How to deal with color-blocks?

[volence]

I am a newbie to AVC, and I've been trying x264 encode these days. When I was encoding an anime, there was a sence like this: a person with red color slowly move from left to right, and the whole picture fade to black at the same time. After encoding, I found there were heavy color blocks around the person, even if I use the AE-Max profile in meGUI. Then I change the proflie, set the M.E Range to 32 and sence change sensitivity to 60, set the de-block strength and thresold to 1, set B-frames to 8, and still use automated 2-pass and set bitrate to 1200. Though the encoding time is doubled, I found the block is even more heavier. I don't konw where is the problem. I also tried XviD, use 2-pass, no same problem.
Thanks all.

[DarkZell666]

I personnally can't visualise (imagine) how the bug looks like from the way you described it. Please post a screenshot (or an encoded sample that has the problem if you can).

[volence]

Oh, sorry I forget to post a snapshoot. Like this:
http://img10.picsplace.to/19/snapshot_000.JPG
can u see the picture? Look at the person, terrible blocks. The sence is: the person is moving horizontally, and the whole screen is fading out.

[DarkZell666]

The whole picture has blocks, it's not only the red girl (but blocks show more easily on blue, green, and red).

Could you post a screenshot of the source ? (the same frame if possible ;)) I suspect those were already there, simply because the source looks like it is DVB. It's wierd that you didn't see the problem with XviD though ... oO

[DigitalDeviant]

I had a the same problem but to a much lesser degree. It's the opening from the new Baldr Force OVA. I only got a few blocks in her hair during the fade using AE-Max quality bitrate 1000. It wasn't really a big deal. I didn't see any real problem with the DVD but then again I didn't really look for it. I might give it another go next week and if I clear it up anymore I'll let you know.

[volence]

Well, I've just tried another time, using CQ18, then there is no more blocks... I think the problem should be lack of bitrate.

[Sharktooth]

Define a zone with higher bitrate in the problematic area.

[check]

adaptive quantization should help. Try adding this to the custom commandline entrybox:
--aq-strength 0.4

[volence]

Define a zone with higher bitrate in the problematic area.

Yes, I've tried this. But I don't konw how to set the bit rate to the whole anime. I tried to set 2-pass bitrate 2000, and set the problemetic zone to Q16, but I found that only the zone has not blocks, other part become blocked... Should I raise the average bit rate? But when I use 1200, only the problemetic area has problem, other part seems OK. I'm considering what should I do ?

[volence]

adaptive quantization should help. Try adding this to the custom commandline entrybox:
--aq-strength 0.4

Oh, what is the meaning of this option?
I'm sorry I was a newbie...