The following code illustrates how to obtain the number of IOProcs matching the specified format data.

   MMFORMATINFO mmformatinfo;
   LONG lNumFormats;
   ULONG  ulReserved = 0L;
   ULONG  ulFlags = 0L;
   ULONG  rc;
    ...

   memset( &mmformatinfo, '\0', sizeof(MMFORMATINFO) );
   mmformatinfo.ulMediaType |= MMIO_MEDIATYPE_AUDIO;
   mmformatinfo.ulStructLen=sizeof(MMFORMATINFO);

   rc = mmioQueryFormatCount( &mmformatinfo,
                              &lNumFormats,
                              ulReserved,
                              ulFlags);
   if (rc)
     /* error */
   else
    ...