[FFmpeg-user] How to remove duplicate frames

[Mike Martin]

Hi, every so often I come across a downloaded video where the source has
multiple stall moments, where the same frame shows for several seconds (up
to a minute) and then continues.

I have looked at mpdecimate,but the audio sync is totally destroyed, as per
various variations of the following common line

ffmpeg -i input.mp4  -vf mpdecimate,setpts=N/25/TB -c:a copy -vsync 0
out.mp4

with vsync nothing changes , without massive desync

any suggestions?

Mike