[MPlayer-users] MPlayer-1.0pre4 bug with divx4 multipass filter

[D Richard Felker III]

On Sat, Sep 11, 2004 at 12:26:52PM +0400, Vladimir Mosgalin wrote:
> On Fri, 10 Sep 2004, D Richard Felker III wrote:
> 
> DRFI>> Try xvid. It's much better than both of them on high bitrate. I'm
> DRFI>> pretty
> DRFI>
> DRFI>false. lavc is the best, just try comparing psnr or double-blind.
> 
> I learned this a long time ago - never ever compare psnr, it's quite
> meaningless. Large difference in psnr values can easily be seen, and
> small differences can't be trusted at all.

then do double blind.

> DRFI>perhaps you're just using dumb options.
> 
> You just haven't tried right xvid options or saw only very old xvid
> versions, that's why you are saying so.  I encoded a lot with lavc
> before, and now I can say for sure: lavc sucks a lot comparing with
> xvid.

i still maintain you're doing something wrong.

> lavc _can_ be sometimes better than xvid: when you need realtime
> encode, or when you are encoding to low or average bitrate and aim for
> postprocessing with pp or spp filters.
> 
> But when making high-quality dvd-rips, you can't even compare lavc and
> xvid. With postprocessing, hq rips look bad - all the details are

i never use postproc. too slow anyway.

> blurred away. So I always make rips that do not need postprocessing
> (1700-2500kbit/s depending on material is enough to make very hq rip

normal bitrate for a dvdrip is 1300-1500, at least for anime. i've
been away from hollywood crap so long i don't even remember what you
want for that... keep in mind anime is normally 4:3 or 16:9 rather
than 64:27, so you have more pixels to encode.

btw is part of your idea of "hq" keeping all the noise and artifacts
from the bad dvd encode? these should be removed before encoding...

> with the right settings). Sadly, on most types on content it's nearly
> impossible with lavc. Scenes with qp=2 look extremly bad (and I don't
> want to discuss my monitor, gamma, brightness and eyes - they are
> perfectly well).

scenes with q=2 will look perfectly good on either lavc or xvid.

> In a lot of scenes, you can see blocks everywhere!
> With xvid, qp=2 will lead to perfect result. The bitrate will be
> ~1.3-1.5 times higher than with lavc, though; but with qp=3, the result
> is still much better than lavc's and bitrate is smaller.

rotfl... q=3??

> That's where b-frames kick in and improve quality a lot. With the
> "regular" xvid settings for the first pass, i/p frames with qp=2 and 2
> b-frames with qp=4, the quality almost always is very good.  On the
> second pass, bitrate can be reduced by 20-30% without visible quality

i would recommend disabling b frames. they lower quality in most
cases, and they're just a stupid hack.

> loss. At the same bitrate, lavc produces only low-quality video that can
> either be watched with postprocessing (thus with washed out details), or
> with a lot of blocking.

huh? i never watch with postproc and never have any blocks. maybe i'll
try using eq2 with gamma boosted to 5.0 or something like your monitor
to see if they appear... :)

> With xvid, it's extremly hard to find the content that will lead to
> blocks at the same bitrate. The still frames everywhere, even on fast
> motion scenes look exactly like original ones.  When switching between
> two, eye can't tell the difference. With lavc, it is only possible with
> qp=1 and insanely high bitrates (higher than original ones).

possible with q=2 and even q=3 for most scenes.

rich