The IAudioSessionManager interface enables a client to access the session controls and volume controls for both cross-process and process-specific audio sessions. The client obtains a reference to an IAudioSessionManager interface by calling the IMMDevice::Activate method with parameter iid set to REFIID IID_IAudioSessionManager.
This interface enables clients to access the controls for an existing session without first opening a stream. This capability is useful for clients of higher-level APIs that are built on top of WASAPI and use session controls internally but do not give their clients access to session controls.
In Windows Vista, the higher-level APIs that use WASAPI include Media Foundation, DirectSound, the Windows multimedia waveInXxx, waveOutXxx, and mciXxx functions, and third-party APIs.
When a client creates an audio stream through a higher-level API, that API typically adds the stream to the default audio session for the client's process (the session that is identified by the session GUID value, GUID_NULL), but the same API might not provide a means for the client to access the controls for that session. In that case, the client can access the controls through the IAudioSessionManager interface.
For a code example that uses the IAudioSessionManager interface, see Audio Events for Legacy Audio Applications.
The IAudioSessionManager interface has these methods.
|IAudioSessionManager::GetAudioSessionControl||The GetAudioSessionControl method retrieves an audio session control.|
|IAudioSessionManager::GetSimpleAudioVolume||The GetSimpleAudioVolume method retrieves a simple audio volume control.|
|Windows version||Windows Vista [desktop apps only] Windows Server 2008 [desktop apps only]|