midiStreamOpen

The midiStreamOpen function opens a MIDI stream for output. By default, the device is opened in paused mode. The stream handle retrieved by this function must be used in all subsequent references to the stream.

MMRESULT midiStreamOpen(
  LPHMIDISTRM lphStream,  
  LPUINT puDeviceID,      
  DWORD cMidi,            
  DWORD dwCallback,       
  DWORD dwInstance,       
  DWORD fdwOpen           
);
 

Parameters

lphStream

Address of a variable to contain the stream handle when the function returns.

puDeviceID

Address of a device identifier. The device is opened on behalf of the stream and closed again when the stream is closed.

cMidi

Reserved; must be 1.

dwCallback

Address of a callback function, an event handle, a thread identifier, or a handle of a window or thread called during MIDI playback to process messages related to the progress of the playback. If no callback mechanism is desired, specify NULL for this parameter.

dwInstance

Application-specific instance data that is returned to the application with every callback function.

fdwOpen

Callback flag for opening the device. One of the following callback flags must be specified:

CALLBACK_EVENT

The dwCallback parameter is an event handle. This callback mechanism is for output only.

CALLBACK_FUNCTION

The dwCallback parameter is a callback procedure address.

CALLBACK_NULL

There is no callback mechanism. This is the default setting.

CALLBACK_THREAD

The dwCallback parameter is a thread identifier.

CALLBACK_WINDOW

The dwCallback parameter is a window handle.

Return Values

Returns MMSYSERR_NOERROR if successful or an error otherwise. Possible error values include the following:

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in mmsystem.h.
  Import Library: Use winmm.lib.

See Also

Musical Instrument Digital Interface (MIDI) Overview, MIDI Functions