ffmpeg concat video then the video is weird

Interestingly, the sync could be restored temporarily by advancing the movie progress slider to any point in the movie, but then the sync would be lost again as the movie continued to play in iOs. The symptom for iOs playing this concatenated mp4 was initially good synchronization followed by an increasing loss of synchronization as the movie played, with audio going faster than video.

In my case, I was also concatenating files, and found audio/video sync problems with iOs, but not with Windows (e.g., VLC media player showed no synchronization problems using the same mp4 file). I encountered a similar problem and found a solution that worked, at least for me. Where segments.txt consists of the names of the padded files. Step 2 Concat ffmpeg -f concat -i segments.txt -c copy test.mov Generate segments with synced streams ffmpeg -y -ss 00:00:02.750 -i input.MOV -c copy -t 00:00:05.880 -avoid_negative_ts make_zero -fflags +genpts segment.MOV Step 1 Pad out the audio in each segment ffmpeg -i segment1.mov -af apad -c:v copy -shortest -avoid_negative_ts make_zero -fflags +genpts padded1.mov

Ffmpeg concat video then the video is weird