WO2024017188A1 - Procédé et appareil pour un mélange de prédiction dans un système de codage vidéo - Google Patents

Procédé et appareil pour un mélange de prédiction dans un système de codage vidéo Download PDF

Info

Publication number
WO2024017188A1
WO2024017188A1 PCT/CN2023/107688 CN2023107688W WO2024017188A1 WO 2024017188 A1 WO2024017188 A1 WO 2024017188A1 CN 2023107688 W CN2023107688 W CN 2023107688W WO 2024017188 A1 WO2024017188 A1 WO 2024017188A1
Authority
WO
WIPO (PCT)
Prior art keywords
intra
prediction
candidate
mode
candidate list
Prior art date
Application number
PCT/CN2023/107688
Other languages
English (en)
Inventor
Man-Shu CHIANG
Yu-Ling Hsiao
Chih-Wei Hsu
Original Assignee
Mediatek Inc.
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 Mediatek Inc. filed Critical Mediatek Inc.
Publication of WO2024017188A1 publication Critical patent/WO2024017188A1/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
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/11—Selection of coding mode or of prediction mode among a plurality of spatial predictive coding modes
    • 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
    • H04N19/119—Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
    • 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
    • H04N19/17—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 an image region, e.g. an object
    • H04N19/176—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 an image region, e.g. an object the region being a block, e.g. a macroblock
    • 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
    • H04N19/593—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial prediction techniques

