consists of one picture header NAL unit, one coded picture, which comprises of one or more VCL NAL units, and zero or more non-VCL NAL units.
  • VCL NAL units to coded pictures.
  • An access unit consists of one or more layer access units in increasing order of nuhjayerjd.
  • the first access unit in the bitstream starts with the first NAL unit of the bitstream.
  • firstPicHeaderNalUnitlnAu be a picture header NAL unit that is the picture header of the first coded picture for which the derived PicOrderCntVal differs from the PicOrderCntVal of the previous coded picture.
  • nal_unit_type in the range of UNSPEC28..UNSPEC29 (when present).
  • Each layer access unit shall include one and only one picture header NAL unit, which shall precede the first VCL NAL unit of the layer access unit.
  • nal_unit_type equal to SUFFIX_SEI_NUT, FD_NUT, or RSV_NVCL_27, or in the range of UNSPEC_30..UNSPEC_31 in a layer access unit shall not precede the first VCL NAL unit of the layer access unit.
  • NAL unit When an end of sequence NAL unit is present in an access unit, it shall be the last NAL unit among all NAL units with in the access unit other than an end of bitstream NAL unit (when present).
  • the picture header contains information that is common for all slices of the coded picture for which the next VCL NAL unit in decoding oder is the first coded slice.
  • pic_type indicates the the characterization of the coded pictures as listed in Table 73 for the given value of pic_type.
  • the value of pic_type shall be equal to 0 to 5, inclusive, in bitstreams conforming to this version of this Specification. Other values of pic_type are reserved for future use by ITU-T
  • pic_type pic_parameter_set_id specifies the value of pps_pic_parameter_set_id for the PPS in use.
  • the value of pic_parameter_set_id shall be in the range of 0 to 63, inclusive.
  • non_reference_picture_flag 1 specifies the picture associated with the picture header is never used as a reference picture.
  • non_reference_picture_flag 0 specifies the picture may or may not be used as a reference picture.
  • colour_plane_id specifies the colour plane associated with the picture associated with the picture header when separate_colour_plane_flag is equal to 1.
  • the value of colour_plane_id shall be in the range of 0 to 2, inclusive.
  • colour_plane_id values 0, 1 and 2 correspond to the Y, Cb and Cr planes, respectively.
  • pic_order_cnt_lsb specifies the picture order count modulo MaxPicOrderCntLsb for the picture associated with the picture header.
  • the length of the pic_order_cnt_lsb syntax element is log2_max_pic_order_cnt_lsb_minus4 + 4 bits.
  • the value of the pic_order_cnt_lsb shall be in the range of 0 to MaxPicOrderCntLsb - 1, inclusive.
  • recovery_poc_cnt specifies the recovery point of decoded pictures in output order.
  • the picture picA is referred to as the recovery point picture. Otherwise, the first picture in output order that has PicOrderCntVal greater than the PicOrderCntVal of the current picture plus the value of recovery_poc_cnt is referred to as the recovery point picture.
  • the recovery point picture shall not precede the current GDR picture in decoding order.
  • the value of recovery_poc_cnt shall be in the range of 0 to MaxPicOrderCntLsb - 1, inclusive.
  • variable RpPicOrderCntVal is derived as follows:
  • no_output_of_prior_pics_flag affects the output of previously-decoded pictures in the decoded picture buffer after the decoding of a CLVSS picture that is not the first picture in the bitstream as specified in Annex C.
  • pic_output_flag affects the decoded picture output and removal processes as specified in Annex C. When pic_output_flag is not present, it is inferred to be equal to 1.
  • pi c _rpl_present_flag 1 specifies that reference picture list signalling is present in the picture header.
  • pi c _ r pl_p r esent_flag 0 specifies that reference picture list signalling is not present in the picture header and may be present in slice headers of slices of the picture. When not present, the value of pi c _ r pl_present_flag is inferred to be equal to 0.
  • pic_rpl_sps_flag[ i ] 1 specifies that reference picture list i of the picture is derived based on one of the ref_pic_list_struct( listldx, rplsldx ) syntax structures with listldx equal to i in the SPS.
  • ref_pic_list_sps_flag[ i ] 0 specifies that reference picture list i of the picture is derived based on the ref_pic_list_struct( listldx, rplsldx ) syntax structure with listldx equal to i that is directly included in the picture header.
  • pic_rpl_sps_flag[ i ] is inferred to be equal to 0.
  • pic_rpl_sps_flag[ i ] is inferred to be equal to pps_ref_pic_list_sps_idc[ i ] - 1.
  • pic_rpl_idx[ i ] specifies the index, into the list of the ref_pic_list_struct( listldx, rplsldx ) syntax structures with listldx equal to i included in the SPS, of the ref_pic_list_struct( listldx, rplsldx ) syntax structure with listldx equal to i that is used for derivation of reference picture list i of the current picture.
  • pic_rpl_idx[ i ] is represented by Ceil( Log2( num_ref_pic_lists_in_sps[ i ] ) ) bits.
  • the value of pic_rpl_idx[ i ] is inferred to be equal to 0.
  • the value of pic_rpl_idx[ i ] shall be in the range of 0 to num_ref_pic_lists_in_sps[ i ] - 1, inclusive.
  • pic_rpl_sps_flag[ i ] When pic_rpl_sps_flag[ i ] is equal to 1 and num_ref_pic_lists_in_sps[ i ] is equal to 1, the value of pic_rpl_idx[ i ] is inferred to be equal to 0.
  • pic_rpl_sps_flag[ i ] is equal to 1 and rpll_idx_present_flag is equal to 0, the value of pic_rpl_idx[ 1 ] is inferred to be equal to pic_rpl_idx[ 0 ].
  • PicRplsIdx[ i ] pic_rpl_sps_flag[ i ] ? pic_rpl_idx[ i ] : num_ref_pic_lists_in_sps[ i ] (7-95)
  • pic_poc_lsb_lt[ i ] [ j ] specifies the value of the picture order count modulo MaxPicOrderCntLsb of the j-th LTRP entry in the i-th reference picture list for the picture associated with the picture header.
  • the length of the pic_poc_lsb_lt[ i ][ j ] syntax element is log2_max_pic_order_cnt_lsb_minus4 + 4 bits.
  • pic_poc_lsb_lt[ i ] [ j ] : rpls_poc_lsb_lt[ listldx ] [ PicRplsIdx[ i ] ] [ j ]
  • pic_delta_poc_msb_present_flag[ i ][ j ] 1 specifies that pic_delta_poc_msb_cycle_lt[ i ][ j ] is present.
  • pic_delta_poc_msb_present_flag[ i ][ j ] 0 specifies that pic_delta_poc_msb_cycle_lt[ i ][ j ] is not present.
  • prevTidOPic be the previous picture in decoding order that has nuhjayerjd the same as the picture header, has Temporalld equal to 0, and is not a RASL or RADL picture.
  • setOfPrevPocVals be a set consisting of the following: the PicOrderCntVal of prevTidOPic, the PicOrderCntVal of each picture that is referred to by entries in RefPicList[ 0 ] or RefPicList[ 1 ] of prevTidOPic and has nuh layer id the same as the current picture, the PicOrderCntVal of each picture that follows prevTidOPic in decoding order, has nuh layer id the same as the current picture, and precedes the current picture in decoding order.
  • PicFullPocLt[ i ][ j ] PicOrderCntVal - deltaPocMsbCycleLt[ i ][ j ] * MaxPicOrderCntLsb - ( PicOrderCntVal & ( MaxPicOrderCntLsb - 1 ) ) + PicPocLsbLt[ i ] [ j ]
  • pic_delta_poc_msb_cycle_lt[ i ][ j ] shall be in the range of 0 to 2(32 - iog2_max_pic_order_cnt_isb_minus4 - 4 ), inclusive.
  • pic_delta_poc_msb_cycle_lt[ i ][ j ] is inferred to be equal to 0.
  • pic_temporal_mvp_enabled_flag specifies whether temporal motion vector predictors can be used for inter prediction.
  • pic_temporal_mvp_enabled_flag is equal to 0
  • the syntax elements of the picture associated with the picture header shall be constrained such that no temporal motion vector predictor is used in decoding of the picture. Otherwise (pic_temporal_mvp_enabled_flag is equal to 1), temporal motion vector predictors may be used in decoding of the picture.
