Including Header Files

When using the Multimedia extensions, you must include one or more of the following header files in all source modules that call a Multimedia extensions function. These header files depend on declarations made in the WINDOWS.H header file. If you include any of the following header files, you must first include WINDOWS.H:

MMSYSTEM.H (for system functions)

MMP.H (for movie-playback functions)

The header files provide function prototypes as well as definitions of data types and constants.