Opening
and Closing Device Drivers
You must open
a MIDI device before using it, and you should close the device as soon as you
finish using it. Windows provides the following functions to open and close
different types of MIDI devices:
|
midiInClose |
Closes a
specified MIDI input device. |
|
midiInOpen |
Opens a
specified MIDI input device for recording. |
|
midiOutClose |
Closes a
specified MIDI output device. |
|
midiOutOpen |
Opens a
MIDI output device for playback. |
Each function
that opens a MIDI device takes as parameters a device identifier, an address of
a memory location, and some parameters unique to MIDI devices. The memory
location is filled with a device handle, which is used to identify the open
audio device in calls to other audio functions.
Many MIDI
functions can accept either a device handle or a device identifier. Although
you can use a device handle wherever you would use a device identifier, you
cannot always use a device identifier when a handle is called for.
Note MIDI devices
are not necessarily shareable, so a particular device may not be available when
a user requests it. If this happens, the application should notify the user and
allow the user to try to open the device again.