I'm trying to change the framerate of an MP4 video (it's a 120fps GoPro video, I want to play it back at 30fps for a slow-motion effect).
I'm using avconv for this:
avconv -i SourceMovie.mp4 -vf setpts=4.0*PTS -r 30 DestMovie.mp4
That technically works, but it reencodes the movie. In addition to being slow, it's obviously a quality issue. Technically there should be a way to just set the fps in the header of video, how can I change that? (Any tool other than avconv would work too.)
Best Answer
MP4Box can do it.
The command
creates the files
test
andtest_track1.h264
. You can now create an mp4 file with whichever supported framerate you would like (30 in this example):MP4Box is part of the
gpac
package, so make sure it's installed.