Definitions

  • the present invention is a non-Provisional Application of and claims priority to U.S. Provisional Patent Application No. 63/369,092, filed on July 22, 2022.
  • the U.S. Provisional Patent Application is hereby incorporated by reference in its entirety.
  • the present invention relates to video coding system.
  • the present invention relates to blending predictors using efficiency shared candidate list for GPM (Geometric Partitioning Mode) intra prediction and SGPM (Spatial GPM) .
  • VVC Versatile video coding
  • JVET Joint Video Experts Team
  • MPEG ISO/IEC Moving Picture Experts Group
  • ISO/IEC 23090-3 2021
  • Information technology -Coded representation of immersive media -Part 3 Versatile video coding, published Feb. 2021.
  • VVC is developed based on its predecessor HEVC (High Efficiency Video Coding) by adding more coding tools to improve coding efficiency and also to handle various types of video sources including 3-dimensional (3D) video signals.
  • HEVC High Efficiency Video Coding
  • Fig. 1A illustrates an exemplary adaptive Inter/Intra video coding system incorporating loop processing.
  • Intra Prediction the prediction data is derived based on previously coded video data in the current picture.
  • Motion Estimation (ME) is performed at the encoder side and Motion Compensation (MC) is performed based of the result of ME to provide prediction data derived from other picture (s) and motion data.
  • Switch 114 selects Intra Prediction 110 or Inter-Prediction 112 and the selected prediction data is supplied to Adder 116 to form prediction errors, also called residues.
  • the prediction error is then processed by Transform (T) 118 followed by Quantization (Q) 120.
  • T Transform
  • Q Quantization
  • the transformed and quantized residues are then coded by Entropy Encoder 122 to be included in a video bitstream corresponding to the compressed video data.
  • the bitstream associated with the transform coefficients is then packed with side information such as motion and coding modes associated with Intra prediction and Inter prediction, and other information such as parameters associated with loop filters applied to underlying image area.
  • the side information associated with Intra Prediction 110, Inter prediction 112 and in-loop filter 130, are provided to Entropy Encoder 122 as shown in Fig. 1A. When an Inter-prediction mode is used, a reference picture or pictures have to be reconstructed at the encoder end as well.
  • the transformed and quantized residues are processed by Inverse Quantization (IQ) 124 and Inverse Transformation (IT) 126 to recover the residues.
  • the residues are then added back to prediction data 136 at Reconstruction (REC) 128 to reconstruct video data.
  • the reconstructed video data may be stored in Reference Picture Buffer 134 and used for prediction of other frames.
  • incoming video data undergoes a series of processing in the encoding system.
  • the reconstructed video data from REC 128 may be subject to various impairments due to a series of processing.
  • in-loop filter 130 is often applied to the reconstructed video data before the reconstructed video data are stored in the Reference Picture Buffer 134 in order to improve video quality.
  • deblocking filter (DF) may be used.
  • SAO Sample Adaptive Offset
  • ALF Adaptive Loop Filter
  • the loop filter information may need to be incorporated in the bitstream so that a decoder can properly recover the required information. Therefore, loop filter information is also provided to Entropy Encoder 122 for incorporation into the bitstream.
  • DF deblocking filter
  • SAO Sample Adaptive Offset
  • ALF Adaptive Loop Filter
  • Loop filter 130 is applied to the reconstructed video before the reconstructed samples are stored in the reference picture buffer 134.
  • the system in Fig. 1A is intended to illustrate an exemplary structure of a typical video encoder. It may correspond to the High Efficiency Video Coding (HEVC) system, VP8, VP9, H. 264 or VVC.
  • HEVC High Efficiency Video Coding
  • the decoder can use similar or portion of the same functional blocks as the encoder except for Transform 118 and Quantization 120 since the decoder only needs Inverse Quantization 124 and Inverse Transform 126.
  • the decoder uses an Entropy Decoder 140 to decode the video bitstream into quantized transform coefficients and needed coding information (e.g. ILPF information, Intra prediction information and Inter prediction information) .
  • the Intra prediction 150 at the decoder side does not need to perform the mode search. Instead, the decoder only needs to generate Intra prediction according to Intra prediction information received from the Entropy Decoder 140.
  • the decoder only needs to perform motion compensation (MC 152) according to Inter prediction information received from the Entropy Decoder 140 without the need for motion estimation.
  • an input picture is partitioned into non-overlapped square block regions referred as CTUs (Coding Tree Units) , similar to HEVC.
  • CTUs Coding Tree Units
  • Each CTU can be partitioned into one or multiple smaller size coding units (CUs) .
  • the resulting CU partitions can be in square or rectangular shapes.
  • VVC divides a CTU into prediction units (PUs) as a unit to apply prediction process, such as Inter prediction, Intra prediction, etc.
  • the VVC standard incorporates various new coding tools to further improve the coding efficiency over the HEVC standard.
  • various new coding tools some coding tools relevant to the present invention are reviewed as follows.
  • JVET-T2002 Section 3.4.
  • VTM 11 Versatile Video Coding and Test Model 11
  • JVET-T2002 Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29, 20th Meeting, by teleconference, 7 –16 October 2020, Document: JVET-T2002
  • motion parameters consist of motion vectors, reference picture indices and reference picture list usage index, and additional information needed for the new coding feature of VVC to be used for inter-predicted sample generation.
  • the motion parameter can be signalled in an explicit or implicit manner.
  • a merge mode is specified whereby the motion parameters for the current CU, which are obtained from neighbouring CUs, including spatial and temporal candidates, and additional schedules introduced in VVC.
  • the merge mode can be applied to any inter-predicted CU, not only for skip mode.
  • the alternative to the merge mode is the explicit transmission of motion parameters, where motion vector, corresponding reference picture index for each reference picture list and reference picture list usage flag and other needed information are signalled explicitly per each CU.
  • VVC includes a number of new and refined inter prediction coding tools listed as follows:
  • MMVD Merge mode with MVD
  • SMVD Symmetric MVD
  • AMVR Adaptive motion vector resolution
  • Motion field storage 1/16 th luma sample MV storage and 8x8 motion field compression
  • the merge candidate list is constructed by including the following five types of candidates in order:
  • the size of merge list is signalled in sequence parameter set (SPS) header and the maximum allowed size of merge list is 6.
  • SPS sequence parameter set
  • TU truncated unary binarization
  • VVC also supports parallel derivation of the merge candidate lists (or called as merging candidate lists) for all CUs within a certain size of area.
  • the derivation of spatial merge candidates in VVC is the same as that in HEVC except that the positions of first two merge candidates are swapped.
  • a maximum of four merge candidates (B 0 , A 0 , B 1 and A 1 ) for current CU 210 are selected among candidates located in the positions depicted in Fig. 2.
  • the order of derivation is B 0 , A 0 , B 1 , A 1 and B 2 .
  • Position B 2 is considered only when one or more neighbouring CU of positions B 0 , A 0 , B 1 , A 1 are not available (e.g. belonging to another slice or tile) or is intra coded.
  • a scaled motion vector is derived based on the co-located CU 420 belonging to the collocated reference picture as shown in Fig. 4.
  • the reference picture list and the reference index to be used for the derivation of the co-located CU is explicitly signalled in the slice header.
  • the scaled motion vector 430 for the temporal merge candidate is obtained as illustrated by the dotted line in Fig.
  • tb is defined to be the POC difference between the reference picture of the current picture and the current picture
  • td is defined to be the POC difference between the reference picture of the co-located picture and the co-located picture.
  • the reference picture index of temporal merge candidate is set equal to zero.
  • the position for the temporal candidate is selected between candidates C 0 and C 1 , as depicted in Fig. 5. If CU at position C 0 is not available, is intra coded, or is outside of the current row of CTUs, position C 1 is used. Otherwise, position C 0 is used in the derivation of the temporal merge candidate.
  • the history-based MVP (HMVP) merge candidates are added to the merge list after the spatial MVP and TMVP.
  • HMVP history-based MVP
  • the motion information of a previously coded block is stored in a table and used as MVP for the current CU.
  • the table with multiple HMVP candidates is maintained during the encoding/decoding process.
  • the table is reset (emptied) when a new CTU row is encountered. Whenever there is a non-subblock inter-coded CU, the associated motion information is added to the last entry of the table as a new HMVP candidate.
  • the HMVP table size S is set to be 6, which indicates up to 5 History-based MVP (HMVP) candidates may be added to the table.
  • HMVP History-based MVP
  • FIFO constrained first-in-first-out
  • HMVP candidates could be used in the merge candidate list construction process.
  • the latest several HMVP candidates in the table are checked in order and inserted to the candidate list after the TMVP candidate. Redundancy check is applied on the HMVP candidates to the spatial or temporal merge candidate.
  • Pairwise average candidates are generated by averaging predefined pairs of candidates in the existing merge candidate list, using the first two merge candidates.
  • the first merge candidate is defined as p0Cand and the second merge candidate can be defined as p1Cand, respectively.
  • the averaged motion vectors are calculated according to the availability of the motion vector of p0Cand and p1Cand separately for each reference list. If both motion vectors are available in one list, these two motion vectors are averaged even when they point to different reference pictures, and its reference picture is set to the one of p0Cand; if only one motion vector is available, use the one directly; and if no motion vector is available, keep this list invalid. Also, if the half-pel interpolation filter indices of p0Cand and p1Cand are different, it is set to 0.
  • the zero MVPs are inserted in the end until the maximum merge candidate number is encountered.
  • MMVD Merge Mode with MVD
  • the merge mode with motion vector differences is introduced in VVC.
  • a MMVD flag is signalled right after sending a regular merge flag to specify whether MMVD mode is used for a CU.
  • MMVD after a merge candidate is selected (referred as a base merge candidate in this disclosure) , it is further refined by the signalled MVDs information.
  • the further information includes a merge candidate flag, an index to specify motion magnitude, and an index for indication of motion direction.
  • MMVD mode one for the first two candidates in the merge list is selected to be used as MV basis.
  • the MMVD candidate flag is signalled to specify which one is used between the first and second merge candidates.
  • Distance index specifies motion magnitude information and indicates the pre-defined offset from the starting points (612 and 622) for a L0 reference block 610 and L1 reference block 620. As shown in Fig. 6 an offset is added to either horizontal component or vertical component of the starting MV, where small circles in different styles correspond to different offsets from the centre.
  • the relation of distance index and pre-defined offset is specified in Table 1.
  • Direction index represents the direction of the MVD relative to the starting point.
  • the direction index can represent the four directions as shown in Table 2. It is noted that the meaning of MVD sign could be variant according to the information of starting MVs.
  • the starting MVs are an un-prediction MV or bi-prediction MVs with both lists pointing to the same side of the current picture (i.e. POCs of two references both larger than the POC of the current picture, or both smaller than the POC of the current picture)
  • the sign in Table 2 specifies the sign of the MV offset added to the starting MV.
  • the starting MVs are bi-prediction MVs with the two MVs pointing to the different sides of the current picture (i.e.
  • the sign in Table 2 specifies the sign of MV offset added to the list0 MV component of the starting MV and the sign for the list1 MV has an opposite value. Otherwise, if the difference of POC in list 1 is greater than list 0, the sign in Table 2 specifies the sign of the MV offset added to the list1 MV component of starting MV and the sign for the list0 MV has an opposite value.
  • the MVD is scaled according to the difference of POCs in each direction. If the differences of POCs in both lists are the same, no scaling is needed. Otherwise, if the difference of POC in list 0 is larger than the one in list 1, the MVD for list 1 is scaled, by defining the POC difference of L0 as td and POC difference of L1 as tb, described in Fig. 4. If the POC difference of L1 is greater than L0, the MVD for list 0 is scaled in the same way. If the starting MV is uni-predicted, the MVD is added to the available MV.
