[MPlayer-users] Re: Problem Encoding Solid Color Objects With LAVC MPEG4

Angel angel at knight-industries.com
Tue Sep 23 21:44:25 CEST 2003

Rich wrote:
> I agree. There are no blocking artifacts in either. Perhaps Angel was
> confusing them with some different sort of artifact -- just plain
> noise -- but as far as I can tell that has nothing to do with the
> encode but rather it's just noise in the source. Using the hqdn3d
> filter might help that.

As I stated in my last post... the problem is far less noticeable on a 
computer monitor (which I assume is how you viewed it). The problem I'm 
talking about is the fact that the noisy background on the wall looks like 
large blocks moving around in the lavc version. The divx / xvid version does 
not do this. The source consists of a noisy background wall... that is how it 
should look in the encoded version (especially with a bitrate of 1500 and 
little to no motion). The lavc version makes the background look noisy by 
shifting large solid color blocks around. This is VERY noticeable on a T.V.

Fabio wrote:
> I've just seen your samples. Are the blocking artifacts more noticeable in 
> some places than others? Because, honestly, I cannot spot much difference 
> from divx to lavc, and I didn't try the xvid one because obviously it is 
> twice the size so I think a comparison won't be fair.
> For what I can see, both are good quality. I can't see any blocking artifact 
> in any of the two.

Yes the artifacts are worse in some places then others. If you look at the 
background wall in the lavc version... there are parts of it that look like 
they consist of large blocks shifting around. As for the xvid version being 
larger... I used the same bitrate, cropping, and scaling values as the lavc 
version. On both encodings, I left the min/max quantizer and rate control at 
the defaults.


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