orion44
29th April 2023, 10:52
The documentation about VP8 on the internet is confusing. From what I've read, it has constant quality mode in one pass,
which is probably constant quantizer mode, without regard to visual perception.
VP9, however, does seem to have a mode similar to CRF, to achieve a certain perceptual quality level, but you have to do it in two passes:
ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 -pass 1 -an -f null /dev/null && \
ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 -pass 2 -c:a libopus output.webm
I was just curious, if anyone knows, does this also work with VP8?
Can FFmpeg's libvpx achieve a certain perceptual quality level in two passes, similar to x264's CRF?
which is probably constant quantizer mode, without regard to visual perception.
VP9, however, does seem to have a mode similar to CRF, to achieve a certain perceptual quality level, but you have to do it in two passes:
ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 -pass 1 -an -f null /dev/null && \
ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 -pass 2 -c:a libopus output.webm
I was just curious, if anyone knows, does this also work with VP8?
Can FFmpeg's libvpx achieve a certain perceptual quality level in two passes, similar to x264's CRF?