[FFmpeg-devel] [PATCH] Change libvpx-vpx default to crf=32.

[Elliott Karpilovsky]

On Tue, Aug 27, 2019 at 8:05 AM Michael Niedermayer
<michael at niedermayer.cc> wrote:
>
> On Sun, Aug 25, 2019 at 04:43:31PM -0700, Elliott Karpilovsky wrote:
> > Current default is 200kbps, which produces inconsistent
> > results (too high for low-res, too low for hi-res). Use
> > CRF instead, which will adapt. Affects vp8/vp9. Also
> > have VP8 use a default bitrate of 256kbps.
> > ---
> >  libavcodec/libvpxenc.c | 71 +++++++++++++++++++++++++++++++++++-------
> >  1 file changed, 60 insertions(+), 11 deletions(-)
>
> breaks:
> ./ffmpeg -i mm.mpg  -vcodec libvpx-vp9 -lossless 1 -vframes 1 -an  vpx-lossless.mkv
> ...
> [libvpx-vp9 @ 0x2ed9080] Neither bitrate nor constrained quality specified, using default CRF of 32
> [libvpx-vp9 @ 0x2ed9080] CQ level 32 must be between minimum and maximum quantizer value (0-0)
> Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
> Conversion failed!
>

Thanks for catching this. I will send an updated patch that accounts
for lossless mode. I checked and didn't see any other options that
could cause problems. If I missed any others, please let me know.