  • HEVC high definition motion model
  • MCP motion compensation prediction
  • a block-based affine transform motion compensation prediction is applied. As shown Figs. 7A-B, the affine motion field of the block 710 is described by motion information of two control point (4-parameter) in Fig. 7A or three control point motion vectors (6-parameter) in Fig. 7B.
  • motion vector at sample location (x, y) in a block is derived as:
  • motion vector at sample location (x, y) in a block is derived as:
  • block based affine transform prediction is applied.
  • the motion vector of the centre sample of each subblock is calculated according to above equations, and rounded to 1/16 fraction accuracy.
  • the motion compensation interpolation filters are applied to generate the prediction of each subblock with the derived motion vector.
  • the subblock size of chroma-components is also set to be 4 ⁇ 4.
  • the MV of a 4 ⁇ 4 chroma subblock is calculated as the average of the MVs of the top-left and bottom-right luma subblocks in the collocated 8x8 luma region.
  • affine motion inter prediction modes As is for translational-motion inter prediction, there are also two affine motion inter prediction modes: affine merge mode and affine AMVP mode.
  • AF_MERGE mode can be applied for CUs with both width and height larger than or equal to 8.
  • the CPMVs Control Point MVs
  • CPMVP CPMV Prediction
  • the following three types of CPVM candidate are used to form the affine merge candidate list:
  • VVC there are two inherited affine candidates at most, which are derived from the affine motion model of the neighbouring blocks, one from left neighbouring CUs and one from above neighbouring CUs.
  • the candidate blocks are the same as those shown in Fig. 2.
  • the scan order is A 0 ->A 1
  • the scan order is B0->B 1 ->B 2 .
  • Only the first inherited candidate from each side is selected. No pruning check is performed between two inherited candidates.
  • a neighbouring affine CU is identified, its control point motion vectors are used to derived the CPMVP candidate in the affine merge list of the current CU. As shown in Fig.
  • Constructed affine candidate means the candidate is constructed by combining the neighbouring translational motion information of each control point.
  • the motion information for the control points is derived from the specified spatial neighbours and temporal neighbour for a current block 1010 as shown in Fig. 10.
  • CPMV 1 the B2->B3->A2 blocks are checked and the MV of the first available block is used.
  • CPMV 2 the B1->B0 blocks are checked and for CPMV 3 , the A1->A0 blocks are checked.
  • TMVP is used as CPMV 4 if it’s available.
  • affine merge candidates are constructed based on the motion information.
  • the following combinations of control point MVs are used to construct in order:
  • the combination of 3 CPMVs constructs a 6-parameter affine merge candidate and the combination of 2 CPMVs constructs a 4-parameter affine merge candidate. To avoid motion scaling process, if the reference indices of control points are different, the related combination of control point MVs is discarded.
  • Affine AMVP mode can be applied for CUs with both width and height larger than or equal to 16.
  • An affine flag in the CU level is signalled in the bitstream to indicate whether affine AMVP mode is used and then another flag is signalled to indicate whether 4-parameter affine or 6-parameter affine is used.
  • the difference of the CPMVs of current CU and their predictors CPMVPs is signalled in the bitstream.
  • the affine AVMP candidate list size is 2 and it is generated by using the following four types of CPVM candidate in order:
  • the checking order of inherited affine AMVP candidates is the same as the checking order of inherited affine merge candidates. The only difference is that, for AVMP candidate, only the affine CU that has the same reference picture as current block is considered. No pruning process is applied when inserting an inherited affine motion predictor into the candidate list.
  • Constructed AMVP candidate is derived from the specified spatial neighbours shown in Fig. 10. The same checking order is used as that in the affine merge candidate construction. In addition, the reference picture index of the neighbouring block is also checked. In the checking order, the first block that is inter coded and has the same reference picture as in current CUs is used. When the current CU is coded with the 4-parameter affine mode, and mv 0 and mv 1 are both availlalbe, they are added as one candidate in the affine AMVP list. When the current CU is coded with 6-parameter affine mode, and all three CPMVs are available, they are added as one candidate in the affine AMVP list. Otherwise, the constructed AMVP candidate is set as unavailable.
  • mv 0 , mv 1 and mv 2 will be added as the translational MVs in order to predict all control point MVs of the current CU, when available. Finally, zero MVs are used to fill the affine AMVP list if it is still not full.
  • the CPMVs of affine CUs are stored in a separate buffer.
  • the stored CPMVs are only used to generate the inherited CPMVPs in the affine merge mode and affine AMVP mode for the lately coded CUs.
  • the subblock MVs derived from CPMVs are used for motion compensation, MV derivation of merge/AMVP list of translational MVs and de-blocking.
  • affine motion data inheritance from the CUs of the above CTU is treated differently for the inheritance from the normal neighbouring CUs. If the candidate CU for affine motion data inheritance is in the above CTU line, the bottom-left and bottom-right subblock MVs in the line buffer instead of the CPMVs are used for the affine MVP derivation. In this way, the CPMVs are only stored in a local buffer. If the candidate CU is 6-parameter affine coded, the affine model is degraded to 4-parameter model. As shown in Fig.
  • FIG. 11 along the top CTU boundary, the bottom-left and bottom right subblock motion vectors of a CU are used for affine inheritance of the CUs in bottom CTUs.
  • line 1110 and line 1112 indicate the x and y coordinates of the picture with the origin (0, 0) at the upper left corner.
  • Legend 1120 shows the meaning of various motion vectors, where arrow 1122 represents the CPMVs for affine inheritance in the local buff, arrow 1124 represents sub-block vectors for MC/merge/skip/AMVP/deblocking/TMVPs in the local buffer and for affine inheritance in the line buffer, and arrow 1126 represents sub-block vectors for MC/merge/skip/AMVP/deblocking/TMVPs.
  • AMVR Adaptive Motion Vector Resolution
  • MVDs motion vector differences
  • a CU-level adaptive motion vector resolution (AMVR) scheme is introduced.
  • AMVR allows MVD of the CU to be coded in different precisions.
  • the MVDs of the current CU can be adaptively selected as follows:
  • Normal AMVP mode quarter-luma-sample, half-luma-sample, integer-luma-sample or four-luma-sample.
  • Affine AMVP mode quarter-luma-sample, integer-luma-sample or 1/16 luma-sample.
  • the CU-level MVD resolution indication is conditionally signalled if the current CU has at least one non-zero MVD component. If all MVD components (that is, both horizontal and vertical MVDs for reference list L0 and reference list L1) are zero, quarter-luma-sample MVD resolution is inferred.
  • a first flag is signalled to indicate whether quarter-luma-sample MVD precision is used for the CU. If the first flag is 0, no further signalling is needed and quarter-luma-sample MVD precision is used for the current CU. Otherwise, a second flag is signalled to indicate half-luma-sample or other MVD precisions (integer or four-luma sample) is used for a normal AMVP CU. In the case of half-luma-sample, a 6-tap interpolation filter instead of the default 8-tap interpolation filter is used for the half-luma sample position.
  • a third flag is signalled to indicate whether integer-luma-sample or four-luma-sample MVD precision is used for the normal AMVP CU.
  • the second flag is used to indicate whether integer-luma-sample or 1/16 luma-sample MVD precision is used.
  • the motion vector predictors for the CU will be rounded to the same precision as that of the MVD before being added together with the MVD.
  • the motion vector predictors are rounded toward zero (that is, a negative motion vector predictor is rounded toward positive infinity and a positive motion vector predictor is rounded toward negative infinity) .
  • the encoder determines the motion vector resolution for the current CU using RD check.
  • the RD check of MVD precisions other than quarter-luma-sample is only invoked conditionally in VTM11.
  • the RD cost of quarter-luma-sample MVD precision and integer-luma sample MV precision is computed first. Then, the RD cost of integer-luma-sample MVD precision is compared to that of quarter-luma-sample MVD precision to decide whether it is necessary to further check the RD cost of four-luma-sample MVD precision.
  • the RD check of four-luma-sample MVD precision is skipped. Then, the check of half-luma-sample MVD precision is skipped if the RD cost of integer-luma-sample MVD precision is significantly larger than the best RD cost of previously tested MVD precisions.
  • affine AMVP mode For the affine AMVP mode, if the affine inter mode is not selected after checking rate-distortion costs of affine merge/skip mode, merge/skip mode, quarter-luma-sample MVD precision normal AMVP mode and quarter-luma-sample MVD precision affine AMVP mode, then 1/16 luma-sample MV precision and 1-pel MV precision affine inter modes are not checked. Furthermore, affine parameters obtained in quarter-luma-sample MV precision affine inter mode are used as starting search point in 1/16 luma-sample and quarter-luma-sample MV precision affine inter modes.
  • the CIIP prediction combines an inter prediction signal with an intra prediction signal.
  • the inter prediction signal in the CIIP mode P inter is derived using the same inter prediction process applied to regular merge mode; and the intra prediction signal P intra is derived following the regular intra prediction process with the planar mode. Then, the intra and inter prediction signals are combined using weighted averaging, where the weight value wt is calculated depending on the coding modes of the top and left neighbouring blocks (as shown in Fig. 12) of current CU 1210 as follows:
  • GPS Geometric Partitioning Mode
  • a Geometric Partitioning Mode (GPM) is supported for inter prediction as described in JVET-W2002 (Adrian Browne, et al., Algorithm description for Versatile Video Coding and Test Model 14 (VTM 14) , ITU-T/ISO/IEC Joint Video Exploration Team (JVET) , 23rd Meeting, by teleconference, 7–16 July 2021, document: document JVET-M2002) .
  • the geometric partitioning mode is signalled using a CU-level flag as one kind of merge mode, with other merge modes including the regular merge mode, the MMVD mode, the CIIP mode and the subblock merge mode.
  • the GPM mode can be applied to skip or merge CUs having a size within the above limit and having at least two regular merge modes.
  • a CU When this mode is used, a CU is split into two parts by a geometrically located straight line in certain angles.
  • VVC In VVC, there are a total of 20 angles and 4 offset distances used for GPM, which has been reduced from 24 angles in an earlier draft. The location of the splitting line is mathematically derived from the angle and offset parameters of a specific partition.
  • VVC there are a total of 64 partitions as shown in Fig. 13, where the partitions are grouped according to their angles and dashed lines indicate redundant partitions.
  • Each part of a geometric partition in the CU is inter-predicted using its own motion; only uni-prediction is allowed for each partition, that is, each part has one motion vector and one reference index.
  • each line corresponds to the boundary of one partition.
  • partition group 1310 consists of three vertical GPM partitions (i.e., 90°) .
  • Partition group 1320 consists of four slant GPM partitions with a small angle from the vertical direction.
  • partition group 1330 consists of three vertical GPM partitions (i.e., 270°) similar to those of group 1310, but with an opposite direction.
  • the uni-prediction motion constraint is applied to ensure that only two motion compensated prediction are needed for each CU, same as the conventional bi-prediction.
  • the uni-prediction motion for each partition is derived using the process described later.
  • a geometric partition index indicating the selected partition mode of the geometric partition (angle and offset) , and two merge indices (one for each partition) are further signalled.
  • the number of maximum GPM candidate size is signalled explicitly in SPS (Sequence Parameter Set) and specifies syntax binarization for GPM merge indices.
  • the uni-prediction candidate list is derived directly from the merge candidate list constructed according to the extended merge prediction process.
  • n the index of the uni-prediction motion in the geometric uni-prediction candidate list.
  • These motion vectors are marked with “x” in Fig. 14.
  • the L (1 -X) motion vector of the same candidate is used instead as the uni-prediction motion vector for geometric partitioning mode.
  • blending is applied to the two prediction signals to derive samples around geometric partition edge.
  • the blending weight for each position of the CU are derived based on the distance between individual position and the partition edge.
