Re: [mpeg2-dev] A funny stream

[Michel L. <wa...@zo...>]

On Thu, Nov 08, 2001 at 05:13:38PM +0700, Peter Gubanov wrote:
> >run with mplayer -vc ffdivx foo.avi
> >apply the attached patch and compare
> Gonna check this later today or tomorrow.

> >HorizontalStripes has (faint, but still visible, and statistically
> >they shouldnt be visible) stripes, and Lorenna has weird colors at
> >some points.
> Could you tell me time/frame positions? Maybe I miss something...

Well in HorizontalStripes, I can see some faint but visible stripes on
the mostly-uniform greyish background at the start of the movie. In
the Lorenna stream it looks more like color drift, like if you had
some bias in the IDCT and after a while the colors are purple-ish. You
can see that best in the crossfade around the end of that stream - it
doesnt look the same if you apply the simple_idct patch.

Basically the simple_idct patch seems to behave better than "our" idct
on both of these streams, even though they have almost identical
precision when running the ieee1180 tests. I'm puzzled.

I suspect you wont see any of this when using the windows divx
decoder, as it probably matches exactly what the encoder is doing
anyways.

Cheers,

-- 
Michel "Walken" LESPINASSE
Is this the best that god can do ? Then I'm not impressed.