How do you make thumbnails of videos? Using flowplayer free

I'm making a "video sharing site" just for learning and fun. I am using FlowPlayer as my player for videos. Now Im gonna make a page that will list every video, and a want preview picture of the video. Like: http://www.youtube.com/video开发者_如何学Gos

How do you do that? With the player or can you do it with php?? Ive looked true Flowplayer forums. But I cant find anything.

Would really appricate some help.

Joel

ffmpeg is the usual utility to handle video, both to convert and making thumbnails

from PHP it being handled using system() function, as any other command-line utility