Abstract – Efficient implementations of contemporary
standard audio decoders on low cost processors without
floating point ALU are discussed in the paper. Various data
representations using native fixed point arithmetics as well
as simulated floating point arithmetics are considered. The
effects of limited precision in fast cosine transform implementation
are simulated and discussed. Real-world examples
with various commercial audio recordings show, that
the impact of a finite word length on the final decoded audio
quality is not very significant since the artifacts resulting
from rounding are often negligible compared to coding
artifacts.

Keywords: Audio decoding, audio fidelity, MPEG, finite word length, rounding noise