  • pic_level_joint_cbcr_sign_flag 1 specifies that slicej ' oint_cbcr_sign_flag is not present in slice header.
  • pic_levelj ' oint_cbcr_sign_flag 0 specifies that slicej ' oint_cbcr_sign_flag may be present in slice header.
  • the value of pic_levelj ' oint_cbcr_sign_flag is inferred to be equal to 0.
  • pic_level_alf_enabled_flag 1 specifies that adaptive loop filter is enabled for all slices belong to the picture associated with the picture header and may be applied to Y, Cb, or Cr colour component in the slices.
  • pic_level_alf_enabled_flag 0 specifies that adaptive loop filter may be disabled for one, or more, or all slices belong to the picture associated with the picture header.
  • pic_level_alf_enabled_flag is inferred to be equal to 0.
  • pic_num_alf_aps_ids_luma specifies the number of ALF APSs that the slices belong to the picture associated with the picture header refers to.
  • slice_num_alf_aps_ids_luma shall be in the range of 0 to 7, inclusive.
  • pic_alf_aps_id_luma[ i ] specifies the adaptation_parameter_set_id of the i-th ALF APS that the luma component of the slices of the picture associated with the picture header refers to.
  • pic_alf_chroma_idc 0 specifies that the adaptive loop filter is not applied to Cb and Cr colour components.
  • pic_alf_chroma_idc 1 indicates that the adaptive loop filter is applied to the Cb colour component.
  • pic_alf_chroma_idc indicates that the adaptive loop filter is applied to the Cr colour component.
  • pic_alf_chroma_idc 3 indicates that the adaptive loop filter is applied to Cb and Cr colour components.
  • pic_alf_chroma_idc is not present, it is inferred to be equal to 0.
  • pic_alf_ a ps_id_chroma specifies the adaptation_parameter_set_id of the ALF APS that the chroma component of the slices of the picture associated with the picture header refers to.
  • pic_level_lmcs_enabled_flag 1 specifies that luma mapping with chroma scaling is enabled for all slices belong to the picture associated with the picture header.
  • pic_level_lmcs_enabled_flag 0 specifies that luma mapping with chroma scaling may be disabled for one, or more, or all slices belong to the picture associated with the picture header.
  • pic_level_lmcs_enabled_flag 0 specifies that luma mapping with chroma scaling may be disabled for one, or more, or all slices belong to the picture associated with the picture header.
  • pic_level_lmcs_enabled_flag is inferred to be equal to 0.
  • pic_lmcs_aps_id specifies the adaptation_parameter_set_id of the LMCS APS that the slices of the picture associated with the picture header refers to.
  • pic_chroma_residual_scale_flag 1 specifies that chroma residual scaling is enabled for the all slices belong to the picture associated with the picture header.
  • pic_chroma_residual_scale_flag 0 specifies that chroma residual scaling may be disabled for one, or more, or all slices belong to the picture associated with the picture header.
  • pic_chroma_residual_scale_flag not present, it is inferred to be equal to 0.
  • pic_level_scaling_list_present_flag 1 specifies that the scaling list data used for slices of the picture associated with the picture header is derived based on the scaling list data contained in the referenced scaling list APS.
  • pic_level_scaling_list_present_flag 0 specifies that the scaling list data used for one, or more, or all slices of the picture associated with the picture header is the default scaling list data derived specified in clause 7.4.3.16. When not present, the value of pic_level_scaling_list_present_flag is inferred to be equal to 0.
  • pic_scaling_list_aps_id specifies the adaptation_parameter_set_id of the scaling list APS.
  • a picture header syntax may be defined using the following table: Table 8. Picture header syntax Correspondingly with the picture-level syntax described by the table above, a slice header syntax may be defined as shown in the table below:
  • semantics of a picture header may be described as follows.
  • slice_pic_parameter_set_id specifies the value of pps_pic_parameter_set_id for the PPS in use.
  • the value of slice_pic_parameter_set_id shall be in the range of 0 to 63, inclusive.
  • non_reference_picture_flag 1 specifies the picture containing the slice is never used as a reference picture.
  • non_reference_picture_flag 0 specifies the picture containing the slice may or may not be used as a reference picture.
  • colour_plane_id specifies the colour plane associated with the current slice RBSP when separate_colour_plane_flag is equal to 1. The value of colour_plane_id shall be in the range of 0 to 2, inclusive. colour_plane_id values 0, 1 and 2 correspond to the Y, Cb and Cr planes, respectively.
  • slice_pic_order_cnt_lsb specifies the picture order count modulo MaxPicOrderCntLsb for the current picture.
  • the length of the slice_pic_order_cnt_lsb syntax element is log2_max_pic_order_cnt_lsb_minus4 + 4 bits.
  • the value of the slice_pic_order_cnt_lsb shall be in the range of 0 to MaxPicOrderCntLsb - 1, inclusive.
  • pic_output_flag affects the decoded picture output and removal processes as specified in Annex C.
  • partition_constraints_override_flag 1 specifies that partition constraint parameters are present in the slice header.
  • partition_constraints_override_flag 0 specifies that partition constraint parameters are not present in the slice header.
  • the value of partition_constraints_override_flag is inferred to be equal to 0.
  • slice_log2_diff_min_qt_min_cb_luma specifies the difference between the base 2 logarithm of the minimum size in luma samples of a luma leaf block resulting from quadtree splitting of a CTU and the base 2 logarithm of the minimum coding block size in luma samples for luma CUs in the current slice.
  • the value of slice_log2_diff_min_qt_min_cb_luma shall be in the range of 0 to CtbLog2SizeY - MinCbLog2SizeY, inclusive.
  • the value of slice_log2_diff_min_qt_min_cb_luma is inferred as follows:
  • slice_log2_diff_min_qt_min_cb_luma If slice type equal to 2 (I), the value of slice_log2_diff_min_qt_min_cb_luma is inferred to be equal to sps_log2_diff_min_qt_min_cb_intra_slice_luma
  • slice_log2_diff_min_qt_min_cb_luma is inferred to be equal to sps_log2_diff_min_qt_min_cb_inter_slice.
  • slice_max_mtt_hierarchy_depth_luma specifies the maximum hierarchy depth for coding units resulting from multi-type tree splitting of a quadtree leaf in the current slice.
  • the value of slice_max_mtt_hierarchy_depth_luma shall be in the range of 0 to CtbLog2SizeY - MinCbLog2SizeY, inclusive.
  • slice_max_mtt_hierarchy_depth_luma is inferred as follows: If slice type equal to 2 (I), the value of slice max mtt hierarchy depth luma is inferred to be equal to sps_max_mtt_hierarchy_depth_intra_slice_luma
  • slice_log2_diff_max_bt_min_qt_luma shall be in the range of 0 to CtbLog2SizeY - MinQtLog2SizeY, inclusive.
  • slice_log2_diff_max_bt_min_qt_luma is inferred as follows:
  • slice_log2_diff_max_bt_min_qt_luma is inferred to be equal to sps_log2_diff_max_bt_min_qt_intra_slice_luma
  • slice_log2_diff_max_bt_min_qt_luma specifies the difference between the base 2 logarithm of the maximum size (width or height) in luma samples of a luma coding block that can be split using a ternary split and the minimum size (width or height) in luma samples of a luma leaf block resulting from quadtree splitting of a CTU in in the current slice.
  • slice_max_mtt_hierarchy_depth_chroma When not present, the values of slice_max_mtt_hierarchy_depth_chroma is inferred to be equal to sps_max_mtt_hierarchy_depth_intra_slices_chroma.
