IAudioVolumeDuckNotification::OnVolumeDuckNotification method (audiopolicy.h)

Article
02/22/2024

The OnVolumeDuckNotification method sends a notification about a pending system ducking event. For more information, see Implementation considerations for ducking notifications.

Syntax

HRESULT OnVolumeDuckNotification(
  [in] LPCWSTR sessionID,
  [in] UINT32  countCommunicationSessions
);

Parameters

[in] sessionID

A string containing the session instance identifier of the communications session that raises the the auto-ducking event. To get the session instance identifier, call IAudioSessionControl2::GetSessionInstanceIdentifier.

[in] countCommunicationSessions

The number of active communications sessions. If there are n sessions, the sessions are numbered from 0 to –1.

Return value

If the method succeeds, it returns S_OK.

Remarks

After the application registers its implementation of the IAudioVolumeDuckNotification interface by calling IAudioSessionManager2::RegisterDuckNotification, the session manager calls OnVolumeDuckNotification when it wants to send a notification about when ducking begins. The application receives the event notifications in the form of callbacks.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	audiopolicy.h