MM_MIM_MOREDATA

Artikel
12/10/2007

The MM_MIM_MOREDATA message is sent to a callback window when a MIDI message is received by a MIDI input device but the application is not processing MIM_DATA messages fast enough to keep up with the input device driver. The window receives this message only when the application specifies MIDI_IO_STATUS in the call to the midiInOpen function.

MM_MIM_MOREDATA 
wParam = (WPARAM) hInput 
lParam = (LPARAM) (DWORD) lMidiMessage

Parameters

hInput

Handle to the MIDI input device that received the MIDI message.

lMidiMessage

Specifies the MIDI message that was received. The message is packed into a doubleword value as follows:

High word	High-order byte	Not used.
	Low-order byte	Contains a second byte of MIDI data (when needed).
Low word	High-order byte	Contains the first byte of MIDI data (when needed).
	Low-order byte	Contains the MIDI status.

The two MIDI data bytes are optional, depending on the MIDI status byte.

Return Values

This message does not return a value.

Remarks

If your application will receive MIDI data faster than it can process it, you should not use a window callback mechanism. To maximize speed, use a callback function, and use the MIM_MOREDATA message instead of MM_MIM_MOREDATA.

An application should do only a minimal amount of processing of MM_MIM_MOREDATA messages. (In particular, applications should not call the PostMessage function while processing MM_MIM_MOREDATA.) Instead, the application should place the event data into a buffer and then return.

When an application receives an MM_MIM_DATA message after a series of MM_MIM_MOREDATA messages, it has caught up with incoming MIDI events and can safely call time-intensive functions.

MIDI messages received from a MIDI input port have running status disabled; each message is expanded to include the MIDI status byte.

This message is not sent when a MIDI system-exclusive message is received. No time stamp is available with this message. For time-stamped input data, you must use the messages that are sent to callback functions.

Requirements

**  Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
**  Windows 95/98/Me:** Included in Windows 95 and later.
**  Header:** Declared in Mmsystem.h; include Windows.h.

Freigeben über

MM_MIM_MOREDATA

Zusätzliche Ressourcen