1. Command ls /dev/video* tells the video device.
2. Command arecord -l tells the audio devices
An example:
mint@mint ~ $ arecord -l
**** Luettelo CAPTURE laitteista ****
kortti 0: V8237 [VIA 8237], laite 0: VIA 8237 [VIA 8237]
Alalaitteet: 1/1
Alalaite #0: subdevice #0
kortti 0: V8237 [VIA 8237], laite 1: VIA 8237 [VIA 8237]
Alalaitteet: 1/1
Alalaite #0: subdevice #0
kortti 2: U0x46d0x8ad [USB Device 0x46d:0x8ad], laite 0: USB Audio [USB Audio]
Alalaitteet: 1/1
Alalaite #0: subdevice #0
If wanting to use web camera´s audio, the card is U0x46d0x8ad and plughw is U0x46d0x8ad
Now we have components for recording from web camera, and the recording command is
avconv -f video4linux2 -r 25 -i /dev/video0 -f alsa -i plughw:U0x46d0x8ad,0 -ar 22050 -ab 64k -strict experimental -acodec aac -vcodec mpeg4 -y webcam.avi
Also VHS video capturing is working using command
avconv -f video4linux2 -s 1280x1024 -r 25 -i /dev/video1 -f alsa -i plughw:Grabby,0 -ar 48000 -ab 320k -strict experimental -acodec aac -vcodec mpeg4 -y vhs4.avi
Capturing using mencoder
mencoder tv:// -tv driver=v4l2:width=800:height=600:device=/dev/video0:fps=30:outfmt=yuy2:forceaudio:alsa:adevice=hw.1,0 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=1800 -ffourcc xvid -oac mp3lame -lameopts cbr=128 -o output.avi