It might actually be easier for me to do the PAL speedup myself and upload new AC3 files--wouldn't take as long to upload. But then, if you had the PCM files to work with, you could put them through an upmixing algorithm like the one Satanika posted above to get five channels and then combine with the LFE to get 5.1 format, since some receivers might not like 2.1 files. I might have done that myself, but none of the processes I've tried have worked on my computer, although I'm sure they would work on other people's computers. I experimented a bit with doing it manually, ie combining them at various volumes and using phase cancellation to derive each channel. I think it sounded reasonably good, but the channel separation wasn't that high, certainly not when compared to what Prologic 2 or Neo:6 can accomplish, so I ultimately concluded it wasn't worth continuing, at least not for my setup.