Joint Collaborative Team on Video Coding (jct-vc)

5.9Block structures and partitioning

5.9.1General

JCTVC-I0150 Virtual large transform unit over maximum transform size with zero CBF [J. Kim, B. Jeon (LG)]
JCTVC-I0332 Unified CBFU and CBFV Coding in RQT [L. Guo, X. Wang, M. Karczewicz (Qualcomm)]
JCTVC-I0471 Crosscheck Report for Unified CBFU and CBFV Coding in JCTVC-I0332 [X. Guo (MediaTek)] [late] [miss]
JCTVC-I0334 Proposed Fix on CBFY Inference at Minimum TU Size [L. Guo, M. Karczewicz (Qualcomm)]
JCTVC-I0516 Cross-check of JCTVC-I0334 [J. Xu (Microsoft)] [late]

5.9.2NSQT/AMP

JCTVC-I0224 Results for Non-Square Intra Prediction with NSQT [X. Zhang, S. Liu, S. Lei (MediaTek)]

This contribution reports methods and results for utilizing non-square intra prediction with NSQT. The fundamentals are same as the methods proposed in AHG16 in the 8^th JCT-VC meeting. The coding efficiency and run-time of the proposed methods built on top of HM6.0 software are reported. Experimental results report average 1.3% BD-rate reduction for All Intra HE10 with encoding runtime increase of 31%. For Random access HE10, experimental results report average 0.6% BD-rate reduction with encoding runtime increase of 4%. For Low delay HE10, experimental results report average 0.3% BD-rate reduction with encoding runtime increase of 3%. The average decoding runtime variation is negligible. With further encoder complexity reduction, experimental results report average 1.1% BD-rate reduction for All Intra HE10 with encoding runtime increase of 22% and negligible decoding runtime variation.

Gain without non-square transforms? A: Certainly less, perhaps half.

Concerns raised that this is a non-trivial change, and it builds on NSQT which is still not fully stable yet. It should not be done at this late stage. Could potentially be interesting for future profiles.

JCTVC-I0418 Cross-verification of Results for Non-Square Intra Prediction with NSQT (JCTVC-I0224) [R. Cohen (MERL)]
JCTVC-I0323 Crosscheck of Non-Square Intra Prediction with NSQT (JCTVC-I0224) [Y. Chiu, W. Zhang, L. Xu, Y. Han (Intel)] [late]
JCTVC-I0305 Test results on AMP and NSQT [X. Zheng (HiSilicon), L. Liu (HiSilicon), H. Yu (Huawei), I.-K. Kim (Samsung)]

Nothing new technically – this document summarizes the performance which can be used in the profile/level discussion

JCTVC-I0517 Cross-check of JCTVC-I0305 [J. Xu (Microsoft)] [late]
JCTVC-I0197 Cross verification of JCTVC-I0305 on NSQT from Huawei [E. Francois (Canon)] [late]
JCTVC-I0306 Implementation of NSQT in HM [X. Zheng (HiSilicon)] [late]

For information, describing software, no change relative to the status of San Jose meeting.

Note: The current CD text has bugs (tickets 505 and 506). It is suggested to provide a late input with proposed improved and bug free text on the basis of JCTVC-I0030. (revisit - to be confirmed by CD editor).

JCTVC-I0308 Implicit TU split process for asymmetric partitions [X. Zheng (HiSilicon), Y. Yuan, Y. He (Tsinghua)]

This contribution provides an implicit TU split solution for asymmetric partitions when “QuadtreeTUMaxDepthInter” is set to 1 and NSQT is switched of. Experimental results show that the proposed solution contributes average coding gain of 0.2% for RA-Main and RA-HE10, 0.4% for LDB-Main and LDB-HE10. Both encoder and decoder complexity are same as HM6.0.

Presentation not uploaded.

One hint: This implicit splitting may be problematic with minimum transform size. Also not clear whether all cases of AMP are covered.

No support by other companies.

