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

[Corey Hickey]

nicolas.hesler at sheridanc.on.ca wrote:
> Because I had started going off on a tangent in my previous thread on
> B frames and GOP, I've decided to start this thread to address the
> specific issue started at the end of that thread.
> 
> http://lists.mplayerhq.hu/pipermail/mencoder-users/2007-June/006165.html
> 
> 
> 
> I'm trying to find a *sweet* highest quality mpeg-2 DVD encode for
> 24fps cartoon content. I've noticed that on certain videos,
> pulsating occurs on keyframes (I-frames),and especially visible in
> darker picture areas.  I adjusted lavcopts
> vi_qfactor=0:vi_qoffset=0.1 (or as zeroed as possible) which seemed
> to *slightly minimize the pulsating.  After much shooting in the
> dark, I discovered that by changing lmin to a higher value (lmin=4 or
> lmin=5), I was able to eliminate the pulsating effect.  From what I
> understand, however, this decreases the overall quality (while
> increasing compressibility) but I'm aiming to get the best quality
> possible.

I'm curious about this. Can you provide a sample command line and 
_source_ video long enough to see this effect?

Upload to ftp://upload.mplayerhq.hu/MPlayer/incoming/ or any public 
http/ftp server.

-Corey