[MPlayer-users] Re: Converting 23.976 to 25fps

[D Richard Felker III]

On Mon, Jan 12, 2004 at 05:43:49PM +0100, Martin Emrich wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Am So, den 11.01.2004 schrieb Martin Emrich um 19:53:
> 
> > But I won't open the champagne unless the SVCD plays in 
> > the DVD player... ;-)
> 
> *foomp* ;-) It works, just tested in the standalone DVD player.
> This is what I did:
> 
> --------
> 0. free up some space (approx. 5-7GB temp should suffice ;-)
> 1. Recode avi to PCM audio
> 
> mencoder ${SOURCE_AVI} -o movie-with-pcm.avi -oac pcm -ovc copy
> 
> 2. Hack source avi:
> 
> AVI Header: replace source frame time 
> 1/23.976 * 10^6 µs = 41708 = 0xA2EC = EC A2 00 00 with 
> 1/25.000 * 10^6 µs = 40000 = 0x9C40 = 40 9C 00 00
> 
> Video STREAM Header: replace source frame rate 
> 23.976fps * 10^4 = 239759 = 0x3A887 = 8F A8 03 00 with 
> 25.000fps * 10^4 = 250000 = 0x3D090 = 90 D0 03 00
> 
> Audio: replace source sampling freq 
> 44100Hz = 0xAC44 = 44 AC 00 00 with 
> 45983Hz = 0xB39F = 9F B3 00 00
> # (or whatever the original sample rate is - bc knows the answer)
> 
> Audio: replace source data rate 
> 176400 byte/sec = 0x2B110 = 10 B1 02 00 with
> 183932 byte/sec = 0x2CE7C = 7C CE 02 00
> 
> (use the search option of your favourite hex editor. hexedit likes files
> >2GB, so I use it.)
> 
> 3. extract audio
> mplayer movie-with-pcm.avi -dumpaudio -dumpfile moviesound.raw
> 
> 4. resample audio to 44100 Hz
> sox -w -s -c 2 -r 45983 -t .raw moviesound.raw -r 44100 moviesound.wav \
> resample
> rm moviesound.raw
> 
> 5. multiplex new sound back in
> mencoder movie-with-pcm.avi -o new-movie-file.avi -audiofile \
> moviesound.wav -oac copy -ovc copy

mencoder can do steps 3-5 for you (resampling audio)! Just use:

mencoder -ovc copy -oac pcm -srate 44100 movie-with-pcm.avi -o new-movie-file.avi

> 6. recode to svcd or whatever
> # Don't forget to rescale/expand to correct aspect ratio/resolution.
>  
> recoder -i new-movie-file.avi -o ${SOURCE_AVI}.mpg -p svcd -a mp2 -b 160
> -S 800 -f scale=480:576 -c 1
> --------
> 
> Thanks for all your hints!

Glad to hear it worked!

Rich