[MEncoder-users] RGB => YV12 conversion

[Vladimir Mosgalin]

Hi RC!

 On 2005.09.25 at 17:24:50 -0700, RC wrote next:

> > sometimes. If you've got enough bitrate, p-frames only sequence can
> > produce nice looking fade in, but b-frames almost always make it
> > worse. But really, it depends..
> 
> Well if you have a very high bitrate,  Lavc will just make every
> frame of a fade a keyframe, so it will look perfect.  I've never seen a
> good-looking fade in/out with p-frames.

Hmm.. maybe, the point is that b-frames destroy perfectness. Disabling
them help. I don't remember this for sure, but you are probably right.

> > While I need "the least possible bitrate for encode that my eye can't
> > distinguish from dvd". 
> 
> I'm beginning to suspect you're someone who needs noise in the video. 
> Leave out all other postprocessing, and just use -vf noise on a lavc
> MPEG-4 video and see if that's the reason.  If so you can try lavc
> encoding with nsse.  (I find sse in general to not be very good, but
> that's the only lavc *cmp function that preserves noise)

I need noise? Yes, that's right, I always use -vf noise=10uah:3uah on
playback. It hides a lot of artifacts. However, I denoise original
content before encoding, it always helps.

> > I haven't tried qns=3, and turning on b-frames never (at least I don't
> > remember) helped me on animation when encoding with lavc, but I
> > wouldn't say that it is that much better than xvid.. It is better in
> > some cases, but not in the most of them.
> 
> I'd love to see a sample of good looking animation
> with Xvid at 720x480/24fps with bitrates of ~200.

I already said that I'm not interested in such bitrates.. No codec will
produce good-looking animation at any resolution with bitrate of 500
kbit/s. Maybe it won't swarm with artifacts, but then low resolution and
aliasing will destroy the quality. And no small details at all..

Depending on the kind of animation, sometimes 1300-1500 is enough for
704x480. Sometimes you have to go as high as 2200-2500 for 704x360, or
you'll see a lot of artifacts in fast scenes.

-- 

Vladimir