On Tue, Jun 27, 2023 at 12:07 PM Ronald S. Bultje <rsbul...@gmail.com> wrote: > > Hi Vignesh, > > On Tue, Jun 27, 2023 at 1:55 PM Vignesh Venkat < > vigneshv-at-google....@ffmpeg.org> wrote: > > > > >>> In some versions of libsvtav1, setting intra_period_length to 0 > > > [..] > > > > >>> SVT-AV1 Bug: https://gitlab.com/AOMediaCodec/SVT-AV1/-/issues/2076 > > > >>> > > > >>> Example command: ffmpeg -f lavfi -i > > testsrc=duration=1:size=64x64:rate=30 -c:v libsvtav1 -g 1 -y test.webm > > > >>> > > > >>> Before: Only first frame is keyframe. > > > >>> After: All frames are keyframes. > > > [..] > > > From what i tested, it seems to be there on the tip of tree SVT-AV1 as > > well. So we can't guard it with macros until the issue is fixed. > > > > Isn't this the expected behaviour, btw? > > See https://gitlab.com/AOMediaCodec/SVT-AV1/-/blob/master/Docs/Parameters.md > > "Keyint --keyint [-2-(2^31)-1] -2 GOP size (frames), use s suffix for > seconds (SvtAv1EncApp only) [-2: ~5 seconds, -1: "infinite" only for CRF, > 0: == -1] " > > note the final parts: 0=-1, and -1 means "infinite" keyint (i.e. never > insert a new KF). Since FFmpeg's wrapper sets keyint to "gopsize value > minus 1", "-g 1" seems to become equivalent to "--keyint 0" on the SVT-AV1 > commandline, unless there's some discrepancy between API and CLI interface. >
Yes, it might be working as documented in the SVT-AV1 API. But the point is that we would need a way to force all key frames (as i think that is what a user would mean when they set "-g 1" in ffmpeg?). > (I admit that if I set it to 1, I don't actually get keyframes, but rather > intraonly frames for all except the first frame. --keyint 2 correctly uses > key - inter pairs. But your "before" statement above appeared to suggest > that the first keyframe is followed by inter frames, not intraonly frames. > If you meant "intraonly after key" instead of "inter after key", you should > probably note that more explicitly. This may also help upstream reproduce > in #2076 so they can fix it going forward.) yeah i wasn't really paying attention to whether the subsequent frames were intra-only or inter frames. i was just looking at whether or not they were keyframes. :) i will update the upstream bug to clarify this part. but in the meantime, i think this patch is reasonable to replicate the behavior of other AV1 encoders with -g 1. > > Ronald > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". -- Vignesh _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
