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

Moritz Barsnick barsnick at gmx.net
Tue Jan 3 20:01:35 EET 2017

On Tue, Jan 03, 2017 at 17:34:10 +0000, Demián Andrés Rodriguez wrote:
> I hardly believe my cpu cannot encode vp9 properly, since cpu does not go
> beyond 100% while using h264 uses more than 300% cpu.

Well, the performance numbers I quoted certainly show that. Perhaps
one of your components was compiled without assembly support, or you
need to enable threading for libvpx somehow or so... but as is, it's
too slow.

> Also, h264 encoding produces a very good video output but audio stutters
> and is very unclear. There are gaps in the middle...

Does it encode at realtime, i.e. speed >= 1.0?

> Also, setting -video_size 480x240 seems to have no effect at all. How can I
> change output video size?

"-scale 480x240" or insert the scale filter: "-vf scale=480:240" (or
"-vf scale=480:-2". A smaller output should encode significantly

Before you don't achieve fps>=25/speed>=1.0, I believe we don't need to
further debug the audio issues. (I'm not ruling out that there are
further issues, I'm just trying to tell you what's obvious to me.)


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