  • slice_log2_diff_max_bt_min_qt_chroma specifies the difference between the base 2 logarithm of the maximum size (width or height) in luma samples of a chroma coding block that can be split using a binary split and the minimum size (width or height) in luma samples of a chroma leaf block resulting from quadtree splitting of a chroma CTU with treeType equal to DUAL_TREE_CHROMA in the current slice.
  • slice_log2_diff_max_bt_min_qt_chroma shall be in the range of 0 to CtbLog2SizeY - MinQtLog2SizeC, inclusive.
  • the value of slice_log2_diff_max_bt_min_qt_chroma is inferred to be equal to sps_log2_diff_max_bt_min_qt_intra_slice_chroma
  • slice_log2_diff_max_tt_min_qt_chroma specifies the difference between the base 2 logarithm of the maximum size (width or height) in luma samples of a chroma coding block that can be split using a ternary split and the minimum size (width or height) in luma samples of a chroma leaf block resulting from quadtree splitting of a chroma CTU with treeType equal to DUAL_TREE_CHROMA in the current slice.
  • MinQtLog2SizeY MinCbLog2SizeY + slice_log2_diff_min_qt_min_cb_luma (7-99)
  • MinQtLog2SizeC MinCbLog2SizeY + slice_log2_diff_min_qt_min_cb_chroma (7-100)
  • MinQtSizeY 1 « MinQtLog2SizeY (7-101)
  • MinQtSizeC 1 « MinQtLog2SizeC (7-102)
  • MaxBtSizeY 1 « ( MinQtLog2SizeY + slice_log2_diff_max_bt_min_qt_luma ) (7-103)
  • MinBtSizeY 1 « MinCbLog2SizeY (7-105)
  • MaxTtSizeY 1 « ( MinQtLog2SizeY + slice_log2_diff_max_tt_min_qt_luma ) (7-106)
  • MaxTtSizeC 1 « ( MinQtLog2SizeC + slice_log2_diff_max_tt_min_qt_chroma ) (7-107)
  • MinTtSizeY 1 « MinCbLog2SizeY (7-108)
  • MaxMttDepthY slice max mtt hierarchy depth luma (7-109)
  • MaxMttDepthC slice max mtt hierarchy depth chroma (7-110) slice_temporal_mvp_enabled_flag specifies whether temporal motion vector predictors can be used for inter prediction. If slice_temporal_mvp_enabled_flag is equal to 0, the syntax elements of the current picture shall be constrained such that no temporal motion vector predictor is used in decoding of the current picture. Otherwise (slice_temporal_mvp_enabled_flag is equal to 1), temporal motion vector predictors may be used in decoding of the current picture.
  • slice_temporal_mvp_enabled_flag When slice_temporal_mvp_enabled_flag is not present, the following applies:
  • mvd_ll_zero_flag 0 indicates that the mvd_coding( xO, yO, 1 ) syntax structure is parsed.
  • the value of mvd_ll_zero_flag is inferred to be equal to pps_mvd_ll_zero_idc - 1.
  • six_minus_max_num_merge_cand specifies the maximum number of merging motion vector prediction (MVP) candidates supported in the slice subtracted from 6.
  • MVP merging motion vector prediction
  • MaxNumMergeCand 6 - six minus max num merge cand (7-111)
  • MaxNumMergeCand shall be in the range of 1 to 6, inclusive.
  • the value of six_minus_max_num_merge_cand is inferred to be equal to pps_six_minus_max_num_merge_cand_plusl - 1.
  • five_minus_max_num_subblock_merge_cand specifies the maximum number of subblock-based merging motion vector prediction (MVP) candidates supported in the slice subtracted from 5.
  • sps affine enabled flag is equal to 0, the value of five_minus_max_num_subblock_merge_cand is inferred to be equal to 5 - ( sps sbtmvp enabled flag && slice temporal mvp enabled flag ).
  • MaxNumSubblockMergeCand The maximum number of subblock-based merging MVP candidates, MaxNumSubblockMergeCand is derived as follows:
  • MaxNumSubblockMergeCand 5 - five_minus_max_num_subblock_merge_cand (7-112) The value of MaxNumSubblockMergeCand shall be in the range of 0 to 5, inclusive.
  • slice_fpel_mmvd_enabled_flag 1 specifies that merge mode with motion vector difference uses integer sample precision in the current slice.
  • slice_fpel_mmvd_enabled_flag 0 specifies that merge mode with motion vector difference can use fractional sample precision in the current slice. When not present, the value of slice_fpel_mmvd_enabled_flag is inferred to be 0.
  • slice_disable_bdof_dmvr_flag 1 specifies that neither of bi-directional optical flow inter prediction and decoder motion vector refinement based inter bi-prediction is enabled in the current slice.
  • slice_disable_bdof_dmvr_flag 0 specifies that bi-directional optical flow inter prediction or decoder motion vector refinement based inter bi-prediction may or may not be enabled in the current slice.
  • slice_disable_bdof_dmvr_flag is not present, the value of slice_disable_bdof_dmvr_flag is inferred to be 0.
  • max_num_merge_cand_minus_max_num_triangle_cand specifies the maximum number of triangular merge mode candidates supported in the slice subtracted from MaxNumMergeCand.
  • max_num_merge_cand_minus_max_num_triangle_cand is not present, and sps_triangle_enabled_flag is equal to 1 and MaxNumMergeCand greater than or equal to 2
  • max_num_merge_cand_minus_max_num_triangle_cand is inferred to be equal to pps_max_num_merge_cand_minus_max_num_triangle_cand_minusl + 1.
  • MaxNumTriangleMergeCand shall be in the range of 2 to MaxNumMergeCand, inclusive.
  • MaxNumTriangleMergeCand is set equal to 0.
  • slice_six_minus_max_num_ibc_merge_cand specifies the maximum number of IBC merging block vector prediction (BVP) candidates supported in the slice subtracted from 6.
  • BVP block vector prediction
  • MaxNumlbcMergeCand 6 - slice_six_minus_max_num_ibc_merge_cand (7-114)
  • MaxNumlbcMergeCand shall be in the range of 1 to 6, inclusive.
  • dep_quant_enabled_flag 0 specifies that dependent quantization is disabled.
  • dep_quant_enabled_flag 1 specifies that dependent quantization is enabled.
  • the value of dep_quant_enabled_flag is infered to be equal to pps_dep_quant_enable_idc - 1.
  • sign_data_hiding_enabled_flag 0 specifies that sign bit hiding is disabled.
  • sign_data_hiding_enabled_flag 1 specifies that sign bit hiding is enabled.
  • slice_lmcs_enabled_flag 1 specifies that luma mapping with chroma scaling is enabled for the current slice.
  • slice_lmcs_enabled_flag 0 specifies that luma mapping with chroma scaling is not enabled for the current slice.
  • slice_lmcs_enabled_flag not present, it is inferred to be equal to 0.
  • slice_lmcs_aps_id specifies the adaptation_parameter_set_id of the LMCS APS that the slice refers to.
  • slice_chroma_residual_scale_flag 1 specifies that chroma residual scaling is enabled for the current slice.
  • slice_chroma_residual_scale_flag 0 specifies that chroma residual scaling is not enabled for the current slice.
  • slice_scaling_list_present_flag 1 specifies that the scaling list data used for the current slice is derived based on the scaling list data contained in the referenced scaling list APS.
  • slice_scaling_list_present_flag 0 specifies that the scaling list data used for the current pictureis the default scaling list data derived specified in clause 7.4.3.16. When not present, the value of slice_scaling_list_present_flag is inferred to be equal to 0.
  • slice_scaling_list_aps_id specifies the adaptation_parameter_set_id of the scaling list APS.
  • the Temporalld of the APS NAL unit having aps_params_type equal to SCALING_APS and adaptation_parameter_set_id equal to slice_scaling_list_aps_id shall be less than or equal to the Temporalld of the coded slice NAL unit.
  • the access unit delimiter is used to indicate the start of an access unit and the type of slices present in the coded pictures in the access unit containing the access unit delimiter NAL unit. There is no normative decoding process associated with the access unit delimiter.
  • pic_type indicates that the slice_type values for all slices of the coded pictures in the access unit containing the access unit delimiter NAL unit are members of the set listed in Table 73 for the given value of pic_type.