JCTVC-I0452 Cross-check on implicit TU split prcoess for asymmetric partitions (JCTVC-I0308) [I.-K Kim (Samsung)] [late]
JCTVC-I0150 Virtual large transform unit over maximum transform size with zero CBF [J. Kim, B. Jeon (LG)]

This contribution proposes virtual transform units whose width and height are twice larger than the maximum transform size. When the virtual transform is applied, the luma CBF of the TU is derived as zero and the maximum size transform is applied to chroma components. It states 0.1%, -0.4%, -0.6% and 0.1%, -0.5%, -0.8% BDrate respectively in AIMAIN and AIHE10 condition. It also states 0.1%, -0.6%, -0.6% and 0.1%, -0.5%, -0.5% BDrate respectively in RAMAIN and RAHE10 condition. It states 0.1%, -0.7%, -0.9% and 0.1%, -0.9%, -1.0% BDrate respectively in the LBMAIN and RBHE10 condition.

One expert comments that the 32x32 was removed by purpose to reduce complexity (for the case of 4:2:0 and main profile). The text does not have the restriction in general

No overall gain obvious (loss in luma is observed).

No action.

JCTVC-I0146 Virtual non square transform unit over maximum transform size with zero CBF [J. Kim, B. Jeon (LG)]

In this contribution, virtual non square transforms whose size is larger than maximum transform size are proposed. When virtual non square transform is applied, luma CBF of the TU is derived as zero. It shows 0.0%, -0.2%, -0.1% gain for RAHE10 and 0.1%, -0.4% -0.7% gain for LDHE10 under the common condition with maximum CU size of 64x64 and maximum TU size of 32x32.

No action.

JCTVC-I0086 Cross-check of JCTVC-I0146 on virtual NSQT [Y. Lin (HiSilicon)] [late]
JCTVC-I0149 Coherent transform split pattern for non square transform units [J. Kim, B. Jeon (LG)]

In this contribution, the transform split pattern of non square transform TUs is restrained consistent regardless of the size of CU. Currently a TU in a CU larger than the maximum transform size is split into four square TUs until the TU size is equal to the maximum TU size. And then each square TU is split into four non square TUs. In this contribution, a transform unit is always split into four non square TUs regardless TU or CU sizes. It stats 0.0%, -0.1%, 0.0% gain for RAHE10 and 0.1%, -0.1% -0.3% gain for LDHE10 under the common condition.

Presentation not uploaded.

No interest of other parties.

Claimed to be a simplification of syntax, but no draft text is provided.

No action.

JCTVC-I0445 Cross-check report of JCTVC-I0149 on transform split pattern of NSQT [Y. Lin (HiSilicon)] [late]
JCTVC-I0146 Virtual non square transform unit over maximum transform size with zero CBF [J. Kim, B. Jeon (LG)]
JCTVC-I0086 Cross-check of JCTVC-I0146 on virtual NSQT [Y. Lin (HiSilicon)] [late]
JCTVC-I0149 Coherent transform split pattern for non square transform units [J. Kim, B. Jeon (LG)]
JCTVC-I0445 Cross-check report of JCTVC-I0149 on transform split pattern of NSQT [Y. Lin (HiSilicon)] [late]
JCTVC-I0224 Results for Non-Square Intra Prediction with NSQT [X. Zhang, S. Liu, S. Lei (MediaTek)]
JCTVC-I0418 Cross-verification of Results for Non-Square Intra Prediction with NSQT (JCTVC-I0224) [R. Cohen (MERL)]
JCTVC-I0323 Crosscheck of Non-Square Intra Prediction with NSQT (JCTVC-I0224) [Y. Chiu, W. Zhang, L. Xu, Y. Han (Intel)] [late]
JCTVC-I0305 Test results on AMP and NSQT [X. Zheng (HiSilicon), L. Liu (HiSilicon), H. Yu (Huawei), I.-K. Kim (Samsung)]
JCTVC-I0517 Cross-check of JCTVC-I0305 [J. Xu (Microsoft)] [late]
JCTVC-I0197 Cross verification of JCTVC-Ixxx on NSQT from Huawei [E. Francois (Canon)] [late]
JCTVC-I0306 Implementation of NSQT in HM [X. Zheng (HiSilicon)] [late]
JCTVC-I0308 Implicit TU split process for asymmetric partitions [X. Zheng (HiSilicon), Y. Yuan, Y. He (Tsinghua)]
JCTVC-I0452 Cross-check on implicit TU split prcoess for asymmetric partitions (JCTVC-I0308) [I.-K Kim (Samsung)] [late]