[MPlayer-users] Convert 23.97fps to PAL 25fps w/o duplicate frames

[D Richard Felker III]

On Sat, Mar 26, 2005 at 12:59:51PM +1200, Greg Trounson wrote:
> Hi,
> 
> I'm trying to master some clips to PAL DVD, using mencoder -> avidemux -> 
> dvdauthor, with as high a quality as possible.
> 
> If my sources are 23.97fps NTSC, then I need to convert them to PAL frame 
> rate before passing it to avidemux (avidemux automatically takes care of 
> the resolution).
> 
> mencoder -ofps 25 doesn't cut it, since it inserts duplicate frames, 
> producing an irritating jerkiness every second or so when played back. 
> Commercially made DVDs get around this by just speeding up the playback 
> rate 4%, so every single frame is played, but the action is slightly 
> faster and the sound is slightly higher pitched (nearly a semitone, I'm 
> told).  This is why Region 4 DVDs generally have a shorter running time 
> than Region 1.
> 
> My question is, how can I get mencoder to convert a movie clip to 25fps 
> by /only/ speeding up the video and audio playback rate (ie without 
> duplicating frames)?

Use latest cvs and pass the option -speed 25025/24000. You'll also
need -srate 44100 or 48000 to force the audio to get resampled back to
a valid samplerate for encoding, and you might want to include -ofps
25 too just to make sure a slight error doesn't result in it being
25.0001 fps or something stupid.

Rich