[MPlayer-users] Encoding with video from one movie and audio from another

[Adam Rice]

Quoting romildo at uber.com.br (romildo at uber.com.br):
> Movie1:
> 	25 fps
> 	151.962 frames
> 	6078.48 s
> 
> Movie2:
> 	29.970 fps
> 	190.029 frames
> 	6340.64 s
> 
> First I do not understand why the movies have different duration times,
> as they have the same content. Watching both movies in paralell shows me
> that Movie2 runs slower than Movie1. This difference in duration times
> is making things difficult to me.

I think I can explain this. Both come from a 24 fps source movie. Movie1 has
been encoded to PAL, which involves slowing it down by 1 fps. Movie2 has been
encoded to NTSC, which involves a process called telecine, which adds
interlacing and shows frames for varying durations but preserves
approximately the original speed.

Before you try anything else, try watching Movie2 with the -vf pullup flag.
This reverses the telecine process, and you may find this makes it acceptable.

Failing that, you can dump audio from Movie2 with a command something like:

mplayer -dumpaudio -dumpfile audio.mp3 -novideo Movie2

and then re-encode Movie1 with something like:

mencoder -ovc copy -fps 25 -ofps 24 -oac copy -o NewMovie.avi -audiofile
audio.mp3 Movie1

I haven't tried this, so I'm not sure that -ovc copy will work properly
together with -ofps. If not, you'll need to fiddle with -ovc lavc and
-lavcopts until you get something satisfactory.

Even so, you may still need to adjust the speed of the audio slightly to get
proper audio sync. I don't know how best to do this.

Adam

-- 
Adam Rice -- adamrice at ntlworld.com -- Blackburn, Lancashire, England