Wouldn't a dedicated encoder like AME or even MPEG StreamClip give you better compression options rather than AE? I then to think that AE isn't the best for complex compressions and I try to do those elsewhere, like in MPEG StreamClip where I can use features like 2 pass encoding.
tt
From: "Robert Kjettrup" <robert@stvmayday.dk>
Just a quick followup on the h264 issue... with several mail back and forth with Adobe, the issue was found. It is CBR vs VBR encoding in CS6, i had all my h264 presets set to CBR and they renders unwatchable files in CS6 (at least on my win7 machine).
So just render h264 VBR files and everything works :-)
a fix would be nice to have, and i guess it is coming now adobe is aware of it, since i tend to get better quality with CBR encoding, fades especially looks pixelated with VBR encoding.