MCI_INFO
The MCI_INFO
command retrieves string information from a device. All devices recognize this
command. Information is returned in the lpstrReturn member of the
structure identified by lpInfo. The dwRetSize member specifies
the buffer length for the returned data.
MCIERROR mciSendCommand(MCIDEVICEID wDeviceID,
MCI_INFO,
DWORD dwFlags, (DWORD)
(LPMCI_INFO_PARMS) lpInfo);
Parameters
wDeviceID
Device
identifier of the MCI device that is to receive the command message.
dwFlags
MCI_NOTIFY,
MCI_WAIT, or, for digital-video and VCR devices, MCI_TEST. For information
about these flags, see The Wait, Notify, and Test Flags.
lpInfo
Address of an
MCI_INFO_PARMS
structure. (Devices with extended command sets might replace this structure
with a device-specific structure.)
Return Values
Returns zero
if successful or an error otherwise.
Remarks
The following
additional standard and command-specific flag applies to all devices supporting
MCI_INFO:
MCI_INFO_PRODUCT
Obtains a
description of the hardware associated with a device. Devices should supply a
description that identifies both the driver and the hardware used.
The following
additional flags apply to the cdaudio device type:
MCI_INFO_MEDIA_IDENTITY
Produces a
unique identifier for the audio CD currently loaded in the player being
queried. This flag returns a string of 16 hexadecimal digits.
MCI_INFO_MEDIA_UPC
Produces the
Universal Product Code (UPC) that is encoded on an audio CD. The UPC is a
string of digits. It might not be available for all CDs.
The following
additional flags apply to the digitalvideo device type:
MCI_DGV_INFO_ITEM
A constant
indicating the information desired is included in the dwItem member of
the structure identified by lpInfo. The following constants are defined
for digital-video devices:
MCI_DGV_INFO_AUDIO_ALG
Returns the
name for the current audio compression algorithm.
MCI_DGV_INFO_AUDIO_QUALITY
Returns the
name for the current audio quality descriptor.
MCI_DGV_INFO_STILL_ALG
Returns the
name for the current still image compression algorithm.
MCI_DGV_INFO_STILL_QUALITY
Returns the
name for the current still image quality descriptor.
MCI_DGV_INFO_USAGE
Returns a
string describing usage restrictions that might be imposed by the owner of the
visual or audible data in the workspace.
MCI_DGV_INFO_VIDEO_ALG
Returns the
name for the current video compression algorithm.
MCI_DGV_INFO_VIDEO_QUALITY
Returns the
name for the current video quality descriptor.
MCI_INFO_VERSION
Returns the
release level of the device driver and hardware. Device driver developers must
document the syntax of the returned string.
MCI_DGV_INFO_TEXT
Obtains the
window caption.
MCI_INFO_FILE
Obtains the
path and filename of the last file specified with the MCI_OPEN or MCI_LOAD command. If a file has not
been specified, the device returns a null-terminated string. This flag is
supported only by devices that return TRUE to the MCI_GETDEVCAPS_USES_FILES
flag of the MCI_GETDEVCAPS
command.
For
digital-video devices, lpInfo points to an MCI_DGV_INFO_PARMS structure.
The following
additional flags apply to the sequencer device type:
MCI_INFO_COPYRIGHT
Obtains the
MIDI file copyright notice from the copyright meta event.
MCI_INFO_FILE
Obtains the
filename of the current file. This flag is supported only by devices that return
TRUE when you call the MCI_GETDEVCAPS command with the MCI_GETDEVCAPS_USES_FILES
flag.
MCI_INFO_NAME
Obtains the
sequence name from the sequence/track name meta event.
The following
additional flag applies to the vcr device type:
MCI_VCR_INFO_VERSION
Sets lpstrReturn
member of the MCI_INFO_PARMS structure to point to the version number. Also sets the dwRetSize
member equal to the length of the string pointed to.
The following
additional flags apply to the overlay device type:
MCI_INFO_FILE
Obtains the
filename of the current file. This flag is supported only by devices that
return TRUE to the MCI_GETDEVCAPS_USES_FILES flag of the MCI_GETDEVCAPS command.
MCI_OVLY_INFO_TEXT
Obtains the
caption of the window associated with the video-overlay device.
The following
additional flags apply to the waveaudio device type:
MCI_INFO_FILE
Obtains the
filename of the current file. This flag is supported by devices that return
TRUE when you call the MCI_GETDEVCAPS command with the MCI_GETDEVCAPS_USES_FILES
flag.
MCI_WAVE_INPUT
Obtains the
product name of the current input.
MCI_WAVE_OUTPUT
Obtains the
product name of the current output and its value is device specific.
See Also