[MPlayer-users] Recoding to VCD Using MEncoder Only

[Gordan Bobic]

On Monday 10 May 2004 16:26, Nico Sabbi wrote:
> Gordan Bobic wrote:
> >Is there any reason why this cannot be done? I presume that it
> > cannot be done, since I have found the mencvcd script in the TOOLS
> > directory which seems to use an exceedingly long winded way of
> > recoding files into VCD format, using mjpegtools.
> >
> >I think I have managed to get the mencoder setup almost right to
> > achieve the same thing without the clutter of all the other
> > seemingly inferior tools and overheads of doing the same job
> > several times, but I am stuck in one last tiny detail.
> >
> >Here is the script I use:
> >
> >#!/bin/bash
> >mencoder	-oac lavc	\
> >		-ovc lavc	\
> >		-ofps 25	\
> >		-of mpeg	\
> >		-lavcopts
> >vcodec=mpeg1video:acodec=mp2:vbitrate=1150:abitrate=224:vrc_buf_size
> >=327:vrc_maxrate=1150
>
> you missed keyint=12, but generally dvd players tolerate much longer
> values;

Ah, OK. Is 12 really what the spec for VCD says? That sounds rather 
small...

> 2 passes and mbd=2 are reccomended

OK, I'll try it with mbd=2 and see if it looks better...

> >\
> >		-vf scale=352:288,dsize=4/3	\
> >		-af resample=44100:0:2	\
> >		$1 -o $2
> >
> >This seems to work really well, except for one small problem - the
> >"-af resample=44100:0:2" part doesn't seem to do what the
> > documentation says it should (or maybe I am reading it wrong).
>
> -srate 44100 usually works well

Ah, excellent, thanks, that did the trick. :-)

> >I have videos encoded with varying frequencies other than 44100
> > (e.g. 22050, 48000), and I have to make this into 44100 to make it
> > VCD compliant. However, the files encoded using the above script
> > still have the same audio frequency (confirmed using "mplayer
> > -identify") as the source file. The video seems to be in the
> > correct format, but the audio is not.
> >
> >What I am I doing wrong? I would really like to avoid using the
> >mjpegtools script if at all possible because it takes much longer.

One last problem - the "dsize=4/3" (or "dsize=1.333333") parameter 
doesn't seem to set the aspect ratio in the resulting file. I know that 
this is being really pedantic, but I have heard that VCD MPEG video 
should have it. Can anybody confirm or deny this, and if it is 
required, how do I make it stick on the encoded file?

Thanks.

Gordan