  • the value of pic_type shall be equal to 0, 1 or 2 in bitstreams conforming to this version of this Specification. Other values of pic_type are reserved for future use by ITU-T
  • single_slice_in_pic_flag in SPS.
  • AUD is not mandated to be present.
  • single_slice_in_pic_flag can be used to condition the presence of other syntax elements such as num_bricks_in_slice_minusl; signal a flag aud_in_next_access_unit_present_flag in AUD to specify if AUD is present for next AU.
  • AUD is mandated only when there are more than 1 subpicture.
  • Embodiments of the invention signal any information related to BDOF, DMVR and similar video coding tools, e.g. any other motion refinement video coding tools for bi-directional prediction, only for B-slices.
  • sps bdof dmvr slice present flag equal to 1 specifies that slice disable bdof dmvr flag is present in slice headers referring to the SPS.
  • sps bdof dmvr slice present flag 0 specifies that slice disable bdof dmvr flag is not present in slice headers referring to the SPS.
  • slice disable bdof dmvr flag 1 specifies that neither of bi-directional optical flow inter prediction and decoder motion vector refinement based inter bi-prediction is enabled in the current slice.
  • pic disable bdof dmvr flag has the same semantics as slice disable bdof dmvr flag given in any of the disclosed embodiments.
  • semantics of the DMVR and BDOF related flags may be defined as follows.
  • sps bdof dmvr slice present flag 1 specifies that slice disable bdof dmvr flag is present in slice headers referring to the SPS.
  • sps bdof dmvr slice present flag 0 specifies that slice disable bdof dmvr flag is not present in slice headers referring to the SPS.
  • the value of sps bdof dmvr slice present flag is inferred to be equal to 0.
  • slice disable bdof dmvr flag 1 specifies that neither of bi-directional optical flow inter prediction and decoder motion vector refinement based inter bi-prediction is enabled in the current slice.
  • slice disable bdof dmvr flag 0 specifies that bi-directional optical flow inter prediction or decoder motion vector refinement based inter bi-prediction may or may not be enabled in the current slice.
  • slice disable bdof dmvr flag When slice type is not equal to B, the value of slice disable bdof dmvr flag is inferred to be 1. Otherwise, when slice disable bdof dmvr flag is not present, the value of slice disable bdof dmvr flag is inferred to be 0.
  • pic disable bdof dmvr flag When pic type is not equal to B, the value of pic disable bdof dmvr flag is inferred to be 1. Otherwise, when pic disable bdof dmvr flag is not present, the value of pic disable bdof dmvr flag is inferred to be 0.
  • Semantics of BDOF and DMVR syntax elements is as follows: sps_bdof_enabled_flag equal to 0 specifies that the bi-directional optical flow inter prediction is disabled. sps_bdof_enabled_flag equal to 1 specifies that the bi-directional optical flow inter prediction is enabled. sps_bdof_slice_present_flag equal to 1 specifies that slice_disable_bdof_flag is present in SHs referring to the SPS. sps_bdof_slice_present_flag equal to 0 specifies that slice_disable_bdof_flag is not present in SHs referring to the SPS.
  • sps_bdof_slice_present_flag When sps_bdof_slice_present_flag is not present, the value of sps_bdof_slice_present_flag is inferred to be equal to 0.
  • sps_dmvr_enabled_flag 1 specifies that decoder motion vector refinement based inter bi- prediction is enabled.
  • sps_dmvr_enabled_flag 0 specifies that decoder motion vector refinement based inter bi-prediction is disabled.
  • slice_disable_bdof_flag 1 specifies that bi-directional optical flow inter prediction based inter bi- prediction is disabled in the slice associated with the SH.
  • slice_disable_bdof_flag 0 specifies that bi-directional optical flow inter prediction based inter bi-prediction may or may not be enabled in the slice associated with the SH.
  • slice_disable_dmvr_flag 1 specifies that decoder motion vector refinement based inter bi- prediction is disabled in the slice associated with the SH.
  • slice_disable_dmvr_flag 0 specifies that decoder motion vector refinement based inter bi-prediction may or may not be enabled in the slice associated with the SH.
  • the value of slice_disable_dmvr_flag is inferred to be 1.
  • Embodiments described by Table 16 and Table 17 differs from the ones given in Table 14 and Table 15 by the conditional checks on the slice type.
  • Table 16 and Table 17 check of whether a slice type is non-intra is independent from checking whether the slice type allows bi- directional inter-prediction when performing BDOF and DMVR related checks.
  • Table 14 and Table 15 demonstrate two possible orders of BDOF and DMVR checks. Similarly, Table 16 and Table 17 shows the case when BDOF check precedes DMVR check and vice versa.
  • Slice-level BDOF flag (“slice_disable_bdof_flag”) is further used in the decoding process to disable the BDOF processing at the CU level.
  • slice_disable_bdof_flag is further used in the decoding process to disable the BDOF processing at the CU level.
  • This process is invoked when decoding a coding unit coded in inter prediction mode.
  • variable cbHeight specifying the height of the current coding block in luma samples
  • numSbX and numSbY specifying the number of luma coding subblocks in horizontal and vertical direction
  • predSamplesL0 b predSamplesL1L and predSampleslntra L be (cbWidth)x(cbHeight) arrays of predicted luma sample values and, predSamplesL0 cb ,, predSamplesLlcb, predSamplesLO cr and predSamplesL1cr, predSampleslntracb, and predSamplesIntra cr be (cbWidth / SubWidthC)x(cbHeight / SubHeightC) arrays of predicted chroma sample values.
  • variable currPic specifies the current picture and the variable bdofFlag is derived as follows:
  • bdofFlag is set equal to TRUE.
  • predFlagL0[ xSbldx ][ ySbldx ] and predFlagLl[ xSbldx ][ ySbldx ] are both equal to 1.
  • DiffPicOrderCnt( currPic, RefPicList[ 0 ][ refldxLO ] ) is equal to DiffPicOrderCnt( RefPicList[ 1 ][ refldxLl ], currPic).
  • RefPicList[ 0 ][ refldxLO ] is a short-term reference picture and RefPicList[ 1 ][ refldxLl ] is a short-term reference picture.
  • - luma_weight_I0_flag[ refldxL0 ] and luma_weight_ll_flag[ refldxLl ] are both equal to 0.
  • - cbWidth is greater than or equal to 8.
  • RefPiclsScaled[ 0 ][ refldxLO ] is equal to 0 and RefPiclsScaled[ 1 ][ refldxLl ] is equal to 0.
  • bdofFlag is set equal to FALSE.
  • Slice-level DMVR flag (“slice_disable_dmvr_flag”) is used to disable DMVR process at the CU level as follows:
  • variable cbWidth specifying the width of the current coding block in luma samples
  • variable cbHeight specifying the height of the current coding block in luma samples
  • variable treeType specifying whether a single or a dual tree is used and if a dual tree is used, it specifies whether the current tree corresponds to the luma or chroma components.
  • Output of this process is a modified reconstructed picture before in-loop filtering.
  • the derivation process for quantization parameters as specified in clause 8.7.1 is invoked with the luma location ( xCb, yCb ), the width of the current coding block in luma samples cbWidth and the height of the current coding block in luma samples cbHeight, and the variable treeType as inputs.
  • the decoding process for coding units coded in inter prediction mode consists of the following ordered steps:
  • variable dmvrFlag is set equal to 0 and the variable hpellfldx is set equal to 0.
  • the motion vector components and reference indices of the current coding unit are derived as follows:
