waveOutProc

The waveOutProc function is the callback function used with the waveform-audio output device. The waveOutProc function is a placeholder for the application-defined function name. The address of this function can be specified in the callback-address parameter of the waveOutOpen function.

void CALLBACK waveOutProc(
  HWAVEOUT hwo,      
  UINT uMsg,         
  DWORD dwInstance,  
  DWORD dwParam1,    
  DWORD dwParam2     
);
 

Parameters

hwo

Handle of the waveform-audio device associated with the callback.

uMsg

Waveform-audio output message. It can be one of the following values:

WOM_CLOSE

Sent when the device is closed using the waveOutClose function.

WOM_DONE

Sent when the device driver is finished with a data block sent using the waveOutWrite function.

WOM_OPEN

Sent when the device is opened using the waveOutOpen function.

dwInstance

User-instance data specified with waveOutOpen.

dwParam1

Message parameters.

dwParam2

Message parameters.

Return Values

This function does not return a value.

Remarks

Applications should not call any system-defined functions from inside a callback function, except for EnterCriticalSection, LeaveCriticalSection, midiOutLongMsg, midiOutShortMsg, OutputDebugString, PostMessage, PostThreadMessage, SetEvent, timeGetSystemTime, timeGetTime, timeKillEvent, and timeSetEvent. Calling other wave functions will cause deadlock.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Import Library: User-defined.

See Also

Waveform Audio Overview, Waveform Functions, EnterCriticalSection, LeaveCriticalSection, midiOutLongMsg, midiOutShortMsg, OutputDebugString, PostMessage, PostThreadMessage, SetEvent, timeGetSystemTime, timeGetTime, timeKillEvent, timeSetEvent, waveOutClose, waveOutOpen, waveOutWrite, WOM_CLOSE, WOM_DONE, WOM_OPEN