[MEncoder-users] lavc or xvid

[Phil Ehrens]

RC wrote:
> On Tue, 4 Sep 2007 16:08:40 -0700
> Phil Ehrens <phil at slug.org> wrote:
> 
> > Eek! nr=300?! Alright, I admit it... I reported the same thing
> > once (or twice). If the source genuinely has significant gaussian
> > noise, nr=300 can perform miracles... HOWEVER, if you are starting
> > with good clean source (like a well-made dvd), nr=10 to nr=30 is
> > more realistic.
> 
> Almost every DVD I've seen has significant noise, and nr=300 helps a
> lot (and I've done several visual and PSNR tests to demonstrate that).
> That even goes for the newest digitally-recorded films. The few DVDs
> that don't have noise really stand out as unusually clear (appearing
> almost fake or cartoon-like), and in most cases, was a direct result of
> heavily denoising before encoding.

Maybe we are at odds here because of target bitrate? I can see
where nr=300 might be a typical setting if the target bitrate
is 600-800 kbps. Using nr=10 would be practically pointless
at those bitrates. Ah well, that's the danger of recommending
values for things like this... Too many independent variables.

> > These numbers are for 2-pass encodes. If you are doing single-pass
> > encodes, hqdn3d will behave much more sanely than nr. But if you
> > are doing multi-pass, nr will be better on all live action. Anime
> > seems to really love hqdn3d, however.
> 
> Unless it's extremely noisy material, I wouldn't use hqdn3d at all. With
> default values, it causes blockiness, fades color, and leaves a very
> noticable trail behind objects in motion. (the latter seriously disturbs
> me). I didn't mind 2:1:1, but at such low values, there's little
> benefit to denoising at all. 

I think that stating it that way, without qualification, does a
disservice to hqdn3d, which works wonders when used with animation.