Generating Video Thumbnails With FFMPEG

Check out flowplayer's - http://flowplayer.org/tutorials/generating-thumbs.html

In short,

ffmpeg -i [video_file] -f image2 -vframes 1 [output_image].jpg


For example,

ffmpeg -ss 12 -i flowplayer.mov -f image2 -vframes 1 flowplayer-12.jpg