Joint Video Experts Team (jvet) of itu-t sg 6 wp and iso/iec jtc 1/sc 29/wg 11

7Non-CfP Technology proposals (37)

7.1Additional information on CfP contributions (6)

Contributions in this category were discussed Saturday 14 April 0930–1030 (chaired by GJS & JRO).

JVET-J0047 Improvement on top of Tencent’s CfP response [X. Li, X. Xu, X. Zhao, J. Ye, L. Zhao, S. Liu, M. Xu, G. Li (Tencent)]

PresentedThis contribution was presented Saturday 0950 (GJS(chaired by GJS and JRO).

This contribution summarizes the more recent work on top of Tencent’sthe CfP response ion the SDR contentcategory by Tencents. Three elements of the response, i.e., block structure, intra block copy and merge candidate list construction, weare reportedly refined. One encoder- only feature, i.e., adaptive chroma QP offset, wais newly introduced. It is reported that 7.67% and 38.16% luma BD rate reduction over the JEM and HM RA anchors was obtained, respectively.

Elements of the presented additional developments:

• 
  “Split to square” – split into same-size square blocks whatever the aspect ratio of non-square higher level is
  
• 
  Derivinge automatically split options at the picture boundary to save signalling
  
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  IBC aligned with inter (as in SCM, via refindex) (see JVET-J0050)
  
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  Merge list construction (see JVET-J0058)
  
• 
  Adaptive chroma QP offset (see JVET-J0055)
  

(These elements were all to be reportedfurther discussed in subsequent separate documents.)

JVET-J0049 Coding performance of Tencent’s structure-only scheme [X. Li, X. Zhao, S. Liu (Tencent)]

PresentedThis contribution was presented Saturday 1005 (GJS(chaired by GJS and JRO).

This contribution reports the coding performance of Tencent’s structure-only scheme. The scheme is on top of Next Software with newly introduced structure modifications while disabling Next tools by configuration options. Compared to the HM-16.6 anchor, over 12% luma BD rate reduction for constraint sets 1 and 2 (i.e., RA and LD) weare reportedly achieved, respectively.

The chroma gain is higher than the luma gain. The CTU size for the test was 256×256 (on both sides of the comparison).

“Structure only” refers to a configuration where only the partitioning part is enabled relative to the HM. This is a combination of the QT/BT/TT and split-to-square partitioning types. Multi-parameter CABAC is also used for efficient coding of 4x4 blocks. The mMax CTU size is 256x256. A sSeparate tree for intra luma and /chroma is also used.

Comments from the discussion:

• 
  The "split to square" aspect was said to be provide about 0.5% gain.
  
• 
  It was remarked that QTBT has about 5% gain.
  
• 
  The HM also does not have a separate tree structure for luma and chroma for intra slices.
  

JVET-J0055 Adaptive chroma QP offset on top of Tencent's CfP response [M. Xu, X. Li, S. Liu (Tencent)]

This contribution was discussed Saturday 14 April 1025–1040 (chaired by GJS and JRO).

This contribution describes an encoder only method, i.e., adaptive chroma QP offset , on top of the Tencent’s CfP response JVET-J0029 and implemented in the context of proposal JVET-J0047. It is reported that the proposed method brings an average of −2.06% luma BD rate change for SDR constraint set 1 (i.e., LD).

The proposal is a slice-level adaptive chroma QP offset, where the chroma QP offset is activated based on the criterion lumaPSNR+TH < chromaPSNR, which is determined based on the values of the previous decoded frame.

A gGain in luma was reported, but with a loss forin chroma. The scheme sSeems to be effective mostly for particular test sequences.

Question: HasIt was asked whether the scheme it had been studied visually. This had ? Nnot yet been done.

It wais also pointed out that the possibility of changing it on a picture by picture basis may be undesirable, as it may cause visual temporal fluctuations in picture quality.

The proponents dido not claim that the criterion is optimum yet.

Comments from the discussion:

• 
  Some significant chroma fidelity losses were observed, especially for the chroma-rich CampfireParty and ParkRunning test sequences.
  

