Entropy coding option #1318

deiteris · 2022-12-21T21:42:20Z

In h264 codec, CABAC entropy coding may save up to 20% of the bitrate budget, but increases the decoder latency by 2+ times depending on the target bitrate and may also increase encoder load. This significantly reduces the decoder throughput which may be incomparable to gained quality, so CAVLC can be used for very high bitrate or high encoder/decoder load scenarios without significant perceived quality loss.

Graph with CAVLC

Graph with CABAC

zarik5 · 2022-12-21T22:46:48Z

I think the default value should be CAVLC, since it's the option that behaves more consistently and gives overall lower latency.

alvr/server/cpp/platform/linux/EncodePipelineNvEnc.cpp

deiteris · 2022-12-23T13:13:25Z

Ready to merge if it's all good. Though would be great to see some testing on nvidia cards and Linux.

nowrep

VAAPI part tested and it does actually reduce decoder latency.

* Add entropy coding option * Use CAVLC as default option * Update description for entropy options * Add entropy coding option to Linux * Fix indentation * Add missing break statements

nowrep reviewed Dec 22, 2022

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alvr/server/cpp/platform/linux/EncodePipelineNvEnc.cpp Outdated Show resolved Hide resolved

deiteris added 2 commits December 22, 2022 10:59

Add entropy coding option

d99b02d

Use CAVLC as default option

d2beb67

deiteris force-pushed the entropy-option branch 2 times, most recently from ada3e21 to ea90362 Compare December 22, 2022 09:50

deiteris requested a review from nowrep December 22, 2022 09:51

deiteris added 3 commits December 22, 2022 13:29

Update description for entropy options

d9c74ed

Add entropy coding option to Linux

b1f27da

Fix indentation

2878200

deiteris force-pushed the entropy-option branch from 6dc39f5 to 2878200 Compare December 22, 2022 11:30

Add missing break statements

493a3c2

nowrep approved these changes Dec 23, 2022

View reviewed changes

zarik5 merged commit ef88313 into alvr-org:master Dec 24, 2022

zarik5 pushed a commit that referenced this pull request Feb 9, 2023

Entropy coding option (#1318)

1937ce1

* Add entropy coding option * Use CAVLC as default option * Update description for entropy options * Add entropy coding option to Linux * Fix indentation * Add missing break statements

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Entropy coding option #1318

Entropy coding option #1318

deiteris commented Dec 21, 2022 •

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zarik5 commented Dec 21, 2022

deiteris commented Dec 23, 2022

nowrep left a comment

Entropy coding option #1318

Entropy coding option #1318

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deiteris commented Dec 21, 2022 • edited Loading

zarik5 commented Dec 21, 2022

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deiteris commented Dec 21, 2022 •

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