[MEncoder-users] Encodes for slow laptop

[R.L. Horn]

On Sun, 8 Jun 2008, Stella-Terra Clemens wrote:

> Unfortunately, I'm having a hard time getting really consistant results.
> Mostly my problem is that I can't keep audio sync.

What does the mplayer output look like (particularly the "A:" "V:" and 
"A-V:" bits)?  If they're in sync, but audio is still noticeably off, try 
"-ao oss" with mplayer.

> Mainly I've been trying to use XviD, but is there something else that 
> would be better in this circumstance?

I prefer the lavc MPEG-4 coder.  Unless you specify otherwise, mplayer's
going to be using the lavc decoder with XviD anyway.  However, if you plan 
on playing the video with anything other than linux players, you'll likely 
have to use something like "-ffourcc DX50" or "-ffourcc XVID" (recognition 
of the "FMP4" fourcc isn't all that great).

> Finally, I wanted to know about resolutions.  I've been reading 
> conflicting things about resizing.  My instinct is to always crop as 
> little as possible and then resize to mod16, but I've recently been 
> reading that it's a bad idea to resize at all.

It's not something you should do without a compelling reason (in this 
case, getting the video decoded in time might be a compelling reason). 
Sticking to (at least) mod8 (mod16 with H.264) is a good idea and, for 
interlaced video, always give the scale filter the extra ":1" for field 
scaling.

Best, I believe, is to just crop unwanted parts of the frame (particularly 
letterbox/pillarbox bands) and make certain the correct aspect ratio ends 
up in the stream (if encoding with lavc, "-lavcopts autoaspect" almost 
always gets it right).  As a rule, stick to even numbers for the crop 
origin because of chroma subsampling and field interleaving.