The multimedia file I/O services use I/O procedures to handle the physical input and output associated with reading and writing different types of storage systems. I/O procedures know how to open, close, read, write, and seek a particular type of storage system. Applications can supply custom I/O procedures for accessing unique storage systems such as databases or file archives. Use the following functions for working with custom I/O procedures:
mmioInstallIOProc
Installs, removes, or locates an I/O procedure.
mmioSendMessage
Sends a message to an I/O procedure associated with a specified file.