IDirectMusicSynth::GetLatencyClock method (dmusics.h)
The GetLatencyClock method retrieves a reference to the IReferenceClock interface (described in the Microsoft Windows SDK documentation) of the reference-clock object that tracks the current mix time.
Syntax
HRESULT GetLatencyClock(
IReferenceClock **ppClock
);
Parameters
ppClock
Output pointer for the latency clock. This parameter points to a caller-allocated pointer variable into which the method writes a pointer to the latency-clock object's IReferenceClock interface. Through this interface, the synthesizer is able to get the current mix time. Specify a valid, non-NULL pointer value for this parameter.
Return value
GetLatencyClock returns S_OK if the call was successful. Otherwise, the method returns an appropriate error code. The following table shows some of the possible return status codes.
| Return code | Description |
|---|---|
|
Indicates that the method was unable to access the latency clock. |
|
Indicates that the ppClock pointer is not valid. |
|
Indicates that the IDirectMusicSynthSink object was not connected. |
|
Indicates that the synth is not open or is not properly configured. |
Remarks
This method returns the latency clock created by the wave sink (IDirectMusicSynthSink) object, which handles the output audio stream. The latency clock returns the current render time whenever its IReferenceClock::GetTime method is called. This time is always relative to the time established by the master clock (installed in the synthesizer and wave sink through a call to IDirectMusicSynth::SetMasterClock and IDirectMusicSynthSink::SetMasterClock). The latency time is used by the performance to identify the next available time to start playing a note. The latency should not exceed 450 milliseconds.
For more information about latency clocks, see Synthesizer Latency. Also see the description of the IDirectMusic and IReferenceClock interfaces in the Windows SDK documentation.
The ppClock parameter follows the reference-counting conventions for COM objects.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | dmusics.h (include Dmusics.h) |