Blotchy backgrounds etc.

[omarh]

For the most part i've been getting pretty amazing DIVX encodes from DVD movies. But I started watching one of my divx movies for the first time (instead of just spot checking it like i've been doing), and I noticed something that is a little annoying.

Basically the video qualitiy is outstanding most of the time but occasionally certain areas have a weird blotchy appearance. For example, this guy's black jacket, it looks like a mosaic pattern on it....then sometimes the black background at night..or shadows...they look blotchy. the weird thing is, their faces and other features look fine....

anyone know what setting in divx 4.11 i can change to prevent this kind of problem???

[Jacksindecision]

It is very normal to see this on DivX movies. The only thing that can be done to prevent this is to encode the video at a higher bitrate. Usually those kinds of effects appear on large, solid colored parts of the movie, like a blue sky, lake, or, using your example, a person's solid black jacket. Every movie is different so there is no definite bitrate that I can recommend.

[omarh]

I found that this mostly goes away if you increase the bitrate to a level similar to mpeg-2!!

[CrazyLegsMC]

RE:

Also, imo, ive found that rasing the luminance by 25 (using XMepg)
made the dark scences look like less mosaic like

but this is just my opinion

[omarh]

I was reading Rick's DIVX guide, and under the quality article he wrote, he mentions how mpeg movies are made up of 16x16 blocks. So if you reduce the resolution so you use fewer blocks, you can get nicer looking images. So I reduced the resolution and kept it at a multiple of 16 and the result is MUCH better. I think I pretty much eliminated the weird blotchiness I was having...or at least minimized it to the point where it doesn't bug me anymore.