  • dmvrFlag is set equal to 1:
  • predFlagL0[ 0 ][ 0 ] and predFlagLl[ 0 ][ 0 ] are equal to 1 - mmvd_merge_flag[ xCb ] [ yCb ] is equal to 0
  • RefPicList[ 0 ] [ refldxLO ] is a short-term reference picture and RefPicList[ 1 ] [ refldxLl ] is a short-term reference picture.
  • RefPiclsScaled[ 0 ][ refldxLO ] is equal to 0 and RefPiclsScaled[ 1 ][ refldxLl ] is equal to 0.
  • the reference picture consisting of an ordered two-dimensional array refPicLXi of luma samples and two ordered two-dimensional arrays refPicLXc b and refPicLXcr of chroma samples is derived by invoking the process specified in clause 8.5.6.2 with X and refldxLX as inputs.
  • numSbX ( cbWidth > 16 ) ? ( cbWidth » 4 ) : 1 (461)
  • numSbY ( cbHeight > 16 ) ? ( cbHeight » 4 ) : 1 (462)
  • sbWidth ( cbWidth > 16 ) ? 16 : cbWidth (463)
  • sbHeight ( cbHeight > 16 ) ? 16 : cbHeight (464)
  • the decoder side motion vector refimenent process specified in clause 8.5.3.1 is invoked with xSb[ xSbldx ][ ySbldx ], ySb[ xSbldx ][ ySbldx ], sbWidth, sbHeight, the motion vectors mvLX[ xSbldx ][ ySbldx ] and the reference picture array refPicLXi as inputs and delta motion vectors dMvLX[ xSbldx ][ ySbldx ] with X equal to 0 and 1, and the mimimum sum of absolute difference in decoder side motion vector refimenent process dmvrSad[ xSbldx ][ ySbldx ] as outputs.
  • ChromaArrayType When ChromaArrayType is not equal to 0, the derivation process for chroma motion vectors in clause 8.5.2.13 is invoked with mvLX[ xSbldx ][ ySbldx ] and refldxLX as inputs, and mvCLX[ xSbldx ][ ySbldx ] as outputs with X equal to 0 and 1.
  • ChromaArrayType is not equal to 0, and treeType is equal to SINGLE_TREE, and predFlagLX[ 0 ] [0 ], with X being 0 or 1, is equal to 1, the derivation process for chroma motion vectors in clause 8.5.2.13 is invoked with mvLX[ 0 ][ 0 ] and refldxLX as inputs, and mvCLX[ 0 ][ 0 ] as output.
  • na When a relational operator is applied to a syntax element or variable that has been assigned the value "na” (not applicable), the value "na” is treated as a distinct value for the syntax element or variable. The value “na” is considered not to be equal to any other value.
  • Bits shifted into the most significant bits (MSBs) as a result of the right shift have a value equal to the MSB of x prior to the shift operation.
  • MSBs most significant bits
  • x ⁇ y Arithmetic left shift of a two's complement integer representation of x by y binary digits. This function is defined only for non-negative integer values of y.
  • Bits shifted into the least significant bits (LSBs) as a result of the left shift have a value equal to 0.
  • x y..z x takes on integer values starting from y to z, inclusive, with x, y, and z being integer numbers and z being greater than y.
  • Asin( x ) the trigonometric inverse sine function, operating on an argument x that is in the range of -1.0 to 1.0, inclusive, with an output value in the range of -p ⁇ 2 to p ⁇ 2, inclusive, in units of radians
  • Clipl c ( x ) Clip3( 0, ( 1 « BitDepth c ) - 1, x ) x ; z ⁇ x
  • Cos( x ) the trigonometric cosine function operating on an argument x in units of radians.
  • Round( x ) Sign( x ) * Floor( Abs( x ) + 0.5 )
  • statement 1 If one or more of the following conditions are true, statement 1 :
  • a type of a slice (slice type) of the video sequence (to be encoded) allows bi-directional inter-prediction (e.g. is a bi-directional inter-prediction slice or B-slice),
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • information related to motion refinement video coding tools for bi-directional prediction e.g., a flag of applying affine motion model, a weight index for bi-prediction with cu-level weights
  • inter-prediction for bi-directionally predicted block and refining motion information for this prediction according to the slice- and block-level information related to motion refinement video coding tools for bi-directional prediction
  • a type of a slice (slice type) of the video sequence (to be encoded) allows bi-directional inter-prediction (e.g. is a bi-directional inter-prediction slice or B-slice),
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • CB coding block
  • CU coding unit
  • Embodiments provide a method for encoding a video sequence (e.g. a coded video sequence, CVS) using motion refinement video coding for bi-directional prediction, wherein the method comprises:
  • a video sequence e.g. a coded video sequence, CVS
  • CVS coded video sequence
  • block-level e.g. coding block (CB)
  • CU coding unit
  • Embodiments provide a method for decoding a video sequence (e.g. a coded video sequence, CVS) using non-rectangular subblock partitioning and prediction, wherein the method comprises:
  • a video sequence e.g. a coded video sequence, CVS
  • CVS coded video sequence
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • motion refinement video coding tools for bi-directional prediction e.g., a flag of applying affine motion model, a weight index for bi-prediction with cu-level weights
  • Embodiments provide a method for decoding a video sequence (e.g. a coded video sequence, CVS) using non-rectangular subblock partitioning and prediction, wherein the method comprises:
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • CB coding block
  • CU coding unit
  • - decoding the block of the video sequence by decoding at least one block predicted using motion refinement video coding tools for bi-directional prediction (e.g. by inverse transformation and dequantization of the residuals, e.g. obtained from the bitstream, and reconstructing the non-rectangular subblocks respectively the block based on the dequantized residual and the predictor obtained from the inter-prediction).
  • motion refinement video coding tools for bi-directional prediction e.g. by inverse transformation and dequantization of the residuals, e.g. obtained from the bitstream, and reconstructing the non-rectangular subblocks respectively the block based on the dequantized residual and the predictor obtained from the inter-prediction.
  • Embodiments provide a method for decoding a video sequence (e.g. a coded video sequence, CVS) using motion refinement video coding for bi-directional prediction, wherein the method comprises:
  • a video sequence e.g. a coded video sequence, CVS
  • CVS coded video sequence
  • block-level e.g. coding block (CB) level or coding unit (CU) level
  • block-level information relates to motion refinement video coding tools for bi-directional prediction
  • Embodiments provide for an efficient encoding and/or decoding and corresponding signalling using motion refinement video coding tools for bi-directional prediction like BDOF and / or DMVR and signal related information in slice headers only for slices which allow or enable bidirectional inter-prediction, e.g. in bidirectional (B) prediction slices, also called B-slices.
  • B bidirectional prediction slices
  • the slice level information related to motion refinement video coding tools for bi-directional prediction may be signaled only for B-slices.
  • the slice level information related to motion refinement video coding tools for bi-directional prediction may be signaled for B-slices.
  • the slice level information related to motion refinement video coding tools for bi-directional prediction may be inferred to be equal to values that disable said motion refinement video coding tools when it is not signaled for B-slices.
  • the method may comprise obtaining sequence parameter set (SPS)-level information (e.g., sps bdof dmvr slice present flag) related to the motion refinement video coding which indicates that signaling slice-level information for the motion refinement video coding is allowable.
