ffmpeg recording desktop audio properly

CQ1ST · 09-08-2011, 02:22 AM

Hi, I'm recording my desktop with this ffmpeg command:

Code:

ffmpeg -f alsa -ac 2 -i hw:0,0 -f x11grab -r 30 -s $(xwininfo -root | grep 'geometry' | awk '{print $2;}') 
-i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0 -y output.mkv

and although it's working, I'm getting tinny, far-away sounding audio.
Is there a way to more directly capture the sound or just get it sounding good?

teckk · 09-08-2011, 08:37 PM

Make sure that you have the record volume controls turned up. Could be called ogain, igain, pcm1, rec etc. depending on your sound system. Gmixer does a good job showing all of them.

Your command looks fine. Bet it's a volume control.

CQ1ST · 09-14-2011, 01:46 AM

oh that sux, I recorded myself trying "every" setting in alsamixer and still didn't get good sound

I'm stumped

teckk · 09-14-2011, 07:21 PM

Since you're having problems with the audio you might try to troubleshoot just it.
Launch ffmpeg with

Code:

ffmpeg -f alsa -i hw:0,0 -vn -acodec libmp3lame -ab 128k capture.mp3

or

Code:

ffmpeg -f alsa -i /dev/dsp -vn -acodec libmp3lame -ab 128k capture.mp3

Then play a media file or speek into your mic. That will get you 128k mp3 audio that any Linux or BSD box should do. Eliminate pcm or x264 as a cause. If you still don't have audio then find that mixer control that isn't up.

CQ1ST · 09-21-2011, 05:09 AM

Hey, thanks for your help but I'm not getting good results from linux. I guess it's a problem with alsa, but I can't really be fussed installing gstreamer, trying oss or fixing the audio with audacity, so I'll prolly just try windows (when it's convenient to do so) -it's not a high priority, I just wanted to record some streaming tv at dw-world (tomorrow today, if you're interested) but I can just watch it once, 'cause I'm not fussed