[MPlayer-users] lavc vs. xvid (and improving lavc quality)

[Vladimir Mosgalin]

On Tue, 1 Jun 2004, D Richard Felker III wrote:

DRFI>On Tue, Jun 01, 2004 at 06:38:32AM +0400, Vladimir Mosgalin wrote:
DRFI>> DRFI>It's not suffering, but having a good monitor. On a good monitor, low
DRFI>> DRFI>levels will be very close to one another. Otherwise dark areas will
DRFI>> DRFI>have ugly banding from visible "steps" in the brightness level, and
DRFI>> DRFI>everything just looks way too bright.
DRFI>> 
DRFI>> My monitor's brightness & gamma are calibrated to 2.5 gamma, and I see
DRFI>> a lot of blocks and defects with vqscale=2 & original resolution
DRFI>> (without scaling) on certain dvd rips. Of course, -vf pp removes them,
DRFI>> but it removes details as well and blurs everything.  -vf noise=12uah
DRFI>> improves picture, but not much.
DRFI>
DRFI>Turn gamma correction OFF!

*looks puzzled* Which gamma correction?

I mean that my monitor's brightness is tweaked to the right level, and
gamma is set to 1.01, 1.05 & 1.04 for rgb to get the correct 2.5 gamma.
I use no gamma correction in mplayer, but I use -vf x11 to pick those
values up.

If I return gamma to 1, 1, 1, colors will change slightly to less
correct values, that's all...

OK, I'm gonna try xvid and tell if I see the same problems. Maybe really
it's time to say goodbye to lavc. It may be good at middle & low
bitrates, but when trying to encode dvds to get vhq rips, its behaviour
isn't good. On the other hand, sometimes it everything goes well - when
the picture is clean and simple. But on dvds with a lot of detais
(which can be ripped, but the bitrate can get as high as was on original
dvd - I only met that once, though) or on noisy or lq dvds, it doesn't
preserve original quality. Quality drops a lot, at least with vqscale=2.
To prevent questions: yes I use hqdn3d, but with lesser strength than
default, and I don't use pp on dvds, it almost always only reduces
quality. Blocking artifacts are very rare on dvds, mostly there are some
other kinds of them...

-- 

Vladimir