  • SPS sequence parameter set
  • the motion refinement video coding may comprise or be BDOF.
  • the motion refinement video coding may comprise or be DMVR.
  • the motion refinement video coding may comprise or be at least one of BDOF and DMVR.
  • the method may comprise the following steps
  • sequence parameter set (SPS)-level BDOF flag e.g., sps_bdof_slice_present_flag
  • sequence parameter set (SPS)-level BDOF flag) e.g., sps_bdof_slice_present_flag
  • the method may comprise the following steps
  • sequence parameter set SPS-level DMVR flag (e.g., sps_dmvr_slice_present flag) related to decoder-side motion vector refinement which (SPS-level DMVR flag) indicates that signalling of a slice-level information related to motion refinement video coding is allowed;
  • the method may further comprise: obtaining sequence parameter set (SPS)-level information (e.g., sps_bdof_dmvr_slice_present flag) related to motion refinement video coding tools for bi- directional prediction; and
  • SPS sequence parameter set
  • the sequence parameter set (SPS)-level information (e.g., sps_bdof_dmvr_slice_present flag) related to motion refinement video coding tools for bi-directional prediction may comprise information related to whether a flag indicating that motion refinement video coding tools for bi-directional prediction (e.g., a parameter, e.g.
  • triangle prediction/partitioning mode and/or GEO prediction/partitioning mode
  • SPS sequence parameter set
  • the method may further comprise: - performing inter-prediction of motion refinement video coding tools for bi-directional prediction (additionally) according to the sequence parameter set level information related to motion refinement video coding tools for bi-directional prediction.
  • the motion refinement video coding tool for bi-directional prediction may comprise or be BDOF.
  • the motion refinement video coding tool for bi-directional prediction may comprise or be DMVR.
  • the motion refinement video coding tools for bi-directional prediction may comprise or be at least one of BDOF and DMVR.
  • Embodiments provide an encoder comprising processing circuitry (e.g. a processor) configured for performing the method according to any one of the foregoing embodiments.
  • processing circuitry e.g. a processor
  • Embodiments provide a decoder comprising processing circuitry (e.g. a processor) configured for performing the method according to any one of the foregoing embodiments.
  • processing circuitry e.g. a processor
  • Embodiments provide an encoder, comprising one or more processors; and a non-transitory computer-readable storage medium coupled to the processors and storing programming for execution by the processors, wherein the programming, when executed by the processors, configures the encoder to carry out the method according to any one of the foregoing embodiments.
  • Embodiments provide a decoder, comprising one or more processors; and a non-transitory computer-readable storage medium coupled to the processors and storing programming for execution by the processors, wherein the programming, when executed by the processors, configures the encoder to carry out the method according to any one of the foregoing embodiments.
  • Embodiments provide a computer program product comprising a program code for performing the method according to any one of the foregoing embodiments.
  • Embodiments provide a non-transitory computer-readable medium carrying a program code which, when executed by a computer device, causes the computer device to perform the method of any one of the foregoing embodiments.
  • a further embodiment provides a method for video encoding, wherein bi-directional prediction is performed using motion refinement, and wherein the method comprises: obtaining SPS-level information related to motion refinement video coding tools for bi- directional prediction;obtaining slice-level information related to motion refinement video coding tools for bi-directional prediction only if a slice type enables bi-directional inter- prediction; obtaining block-level (e.g. CB or CU-level) information related to motion refinement video coding tools for bi-directional prediction; performing bi-directional prediction by using motion refinement; performing transforms for the block; performing quantization for the block; performing residual coding for the block.
  • block-level e.g. CB or CU-level
  • Still further embodiments provide a method of bi-directional inter-prediction of a coding block or coding unit, comprising:
  • Still further embodiments provide a method of bi-directional inter-prediction of a coding block or coding unit, comprising:
  • slice-level information related to motion refinement video coding as a sequence parameter set SPS-level DMVR flag (e.g., sps_dmvr_slice_present_flag) which is obtained from a syntax level higher than slice syntax level and indicates that signalling of a slice-level information related to motion refinement video coding is allowed; and
  • SPS-level DMVR flag e.g., sps_dmvr_slice_present_flag
  • Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another, e.g., according to a communication protocol.
  • computer-readable media generally may correspond to (1) tangible computer-readable storage media which is non-transitory or (2) a communication medium such as a signal or carrier wave.
  • Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this disclosure.
  • a computer program product may include a computer-readable medium.
  • such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.
  • any connection is properly termed a computer-readable medium.
  • a computer-readable medium For example, if instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.
  • DSL digital subscriber line
  • Disk and disc includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
  • processors such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry.
  • DSPs digital signal processors
  • ASICs application specific integrated circuits
  • FPGAs field programmable logic arrays
  • processors may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein.
  • the functionality described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or incorporated in a combined codec. Also, the techniques could be fully implemented in one or more circuits or logic elements.
  • the techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC) or a set of ICs (e.g., a chip set).
  • IC integrated circuit
  • a set of ICs e.g., a chip set.
  • Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, various units may be combined in a codec hardware unit or provided by a collection of interop erative hardware units, including one or more processors as described above, in conjunction with suitable software and/or firmware.
  • the present invention provides methods for encoding and decoding a video sequence using motion refinement video coding tools for bi-directional prediction, wherein the method comprises the following. Determining whether a type of a slice or picture of the video sequence allows bi-directional inter-prediction. Obtaining slice-level or picture-level information related to motion refinement video coding tools for bi-directional prediction only if the slice type or picture type allows bi-directional inter-prediction. Obtaining block-level level or coding unit level information related to motion refinement video coding tools for bi- directional prediction. Performing bi-directional inter-prediction with motion refinement according to the slice- or picture- and block-level information related to motion refinement video coding tools for bi-directional prediction.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)

