> On Apr 25, 2016, at 11:25 AM, Christoph Gerstbauer > <christophgerstba...@gmail.com> wrote: > > Hello, > > I want to make shotdetections (scene cut) with ffmpeg. (a shot is the video > between 2 cuts) > > My syntax knowledge at this time offers to generate only the FIRST FRAME of > each shot. NO LAST FRAME. It would be nice to find also the last frame of a > shot, but anyway this ticket should focus on the threshold itself. > > Actual Syntax to generate shotdetection thumbnails with ffmpeg: > > ffmpeg -i <inputvideo> -vf select='gt(scene\,0.7)' -vsync 0 -an > keyframes%03d.jpg > > the value "0.7" is the threshold. > A higher one will lead to less scenes thumbails - low sensitivity > A lower one will lead to much more thumbnails - high senisitivity > > I mentioned that shotdetection algorythms generally has problems with to dark > scenes, so it would be fine to have a threshold which is DYNAMIC to find > every cut in the video. But my "FFmpeg-Fu" is to weak to find a solution on > my own. > So, is it possible to use a dynamic threshold within ffmpeg scene detection, > and if yes -> how can I do that?
You could also consider using the YDIF values from the signalstats filter. It will quantify the visual difference in the Y plane from one frame to the next and thus spike on scene cuts. Dave Rice _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