  • the two integer blending matrices (W 0 and W 1 ) are utilized for the GPM blending process.
  • the weights in the GPM blending matrices contain the value range of [0, 8] and are derived based on the displacement from a sample position to the GPM partition boundary 1540 as shown in Fig. 15.
  • the weights are given by a discrete ramp function with the displacement and two thresholds as shown in Fig. 16, where the two end points (i.e., - ⁇ and ⁇ ) of the ramp correspond to lines 1542 and 1544 in Fig 15.
  • the threshold ⁇ defines the width of the GPM blending area and is selected as the fixed value in VVC.
  • JVET-Z0137 Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29, 26th Meeting, by teleconference, 20–29 April 2022, JVET-Z0137
  • the blending strength or blending area width ⁇ is fixed for all different contents.
  • the weighing values in the blending mask can be given by a ramp function:
  • the distance for a position (x, y) to the partition edge are derived as:
  • i, j are the indices for angle and offset of a geometric partition, which depend on the signaled geometric partition index.
  • the sign of ⁇ x, j and ⁇ y, j depend on angle index i.
  • Fig. 17 illustrates an example of GPM blending according to ECM 4.0 (Muhammed Coban, et. al., “Algorithm description of Enhanced Compression Model 4 (ECM 4) ” , Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29, 26th Meeting, by teleconference, 20–29 April 2022, JVET-Y2025) .
  • ECM 4 Enhanced Compression Model 4
  • JVET Joint Video Experts Team
  • the size of the blending region on each side of the partition boundary is indicated by ⁇ .
  • the partIdx depends on the angle index i.
  • One example of weigh w 0 is illustrated in Fig. 15, where the angle 1510 and offset ⁇ i 1520 are indicated for GPM index i and point 1530 corresponds to the center of the block.
  • Line 1540 corresponds to the GPM partitioning boundary
  • Mv1 from the first part of the geometric partition, Mv2 from the second part of the geometric partition and a combined MV of Mv1 and Mv2 are stored in the motion filed of a geometric partitioning mode coded CU.
  • sType abs (motionIdx) ⁇ 32 ? 2 ⁇ (motionIdx ⁇ 0 ? (1 -partIdx) : partIdx) (13)
  • motionIdx is equal to d (4x+2, 4y+2) , which is recalculated from equation (6) .
  • the partIdx depends on the angle index i.
  • Mv0 or Mv1 are stored in the corresponding motion field, otherwise if sType is equal to 2, a combined MV from Mv0 and Mv2 are stored.
  • the combined Mv are generated using the following process:
  • Mv1 and Mv2 are from different reference picture lists (one from L0 and the other from L1) , then Mv1 and Mv2 are simply combined to form the bi-prediction motion vectors.
  • the number of directional intra modes in VVC is extended from 33, as used in HEVC, to 65.
  • the new directional modes not in HEVC are depicted as dotted arrows in Fig. 18, and the planar and DC modes remain the same.
  • These denser directional intra prediction modes apply for all block sizes and for both luma and chroma intra predictions.
  • every intra-coded block has a square shape and the length of each of its side is a power of 2. Thus, no division operations are required to generate an intra-predictor using DC mode.
  • blocks can have a rectangular shape that necessitates the use of a division operation per block in the general case. To avoid division operations for DC prediction, only the longer side is used to compute the average for non-square blocks.
  • MPM most probable mode
  • a unified 6-MPM list is used for intra blocks irrespective of whether MRL and ISP coding tools are applied or not.
  • the MPM list is constructed based on intra modes of the left and above neighbouring block. Suppose the mode of the left is denoted as Left and the mode of the above block is denoted as Above, the unified MPM list is constructed as follows:
  • MPM list ⁇ ⁇ Planar, Max, DC, Max -1, Max + 1, Max -2 ⁇
  • MPM list ⁇ ⁇ Planar, Left, Left -1, Left + 1, DC, Left -2 ⁇
  • the first bin of the MPM index codeword is CABAC context coded. In total three contexts are used, corresponding to whether the current intra block is MRL enabled, ISP enabled, or a normal intra block.
  • TBC Truncated Binary Code
  • Conventional angular intra prediction directions are defined from 45 degrees to -135 degrees in clockwise direction.
  • VVC several conventional angular intra prediction modes are adaptively replaced with wide-angle intra prediction modes for non-square blocks.
  • the replaced modes are signalled using the original mode indexes, which are remapped to the indexes of wide angular modes after parsing.
  • the total number of intra prediction modes is unchanged, i.e., 67, and the intra mode coding method is unchanged.
  • top reference with length 2W+1 and the left reference with length 2H+1, are defined as shown in Fig. 19A and Fig. 19B respectively.
  • the number of replaced modes in wide-angular direction mode depends on the aspect ratio of a block.
  • the replaced intra prediction modes are illustrated in Table 3.
  • Chroma derived mode (DM) derivation table for 4: 2: 2 chroma format was initially ported from HEVC extending the number of entries from 35 to 67 to align with the extension of intra prediction modes. Since HEVC specification does not support prediction angle below -135° and above 45°, luma intra prediction modes ranging from 2 to 5 are mapped to 2. Therefore, chroma DM derivation table for 4: 2: 2: chroma format is updated by replacing some values of the entries of the mapping table to convert prediction angle more precisely for chroma blocks.
  • DIMD When DIMD is applied, two intra modes are derived from the reconstructed neighbour samples, and those two predictors are combined with the planar mode predictor with the weights derived from the gradients.
  • the DIMD mode is used as an alternative prediction mode and is always checked in the high-complexity RDO mode.
  • a texture gradient analysis is performed at both the encoder and decoder sides. This process starts with an empty Histogram of Gradient (HoG) with 65 entries, corresponding to the 65 angular modes. Amplitudes of these entries are determined during the texture gradient analysis.
  • HoG Histogram of Gradient
  • the horizontal and vertical Sobel filters are applied on all 3 ⁇ 3 window positions, centered on the pixels of the middle line of the template.
  • Sobel filters calculate the intensity of pure horizontal and vertical directions as G x and G y , respectively.
  • Figs. 20A-C show an example of HoG, calculated after applying the above operations on all pixel positions in the template.
  • Fig. 20A illustrates an example of selected template 2020 for a current block 2010.
  • Template 2020 comprises T lines above the current block and T columns to the left of the current block.
  • the area 2030 at the above and left of the current block corresponds to a reconstructed area and the area 2040 below and at the right of the block corresponds to an unavailable area.
  • a 3x3 window 2050 is used.
  • Fig. 20C illustrates an example of the amplitudes (ampl) calculated based on equation (15) for the angular intra prediction modes as determined from equation (14) .
  • the indices with two tallest histogram bars are selected as the two implicitly derived intra prediction modes for the block and are further combined with the Planar mode as the prediction of DIMD mode.
  • the prediction fusion is applied as a weighted average of the above three predictors.
  • the weight of planar is fixed to 21/64 ( ⁇ 1/3) .
  • the remaining weight of 43/64 ( ⁇ 2/3) is then shared between the two HoG IPMs, proportionally to the amplitude of their HoG bars.
  • Fig. 21 illustrates an example of the blending process. As shown in Fig. 21, two intra modes (M1 2112 and M2 2114) are selected according to the indices with two tallest bars of histogram bars 2110.
  • the three predictors (2140, 2142 and 2144) are used to form the blended prediction.
  • the three predictors correspond to applying the M1, M2 and planar intra modes (2120, 2122 and 2124 respectively) to the reference pixels 2130 to form the respective predictors.
  • the three predictors are weighted by respective weighting factors ( ⁇ 1 , ⁇ 2 and ⁇ 3 ) 2150.
  • the weighted predictors are summed using adder 2152 to generated the blended predictor 2160.
  • the two implicitly derived intra modes are included into the MPM list so that the DIMD process is performed before the MPM list is constructed.
  • the primary derived intra mode of a DIMD block is stored with a block and is used for MPM list construction of the neighbouring blocks.
  • Template-based intra mode derivation (TIMD) mode implicitly derives the intra prediction mode of a CU using a neighbouring template at both the encoder and decoder, instead of signalling the intra prediction mode to the decoder.
  • the prediction samples of the template (2212 and 2214) for the current block 2210 are generated using the reference samples (2220 and 2222) of the template for each candidate mode.
  • a cost is calculated as the SATD (Sum of Absolute Transformed Differences) between the prediction samples and the reconstruction samples of the template.
  • the intra prediction mode with the minimum cost is selected as the DIMD mode and used for intra prediction of the CU.
  • the candidate modes may be 67 intra prediction modes as in VVC or extended to 131 intra prediction modes.
  • MPMs can provide a clue to indicate the directional information of a CU.
  • the intra prediction mode can be implicitly derived from the MPM list.
  • the SATD between the prediction and reconstruction samples of the template is calculated.
  • First two intra prediction modes with the minimum SATD are selected as the TIMD modes. These two TIMD modes are fused with weights after applying PDPC process, and such weighted intra prediction is used to code the current CU.
  • Position dependent intra prediction combination (PDPC) is included in the derivation of the TIMD modes.
  • ISP Intra Sub-Partitions
  • the intra sub-partitions divides luma intra-predicted blocks vertically or horizontally into 2 or 4 sub-partitions depending on the block size. For example, the minimum block size for ISP is 4x8 (or 8x4) . If block size is greater than 4x8 (or 8x4) , then the corresponding block is divided by 4 sub-partitions. It has been noted that the M ⁇ 128 (with M ⁇ 64) and 128 ⁇ N (with N ⁇ 64) ISP blocks could generate a potential issue with the 64 ⁇ 64 VDPU (Virtual Decoder Pipeline Unit) . For example, an M ⁇ 128 CU in the single tree case has an M ⁇ 128 luma TB and two corresponding chroma TBs.
  • the luma TB will be divided into four M ⁇ 32 TBs (only the horizontal split is possible) , each of them smaller than a 64 ⁇ 64 block.
  • chroma blocks are not divided. Therefore, both chroma components will have a size greater than a 32 ⁇ 32 block.
  • a similar situation could be created with a 128 ⁇ N CU using ISP.
  • these two cases are an issue for the 64 ⁇ 64 decoder pipeline.
  • the CU size that can use ISP is restricted to a maximum of 64 ⁇ 64.
  • Fig. 23A and Fig. 23B shows examples of the two possibilities. All sub-partitions fulfil the condition of having at least 16 samples.
  • ISP In ISP, the dependence of 1xN and 2xN subblock prediction on the reconstructed values of previously decoded 1xN and 2xN subblocks of the coding block is not allowed so that the minimum width of prediction for subblocks becomes four samples.
  • an 8xN (N > 4) coding block that is coded using ISP with vertical split is partitioned into two prediction regions each of size 4xN and four transforms of size 2xN.
  • a 4xN coding block that is coded using ISP with vertical split is predicted using the full 4xN block; four transform each of 1xN is used.
  • the transform sizes of 1xN and 2xN are allowed, it is asserted that the transform of these blocks in 4xN regions can be performed in parallel.
  • a 4xN prediction region contains four 1xN transforms
  • the transform in the vertical direction can be performed as a single 4xN transform in the vertical direction.
  • the transform operation of the two 2xN blocks in each direction can be conducted in parallel.
  • reconstructed samples are obtained by adding the residual signal to the prediction signal.
  • a residual signal is generated by the processes such as entropy decoding, inverse quantization and inverse transform. Therefore, the reconstructed sample values of each sub-partition are available to generate the prediction of the next sub-partition, and each sub-partition is processed consecutively.
  • the first sub-partition to be processed is the one containing the top-left sample of the CU and then continuing downwards (horizontal split) or rightwards (vertical split) .
  • reference samples used to generate the sub-partitions prediction signals are only located at the left and above sides of the lines. All sub-partitions share the same intra mode. The followings are summary of interaction of ISP with other coding tools.
  • MRL Multiple Reference Line
  • Entropy coding coefficient group size the sizes of the entropy coding subblocks have been modified so that they have 16 samples in all possible cases, as shown in Table 4. Note that the new sizes only affect blocks produced by ISP in which one of the dimensions is less than 4 samples. In all other cases coefficient groups keep the 4 ⁇ 4 dimensions.
  • CBF coding it is assumed to have at least one of the sub-partitions has a non-zero CBF. Hence, if n is the number of sub-partitions and the first n-1 sub-partitions have produced a zero CBF, then the CBF of the n-th sub-partition is inferred to be 1.
