Reduced floating point for MPEG1/2 layer III decoding
M. Olausson, Andreas Ehliar, Johan Eilert, Dengcheng Liu · 2004
A new approach to decode MPEG 1/2-layer III, mp3, is presented. Instead of converting the algorithm to fixed point, we propose a 16-bit floating point implementation. These 16 bits include 1 sign bit and 15 bits of both mantissa and exponent. The dynamic range is increased by using this 16-bit floating point as compared to both 24 and 32-bit fixed point. The 16-bit floating point is also suitable for fast prototyping. Usually, new algorithms are developed in 64-bit floating point. Instead of using scaling and double precision as in fixed point implementations we can use this 16-bit floating point easily. In addition, this format works well even for memory compiling. The intention of this approach is a fast, simple, low power, and low silicon area implementation for consumer products like cellular phones and PDAs. Both listening tests and tests versus the psychoacoustic model have been completed.