theora dev - Oct 2010 - too mach distortion on color gradient

Hallo all,
i ready send one emeil with screenshots but it seems to take some time
till it will be accepted, so i send one more time with links.
> Hallo all,
> there is sintel online premiere up today http://www.sintel.org/ . But
> oggtheora video is every thing but not gut. I downloaded 720p version
> but IMHO some times it looks  for me like scaled 480p. In my
> experience theora can do better, or em i wrong?
> 
> strings Sintel.2010.720p.Theora-VODO give me fallowing:
> ENCODER=ffmpeg2theora-0.24
> Xiph.Org libtheora 1.1 20090822 (Thusnelda)
> 
> http://shareimage.org/images/yicir19o4035voren5u.png
> http://shareimage.org/images/00v5d065wxwpobfwu3d.png
> http://shareimage.org/images/vd12gz2612ba2w1ji5r.png
> http://shareimage.org/images/srrubfvkflcj8ncd8hx.png
> 
> PS: May be it will be good idea to make ffmpeg2theora write to ENCODER
> section encoder parameters too?

On Sat, Oct 2, 2010 at 3:45 AM, Alexey Fisher
<bug-track at fisher-privat.net> wrote:
> Hallo all,
> i ready send one emeil with screenshots but it seems to take some time
> till it will be accepted, so i send one more time with links.
I'm not able to load any of these links; the server times out.  I'll
go look to see what happened to the original message, though I expect
it bounced because of the attachments....

Monty

Hello,

I've had a ook at these; the problem isn't banding actually, but
blocking (it looks like banding as the loop filter has smoothed the
boudaries).  Very similar to the effect in the 'sunflower' clip from
the demo updates.

First off, Ptalar does handle these cases better than Thusnelda did.
Second, the whole problem stems from the lowest AC coeffs not getting
enough bits, and I'd expect that to be a result of coarse quantizers.
What were the exact command lines used to encode?  I'm only used to
seeing this effect in fairly low bitrate encodes.

Monty