  • MTS flag if a CU uses the ISP coding mode, the MTS CU flag will be set to 0 and it will not be sent to the decoder. Therefore, the encoder will not perform RD tests for the different available transforms for each resulting sub-partition.
  • the transform choice for the ISP mode will instead be fixed and selected according the intra mode, the processing order and the block size utilized. Hence, no signalling is required. For example, let t H and t V be the horizontal and the vertical transforms selected respectively for the w ⁇ h sub-partition, where w is the width and h is the height. Then the transform is selected according to the following rules:
  • ISP mode all 67 intra modes are allowed.
  • PDPC is also applied if corresponding width and height is at least 4 samples long.
  • reference sample filtering process reference smoothing
  • condition for intra interpolation filter selection doesn’t exist anymore, and Cubic (DCT-IF) filter is always applied for fractional position interpolation in ISP mode.
  • JVET-M0425 In the multi-hypothesis inter prediction mode (JVET-M0425) , one or more additional motion-compensated prediction signals are signalled, in addition to the conventional bi-prediction signal.
  • the resulting overall prediction signal is obtained by sample-wise weighted superposition.
  • the weighting factor ⁇ is specified by the new syntax element add_hyp_weight_idx, according to the following mapping (Table 5) :
  • more than one additional prediction signal can be used.
  • the resulting overall prediction signal is accumulated iteratively with each additional prediction signal.
  • the resulting overall prediction signal is obtained as the last p n (i.e., the p n having the largest index n) .
  • p n i.e., the p n having the largest index n
  • up to two additional prediction signals can be used (i.e., n is limited to 2) .
  • the motion parameters of each additional prediction hypothesis can be signalled either explicitly by specifying the reference index, the motion vector predictor index, and the motion vector difference, or implicitly by specifying a merge index.
  • a separate multi-hypothesis merge flag distinguishes between these two signalling modes.
  • MHP is only applied if non-equal weight in BCW is selected in bi-prediction mode. Details of MHP for VVC can be found in JVET-W2025 (Muhammed Coban, et. al., “Algorithm description of Enhanced Compression Model 2 (ECM 2) ” , Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29, 23rd Meeting, by teleconference, 7–16 July 2021, Document: JVET-W2025) .
  • ECM 2 Enhanced Compression Model 2
  • JVET-W0097 Zhipin Deng, et. al., “AEE2-related: Combination of EE2-3.3, EE2-3.4 and EE2-3.5”
  • JVET Joint Video Experts Team
  • JVET-Y0065 JVET-Y0065
  • GPM-MMVD GPM-3.3 on GPM with MMVD
  • EE2-3.4-3.5 on GPM with template matching (GPM-TM) : 1) template matching is extended to the GPM mode by refining the GPM MVs based on the left and above neighbouring samples of the current CU; 2) the template samples are selected dependent on the GPM split direction; 3) one single flag is signalled to jointly control whether the template matching is applied to the MVs of two GPM partitions or not.
  • JVET-W0097 proposes a combination of EE2-3.3, EE2-3.4 and EE2-3.5 to further improve the coding efficiency of the GPM mode. Specifically, in the proposed combination, the existing designs in EE2-3.3, EE2-3.4 and EE2-3.5 are kept unchanged while the following modifications are further applied for the harmonization of the two coding tools:
  • the GPM-MMVD and GPM-TM are exclusively enabled to one GPM CU. This is done by firstly signalling the GPM-MMVD syntax. When both two GPM-MMVD control flags are equal to false (i.e., the GPM-MMVD are disabled for two GPM partitions) , the GPM-TM flag is signalled to indicate whether the template matching is applied to the two GPM partitions. Otherwise (at least one GPM-MMVD flag is equal to true) , the value of the GPM-TM flag is inferred to be false.
  • the GPM merge candidate list generation methods in EE2-3.3 and EE2-3.4-3.5 are directly combined in a manner that the MV pruning scheme in EE2-3.4-3.5 (where the MV pruning threshold is adapted based on the current CU size) is applied to replace the default MV pruning scheme applied in EE2-3.3; additionally, as in EE2-3.4-3.5, multiple zero MVs are added until the GPM candidate list is fully filled.
  • the final prediction samples are generated by weighting inter predicted samples and intra predicted samples for each GPM-separated region.
  • the inter predicted samples are derived by the same scheme as the GPM in the current ECM whereas the intra predicted samples are derived by an intra prediction mode (IPM) candidate list and an index signalled from the encoder.
  • the IPM candidate list size is pre-defined as 3.
  • the available IPM candidates are the parallel angular mode against the GPM block boundary (Parallel mode) , the perpendicular angular mode against the GPM block boundary (Perpendicular mode) , and the Planar mode as shown Figs. 24A-C, respectively.
  • GPM with intra and intra prediction as shown Fig. 24D is restricted in the proposed method to reduce the signalling overhead for IPMs and avoid an increase in the size of the intra prediction circuit on the hardware decoder.
  • a direct motion vector and IPM storage on the GPM-blending area is introduced to further improve the coding performance.
  • Spatial GPM (SGPM) consists of one partition mode and two associated intra prediction modes. If these modes are directly signalled in the bit-stream, as shown in Fig. 25A, it would yield significant overhead bits.
  • a candidate list is employed and only the candidate index is signalled in the bit-stream. Each candidate in the list can derive a combination of one partition mode and two intra prediction modes, as shown in Fig. 25B.
  • a template is used to generate this candidate list.
  • the shape of the template is shown in Fig. 26.
  • a prediction is generated for the template with the partitioning weight extended to the template, as shown in Fig. 26. These combinations are ranked in ascending order of their SATD between the prediction and reconstruction of the template.
  • the length of the candidate list is set equal to 16, and these candidates are regarded as the most probable SGPM combinations of the current block. Both encoder and decoder construct the same candidate list based upon the template.
  • both the number of possible partition modes and the number of possible intra prediction modes are pruned.
  • 26 out of 64 partition modes are used, and only the MPMs out of 67 intra prediction modes are used.
  • JVET-AA0118 Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29, 27th Meeting, by teleconference, 13–22 July 2022, Document: JVET-AA0118) .
  • JVET-Z0124 In JVET-Z0124 (Fan Wang, et. al., “Non-EE2: Spatial GPM” , Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29, 26th Meeting, by teleconference, 20–29 April 2022, Document: JVET-Z0124) , full RDO is processed for every candidate from the candidate list of size 16.
  • the SAD/SATD cost is used to filter the candidates before full RDO. In particular, if the SAD/SATD cost of a candidate is larger than a threshold, this candidate will not go to full RDO.
  • the threshold is the best ever SAD/SATD cost of the current block multiplied by a ratio.
  • the maximum number of full RDO for SGPM is limited to 8 for each block.
  • JVET-Z0124 when deriving the candidate list, for each possible combination of one partition mode and two intra prediction modes, a prediction is generated for the template with the partitioning weight extended to the template, and SATD between the prediction and reconstruction of the template was used as the criterion for ranking.
  • the GPM blending process is not used in the template, and SAD is used as the criterion for ranking instead.
  • the weights in the template are either 1 or 0.
  • the two SADs of the two parts for each partition mode are calculated and saved. To get the SAD of one combination, only one addition of two corresponding SADs is needed.
  • the reordering method for GPM split modes is a two-step process performed after the respective reference templates of the two GPM partitions in a coding unit are generated, as follows:
  • the edge 2720 on the template (2730 and 2732) is extended from that of the current CU 2710, as shown in Fig. 27 illustrates, but GPM blending process is not used in the template area across the edge. After ascending reordering using TM cost, an index is signalled.
  • the GPM and SGPM use similar processing and have shown improvement in coding performance, it is desired to develop a unified approach to simplify the process and/or to further improve the coding performance.
  • a method and apparatus for video coding are disclosed. According to this method, pixel data associated with a current block are received at an encoder side or coded data associated with the current block to be decoded are received at a decoder side, where the current block is coded using coding tools including a first coding tool and a second coding tool.
  • a shared intra candidate list is determined.
  • the current block is partitioned into two regions according to a first target partition, one first hypothesis of intra prediction is derived from the shared intra candidate list, and a blended predictor is determined using first information comprising said one first hypothesis of intra prediction.
  • the current block is partitioned into two regions according to a second target partition, more than one second hypothesis of intra prediction is derived from the shared intra candidate list, and the blended predictor is determined using second information comprising said more than one second hypothesis of intra prediction.
  • the current block is encoded or decoded by using prediction data comprising the blended predictor.
  • the shared intra candidate list comprises intra MPMs (Most Probable Modes) or a subset of the intra MPMs. In another embodiment, the shared intra candidate list comprises any subset of 67 intra prediction modes. In yet another embodiment, the shared intra candidate list comprises one or more DIMD (Decoder-side Intra Mode Derivation) modes derived according to any pre-defined template region. In yet another embodiment, the shared intra candidate list comprises one or more TIMD (Template-based Intra Mode Derivation) modes derived according to any pre-defined template region.
  • DIMD Decoder-side Intra Mode Derivation
  • TIMD Tempolate-based Intra Mode Derivation
  • different shared intra candidate lists are determined for different block sizes.
  • a reordering process is applied to candidates of the shared intra candidate list.
  • the candidates of the shared intra candidate list are reordered according to template matching costs associated with the candidates of the shared intra candidate list.
  • a candidate with a smallest template matching cost is assigned a shortest codeword.
  • unified signalling between the first coding tool and the second coding tool is used, wherein a joint index is signalled or parsed to indicate a selected candidate from reordered shared intra candidate list. For an example of unifying with the SGPM design, after reordering, only the first K candidates with smaller template matching costs are kept in the list for signalling, where K is a pre-defined positive number smaller than or equal to the number of all possible candidates.
  • a unified blending process is applied to the first coding tool and the second coding tool.
  • each candidate of the shared intra candidate list includes a partition mode and an intra prediction mode. In another embodiment, each candidate of the shared intra candidate list includes a partition mode, a motion candidate/information, and an intra prediction mode. In yet another embodiment, each candidate of the shared intra candidate list includes a motion candidate/information and an intra prediction mode. In yet another embodiment, each candidate of the shared intra candidate list includes a partition mode and a motion candidate/information.
  • Fig. 1A illustrates an exemplary adaptive Inter/Intra video coding system incorporating loop processing.
  • Fig. 1B illustrates a corresponding decoder for the encoder in Fig. 1A.
  • Fig. 2 illustrates the neighbouring blocks used for deriving spatial merge candidates for VVC.
  • Fig. 3 illustrates the possible candidate pairs considered for redundancy check in VVC.
  • Fig. 4 illustrates an example of temporal candidate derivation, where a scaled motion vector is derived according to POC (Picture Order Count) distances.
  • POC Picture Order Count
  • Fig. 5 illustrates the position for the temporal candidate selected between candidates C 0 and C 1 .
  • Fig. 6 illustrates the distance offsets from a starting MV in the horizontal and vertical directions according to Merge Mode with MVD (MMVD) .
  • Fig. 7A illustrates an example of the affine motion field of a block described by motion information of two control point (4-parameter) .
  • Fig. 7B illustrates an example of the affine motion field of a block described by motion information of three control point motion vectors (6-parameter) .
  • Fig. 8 illustrates an example of block based affine transform prediction, where the motion vector of each 4 ⁇ 4 luma subblock is derived from the control-point MVs.
  • Fig. 9 illustrates an example of derivation for inherited affine candidates based on control-point MVs of a neighbouring block.
  • Fig. 10 illustrates an example of affine candidate construction by combining the translational motion information of each control point from spatial neighbours and temporal.
