High-Resolution Audio Support
Both the Windows Media Audio 9 Professional codec and the Windows Media Audio 9 Lossless codec support high-resolution audio. High-resolution audio is defined as an audio format with more than 16 bits per sample. The number of bits that are used for an individual audio sample affects the fidelity of the encoded sound wave.
Because PCM-encoded sound formats have been used in Windows operating systems for a long time, some of the Windows functions are old and unable to process high-resolution PCM audio. As a result, high-resolution PCM formats are represented by using different structures than standard audio. For more information, see Working with High-Resolution PCM Audio.