How to capture screenshots from a video clip 50 minutes into the clip and do it fast?

Ok it seems that whenever I tell ffmpeg to take a screen cap half way though the clip (clip can be as long as 10 hours) it uses 100% of 1 cpu core and takes ages… whereas if I let it do a frame at the start it goes real quick, as if it scans though the video to get to the middle instead of just jumping to it!

Here is the code im currently using:

ffmpeg -y 开发者_运维百科-itsoffset -“500"  -i “clipname.mov" -vcodec png -vframes 1 -an -f rawvideo “clipScreenshot001.png”

This can take several minutes.

These are HD videos too, 720p/1080p and allot of the time they are raw unedited clips (e.g. very long).

So I was hoping for some better software that will make screen captures from video much faster (has to be linux and scriptable).

Try to use seek (the -ss flag) instead of delaying (the -itsoffset), i.e.:

ffmpeg -y -ss 3000 -i "clipname.mov" -vframes 1 "clipScreenshot001.png"