[LAU] FFMPEG - Recording sound from jack

Chris Caudle chris at chriscaudle.org
Tue Aug 8 15:11:41 UTC 2017

On Tue, August 8, 2017 9:28 am, list wrote:
> Only Jackd using it - and qjackctl.

Your original email had this as the ffmpeg command:
ffmpeg -f alsa -ac 2 -i hw:1 -f x11grab -s 1920x1080 -r 25 -i :0.0

You are telling ffmpeg to use the ALSA device, but the ALSA device is in 
use by jackd.
If you want to have ffmpeg capture the ALSA device then don't start jackd.
 If you want to have ffmpeg use jackd ports then read the ffmpeg man page
for the correct options.  The "-f" argument would be jack instead of alsa,
but you have to look at all the details of how to get the ports connected
correctly.  I think you need to use qjackctl or jack_connect to connect
the ports after starting ffmpeg.

Chris Caudle

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