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18th Meeting: Teleconference, April 2020 2020-04-03 12:06
AHG15: Issue on chroma scaling matrix for 4:4:4
Authors: K. Abe Panasonic T. Toma Panasonic
Abstract
This contribution points out the issue that VTM-8.0 does not work with enabling scaling matrix for 4:4:4 format and proposes two solutions. Solution1 proposes to fix VTM to strictly align to current VVC specification text, it needs to introduce size64 chroma scaling matrices reusing size32 matrices. Solution2 proposes alternative method of current VVC specification text by introducing size64 chroma scaling matrix using individual matrix id. It can simplify the specification and improve the tuning capability.
Meeting Notes
JVET-R0166 AHG15: Issue on chroma scaling matrix for 4:4:4 [K. Abe, T. Toma (Panasonic)]

This contribution points out the issue that VTM-8.0 does not work with enabling scaling matrix for 4:4:4 format and proposes two solutions. Solution1 proposes to fix VTM to strictly align to current VVC specification text, it needs to introduce size64 chroma scaling matrices reusing size32 matrices. Solution2 proposes alternative method of current VVC specification text by introducing size64 chroma scaling matrix using individual matrix id. It can simplify the specification and improve the tuning capability.

The proposed solution 2 would also require signalling the size 64 chroma matrices for the 4:2:0 case.

It is not fully clear that the separate scaling matrices for chroma block size 64 are really needed.

No support for solution 2.

The AHG meeting recommended to align the VTM with text regarding the upscaling of chroma matrices for 4:4:4 64 size (adopt method1 of JVET-R0166).

Confirmed in track B Tue. Apr. 21.

Decision (SW BF): Adopt JVET-R0166 method 1. Align the VTM with spec. text regarding the upscaling of chroma matrices for 4:4:4 for transform size 64.

References:
JCTVC-F362 JCTVC-H1104 JCTVC-N0192 JVET-P2001 JVET-Q2001
Cited:
JVET-R0015 JVET-S0003
PATENTS:
CN113422961B 0.34 2024-07-19 4087238 0.34 4336838 0.33 US9154780B2 0.32 2015-10-06 20240064330 0.32 20250358442 0.31 EP3876539B1 0.30 2023-12-27 4156689 0.30
ARCHIVE v1 :
JVET-R0166-solution2-JVET-Q2001-vE.docx JVET-R0166.docx JVET-R0166.pdf JVET-R0166_source_cfg_VTM8.0.zip
Decisions
adopted
Decision (SW BF): Adopt JVET-R0166 method 1. Align the VTM with spec. text regarding the upscaling of chroma matrices for 4:4:4 for transform size 64.
Citation