ffmpeg Duplicating Frames

Question

A very annoying situation...
I have an MPG2 video that is at the framerate of 29.97, yet when converting to MP4 frames are duplicated.

That command (straight conversion, no options):
ffmpeg -i ~/Desktop/file.mpg ~/Desktop/file.mp4
causes duplicated frames...

While setting the framerate with:
ffmpeg -i ~/Desktop/file.mpg -framerate 29.97 ~/Desktop/file.mp4
Doesn't work either!

Leading me to try:
ffmpeg -i ~/Desktop/file.mpg -r 29.97 ~/Desktop/file.mp4
Still with duplicated frames!

Finally I tried ffmpeg's 3rd framerate option!:
ffmpeg -i ~/Desktop/file.mpg -vf fps=fps=29.97 ~/Desktop/file.mp4

Except, when it outputted, the audio/video was out of sync!

Which FPS option should I use?

Solution

Use

ffmpeg -i ~/Desktop/file.mpg -vsync 0 ~/Desktop/file.mp4

This skips duplication.

Comments

[Henry7720]

This sounds like it might work, but I get innumerable errors!

[Gyan]

DTS errors? You can ignore those if the file plays correctly. Show the full log.

[l --marc l]

where -vsync 0 is the same as the newer value -vsync passthrough. Each frame is passed with its timestamp from the demuxer to the muxer.