Trying to convert a 1 hour video with 0.02 fps, to a very short one (100 times speed-up) with somethinglike 10 fps to include in a powerpoint presentation.
I did this :
ffmpeg - input.mp4 -filter:v "setpts=0.01*PTS" -r 10 output.mp4
Works great, play nicely with VLC or SMPlayer (which I believe use ffmpeg libraries for decoding). But if played with Windows Media Player, or inserted in a powerpoint presentation, this gives a lot of artifacts...the video is almost not watchable.
Is there a way to make this watchable in powerpoint (i'm guessing the problem lies down with the video renderer used in powerpoint...)