[MEncoder-users] Pulsating I-frames (keyint)

[Vladimir Mosgalin]

Hi Nicolas Hesler!

 On 2007.06.15 at 17:08:31 -0400, Nicolas Hesler wrote next:

> To describe the pulsating in a little more detail:  It isn't the entire 
> frame that is pulsating but rather certain granular areas (consisting of 
> detailed texture).   The pulsating is especially more visible toward the 
> edges of the frame (almost linearly more pulsation from the center out 
> toward the edges) and more visible in darker color areas.  The 
> pulsating, as I mentioned before occurs on I frames (varying keyint, 
> varies the pulse frequency).    I assume that those settings succeed in 
> reducing the flashing because they soften the picture.

Are you talking about encoding or decoding problem? Because I
experienced similar problem which were in fact postprocessing bug. It
was long time ago though, but who knows, maybe your problem is similar.

It was related to per-MB quanitizers and had nothing really to do with
frame quantizers. I wonder if it's possible to force all MB quantizers
be the same as frame quantizer? It'll reduce quality for sure, but you
should try such option (not sure it exists though).

Do you see this defect when you play your file in mplayer with -vf-clr?

-- 

Vladimir