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

[Greg Trounson]

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)?

I know mplayer can do this when playing movies by means of the [ and ] 
keys, but I haven't found a way to do it when converting to a new file. 
Various combinations of -fps and -ofps all seem to produce a movie that 
plays back at the exact same rate as the original (even -ofps 60 made no 
difference).  It seems I can achieve what I want by rendering the video 
separately from the audio but I'd rather not have to split the tracks at 
this point.

Another instance of this problem that comes to mind is speeding up 
slow-moving footage, such as a butterfly emerging from a crysalis, or a 
sunset.

Any ideas?

thanks,
Greg