  • Fig. 11 illustrates an example of affine motion information storage for motion information inheritance.
  • Fig. 12 illustrates an example of the weight value derivation for Combined Inter and Intra Prediction (CIIP) according to the coding modes of the top and left neighbouring blocks.
  • CIIP Combined Inter and Intra Prediction
  • Fig. 13 illustrates an example of the of 64 partitions used in the VVC standard, where the partitions are grouped according to their angles and dashed lines indicate redundant partitions.
  • Fig. 14 illustrates an example of uni-prediction MV selection for the geometric partitioning mode.
  • Fig. 15 illustrates an example of bending weight ⁇ 0 using the geometric partitioning mode.
  • Fig. 16 illustrates an example of GPM blending process according to a discrete ramp function for the blending area around the boundary.
  • Fig. 17 illustrates an example of GPM blending process used for GPM blending in ECM 4.0.
  • Fig. 18 shows the intra prediction modes as adopted by the VVC video coding standard.
  • Figs. 19A-B illustrate examples of wide-angle intra prediction for a block with width larger than height (Fig. 19A) and a block with height larger than width (Fig. 19B) .
  • Fig. 20A illustrates an example of selected template for a current block, where the template comprises T lines above the current block and T columns to the left of the current block.
  • Fig. 20C illustrates an example of the amplitudes (ampl) for the angular intra prediction modes.
  • Fig. 21 illustrates an example of the blending process, where two angular intra modes (M1 and M2) are selected according to the indices with two tallest bars of histogram bars.
  • Fig. 22 illustrates an example of template-based intra mode derivation (TIMD) mode, where TIMD implicitly derives the intra prediction mode of a CU using a neighbouring template at both the encoder and decoder.
  • TIMD template-based intra mode derivation
  • Fig. 23A illustrates an example of Intra Sub-Partition (ISP) , where a block is partitioned into two subblocks horizontally or vertically.
  • ISP Intra Sub-Partition
  • Fig. 23B illustrates an example of Intra Sub-Partition (ISP) , where a block is partitioned into four subblocks horizontally or vertically.
  • ISP Intra Sub-Partition
  • Figs. 24A-C illustrate examples of available IPM candidates: the parallel angular mode against the GPM block boundary (Parallel mode, Fig. 24A) , the perpendicular angular mode against the GPM block boundary (Perpendicular mode, Fig. 24B) , and the Planar mode (Fig. 24C) , respectively.
  • Fig. 24D illustrates an example of GPM with intra and intra prediction, where intra prediction is restricted to reduce the signalling overhead for IPMs and hardware decoder cost.
  • Fig. 25A illustrates the syntax coding for Spatial GPM (SGPM) before using a simplified method.
  • Fig. 25B illustrates an example of simplified syntax coding for Spatial GPM (SGPM) .
  • Fig. 26 illustrates an example of template for Spatial GPM (SGPM) .
  • Fig. 27 illustrates an example of the edge on the template being extended from the template of the current CU, but GPM blending process is not used in the template area across the edge.
  • Fig. 28 illustrates an example of adaptive blending with individual blending sizes for the two blending regions according to one embodiment of the present invention.
  • Fig. 29 illustrates an example of determining costs associated with individual blending sizes based on a template and extended blending regions according to one embodiment of the present invention.
  • Fig. 30 illustrates an example of neighbouring mode information used for the candidate list.
  • Fig. 31 illustrates a flowchart of an exemplary video coding system that utilizes a shared candidate list for GPM intra prediction and SGPM according to an embodiment of the present invention.
  • a hypothesis of prediction means prediction from motion with a pre-defined direction (either list0 or list1) .
  • a hypothesis of prediction means prediction generated from a motion candidate (e.g. a merging candidate or an AMVP candidate) .
  • a hypothesis of prediction means prediction from motion with a pre-defined direction (either list0 or list1) or bi-prediction.
  • a hypothesis of prediction means prediction from an intra candidate or a motion candidate.
  • a hypothesis of prediction means prediction from an intra candidate.
  • the blending-prediction tools refer to (but not limited to) any one or more tools listed as follows or any combination of the listed tools.
  • the blending-prediction tools include bi-prediction motion candidates, which can be merge candidates and/or AMVP candidates.
  • the blending-prediction tools include GPM, one or more variations in GPM extension, and/or spatial GPM.
  • an adaptive blending process is proposed to improve the weighting scheme used in blending predictions.
  • the proposed adaptive blending process can also be applied to one or more mentioned blending-prediction tools and/or any combination of mentioned blending-prediction tools.
  • a partition line (e.g. GPM partition boundary) is defined to divide the current block 2810 into two prediction regions (shown in Fig. 28) .
  • the region near the partition line e.g. theta1 line 2832 to partition line 2820 and partition line 2820 to -theta2 line 2830) is defined as the blending region.
  • multiple e.g. 2, first_hyp_pred and second_hyp_pred
  • weighting referring to W0 [x] [y] ) .
  • ⁇ (x, y) is a sample position in the current block.
  • W0 [x] [y] is the weight for first_hyp_pred and (N –W0 [x] [y] ) is the weight for second_hyp_pred.
  • N is pre-defined as a fix positive integer (e.g. 8, 16, 32, or 64) or specified by a block-level, SPS-level, PPS-level, APS-level, PH-level, and/or SH-level syntax.
  • offset1and shift1 are decided according to N and/or BitDepth.
  • N 8
  • W0 [x] [y] is defined as 0. (or W0 [x] [y] is defined following the derivation for the blending region which results in a value equal to 0 or approaching to 0. )
  • W0 [x] [y] is defined as N. (or W0 [x] [y] is defined following the derivation for the blending region which results in a value equal to N or approaching to N. )
  • thata1 equal to 0 means no blending within the first prediction region. That is, W0 [x] [y] is defined as N in the first prediction region.
  • thata2 equal to 0 means no blending within the second prediction region. That is, W0 [x] [y] is defined as 0 in the second prediction region.
  • W0 [x] [y] is defined according to the distance, theta1 and/or theta2.
  • W0 [x] [y] is defined following the existing GPM weight derivation (e.g. VVC method) by setting the theta (used in GPM weight derivation) as the proposed theta1 or theta2.
  • W0 [x] [y] is defined according to distance and theta1.
  • W0 [x] [y] is defined as (N*(distance (x, y) +theta1) ) / (2*theta1) or can be simplified by quantizing.
  • W0 [x] [y] is defined as ( (distance’ (x, y) + 16*theta1 +offset2) >> shift2) with clipping to [0, N] .
  • ⁇ distance’ can be wIdxL in the GPM introduction section
  • W0 [x] [y] is defined as ( (distance’ (x, y) +16*theta1 + offset3) >> shift3) with clipping to [0, N] .
  • ⁇ distance’ can be wIdxL in the GPM introduction section
  • Offset3 can be N right-shifted by 1.
  • Shift3 can be log2 (N) . Take N equal to 8 as an example. Offset3 will be 4 and shift3 will be 3.
  • W0 [x] [y] is defined according to distance and theta2.
  • W0 [x] [y] is defined as (N* (distance (x, y) +theta2) ) / (2*theta2) or can be simplified by quantizing.
  • W0 [x] [y] is define as ( (distance’ (x, y) + 16*theta2 +offset2) >> shift2) with clipping to [0, N] .
  • ⁇ distance’ can be wIdxL in the GPM introduction section
  • W0 [x] [y] is defined as ( (distance’ (x, y) +16*theta2 + offset3) >> shift3) with clipping to [0, N] .
  • ⁇ distance’ can be wIdxL in the GPM introduction section
  • Offset3 can be N right-shifted by 1.
  • Shift3 can be log2 (N) . Take N equal to 32 as an example. Offset3 will be 16 and shift3 will be 5.
  • W0 [x] [y] is defined as the case “sample (x, y) is at blending region within first prediction region”
  • the case “sample (x, y) is at blending region within second prediction region” any proposed embodiments, or defined as equal weight (N >> 1) .
  • theta1 is predefined as a fix value (e.g. 0, 1/2, 1/4, 1, 2, 4 or 8) or specified by a block-level, SPS-level, PPS-level, APS-level, PH-level, and/or SH-level syntax. This embodiment is applicable for theta2.
  • theta1 is selected from a candidate set including at least one candidate values. This embodiment is applicable for theta2.
  • the candidate set includes at least one of ⁇ 0, 1/2, 1/4, 1, 2, 4 or 8 ⁇ or any combination of the above values.
  • the candidate set varies with the block width, block height, and/or the block area. For example, when the shorter side of the current block is equal to or smaller than a predefined threshold, only smaller values are included in the candidate set; otherwise only larger values are included in the candidate set.
  • theta 1 can be the same or different from theta2.
  • the benefit of allowing different values of theta1 and theta2 is that the best blending quality for diverse video sequences may need different blending regions for first prediction region and second prediction region. For example, if the area of the first prediction region is smaller, theta1 should be smaller than theta2. Or in an inverse way, if the area of the first prediction region is larger, theta1 should be smaller than theta2.
  • theta1 and theta2 have their own candidate sets (e.g. theta1_set and theta2_set) , respectively.
  • one candidate set is the subset of the other candidate set.
  • the candidate numbers for theta1_set and theta2_set are the same.
  • theta1 and theta2 share a single candidate set.
  • theta1 and theta2 are the same.
  • theta1 and theta2 can be the same or different.
  • the candidate number of the candidate set is defined as a fix value (e.g. 3 or 5) or specified by a block-level, SPS-level, PPS-level, APS-level, PH-level, and/or SH-level syntax.
  • the selection of theta1 and theta2 depends on explicit signalling.
  • two individual syntaxes are signalled at block-level, SPS-level, PPS-level, APS-level, PH-level, and/or SH-level syntax to indicate theta1 and theta2, respectively.
  • theta1 and theta 2 are selected from a candidate set including ⁇ 0, 1, 2, 4, 8 ⁇ , respectively.
  • An index e.g. index_theta1, ranging from 0 to 4
  • an index e.g. index_theta2, ranging from 0 to 4
  • a syntax is signalled at the block-level, SPS-level, PPS-level, APS-level, PH-level, and/or SH-level syntax to indicate a combination of theta1 and theta2.
  • Theta1 and theta 2 are selected from a candidate set including ⁇ 0, 1, 2, 4, 8 ⁇ .
  • the candidate combinations of theta1 and theta2, denoted as (theta1, theta2) can be
  • An index (ranging from 0 to the number of candidate combinations-1) is signalled.
  • the index can be signalled with truncated unary coding.
  • the index can be context-coding.
  • the candidate combinations are ordered with their template costs in an ascending order to form a reordered list.
  • Temporal cost measurement can be referenced in the section related to implicit derivation rule in this invention.
  • the signalled index refers to the position of the used combination in the reordered list.
  • the candidate combination with smallest template cost uses the shortest codewords among all candidate combinations.
  • the selection of theta1 and theta2 depends on implicit derivation.
  • template matching is used as the implicit derivation rule:
  • a template (or a neighbouring region of the current block, which was encoded or decoded before the current block) is used to measure the cost for each candidate combination of theta1 and theta2.
  • theta1 and theta 2 are selected from a candidate set including ⁇ 0, 1, 2, 4, 8 ⁇ .
  • the candidate combinations of theta1 and theta2, denoted as (theta1, theta2) can be
  • a template cost is calculated according to the distortion between the “prediction” and reconstruction of the template.
  • the “prediction” is generated by applying GPM with blending (i.e., using the candidate combination) to the template. As shown in Fig. 29, the partition line is extended to the template.
  • the distortion can be SATD, SAD, MSE, SSE, or any distortion measurement equations/metrics.
  • GPM variations/extensions can be any inter or intra modes which
  • a prediction mode refers to a motion candidate, a motion information derived from one or more motion candidates, an intra prediction mode, 7)
  • combining weight for each hypothesis of prediction is not zero. That is, the predicted samples near the split direction are the combination from the predicted samples based on one prediction mode and the predicted samples based on another prediction mode.
  • a GPM variation/extension refers to GPM-MMVD, GPM-TM, GPM-intra, or SGPM.
  • a GPM variation/extension refers to GPM-intra or SGPM.
  • a joint index is used to indicate a combination of “a partition mode and one or more prediction modes for multiple hypotheses of prediction” , a combination of “a subset from the partition mode and the one or more prediction modes for multiple hypotheses of prediction” or a combination of “more than one prediction mode for multiple hypotheses of prediction” .
  • the block is coded with SGPM.
  • the combination includes a partition mode and two intra prediction modes.
  • the combination includes two intra prediction modes.
  • the block is coded with GPM-intra.
  • the combination includes a partition mode, a motion candidate/information, and an intra prediction mode.
  • the combination includes a motion candidate/information and an intra prediction mode.
