[FFmpeg-user] Use multiple lavfi input generators

Nicolas George george at nsup.org
Tue Jul 24 00:33:06 EEST 2018

Elliott Balsley (2018-07-23):
> Ah, I figured it out!  It works in ffmpeg, not in ffplay.

ffplay can only play one input. But you can have two streams in a single
lavfi definition.

ffplay -f lavfi 'testsrc[out0];sine[out1]'

>							    Now is
> there any way to make the sine filter output 24bit?

No. sine uses bit-exact integer arithmetic that would overflow for
larger numbers, and using a larger type would make it slower.

Why would you want 24 bits for that anyway?

> > On Jul 23, 2018, at 2:02 PM, Elliott Balsley <elliottbalsley at gmail.com> wrote:

Please remember that top-posting is forbidden on this list; if you do
not know what it means, look it up.

> > ffplay -f lavfi -i testsrc=s=1920x1080 -i sine=frequency=800

This command also has the flaw of forgetting "-f lavfi" for the second
input; it would not have worked with ffmpeg for that reason, but you
fixed it.


  Nicolas George
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