[MPlayer-users] mencoder lavcopts for decreasing filesize

[Ellis Whitehead]

Quick summary:
If you take a simple lavcopts of:
 vcodec=mpeg4:vbitrate=1500:keyint=125:vqmax=5:vhq
and add:
 mbd=1:vmax_b_frames=2:vi_qfactor=-0.8:preme=0:vqsquish=0:vrc_strategy=0
then you'll get about a 5% filesize reduction.  Add "-vf hqdn3d" to
the mencoder command line and you'll get another 5% (approximately, of
course, depending on video source).


A bit longer:
Last April I submitted bug report #276 about poor mpeg4 encoding
quality in mencoder.
  http://bugzilla.mplayerhq.hu/show_bug.cgi?id=276
I think the problem may have been resolved now, so this email is just
a related note for decreasing mpeg4 filesize by about 10% (plus or
minus a lot, depending on the video source).

For the last year I've been working with mplayer and mencoder for a
couple of large club projects, and gained quite of bit of experience
with them for many different tasks.  I've had to keep extensive notes
(since there's too much to remember), and I started organizing them so
that others might benefit in some little ways.  In particular, I think
I'll try to write up several "tips" pages for some of the more
difficult stuff:

1. mencoder lavcopts for decreasing filesize
2. programming overlay video for mplayer/mencoder
3. splitting and combining DV files
4. high-quality real-time filters
5. using makefiles to handle batch video conversions

I have no idea how much of this I'll really get around to writing up,
but I did a write-up for #1 so far.  I put up a few screenshots on a
webpage for visual comparison.  It's not a rigorous comparison by any
means, but it might help someone who needs to get a few more minutes
of video into a certain amount of space:
 http://www.nowiswhen.net/public/mencoder_lavcopts_size/

Any suggestions for improvement or links to better information are
entirely welcome!

Thanks,
Ellis