This method gets the multimedia device identifier being used by the audio object. The default device identifier for SpMMSysAudio objects that are created using CoCreateInstance is WAVE_MAPPER. For audio objects created using an object token, the identifier is always a specific wave in or wave out device identifier.
HRESULT GetDeviceId(UINT* puDeviceId);
Parameters
- puDeviceId
[out] Pointer to the device identifier.
Return Values
The following table shows the possible return values.
| Value | Description |
|---|---|
| S_OK | Function completed successfully. |
| E_POINTER | puDeviceId is a bad pointer. |
Example
The following code snippet illustrates the use of this method using CoCreateInstance.
HRESULT hr = S_OK;
// create the multimedia input object
hr = cpMMSysAudio.CoCreateInstance(CLSID_SpMMAudioIn);
// Check hr
// get the default device identifier
UINT uiDeviceId;
hr = cpMMSysAudio->GetDeviceId(&uiDeviceId);
// Check hr
// uiDeviceId == WAVE_MAPPER
The following code snippet illustrates the use of ISpMMSysAudio::GetDeviceId
using an ISpObjectToken
HRESULT hr = S_OK;
// get the current multimedia object's object token
hr = cpMMSysAudio.QueryInterface(&cpObjectWithToken);
// Check hr
// Find the preferred multimedia object token
hr = SpFindBestToken(SPCAT_AUDIOIN, L"Technology=MMSys", NULL, &cpObjectToken);
// Check hr
// set the current multimedia object to the preferred multimedia object token
hr = cpObjectWithToken->SetObjectToken(cpObjectToken);
// Check hr
// get the device identifier for the object
UINT uiDeviceId;
hr = cpMMSysAudio->GetDeviceId(&uiDeviceId);
// Check hr
// uiDeviceId != WAVE_MAPPER
Requirements
OS Versions: Windows CE .NET 4.1 and later.
Header: Sapi.h, Sapi.idl.
Link Library: Sapilib.lib.
See Also
ISpMMSysAudio | SAPI Interfaces
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