Ask Slashdot: Full Shoutcast on Linux?
Unfortunately, mpg123 is not GPL, so we can't use it (and, we believe splay (which is GPL) is based too heavily on amp (which means if we use it in our software it could leave us open to a lawsuit from the people who now own amp).
As far as working on the speed of the decoder, we have someone doing that. Unfortunately, writing hand optimized assembly is not something that happens overnight. I personally would rather work on other stuff while this other guy we have works on the optimization.
I am personally interested in seeing what engine X11amp uses whenever they release.