How to record sound from Xvfb on Centos
 

I'm trying to record audio from Xvfb. And I have some problems :

1. What's the different between alsa and pulse. I get confuse
2. Server Centos have no soud card:
arecord -l
arecord: device_list:268: no soundcards found...

modprobe snd-dummy doesn't help. Still no soundcard

2. I may have many Xvfb process, how to record video and audio from specific Xvfb process. I checked this https://trac.ffmpeg.org/wiki/Capture...manapplication but still don't understand how it works.
ffmpeg -f alsa -ac 2 -i hw:0,0 -acodec pcm_s16le output.wav
I seen many command like this, but I don't know how to get hw:0,0 ( id of sound card ? )

Please help. Thanks

Hello and welcome to LQ. This question was sitting for a few days so I'll venture a guess. When I last played with media on Centos I had to install a number of things to get it to work. Some web pages on it. Centos isn't a very good platform for media.

Guess you could try fedora and my guess it you'd find that it would be supported for a test.