Wavedev2 Audio Model (Windows Embedded CE 6.0)
1/6/2010
The Wavedev2 Audio Model implements direct support for the standard wave driver interfaces, and has many similarities to the Unified Audio Model (UAM).
Like the UAM, Wavedev2 implements direct support for the standard wave driver interfaces, and improves on the basic functionality of the MDD and PDD model of audio driver development.
The following list shows some of the features included in Wavedev2 that improve upon the MDD and PDD audio model.
- Wavedev2 contains multiple-stream input and multiple-stream output support with built-in mixing, volume control, format conversion, rate control, and sample-rate conversion. There are no API changes to implement this, as the Wavedev2 Audio Model is taking advantage of the wave API to support these features.
- Wavedev2 uses built-in midi and tone generation. There are no additional entry points into the API, but the driver now understands the WAVEFORMATEX structure.
- Wavedev2 implements audio gain classes to control audio volume levels when a device is receiving a telephone call. This API is exposed by a pair of waveOutMessage values, MM_WOM_SETSECONDARYGAINCLASS and MM_WOM_SETSECONDARYGAINLIMIT.
- Wavedev2 can switch audio output between the handset speaker and larger ringer speaker on a device by sending the waveOutMessage value MM_WOM_FORCESPEAKER.
- If the loopcount on a wave header is set to 0xFFFFFFFF, Wavedev2 treats the audio as an infinite loop that will recycle until it receives a WODM_BREAKLOOP message.
See Also
Concepts
Unified Audio Model
WAV_IOControl Messages and Parameter Structures
Audio Mixer
Waveform Audio Driver
Audio MDD and PDD