How to record your desktop and webcam, or stream them?
Here's the solution:
Go visit:
https://help.ubuntu.com/community/Webcam#VLC
Here's some key references:
VLC is neat
It's better to use the VLC GUI interface to operate.
3.2. VLC
3.2.1. Using the GUI
In VLC, choose 'Open capture device' from the file menu and enter the video and audio device files (see above) in video device name and audio device name, respectively. If you just want a 'mirror' (to see what the webcam is showing), click 'OK' and you're done. If you wish to record, tick off 'Stream/save' in the 'Advanced options' section. Click the settings button right next to it. Tick 'File' off under 'Outputs' and enter a filename. Encapsulation method can be left at the default (MPEG TS). Under 'Transcoding options', tick 'Audio codec' and 'Video codec'. These can also safely be left the defaults (obviously greater compression results in lower file sizes, so experiment). Click 'OK' in the Settings screen and once again in the main webcam screen (Video4linux). If you want to have more control, you can access several settings, including resolution, by clicking the Advanced options button.
3.2.2. Using the Command Line
A simple test of just the video from your webcam can be done as follows. This assumes the webcam is installed as '/dev/video0'.
$ vlc v4l2:///dev/video0
If you wish to be able to quickly start a video session with your webcam, the resulting vlc command is printed in the Customize line at the bottom. You simply need to prepend 'vlc', e.g.
vlc v4l2:// :v4l-vdev="/dev/video0" :v4l-adev="/dev/audio2" :v4l-norm=3 :v4l-frequency=-1 :v4l-caching=300 :v4l-chroma="" :v4l-fps=-1.000000 :v4l-samplerate=44100 :v4l-channel=0 :v4l-tuner=-1 :v4l-audio=-1 :v4l-stereo :v4l-width=640 :v4l-height=480 :v4l-brightness=-1 :v4l-colour=-1 :v4l-hue=-1 :v4l-contrast=-1 :no-v4l-mjpeg :v4l-decimation=1 :v4l-quality=100
The recording instructions will similarly need to be appended. Copy the contents of the 'Stream Output MRL' box under 'Settings' and change ":sout=" to "--sout " and append it to your vlc command:, e.g.
vlc v4l2:// :v4l-vdev="/dev/video0" :v4l-adev="/dev/audio2" :v4l-norm=3 :v4l-frequency=-1 :v4l-caching=300 :v4l-chroma="" :v4l-fps=-1.000000 :v4l-samplerate=44100 :v4l-channel=0 :v4l-tuner=-1 :v4l-audio=-1 :v4l-stereo :v4l-width=640 :v4l-height=480 :v4l-brightness=-1 :v4l-colour=-1 :v4l-hue=-1 :v4l-contrast=-1 :no-v4l-mjpeg :v4l-decimation=1 :v4l-quality=100 --sout "#transcode{vcodec=mp1v,vb=1024,scale=1,acodec=mpga,ab=192,channels=2}:duplicate{dst=std{access=file,mux=mpeg1,dst=/tmp/test.mpg}}"
To simple take a few snapshots, open the webcam without recording and choose 'Snapshot' under the 'Video' menu.
Those are also good.
Mplayer
ffmpeg (for main linux destros)
avconv for ubuntu 12.04+