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xiph / rav1e

The fastest and safest AV1 encoder.
BSD 2-Clause "Simplified" License
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DCT artifacts when top-down coding on 64x64 blocks #2546

Open Uch1haOb1to opened 4 years ago

Uch1haOb1to commented 4 years ago

Maybe add advanced options to rav1e? I mean all the options that are set by ready-made speed presets. I'm interested in testing bottom-up coding with different speed presets, as I think it is bottom-up coding that gets rid of DCT artifacts. Currently, bottom-up coding is enabled only for 1 and 0 presets, and they are slow in themselves. In aom and svt-av1, there are no DCT artifacts in 64x64 blocks, but in rav1e for some reason they are and spoil the picture.

lu-zero commented 4 years ago

You can override the speed settings (it is an hidden option), but sounds like you found maybe a bug, can you share content that shows this behavior and how to reproduce it?

Uch1haOb1to commented 4 years ago

cmd C:\odnako\USB-storage\Av1-encoders\rav1e.exe -v --tiles 8 -s 2 --quantizer 120 C:\odnako\USB-storage\Av1-encoders\anime.y4m -o C:\odnako\s2.ivf C:\odnako\USB-storage\Av1-encoders\rav1e.exe -v --tiles 8 -s 1 --quantizer 120 C:\odnako\USB-storage\Av1-encoders\anime.y4m -o C:\odnako\s1.ivf frame 2 s2-02 s1-02 frame 16 s2-16 s1-16 The more QP, the more such 64x64 blocks of artifacts, while at speed 1 they appear only at very huge QP. Also, the faster the preset, the more artifacts, especially on presets 6-10. Most artifacts are in game content. I've seen this for a long time, the first versions were much worse, but starting from about v0.2.0 everything is the same. I thought it was a temporary solution for high QP and it will be fixed over time, but quite a lot of time has passed, and the artifacts have not gone anywhere. I can throw off examples with different content, but I think you saw these artifacts. They mostly appear with a quantizer bigger than 100. sample.zip