Further study on the aspect of chroma QP offset appears useful.
JVET-J0067 Additional information on HDR video coding technology proposal by Qualcomm and Technicolor [A. K. Ramasubramonian, D. Rusanovskyy, M. Karczewicz (Qualcomm), E. François (Technicolor)]

This contribution was reviewed in the context of the review of the corresponding CfP response contribution JVET-J0021.

JVET-J0072 SoftwareW for technology proposal by Samsung, Huawei, GoPro, and HiSilicon – mobile application scenario (JVET-J0024) [A. Alshin, E. Alshina, K. Choi, N. Choi, W. Choi, S. Jeong, B. Jin, C. Kim, J. Min, J. H. Park, M. Park, M. W. Park, Y. Piao, A. Tamse, H. Yang (Samsung), H. Chen, J. Chen, R. Chernyak, S. Esenlik, A. Filippov, S. Gao, S. Ikonin, A. Karabutov, A. M. Kotra, X. Lu, X. Ma, V. Rufitskiy, T. Solovyev, V. Stepin, M. Sychev, T. Wang, Y.-K. Wang, W. Xu, H. Yang, V. Zakharchenko, H. Zhang, Y. Zhao, Z. Zhao, J. Zhou, C. Auyeung, H. Gao, I. Krasnov, R. Mullakhmetov, B. Wang, Y. F. Wong, G. Zhulikov (Huawei), A. Abbas, D. Newman, J. An, X. Chen, Y. Lin, Q. Yu, J. Zheng (HiSilicon)] [late]

On Wednesday 18 April, the presenter said this had already been adequately considered and did not request an oral presentation of this contribution.

This contribution provides an "IFVC" SW software package. This is an implementation for all tools described in technology proposal by Samsung, Huawei, GoPro, and HiSilicon –for the mobile application scenario. After the CfP bitstream submission, the SW software was reportedly optimized, and cleaned up, and also several minor bugs have had been fixed. Under CS1 constraint set 1 (i.e., RA) test conditions, the IFVC package reportedly provides 36%, 36%, and 37% BD-rate gain over the CfP anchor for Y, Cb, Cr components, correspondentlyrespectively, while encoding and decoding run time is 5× and 3× compared to the CfP anchors, respectively. For example, SW The software can be configured in different ways, e.g., to show 13% gain over the CfP anchors with 15% faster encoder or to provide 19% gain while when the encoder speed is the same as the HM. The dDecoder time is significantly lower (almost half) than the HM anchor in these configurations.
JVET-J0075 Partition only software of the video coding technology proposal by Qualcomm and Technicolor [Y.-W. Chen, W.-J. Chien, H.-C. Chuang, M. Coban, J. Dong, H. E. Egilmez, N. Hu, M. Karczewicz, A. Ramasubramonian, D. Rusanovskyy, A. Said, V. Seregin, G. Van Der Auwera, K. Zhang, L. Zhang (Qualcomm), P. Bordes, Y. Chen, C. Chevance, E. François, F. Galpin, M. Kerdranvat, F. Hiron, P. de Lagrange, F. Le Léannec, K. Naser, T. Poirier, F. Racapé, G. Rath, A. Robert, F. Urban, T. Viellard (Technicolor)] [late]

On Wednesday 18 April, the presenter said this had already been adequately considered and did not request an oral presentation of this contribution.

This contribution describes the subset of the partitioning structure of the Qualcomm Inc. and Technicolor’s joint call-for-proposals response, and it reportedly includes clean software containing only the partitioning structure without the other new tools used in JVET-J0021 and JVET-J0022. A partition-only test reportedly provides 14.27%, 17.38% and 18.04% average luma BD-rate improvement in constraint set 1 (i.e., RA) tests for QTBT, QTBT+TT and QTBT+ABT configurations, respectively. The proposed partitioning includes QTBT structure as in the JEM and triple-tree (TT) partitioning as shown on the next figures.