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17th Meeting: Brussels, January 2020 2020-01-12 14:39
AHG9: A joint solution of constraints on RPR
Authors: Kai Zhang ByteDance Li Zhang ByteDance Ye-Kui Wang ByteDance H. Liu ByteDance Jizheng Xu ByteDance Zhipin Deng ByteDance T.-D. Chuang MediaTek Olena Chubach MediaTek C.-Y. Chen MediaTek C.-W. Hsu MediaTek Lulin Chen MediaTek Y.-W. Huang MediaTek Shawmin Lei MediaTek Yao-Jen Chang Qualcomm Vadim Seregin Qualcomm Muhammed Coban Qualcomm Marta Karczewicz Qualcomm
Abstract
In VVC, scaling ratios of reference pictures in RPR are controlled by scaling windows. In this contribution, the following three sets of constraints presented in JVET-Q0178, JVET-Q0179 JVET-Q0318 and JVET-Q0331 are proposed to clean up the design of RPR:
Meeting Notes
JVET-Q0788 AHG9: A joint solution of constraints on RPR [K. Zhang, L. Zhang, Y.-K. Wang, H. Liu, J. Xu, Z. Deng (Bytedance), T.-D. Chuang, O. Chubach, C.-Y. Chen, C.-W. Hsu, L. Chen, Y.-W. Huang, S.-M. Lei (MediaTek), Y.-J. Chang, V. Seregin, M. Coban, M. Karczewicz (Qualcomm)]

This contribution was discussed Tuesday 14 January at 1110 in Track A (chaired by GJS).

This contribution includes three aspects. The first is addressed by the action taken on JVET-Q0257. The third aspect is the same as the third variation in JVET-Q0179.

The second aspect relates to JVET-Q0318. It is proposed to prohibit cases in which a reference picture is larger (or smaller) than the current picture while the scaling window of the reference picture is smaller (or larger) than the current picture. In other words, it would prohibit upsampling from a larger picture and downsampling from a smaller picture. It was commented that the concern addressed by this proposed constraint could be addressed in other ways.

This was further discussed Tuesday 14 January at 1540 in Track A (chaired by GJS).

The maximum bandwidth issue was adequately addressed by actions taken on other contributions.

The examples showed that there could be a usage that appeared unintuitive, but this did not seem to be a compelling reason to prohibit such behaviour. Trying to prohibit this would also involve drafting of statements describing exactly what to prohibit (and perhaps additional checks needed to determine conformance). No action was thus taken on this.

References:
JVET-Q0178 JVET-Q0179 JVET-Q0318 JVET-Q0331
PATENTS:
20240098254 0.34 20230119708 0.33 202227074257 0.32 20240089504 0.31 20230063674 0.30 20230029791 0.28 20240179350 0.27 202227054080 0.26
ARCHIVE v1 :
JVET-Q0788.docx
Decisions
The examples showed that there could be a usage that appeared unintuitive, but this did not seem to be a compelling reason to prohibit such behaviour. Trying to prohibit this would also involve drafting of statements describing exactly what to prohibit (and perhaps additional checks needed to determine conformance). No action was thus taken on this.
Citation