On Thu, Sep 28, 2023 at 2:05 AM Ronald S. Bultje <rsbul...@gmail.com> wrote: > > Hi Vignesh, > > On Thu, Sep 28, 2023 at 12:14 AM Vignesh Venkatasubramanian via ffmpeg-devel > <ffmpeg-devel@ffmpeg.org> wrote: >> >> SVT-AV1 does not support requesting keyframes at arbitrary points >> by setting pic_type to EB_AV1_KEY_PICTURE. >> >> This patch changes the following: >> * Set pic_type to EB_AV1_KEY_PICTURE only when gop_size == 1. This >> only has an effect in this case (combined with force_key_frames). >> In all other cases, setting this has no effect. >> * Set force_key_frames to 1 only when gop_size == 1, this is >> needed for pic_type request above to work. >> >> Please see the comments in >> https://gitlab.com/AOMediaCodec/SVT-AV1/-/issues/2076 for a bit more >> details. > > > Right. So, if I put my archeologist hat on, is it fair to say that what > probably happened is that force_key_frames used to not exist, and pic_type > worked as per above code. Then force_key_frames was required (because of > quality implications), breaking the above code. And now we're removing the > broken code because otherwise there's a quality penalty. Is that fair? >
Hi Ronald, Yes, i believe your assessment is correct. > I agree it's probably unfair to ask you to fix the broken use case that was > previously possible (I suppose this comes down to exposing an option to set > force_key_frames by having the user indicate s/he'll be using pic_type). > However, maybe we should not remove the dead code, because it's functionally > OK. Maybe we even need a FIXME above the line where we set force_key_frames > only if gop_size==1, explaining this is a bug. WDYT? > > (It feels a bit weird to remove it because it's broken, is what I'm trying to > say, especially because we know how to fix it.) > Makes sense, i have kept the old code in the pic_type setting part and have updated this patch to only set force_key_frames when gop_size == 1. PTAL. > Ronald -- 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".
