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31st Meeting: Geneva, CH, July 2023 2023-07-13 15:53
Non-EE2: Peak Memory Reduction for ECM
Authors: Wenbin Yin ByteDance Kai Zhang ByteDance Li Zhang ByteDance
Abstract
In the current design of adaptive loop filter (ALF) and cross-component adaptive loop filter (CCALF) in ECM-9.0, the filtering unit size is set equal to the CTU size. The calculation of co-variance matrix for each CTU requests is a high memory cost at encoder. In this contribution, it is proposed to allow the filtering unit size larger than the CTU size. By doubling the dimensions of the filtering unit for 4K sequences in RA conditions, the peak required total memory at encoder is reduced from 23.2 GB to 19.6 GB, reportedly. Besides, the encoding time is reportedly reduced by 1~2% since the encoder requires less training rounds and determinations for ALF and CCALF.
Meeting Notes
JVET-AE0257 Non-EE2: Peak Memory Reduction for ECM [W. Yin, K. Zhang, L. Zhang (Bytedance)] [late]

In the current design of adaptive loop filter (ALF) and cross-component adaptive loop filter (CCALF) in ECM-9.0, the filtering unit size is set equal to the CTU size. The calculation of co-variance matrix for each CTU requests is a high memory cost at encoder. In this contribution, it is proposed to allow the filtering unit size larger than the CTU size. By doubling the dimensions of the filtering unit for 4K sequences in RA conditions, the peak required total memory at encoder is reduced from 23.2 GB to 19.6 GB, reportedly. The encoding time is reportedly reduced by 1~2% since the encoder requires less training rounds and determinations for ALF and CCALF.

On top of ECM-9.0, simulation results of the proposed method are reported/estimated as below:

  • RA: *0.02%, 0.08%, 0.21%, 99.4%, 99.9%.

The loss is higher for A classes where the change has an effect.

Final results (incomplete simulation currently) may have higher bit rate increase.

Solutions for memory reduction without normative changes are preferable, normative solutions should not be considered until the problem is better understood.

Cited:
JVET-AE0274 X
ARCHIVE :
JVET-AE0257.pdf JVET-AE0257.xlsm JVET-AE0257_v0.docx JVET-AE0257_v1.docx
Decisions
Solutions for memory reduction without normative changes are preferable, normative solutions should not be considered until the problem is better understood.
Citation