[MEncoder-users] How to encode a DVD

[RC]

On Wed, 6 Jun 2007 19:17:14 -0300
Jorge Peixoto de Morais Neto <please.no.spam.here at gmail.com> wrote:

> precmp=2:cmp=2:subcmp=2

This is a very bad idea.  Without postprocessing, on live-action
material, that will cause the video to be extremely blocky.  Either use
the default SAD (0) or DCT (3).

> keyint=18:

That's a huge waste of bits, and really not necessary.  I believe
standard is 30, and I use keyint=60 myself, without problems.

Also, -lavcopts turbo will really speed-up the first pass, with almost
no quality loss.
 
> I was calculating bitrate for 700 MB but then I learned that a SVCD
> can hold 800 MB. 

A CD holds ~700MBs.  A mode2 CD (audioCD/VCD/SVCD/etc.) holds ~795MB.

With overburning, you can get ~720 and ~825 respectively, with no
problems in any DVD-players I've used.

> 2) When doing multipass encoding, is it a problem to change options
> (like the slight change in bitrate I did)?

Such a tiny change in bitrate won't make a difference.  If you want to
change it much more, I'd suggest doing the first-pass again.



> 3) What is recommended for having a good quality sound encoding with
> mp2 codec? The mplayer web page says that libavcodec's mp2 is no match
> for twolame. But I don't see an option in twolame to resample to 44100
> Hz.

If you have twolame installed, you just have to recompile mplayer to get
-oac twolame.  For resampling, just use mencoder's built-in filters. 
-srate 44100 should work fine.

>  If I output PCM, resample with sox, than compress with twolame,
> will I get good quality?

No idea about sox's resampler, but demuxing audio and video, and
remuxing them together is likely to cause desync.  It's much better to
use mencoder to handle both together, in one step.