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

[David Tarkowski]

Angel wrote:

>[Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
>I've reported this problem before but nothing really came of it. I more or 
>less dismissed the problem as being a limitation of mpeg4/bitrate etc. 
>However, I recently encoded the movie Bad Boys and during one of the scenes 
>there is a solid colored background behind one of the characters and it came 
>out looking like an 8 puzzle with large blocks shifting around. I decided to 
>try encoding the movie using DIVX 5.1 and virtualdub just to see how the 
>results would compare. To my extreme disappointment... the DIVX 5.1 version 
>looked 1000% better. The background looks kind of noisy (as it should) and 
>there are no large blocks moving around. Just for the hell of it... I also 
>tried encoding it using mencoder/xvid. The results were very similar to the 
>DIVX 5.1 results. I don't know if I should report this here or to the ffmpeg 
>list. I am willing to upload the source/results if that would be helpful. 
>Just for reference, here are the encoding parameters used:
>  
>
I've found that adding a slight gaussian blur helps with that kind of 
artifact.  At least it does for animation.  I normally add "-vf scale 
-ssf lgb=1.05:cgb=1.05" when I notice what you describe and it clears it 
right up.

-Dave