Abstract

L'invention concerne des procédés de codage et de décodage d'une séquence vidéo à l'aide d'outils de codage vidéo de raffinement de mouvement pour une prédiction bidirectionnelle, le procédé comprenant les étapes suivantes. La détermination du fait qu'un type d'une tranche ou d'une image de la séquence vidéo permet une inter-prédiction bidirectionnelle. L'obtention d'informations de tranche ou d'image associées à des outils de codage vidéo de raffinement de mouvement pour une prédiction bidirectionnelle uniquement si le type de tranche ou le type d'image permet une inter-prédiction bidirectionnelle. L'obtention d'informations de bloc ou d'unité de codage associées à des outils de codage vidéo de raffinement de mouvement pour une prédiction bidirectionnelle. La réalisation d'une inter-prédiction bidirectionnelle avec un raffinement de mouvement selon les informations de tranche ou d'image et de blocs associées à des outils de codage vidéo de raffinement de mouvement pour une prédiction bidirectionnelle. Le codage ou le décodage de la vidéo par codage ou décodage d'au moins un bloc prédit à l'aide d'outils de codage vidéo de raffinement de mouvement pour une inter-prédiction bidirectionnelle. L'ajout des informations de tranche ou d'image concernant des outils de codage vidéo de raffinement de mouvement pour une prédiction bidirectionnelle à l'en-tête de tranche ou à l'en-tête d'image d'un flux binaire.
PCT/RU2020/050242 2019-09-23 2020-09-23 Signalisation pour raffinement de vecteurs de mouvement WO2021061023A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201962904641P 2019-09-23 2019-09-23
US62/904,641 2019-09-23
US201962955467P 2019-12-31 2019-12-31
US62/955,467 2019-12-31

