[FFmpeg-user] ffmpeg -f avfoundation HELL - please help!

Moritz Barsnick barsnick at gmx.net
Tue Jan 3 19:22:36 EET 2017

On Tue, Jan 03, 2017 at 16:55:47 +0000, Demián Andrés Rodriguez wrote:
> > frame=   16 fps=1.7 q=0.0 Lsize=     998kB time=00:00:09.52 bitrate=858.9kbits/s speed=1.01x
> > video:993kB audio:0kB subtitle:0kB other streams:0kB global headers:4kB
> > frame=   32 fps=3.7 q=0.0 size=       1kB time=00:00:01.65 bitrate=2.6kbits/s speed=0.193x
> > frame=   33 fps=1.5 q=0.0 Lsize=    1423kB time=00:00:09.08 bitrate=1283.6kbits/s speed=0.422x

I think your processor is way too slow to encode this resolution to VP9
in realtime. That probably leads to skipping frames (in the long run),
and as a side effect possibly breaking audio. VP9 encoding is known to
be quite slow. You need to choose a lower resolution, faster encoding
parameters, or even a different codec.

Have you tested with "-c:v libx264 -preset ultrafast", to see whether
the resulting video+audio is fine? (It needs to encode at speed >= 1.0
or fps >= 25 then of course, but I'm quite optimistic that it can.)


More information about the ffmpeg-user mailing list