Well, I can do it and have done it, but hopefully others can do it in a more expedient manner.
I can bring it into Lightwave as a background and render it with no foreground. This will give me an individual image for every frame, with no degradation in quality. Then I can comp the frames back together as whatever I want.
As the saying goes: Don't try this at home. At least not unless you have a few hundred spare gigs of HD space laying around. This method will give me an uncompressed 32 bit image for every single frame.
Don't do the math. It gets scary.
Then, it gets compressed back to a useable level at output.
Direct conversion is possible of course, but is so problematic that few sane people attempt it.
Half (or more) of your direct converted file consists of trash. Information the new format does not need but is afraid to throw away.