[MEncoder-users] change frame rate

[Reimar Döffinger]

On Sun, Feb 19, 2012 at 07:35:35PM +0100, Grozdan wrote:
> On Sun, Feb 19, 2012 at 7:23 PM, Shiyuan <gshy2014 at gmail.com> wrote:
> > Hi,
> >  I have an avi video with 5000 frames. The original frame rate is 15
> > frames/per second, and it takes 300 seconds to play the whole video. I want
> > the video to play faster so that it takes less time to complete, so I
> > change the frame rate using the following command:
> >
> > mencoder in.avi -o out.avi -ofps 100 -ovc copy
> >
> > However, out.avi still take around 300 seconds to complete, even though
> > out.avi does have fps of 100fps according to the info displayed by mplayer.

Yes, -ofps only says how many frames are encoded for one second of
video.
It does not change the speed.
For changing the speed there is the -fps and the -speed option.

> > What command options should I use if I want the output video to be
> > complete  in 50 sec? Thanks.

Most straight-forward would be -speed 50/300 (so 300 seconds become 50
seconds).

> You can't increase the FPS with mencoder. You can only decrease it.

That's not true.