Before the stream is created, you can enable event notification for implicit and explicit events using the SpiEnableEvent function. The following example specifies the EVENT_CUE_TIME_PAUSE flag, which will cause the stream to be paused when the cuepoint is reached. When the stream reaches the event during a play or record, the audio stream handler signals the MCD. Note that the stream is only paused (not stopped).
RC CreateToEvent (INSTANCE *ulpInstance, ULONG ulTo)
{
/* rename this function CreateToEvent */
ULONG ulrc;
/*********************************************************
* Set up a cue time pause event at the place in
* the stream where the caller wants us to play/record
* to. Note: this event will pause the stream and
* will be considerably more accurate than just
* setting a cue point, receiving the event and stopping
* the stream (since a normal cue point will force
* bleed over).
*********************************************************/
ulpInstance->StreamInfo.TimeEvcb.hwndCallback
= ulpInstance->hwndCallBack;
ulpInstance->StreamInfo.TimeEvcb.usDeviceID
= ulpInstance->usWaveDeviceID;
ulpInstance->StreamInfo.TimeEvcb.evcb.ulType
= EVENT_CUE_TIME_PAUSE;
ulpInstance->StreamInfo.TimeEvcb.evcb.ulFlags
= EVENT_SINGLE;
ulpInstance->StreamInfo.TimeEvcb.evcb.hstream
= ulpInstance->StreamInfo.hStream;
ulpInstance->StreamInfo.TimeEvcb.ulpInstance
= (ULONG) ulpInstance;
ulpInstance->StreamInfo.TimeEvcb.evcb.mmtimeStream = ulTo;
/* Enable the cue time pause event. */
ulrc = SpiEnableEvent((PEVCB) &ulpInstance->StreamInfo.TimeEvcb.evcb,
(PHEVENT) &ulpInstance->StreamInfo.hPlayToEvent);
return ( ulrc );
} /* CreateToEvent */
If you enable event notification for a particular event, it is equally important to remove the event handle for the event so it is not used by subsequent commands. When any given event is reported, it must be removed explicitly using the SpiDisableEvent function. Once an event is removed from the system, the event no longer is detected or reported to the application or MCD.
SpiDisableEvent(ulpInstance->StreamInfo.hPlayToEvent);