  • the combination includes a partition mode and an intra prediction mode.
  • the combination includes a partition mode and a motion candidate/information.
  • a combination list is reordered according to a template matching-based method.
  • the combination list including a partition mode, a motion candidate/information, and an intra prediction mode is reordered according to a template matching-based method.
  • the combination list including a motion candidate/information and an intra prediction mode is reordered according to a template matching-based method, and the template matching costs are determined for the combination list and a signalled partition mode.
  • the combination list including a partition mode and an intra prediction mode is reordered according to a template matching-based method, and the template matching costs are determined for a combination list and a signalled motion candidate/information.
  • the combination list including a partition mode and a motion candidate/information is reordered according to a template matching-based method, and the template matching costs are determined for a combination list and a signalled intra prediction mode.
  • the joint index is signalled/parsed in the bitstream.
  • the joint index is coded with truncated unary codewords.
  • the following examples show examples of the combination with the shortest codewords.
  • the combination with the shortest codewords contains a pre-defined mode.
  • the pre-defined mode can be a motion candidate/information with merge index equal to M, where M can be a positive integer, such as 0, 1, ..., or (size of merge candidate list -1) .
  • the pre-defined mode can be an intra prediction mode such as one of planar, DC, horizontal, vertical, parallel mode, and perpendicular mode.
  • the pre-defined mode can be a partition mode with vertical direction, horizontal direction, or diagonal direction.
  • the pre-defined rule depends on the block width, height, area, neighbouring mode information.
  • the joint index indicates a combination from a combination list.
  • the order in the combination list implies the signalling priority order of the combinations. That is, the combination at the first position in the combination list is signalled/parsed with the shortest codewords among all combinations.
  • the combination at the first position in the combination list is predefined.
  • one of planar, DC, horizontal, vertical, parallel mode, and perpendicular mode is predefined at the first position in the combination list when the current block is GPM-intra or SGPM.
  • the pre-defined rule depends on the block width, height, area, neighbouring mode information.
  • the syntax for indicating the combination at the first position in the combination list is coded with one or more contexts.
  • the context selection depends on the block width, height, area, neighbouring mode information.
  • the one or more used contexts are not reused by the remaining combinations in the combination list.
  • the syntax for indicating the combinations at the non-first position in the combination list is not coded with contexts.
  • the joint index indicates a combination from a reordered combination list according to a template matching-based method.
  • the order in the reordered combination list implies the signalling priority order of the combinations. That is, the combination at the first position in the combination list is signalled/parsed with the shortest codewords among all combinations.
  • the syntax for indicating the combination at the first position in the combination list is coded with one or more contexts.
  • the context selection depends on the block width, height, area, neighbouring mode information.
  • the one or more used contexts are not reused by the remaining combinations in the combination list.
  • the syntax for indicating the combinations at the non-first position in the combination list is not coded with contexts.
  • an index is used to indicate a reordered list of prediction mode according to a template matching-based method, where the template matching cost is calculated for a prediction mode in the list of prediction mode, a signalled partition mode, and another prediction mode by another signalled index to indicate a list of another prediction mode.
  • the block is coded with GPM-intra.
  • a list of prediction mode contains one or more intra prediction modes, and the list is reordered according to a template matching-based method where the template matching cost is calculated for an intra prediction mode in the list of intra prediction modes, a signalled partition mode, and an inter prediction mode where an inter prediction mode is determined by a signalled index to indicate a list of inter prediction modes.
  • the design between GPM modes (e.g. GPM and/or different GPM variations/extensions) is proposed to be unified.
  • the benefit is that with the unified design, the circuit can be reused by GPM and/or different GPM variations/extensions.
  • the unified design refers to the blending design (e.g. adaptive blending process) .
  • the candidate set used in an adaptive blending process can be unified.
  • the candidates in the set are unified.
  • the candidates for the first unified GPM mode are the same as a subset of the candidates for the second unified GPM mode.
  • the number of candidates for the first unified GPM mode is the same as the number of candidates for the second unified GPM mode.
  • the selection rule to pick one candidate from the candidate set used in an adaptive blending process can be unified.
  • the selection rule for the first unified GPM mode is the same as the selection rule of the candidates for the second unified GPM mode.
  • the selection rule depends on signalling/parsing in the bitstream.
  • the selection rule depends on the block width, block height, block area, or neighbouring mode information.
  • the unified design refers to generation of a candidate list (e.g. used to get a prediction mode for a hypothesis of prediction) .
  • the candidate list is used to generate the hypothesis of intra prediction for GPM-Intra and to generate one or more hypotheses of intra prediction for SGPM.
  • the candidate list is IPM candidate list.
  • the candidate list is the MPM list used in normal intra mode (e.g. intra mode coding with 67 intra prediction modes or any extension from 67 intra prediction modes such as 131 intra prediction modes) or any subset of the MPM list.
  • normal intra mode e.g. intra mode coding with 67 intra prediction modes or any extension from 67 intra prediction modes such as 131 intra prediction modes
  • subset of the MPM list e.g. intra mode coding with 67 intra prediction modes or any extension from 67 intra prediction modes such as 131 intra prediction modes
  • the subset can be first N candidates in the MPM list used in normal intra mode where N can be any positive integer such as 1, 2, 3, 4, 5, 6, ...or (size_of_MPM_list-1) .
  • the candidate list includes neighbouring mode information (e.g. neighbouring intra prediction mode) , where the neighbouring blocks can be one or more than one of the following, as shown in Fig. 30.
  • neighbouring mode information e.g. neighbouring intra prediction mode
  • the candidate list includes one or more DIMD intra prediction modes (i.e., with two tallest histogram bars)
  • the candidate list includes one or more of DC, HOR, and VER.
  • the order in the candidate list implies the signalling priority order of the candidates. That is, the candidate at the first position in the list is signalled/parsed with the shortest codewords among all candidates.
  • the candidate at the first position in the candidate list is predefined.
  • one of planar, DC, horizontal, vertical, parallel mode, and perpendicular mode is predefined at the first position in the candidate list when the current block is GPM-intra or SGPM.
  • the pre-defined rule depends on the block width, height, area, neighbouring mode information.
  • the syntax for indicating the candidate at the first position in the candidate list is coded with one or more contexts.
  • the context selection depends on the block width, height, area, neighbouring mode information.
  • the one or more used contexts are not reused by the remaining candidates in the candidate list.
  • the syntax for indicating the candidates at the non-first position in the candidate list is not coded with contexts.
  • the proposed methods in this invention can be unified with multiple blending tools.
  • the proposed methods used for GPM, GPM extension, and/or spatial GPM are unified.
  • the proposed methods in this invention can only be applied to some predefined partition lines among all candidate partition lines.
  • the proposed methods in this invention can be enabled and/or disabled according to implicit rules (e.g. block width, height, or area) or according to explicit rules (e.g. syntax on the block, tile, slice, picture, SPS, or PPS level) .
  • implicit rules e.g. block width, height, or area
  • explicit rules e.g. syntax on the block, tile, slice, picture, SPS, or PPS level
  • the proposed method is applied when the block area is larger than a threshold.
  • the proposed method is applied when the longer block side is larger than or equal to a threshold (e.g. 2) multiplied by the shorter block side.
  • block in this invention can refer to TU/TB, CU/CB, PU/PB, a predefined region, or CTU/CTB.
  • AMVP in this invention is like “AMVP” in JVET-T2002 (VVC tool description) .
  • AMVP motion is from a motion candidate with syntax “merge flag” equal to false (e.g. general_merge_flag in VVC equal to false) .
  • any of the foregoing proposed blended prediction methods with a shared candidate list for GPM intra prediction and SGPM can be implemented in encoders and/or decoders.
  • any of the proposed blended prediction methods with a shared candidate list for GPM intra prediction and SGPM can be implemented in an intra/inter coding module (Intra Pred. 150 and/or Inter Pred. 112 in Fig. 1A) of an encoder, an intra prediction module (Intra Pred. 150 in Fig. 1B) and/or a motion compensation module (MC 152 in Fig. 1B) of a decoder.
  • any of the proposed methods can be implemented as a circuit coupled to the intra/inter coding module of an encoder and/or motion compensation module, a merge candidate derivation module of the decoder.
  • Fig. 31 illustrates a flowchart of an exemplary video coding system that utilizes a shared candidate list for GPM intra prediction and SGPM according to an embodiment of the present invention.
  • the steps shown in the flowchart may be implemented as program codes executable on one or more processors (e.g., one or more CPUs) at the encoder side.
  • the steps shown in the flowchart may also be implemented based hardware such as one or more electronic devices or processors arranged to perform the steps in the flowchart.
  • pixel data associated with a current block are received at an encoder side or coded data associated with the current block to be decoded are received at a decoder side in step 3110, where the current block is coded using coding tools including a first coding tool and a second coding tool.
  • a shared intra candidate list is determined in step 3120. Whether the current block is coded in the first coding tool or the second coding tool is checked in step 3130. If the current block is coded in the first coding tool mode, steps 3140 to 3144 are performed. If the current block is coded in the second coding tool, steps 3150 to 3154 are performed.
  • step 3140 the current block is partitioned into two regions according to a first target partition.
  • one first hypothesis of intra prediction is derived from the shared intra candidate list.
  • a blended predictor is determined using first information comprising said one first hypothesis of intra prediction.
  • the current block is partitioned into two regions according to a second target partition.
  • more than one second hypothesis of intra prediction is derived from the shared intra candidate list.
  • the blended predictor is determined using second information comprising said more than one second hypothesis of intra prediction.
  • the current block is encoded or decoded by using prediction data comprising the blended predictor in step 3160.
  • Embodiment of the present invention as described above may be implemented in various hardware, software codes, or a combination of both.
  • an embodiment of the present invention can be one or more circuit circuits integrated into a video compression chip or program code integrated into video compression software to perform the processing described herein.
  • An embodiment of the present invention may also be program code to be executed on a Digital Signal Processor (DSP) to perform the processing described herein.
  • DSP Digital Signal Processor
  • the invention may also involve a number of functions to be performed by a computer processor, a digital signal processor, a microprocessor, or field programmable gate array (FPGA) .
  • These processors can be configured to perform particular tasks according to the invention, by executing machine-readable software code or firmware code that defines the particular methods embodied by the invention.
  • the software code or firmware code may be developed in different programming languages and different formats or styles.
  • the software code may also be compiled for different target platforms.
  • different code formats, styles and languages of software codes and other means of configuring code to perform the tasks in accordance with the invention will not depart from the spirit and scope of the invention.

