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(
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LPHMIDISTRM lphStream, |
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LPUINT puDeviceID, |
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DWORD cMidi, |
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DWORD dwCallback, |
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DWORD dwInstance, |
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DWORD fdwOpen |
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); |
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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:
|
MMSYSERR_BADDEVICEID |
The
specified device identifier is out of range. |
|
MMSYSERR_INVALPARAM |
The given
handle or flags parameter is invalid. |
|
MMSYSERR_NOMEM |
The system
is unable to allocate or lock memory. |