ffmpeg(1) -f video4linux2 -r 30 -i %2Fdev%2Fvideo0 -f alsa -i hw%3A0%2C0 %22%24%40%22
ffmpeg video converter
-r fps
    Set frame rate (Hz value, fraction or abbreviation), (default = 25).
-i filename
    input file name
source manpages: ffmpeg