How to generate video screencaps of video files via linux commandline

I pulled the answer from this site: http://blog.prashanthellina.com/2008/03/29/creating-video-thumbnails-using-ffmpeg/

ffmpeg -itsoffset -4 -i test.avi -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 test.jpg

Where -4 is the number of seconds into the file to grab the screenshot, 320x240 is the screenshot size, and test.jpg is the output file.

Hope this helps.

Use SlickSlice

./slickslice.sh -x video.avi -s 5x3 -e