id summary reporter owner description type status priority milestone component version resolution keywords cc 1501 Wrong slice type when GDR enabled in LDP configuration saurabh.puri "Two defects were noticed in the latest VTM-13.0 and are related to GDR tool being enabled in LDP config. With GDR tool enabled in LDP, the inter-picture is wrongly marked as B-SLICE and therefore, enables bi-directional prediction as shown below. {{{ $ ./EncoderApp.exe -c ~/source/repos/cloudgamingcodec/cfg/encoder_lowdelay_P_vtm.cfg -c ~/source/repos/cloudgamingcodec/cfg/per-sequence/BQSquare.cfg -ipp ../../../../../../../video_sequences/ -f 10 --GdrEnabled=1 --GdrPocStart=0 --GdrPeriod=32 --GdrInterval=16 VVCSoftware: VTM Encoder Version 13.0 [Windows][VS 1929][64 bit] [SIMD=AVX2] TOOL CFG: IBD:1 HAD:1 RDQ:1 RDQTS:1 RDpenalty:0 LQP:0 SQP:0 ASR:0 MinSearchWindow:8 RestrictMESampling:0 FEN:1 ECU:0 FDM:1 ESD:0 TransformSkip:1 TransformSkipFast:1 TransformSkipLog2MaxSize:5 ChromaTS:1 BDPCM:0 Tiles: 1x1 Slices: 1 MCTS:0 SAO:1 ALF:1 CCALF:1 WPP:0 WPB:0 PME:2 WaveFrontSynchro:0 WaveFrontSubstreams:1 ScalingList:0 TMVPMode:1 DQ:1 SignBitHidingFlag:0 RecalQP:0 TOOL CFG: LFNST:0 MMVD:1 Affine:1 AffineType:1 PROF:1 SbTMVP:1 DualITree:1 IMV:1 BIO:0 LMChroma:1 HorCollocatedChroma:1 VerCollocatedChroma:0 MTS: 1(intra) 0(inter) SBT:1 ISP:1 SMVD:0 CompositeLTReference:0 Bcw:0 BcwFast:0 LADF:0 CIIP:1 Geo:0 AllowDisFracMMVD:1 AffineAmvr:0 AffineAmvrEncOpt:0 DMVR:0 MmvdDisNum:6 JointCbCr:1 ACT:0 PLT:0 IBC:0 HashME:0 WrapAround:0 VirtualBoundariesEnabledFlag:1 VirtualBoundariesPresentInSPSFlag:0 Reshape:1 (Signal:SDR Opt:0 CSoffset:1) MRL:1 MIP:0 EncDbOpt:0 FAST TOOL CFG: LCTUFast:1 FastMrg:1 PBIntraFast:1 IMV4PelFast:1 MTSMaxCand: 3(intra) 4(inter) ISPFast:0 AMaxBT:1 E0023FastEnc:1 ContentBasedFastQtbt:0 UseNonLinearAlfLuma:1 UseNonLinearAlfChroma:1 MaxNumAlfAlternativesChroma:8 FastLocalDualTree:2 RPR:0 TemporalFilter:0 started @ Tue Aug 3 15:59:56 2021 POC 0 LId: 0 TId: 0 ( IDR_N_LP, I-SLICE, QP 32 ) 82056 bits [Y 33.8351 dB U 40.0469 dB V 40.1413 dB] [ET 17 ] [L0] [L1] POC 1 LId: 0 TId: 0 ( TRAIL, B-SLICE, QP 32 ) 10080 bits [Y 33.3199 dB U 40.0073 dB V 40.1417 dB] [ET 10 ] [L0 0] [L1 0c] POC 2 LId: 0 TId: 0 ( TRAIL, B-SLICE, QP 32 ) 15816 bits [Y 33.3283 dB U 39.8815 dB V 40.1432 dB] [ET 15 ] [L0 1 0] [L1 1c 0] POC 3 LId: 0 TId: 0 ( TRAIL, B-SLICE, QP 32 ) 16584 bits [Y 33.2873 dB U 39.9254 dB V 40.0040 dB] [ET 14 ] [L0 2 1 0] [L1 2c 1 0] }}} From code, it seems the slice type for inter-picture is hard coded as 'B' when GDR is enabled. Removing the hard coded value in the code seems to fix the above issue but leads to '''segmentation fault''' after I frame. {{{ started @ Tue Aug 3 16:09:56 2021 POC 0 LId: 0 TId: 0 ( IDR_N_LP, I-SLICE, QP 32 ) 82056 bits [Y 33.8351 dB U 40.0469 dB V 40.1413 dB] [ET 18 ] [L0] [L1] Segmentation fault }}} It is noticed that segmentation fault only happens in Affine mode. When the Affine tool is turned OFF in LDP + GDR configuration, the segmentation fault is not observed. This may be due to some missing condition (in the GDR part of the affine tool implementation) which is allowing bi-prediction even when LDP mode is used with GDR. " defect closed major VTM VTM-13.0 fixed GDR LDP jvet@… ksuehring XiangLi fbossen