The MMIO messages are sent to an I/O procedure as a result of an MMIO function call. For example, when an application calls mmioOpen, the MMIOM_OPEN message is sent to an I/O procedure. An application can also send the MMIO messages to an I/O procedure by issuing mmioSendMessage or by directly calling the I/O procedure.
The mmioSendMessage function should be used only to pass user-defined messages, or messages not automatically generated by an MMIO function, to the I/O procedure of the user's application.
When an application issues mmioSendMessage, it passes an hmmio parameter, which MMIO converts to an MMIOINFO block before sending the parameter to the I/O procedure. When an application calls an I/O procedure directly, a pmmioinfo parameter is passed to the I/O procedure instead of an hmmio. The following is a function prototype for a direct I/O procedure call:
LONG APIENTRY MMIOPROC (PVOID pmmioinfo, USHORT usMsg,
LONG lParam1, LONG lParam2);
旼컴컴컴컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿘essage 쿏escription � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_BEGININSERT 쿝equests that all subsequent � � 쿥rites insert data at the current � � 퀂eek position. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_BEGINRECORD 쿝equests all subsequent Writes be � � 쿬onsidered one logical unit by an � � 쿢NDO or REDO. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_BEGINSTREAM 쿞ent before the first mmioRead or � � �mmioWrite to start the stream at � � 퀃he optimum rate for the file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_CLEAR 쿝equests that a specified range be� � 쿭eleted from a file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_CLOSE 쿝equests that the file be closed. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_COPY 쿝equests that a specified range be� � 쿬opied to the clipboard. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_CUT 쿝equests that a specified range be� � 쿬opied to the clipboard and then � � 쿭eleted. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_ENDSTREAM 쿞ent after the last mmioRead or � � �mmioWrite to end the stream. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_DELETE 쿝equests that information be � � 퀁emoved from a file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_ENDINSERT 쿝equests that all subsequent � � 쿥rites overwrite data at the � � 쿬urrent seek position. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_ENDRECORD 쿔ndicates that the logical record � � 쿽peration has ended and data � � 퀂tructures should be updated, if � � 쿻ecessary. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_GETCF 쿚btains the handle (hmmcf) of the � � 쿝IFF compound file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_GETCFENTRY 쿝equests a CTOC entry for an � � 쿮lement of a RIFF compound file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_GETFORMATINFO 쿝equests that the IOProc return an� � �MMFORMATINFO structure. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_GETFORMATNAME 쿝equests the format name for the � � 쿔OProc. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_GETHEADER 쿝equests that the IOProc return � � 쿺edia-specific information. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_IDENTIFYFILE 쿌ttempts to determine if any � � 쿔OProc can process a file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_MULTITRACKREAD 쿝equests that data be read from a � � 쿺ovie file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_MULTITRACKWRITE 쿝equests that data be written to a� � 쿺ovie file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_OPEN 쿝equests that a file be opened or � � 쿭eleted. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_PASTE 쿝equests that data from the � � 쿬lipboard be inserted into a file.� 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_QUERYHEADERLENGTH 쿝equests that the IOProc return � � 퀃he size the header. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_QUERYIMAGE 쿝equests that the IOProc return � � 퀃he currently selected image index� � 쿶n the image file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_QUERYIMAGECOUNT 쿝equests that the IOProc return � � 퀃he number of images stored in the� � 쿶mage file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_READ 쿝equests that bytes be read from � � 쿪n open file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_REDO 쿝equests that the last logical � � 쿪ction which was undone be redone.� 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_SAVE 쿝equests temporary changes in a � � 쿯ile. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_SEEK 쿝equests that the current file � � 쿾osition be moved. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_SEEKBYTIME 쿝equests that the file position be� � 쿺oved relative to some unit of � � 퀃ime. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_SET 쿝equests that extended file � � 쿶nformation be set or queried. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_SETHEADER 쿝equests that the IOProc use � � 쿺edia-specific information when � � 퀇riting or accepting data. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_SETIMAGE 쿞elects a new image index in the � � 쿶mage file. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_STATUS 쿢sed to pass appropriate � � �MCI_STATUS requests to an IOProc. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_TEMPCHANGE 쿝equests that all subsequent � � 쿥rites to the media be treated as � � 퀃emporary changes. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_UNDO 쿝equests that the last logical � � 쿪ction, either a delete, insert, � � 퀅ndo, or redo, be undone. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_WINMSG 쿌llows an application or an MCD to� � 쿾ass PM messages from a window � � 쿾rocedure to an IOProc. � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �MMIOM_WRITE 쿝equests that the bytes be written� � 퀃o an open file. � 읕컴컴컴컴컴컴컴컴컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
The MMIO messages indicate, to the I/O procedure, the type of MMIO operation to be performed. I/O procedures can be called to process files that might or might not use the RIFF format standard.
Note: The compound-file messages must not be used while creating or appending to the compound file itself.