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13th Meeting: Marrakech, January 2019 2019-01-13 14:00
Non-CE4: Temporal MV buffer reduction
Authors: Yi-Wen Chen Kwai X. Wang Kwai
Abstract
In VTM-3.0, for higher coding efficiency, 1/16-pel motion compensation is supported and all the MVs are stored in 1/16-pel precision in the temporal MV buffer. To reduce the size of temporal MV buffer, we propose to store these MVs in 1/4-pel precision in the temporal MV buffer. It is asserted that the proposed method can reduce the required temporal MV buffer size by about 12%. According to the results reported, the proposed simplifications incur 0.03% and 0.09% BD-rate increase under RA and LDB conditions respectively.
Meeting Notes
JVET-M0230 CE4-related: Temporal MV buffer reduction [Y.-W. Chen, X. Wang (Kwai Inc.)]

Notes from BoG report review: 0.03% (100%, 100%)/0.09% (100%, 99%). Lower MV bits.

This is a relevant reduction of buffer. However, it is suggested that instead of using scaling (1/16 to 1/4), simple clipping from 18 to 16 bits should be investigated as well.

In this context, it is mentioned in the Track B discussion if it might be useful to define some restriction of MVs, just to prevent for some future application with extremely large picture sizes valid ranges might be exceeded.

JVET-M0230 CE4-related: Temporal MV buffer reduction [Y.-W. Chen, X. Wang (Kwai Inc.)]

Notes from BoG report review: 0.03% (100%, 100%)/0.09% (100%, 99%). Lower MV bits.

This is a relevant reduction of buffer. However, it is suggested that instead of using scaling (1/16 to 1/4), simple clipping from 18 to 16 bits should be investigated as well.

In this context, it is mentioned in the Track B discussion if it might be useful to define some restriction of MVs, just to prevent for some future application with extremely large picture sizes valid ranges might be exceeded.

References:
JVET-L1010
Cited:
JVET-M0024 JVET-M0591 X
PATENTS:
US20240171735A1 0.70 2024-05-23 EP3928519B1 0.70 2024-04-03 HK40058256A 0.70 2022-04-22 HK40058256B 0.70 2024-08-02 EP3970363B1 0.32 2023-05-17 US20250016348A1 0.28 2025-01-09 EP4246978B1 0.22 2025-09-03 WO2025075879A1 0.20 2025-04-10
ARCHIVE v3 :
JVET-M0230.docx JVET-M0230.pptx JVET-M0230.xlsm JVET-M0230_r1.docx JVET-M0230_r1.pptx JVET-M0230_WD.docx JVET-M0230_WD_r1.docx
Decisions
JVET-M0230 CE4-related: Temporal MV buffer reduction
In this context, it is mentioned in the Track B discussion if it might be useful to define some restriction of MVs, just to prevent for some future application with extremely large picture sizes valid ranges might be exceeded.
Citation