Publications (1)

Publication Number Publication Date
WO2021061023A1 true WO2021061023A1 (fr) 2021-04-01

Family

ID=75165297

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/RU2020/050242 WO2021061023A1 (fr) 2019-09-23 2020-09-23 Signalisation pour raffinement de vecteurs de mouvement

Country Status (1)

Country Link
WO (1) WO2021061023A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022228420A1 (fr) * 2021-04-27 2022-11-03 Beijing Bytedance Network Technology Co., Ltd. Procédé, dispositif et support de traitement vidéo
WO2022262695A1 (fr) * 2021-06-15 2022-12-22 Beijing Bytedance Network Technology Co., Ltd. Procédé, dispositif et support de traitement vidéo
WO2024129612A1 (fr) * 2022-12-12 2024-06-20 Beijing Dajia Internet Information Technology Co., Ltd. Procédés et dispositifs de copie de bloc intra
WO2024145394A1 (fr) * 2022-12-27 2024-07-04 Beijing Dajia Internet Information Technology Co., Ltd. Procédés et dispositifs de copie intra-bloc

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160286230A1 (en) * 2015-03-27 2016-09-29 Qualcomm Incorporated Motion information derivation mode determination in video coding
CN109996081A (zh) * 2017-12-31 2019-07-09 华为技术有限公司 图像预测方法、装置以及编解码器

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160286230A1 (en) * 2015-03-27 2016-09-29 Qualcomm Incorporated Motion information derivation mode determination in video coding
CN109996081A (zh) * 2017-12-31 2019-07-09 华为技术有限公司 图像预测方法、装置以及编解码器

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
BENJAMIN BROSS ET AL.: "Working Draft 5 of Versatile Video Coding", JOINT VIDEO EXPERTS TEAM (JVET) OF ITU-T SG 16 WP 3 AND ISO/IEC JTC 1/SC 29/WG 11, N18370, 14TH MEETING, 19 March 2019 (2019-03-19), Geneva, CH *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022228420A1 (fr) * 2021-04-27 2022-11-03 Beijing Bytedance Network Technology Co., Ltd. Procédé, dispositif et support de traitement vidéo
WO2022262695A1 (fr) * 2021-06-15 2022-12-22 Beijing Bytedance Network Technology Co., Ltd. Procédé, dispositif et support de traitement vidéo
WO2024129612A1 (fr) * 2022-12-12 2024-06-20 Beijing Dajia Internet Information Technology Co., Ltd. Procédés et dispositifs de copie de bloc intra
WO2024145394A1 (fr) * 2022-12-27 2024-07-04 Beijing Dajia Internet Information Technology Co., Ltd. Procédés et dispositifs de copie intra-bloc

Similar Documents

Publication Publication Date Title
EP3868101B1 (fr) Encodeur, décodeur et procédés correspondants pour effectuer un dégroupage de chrominance pour des blocs qui utilisent un codage de chrominance jointe
WO2021045658A2 (fr) Procédé et appareil d'harmonisation de prédiction pondérée avec des modes de fusion non rectangulaires
CA3162821A1 (fr) Filtrage a boucle adaptatif a composante transversale permettant le codage video
US20220217332A1 (en) Harmonizing triangular merge mode with weighted prediction
WO2021061023A1 (fr) Signalisation pour raffinement de vecteurs de mouvement
EP4078967A2 (fr) Procédé et appareil de signalisation du nombre de candidats pour un mode de fusion
EP3963884A1 (fr) Procédé et appareil de compensation d'éclairage local pour prédiction inter
WO2021045657A9 (fr) Dérivation de l'amplitude de vecteurs de mouvement pour filtre d'interpolation amélioré
EP4022906A1 (fr) Procédé et appareil de signalisation de haut niveau pour modes de partitionnement non rectangulaires
WO2020251421A2 (fr) Procédé et appareil de syntaxe de haut niveau pour modes de partitionnement non rectangulaires
WO2021057629A1 (fr) Appareil et procédé permettant d'effectuer un déblocage
EP3977728A2 (fr) Procédé et appareil de codage de vidéos et d'images fixes au moyen d'un ré-échantillonnage adaptatif de forme de blocs résiduels
EP3977745A1 (fr) Procédé et appareil de codage d'image fixe et de vidéo
EP4026321A2 (fr) Procédé et appareil d'harmonisation d'une prédiction pondérée avec une compensation de mouvement basée sur un modèle affine pour une prédiction inter
WO2020263132A1 (fr) Procédé et appareil pour un codage sans perte de vidéo et d'image fixe
WO2021045655A9 (fr) Procédé et appareil de prédiction intra
EP4022908A1 (fr) Procédé et appareil de mode de fusion géométrique simplifiée pour une inter-prédiction
EP3895418A1 (fr) Codeur, décodeur et procédés correspondants de compensation d'éclairage local
WO2020256601A2 (fr) Procédé et appareil de signalisation au niveau de l'image pour affinement de vecteur de mouvement latéral de décodeur et de flux optique bidirectionnel
RU2827439C1 (ru) Межкомпонентная адаптивная контурная фильтрация для кодирования видео
WO2021066680A1 (fr) Procédé et dispositif de signalisation pour les modes de partitionnement
WO2021134393A1 (fr) Procédé et appareil de filtrage avec dégroupage entre limites de blocs prédits à l'aide d'une prédiction pondérée et de modes de fusion non rectangulaires
WO2020251418A2 (fr) Procédé et appareil de signalisation de niveau de tranche pour affinement de vecteur de mouvement latéral de décodeur et de flux optique bidirectionnel
EP4059220A2 (fr) Procédé et appareil de combinaison de prédiction en fonction de la position pour une prédiction intra directionnelle oblique
WO2021040574A1 (fr) Procédé et appareil de codage de vidéos et d'images fixes au moyen d'un ré-échantillonnage adaptatif de forme de blocs résiduels

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20869139

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20869139

Country of ref document: EP

Kind code of ref document: A1