Screenshot from a stream via command line

[larose]

I need to know how to make a screenshot of a stream ( mjpeg or rtsp ) via command line.
i know that it works with the programm itself, but i need to know how to do this via command line.
I hope anybody can help me.

EDIT: The image should be saved into a file.
It can always be overwritten. THX

Thx in advance
larose

[dionoea]

Short answer: use the image video output
Long answer: use search.php with "image" "vout" "snapshot" ...