Hi! I'm using Premiere Pro CS 5.5.1 (latest update) and have a NVIDIA GTX 580 (driver version 280.26) and Windows 7 64bit.
In my project I have layers of transparent PNGs that were exported from Flash, and one has very subtle opacity effects. Unfortunately when I use GPU acceleration, the transparencies get messed up and they look a lot more opaque and colors are distorted.
Is there anything that I can do, except turning off GPU acceleration?
i will add an image that shows how the error looks like:
No, there is really nothing you can do. Linear color processing in 32 bits is part-and-parcel with hardware MPE/GPU acceleration, so no matter what, you'll always have some degree of unexpected (and in my case, unwanted) transparency shifts.
We're told this is "better." Personally, I hate it.
The workaround is to work with GPU acceleration in your project, so that you can enjoy the other benefits of realtime performance, but when it comes time to export, just turn it off. Also, don't use Maximum Render Quality whilst in software mode, since that also enables 32-bit linear color processing.
If you don't think this is a viable workaround, make some noise here: Adobe Feature Request/Bug Report Form
It's not a perfect solution, but you can actually use the transfer mode options (in the opacity effects) for your clip to offset some of the MPE disaster. Copy and paste the effect to your pleasure.
If you find one that works for a lot of your clips, you may want to save a preset so you have it handy when you need it in the future (just name it something like "MPE Opacity FAIL fixed")