Landscapes

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

Abstract

L'invention concerne une liste de candidats partagés pour un GPM et un SGPM. Selon ce procédé, une liste intra de candidats partagée est déterminée. Si le GPM est sélectionné : le bloc actuel est divisé en deux régions GPM selon une première partition cible, une première hypothèse de prédiction intra est dérivée pour une prédiction intra GPM à partir de la liste intra de candidats partagée, et un prédicteur mélangé est déterminé à l'aide de premières informations comprenant ladite première hypothèse de prédiction intra. Si le SGPM est sélectionné : le bloc actuel est divisé en deux régions SGPM selon une seconde partition cible, une ou plusieurs secondes hypothèses de prédiction intra sont dérivées de la liste intra de candidats partagée, et le prédicteur mélangé est déterminé à l'aide de secondes informations comprenant ladite ou lesdites secondes hypothèses de prédiction intra. Le bloc courant est codé ou décodé à l'aide de données de prédiction comprenant le mélange de prédicteurs.
PCT/CN2023/107688 2022-07-22 2023-07-17 Procédé et appareil pour un mélange de prédiction dans un système de codage vidéo WO2024017188A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202263369092P 2022-07-22 2022-07-22
US63/369,092 2022-07-22

Publications (1)

Publication Number Publication Date
WO2024017188A1 true WO2024017188A1 (fr) 2024-01-25

Family

ID=89617131

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/107688 WO2024017188A1 (fr) 2022-07-22 2023-07-17 Procédé et appareil pour un mélange de prédiction dans un système de codage vidéo

Country Status (1)

Country Link
WO (1) WO2024017188A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200120339A1 (en) * 2018-10-11 2020-04-16 Mediatek Inc. Intra Prediction For Multi-Hypothesis
CN113287308A (zh) * 2019-01-17 2021-08-20 腾讯美国有限责任公司 视频编解码方法及装置
US20210392322A1 (en) * 2018-11-12 2021-12-16 Mediatek Inc. Method and Apparatus of Multi-Hypothesis in Video Coding
CN114731427A (zh) * 2019-09-29 2022-07-08 寰发股份有限公司 视频编解码的具有不同色度格式的结合帧内帧间预测的方法和装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200120339A1 (en) * 2018-10-11 2020-04-16 Mediatek Inc. Intra Prediction For Multi-Hypothesis
US20210392322A1 (en) * 2018-11-12 2021-12-16 Mediatek Inc. Method and Apparatus of Multi-Hypothesis in Video Coding
CN113287308A (zh) * 2019-01-17 2021-08-20 腾讯美国有限责任公司 视频编解码方法及装置
CN114731427A (zh) * 2019-09-29 2022-07-08 寰发股份有限公司 视频编解码的具有不同色度格式的结合帧内帧间预测的方法和装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Y. KIDANI (KDDI), H. KATOU (KDDI), K. UNNO (KDDI), K. KAWAMURA (KDDI), N. YAN (KWAI), X. XIU, W. CHEN, H.-J. JHU, C.-W. KUO, X. WA: "EE2-2.7: GPM adaptive blending (JVET-Z0059, JVET-Z0137)", 27. JVET MEETING; 20220713 - 20220722; TELECONFERENCE; (THE JOINT VIDEO EXPLORATION TEAM OF ISO/IEC JTC1/SC29/WG11 AND ITU-T SG.16 ), 6 July 2022 (2022-07-06), XP030302750 *

Similar Documents

Publication Publication Date Title
JP7263529B2 (ja) デコーダ側精緻化ツールのサイズ選択アプリケーション
WO2017084512A1 (fr) Procédé et appareil de prédiction de vecteur de mouvement ou de dérivation de candidat à la fusion lors d'un codage vidéo
JP2022130528A (ja) 映像符号化における動きマージモードのシグナリングのためのシステムおよび方法
JP7318099B2 (ja) ビデオコーディングにおける変換ブロック・サイズ制約
US11356699B2 (en) Method and apparatus of sub-block deblocking in video coding
US20220103854A1 (en) Method and Apparatus of Combined Inter and Intra Prediction for Video Coding
WO2020073920A1 (fr) Procédés et appareils combinant de multiples prédicteurs destinés à une prédiction de bloc dans des systèmes de codage vidéo
WO2024017188A1 (fr) Procédé et appareil pour un mélange de prédiction dans un système de codage vidéo
WO2023207646A1 (fr) Procédé et appareil pour un mélange de prédiction dans un système de codage vidéo
WO2024083115A1 (fr) Procédé et appareil pour mélanger une prédiction intra et inter dans un système de codage vidéo
WO2023207649A1 (fr) Procédé et appareil de dérivation de mouvement côté décodeur dans un système de codage vidéo
WO2024083251A1 (fr) Procédé et appareil de prédiction intra basée sur une zone à l'aide d'une dérivation de mode intra côté modèle ou décodeur dans un système de codage vidéo
US20230209042A1 (en) Method and Apparatus for Coding Mode Selection in Video Coding System
WO2023198142A1 (fr) Procédé et appareil de prédiction implicite de composantes croisées dans un système de codage vidéo
WO2023241637A1 (fr) Procédé et appareil de prédiction inter-composantes avec mélange dans des systèmes de codage vidéo
US20230209060A1 (en) Method and Apparatus for Multiple Hypothesis Prediction in Video Coding System
WO2024012396A1 (fr) Procédé et appareil de prédiction inter à l'aide d'une mise en correspondance de modèles dans des systèmes de codage vidéo
CN113273208A (zh) 仿射预测模式的改进
WO2024083238A1 (fr) Procédé et appareil de prédiction intra pondérée par matrice dans système de codage vidéo
WO2024074134A1 (fr) Prédiction basée sur un mouvement affine dans un codage vidéo
WO2024037649A1 (fr) Extension de compensation d'éclairage local
WO2023116778A1 (fr) Procédé, appareil et support de traitement vidéo
WO2024104420A1 (fr) Améliorations de compensation d'éclairage dans un codage vidéo
WO2024074094A1 (fr) Inter-prédiction dans un codage vidéo
WO2024022145A1 (fr) Procédé et appareil d'amvp avec mode de fusion pour codage vidéo

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: 23842251

Country of ref document: EP

Kind code of ref document: A1