This is a speed and portability optimized version of Andree Buschmann's
MPEG-Plus decoder. Speed enhancement is about 1:4...1:5 relative to the
original source. Some of these optimizations flood back to the original
decoder, but especially on AMD K6-2/AMD K6-III/AMD Athlon/AMD Duron/Intel
Pentium III/Intel Pentium 4 there's still some hand written assembler code
so this decoder ist still much faster.
TODO:
override wip/mppdec ?
