How to screen capture in linux, audio, video, or both.

I initially under estimated the ffmpeg command and have been abusing it for its abilities to convert my audio files after downloading them from youtube!

The all-mighty screen capture command:

ffmpeg -f x11grab -s wxga [or instead of 'wxga' another screen size like 1300, 800] -r 25 -i :0.0 -qscale 0 -f alsa -i hw:0 -strict -2

The all-powerful audio capture command:

ffmpeg -f alsa -i hw:0 [or another alsa device] -strict -2