MCI_INFO
This message returns string information from a media device instance. This information describes static attributes of the device or the loaded media, rather than its capabilities.
Syntax
param1 ULONG ulParam1; /* Information flags. */ param2 PMCI_INFO_PARMS pParam2; /* Pointer to the MCI_INFO_PARMS data structure. */
Parameters
- ulParam1 (ULONG) - input
- This parameter can contain any of the following flags:
- MCI_NOTIFY Posts a notification message when the action completes.
- MCI_WAIT Does not return control until the action is completed.
- MCI_INFO_PRODUCT Returns a description of the hardware associated with the device.
- Device-Specific Extensions
- MCI_INFO_FILE Returns the current file name (CD-XA, Sequencer, Wave Audio, Video Overlay).
- MCI_CD_INFO_ID Returns the 8-byte disc ID (CD Audio).
- MCI_CD_INFO_UPC Returns the disc's UPC/serial number (CD Audio, CD-XA).
- MCI_DGV_INFO_VIDEO_FILE Returns the current digital video file name (Digital Video).
- MCI_DGV_INFO_IMAGE_FILE Returns the current image file name (Digital Video).
- MCI_DGV_INFO_TEXT Returns the display window caption (Digital Video).
- MCI_VD_INFO_LABEL Returns the videodisc label (Videodisc).
- MCI_OVLY_INFO_TEXT Returns the display window caption (Video Overlay).
- pParam2 (PMCI_INFO_PARMS) - input
- A pointer to the MCI_INFO_PARMS structure. The pszReturn field points to the buffer where the string is returned, and ulRetSize specifies the buffer size.
Returns
- rc (ULONG) - returns
-
- MCIERR_SUCCESS Command completed successfully.
- MCIERR_INVALID_DEVICE_ID Invalid device ID.
- MCIERR_INVALID_BUFFER The return buffer is too small.
- MCIERR_FLAGS_NOT_COMPATIBLE More than one info flag was specified.
- MCIERR_MISSING_FLAG A required flag was not specified.
Remarks
- Only one flag** can be used per `MCI_INFO` message. If the provided buffer is too small for the returned string, the system returns `MCIERR_INVALID_BUFFER`, and the ulRetSize field is updated with the required buffer size.
Example Code
The following example illustrates how to retrieve the file name of the currently loaded media.
#define RETBUFSIZE 128
USHORT usDeviceID;
CHAR InfoRet [RETBUFSIZE]; /* Return string buffer */
MCI_INFO_PARMS infoparms;
/* Get the file name of the currently loaded file */
infoparms.pszReturn = (PSZ) &InfoRet; /* Pointer to return buffer */
infoparms.ulRetSize = RETBUFSIZE; /* Return buffer size */
mciSendCommand(usDeviceID, /* Device ID */
MCI_INFO, /* MCI info message */
MCI_WAIT | MCI_INFO_FILE, /* Flags for this message */
(PVOID) &infoparms, /* Data structure */
0); /* No user parm */
/* infoparms.pszReturn now contains the name of the current file */