[MPlayer-users] mencoder options for NTSC television

[Lance Simmons]

I've been using mencoder to record television.  There are so many
differenct options, it's hard to be confident that I'm getting the best
results possible.  If anyone has some general notes about how the
different options interact with each other, and especially for how best
to record NTSC, I'd appreciate it.

Here are some questions I have:

1.  NTSC resolution:  one message when I use mencoder says

 Supported sizes: 48x32 => 768x480

 Does that mean that the height and width I choose have to preserve that
 ratio?  If so, then there are fifteen possible choices:

   48,32
   96,64
   144,96
   192,128
   240,160
   288,192
   336,224
   384,256
   432,288
   480,320
   528,352
   576,384
   624,416
   672,448
   720,450

 Are there any other possibilities?

2. vbitrate:  higher is better, right?  How do I decide what vbitrate to
use?  I've been using 16000, and the results look good.  What's the
benefit of going lower?

3. postprocessing:  what kind of postprocessing is best?  How do I
decide whether to crop or not?  Where in the documentation is there a
clear description of what the various postprocessing options do?  I'm
using lb, because the documentation suggests it, but am open to
suggestions.

Right now, I'm using:

mencoder 
 -tv on:driver=v4l:chanlist=us-cable:norm=NTSC:width=576:height=384
 -ovc lavc
 -lavcopts vcodec=mpeg4:vbitrate=16000
 -oac mp3lame
 -lameopts br=128
 -vop pp=lb
 -o test.avi

The results look good, and these options use between 80% and 90% of one
of my two processors, which is what I'm aiming for.  But can't I do
_better_?

-- 
 .~.
 /V\   Lance Simmons
/( )\  lance at lsimmons.net
^^-^^