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

[Nicolas Hesler]

Vladimir Mosgalin wrote:
> 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 is an encoding problem.   The defect is visible in any/every media 
player.

> 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).
>   

can anyone offer any info on how to do this???
> Do you see this defect when you play your file in mplayer with -vf-clr?
>
>   
yes.