MAD (MPEG Audio Decoder) is a high accuracy MPEG decoder filter. The software is available in open source and for example as a WinAmp plugin. MAD is tested to provide very high accuracy MPEG audio decoding. Now the source code is being ported into a Direct Show filter that player software can utilize for audio decoding.
This is a DirectShow filter for the MAD library. The idea is mostly to provide an example on how to write a DirectShow audio-filter, however the filter itself can be used as a replacement for the standard MPEG 1 Audio Layer 1, 2 and 3 filters.MAD DirectShow Sourceforge project