Lossless AV1 encoding

[birdie]

SVT-AV1 doesn't support it.

Rav1e neither.

libaom-av1 in my own testing (yuv420p10le source, ffmpeg 6.1.1 params: -c:v libaom-av1 -crf 0 -aom-params lossless=1; libaom-3.8.2) produces lossless output only for I (key) frames.

How did I verify?

ffmpeg -i input.mp4  -f framemd5 input.txt
ffmpeg -i output.mp4 -f framemd5 output.txt

Are there any free lossless AV1 encoders?

[Jamaika]

https://gitlab.com/AOMediaCodec/avm/-/commits/main
av2enc_avx.exe -q 100 -444 -size 280x420 -effort 7 -thread 4 -tune ssim input.png/jxl/tiff/wp2 -d output.av2
avifenc_avm_avx.exe -c avm -l -d 8 -y 444 -r full -s 7 -j 4 input.jpg output.avif

[birdie]

I'm not sure how to read your message. I'm talking about encoding video.

[Jamaika]

These are lossless photos. Video I don't know. I-frames

[benwaggoner]

Originally Posted by Jamaika

These are lossless photos. Video I don't know. I-frames

The benefit of interframe encoding for natural image content is a lot smaller for lossless than for lossy. Encoding and decoding are much faster as well.

It's quite common for distribution encoders to not support lossless. As the original reference encoder, I imagine libaom would support it.

What's your scenario for lossless interframe AV1 encoding?

[Balling]

Originally Posted by birdie

SVT-AV1 doesn't support it.

Rav1e neither.

libaom-av1 in my own testing (yuv420p10le source, ffmpeg 6.1.1 params: -c:v libaom-av1 -crf 0 -aom-params lossless=1; libaom-3.8.2) produces lossless output only for I (key) frames.

How did I verify?

ffmpeg -i input.mp4  -f framemd5 input.txt
ffmpeg -i output.mp4 -f framemd5 output.txt

Are there any free lossless AV1 encoders?

This was a known bug, update ffmpeg or use -aom-params lossless=1 for older ffmpeg before 288ca1c66740640d5742f2921efbf502d83f8b6a commit.


https://trac.ffmpeg.org/ticket/7600