[MPlayer-users] Using mencoder to create Windows- and MacOS-friendly movies

[D Richard Felker III]

On Fri, Dec 13, 2002 at 09:46:33AM +0100, January Weiner 3 wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> > > Don't expect them to be able to do
> > > anything more then clicking on a link and seeing what happens.
> > I don't mean to be rude, but that's the way computers are. If you want to
> > support limited users, you have to resort to limited methods.
> 
> Of course!
> 
> > Convert to MPEG1, or (depending on Vinfuxx version) Indeo4 or
> > M$ MPEG4 v3 + ASF format.
> 
> Yes, and all I'm asking is: how to do it :-)
> 
> At first, it seemed to me it should be quite simple, something like convert
> foobar.tif foobar.jpg, now I've dig through tons of manuals, installed
> megabytes of movie-related software, tried a hundred options, and I'm still
> as stupid as I was before.
> 
> Take, for example, mencoder -ovc lavc -lavcopts vcodec=mpeg1video foo.avi
> 
> This should turn the file into an mpeg layer 1 avi, am I correct?  Well,
> it doesn't work in either QTP or WMP.

Yes, it will. Unfortunately, Windows and QT don't support mpeg1 video
in avi files, however, because they're stupid. (They support it just
fine in mpeg files, so it's stupid not to support it in avi.)

> Really, I have been struggling with it for the last week or so.  Here is a
> small exemplary file: hell.pl/january/mysz/mysz.avi (you will find several
> of my attempts to convert it in the same folder(*)).  If any of you manage
> to convert it to a QTP or WMP playable version and tell me how you did it,
> I can send him a postcard from Heidelberg or buy a beer if we meet one fine
> day :-).  Or help to troubleshoot any problem you might have with
> quantitative PCR, sequence database search or LaTeX or whatever I can :-)
> 
> j.
> 
> (*) Contents of hell.pl/january/mysz :
> 
> mysz.avi - the original mjpeg file
> mysz*.avi - files created with different lavc codecs.
> 
> mysz.mpg - this one is working in QTP and WMP, albeit at 25 fps.  I did it
> 	like this:
> 	mencoder -ovc lavc -lavcopts vcodec=mpeg4 mysz.avi
> 	transcode -i test.avi -o mysz -V -y mpeg
> 
> mysz25fps.mpg - this one has the poor quality, but the right speed. It
> 	was done like this:
> 	mencoder -ovc lavc -ofps 25 -lavcopts vcodec=mpeg4 mysz.avi
> 	transcode -i test.avi -o mysz25fps -V -y mpeg

That's because you didn't specify any options and the default bitrate,
etc. are way too low. Try adding vqscale=2:vhq to the lavcopts. I
don't know how to tell transcode what quality to use.

BTW, if your source material is 10 fps, you should probably scale it
up to 30 (3x) instead of 25 (2.5x); I imagine it'll look choppy at 25
fps since some frames will be shown longer than others.

Of course the best of all would be if you could record the original
material at 24, 25, or 30 fps.

BTW2, you might try using ffmpeg instead of mencoder/transcode to do
the conversion. It should be able to make a working mpeg1 file all in
one step. Something like ffmpeg -i mysz.avi -b 400 -r 30 mysz.mpg.


Rich