This document is a preliminary specification for Philips Semiconductors SAA2500 MPEG Audio Source Decoder. The decoder features advanced error protection, integrated audio post processing for control of signal level and inter-channel crosstalk, demultiplexing of ancillary data in the input bitstream, automatic digital de-emphasis of the decoded audio signal, separate master and slave inputs, automatic sample frequency and bit-rate switching in master input mode, automatic synchronization of input and output interface clocks in master input mode, selectable audio output precision of 16, 18, 20 or 22 bits, and low power consumption. It is suitable for applications such as cable and satellite digital radio decoders, video CD, Compact Disc Interactive (CD-I), sold-state audio, and Multimedia Personal Computer (PC).