Supporting Non-PCM Wave Formats

This section describes limitations in earlier versions of Windows that prevented clients from playing non-PCM audio, and presents a set of guidelines for adapting a WDM audio driver to support non-PCM data formats on more recent versions of Windows.

Additionally, this section describes the new subformat GUIDs in Windows 7 that provide support for compressed audio formats.

This section includes the following topics:

Background of Non-PCM Support

Requirements for a Non-PCM Pin Factory

Subformat GUIDs for Compressed Audio Formats

Converting Between Format Tags and Subformat GUIDs

KS Topology Considerations

Specifics for waveOut Clients

Specifics for DirectSound Clients

S/PDIF Pass-Through Transmission of Non-PCM Streams

Specifying AC-3 Data Ranges

Specifying WMA Pro Data Ranges

USB Audio Support for Non-PCM Formats