MCI_OPEN
The MCI_OPEN
command initializes a device or file. All devices recognize this command.
MCIERROR mciSendCommand(MCIDEVICEID wDeviceID,
MCI_OPEN,
DWORD dwFlags, (DWORD)
(LPMCI_OPEN_PARMS) lpOpen);
Parameters
wDeviceID
Device
identifier of the MCI device that is to receive the command message.
dwFlags
MCI_NOTIFY or
MCI_WAIT. For information about these flags, see The Wait, Notify, and Test
Flags.
lpOpen
Address of an
MCI_OPEN_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
MCI_OPEN_TYPE flag must be used whenever a device is specified in the mciSendCommand function. If you open a
device by specifying a device-type constant, you must specify the
MCI_OPEN_TYPE_ID flag in addition to MCI_OPEN_TYPE. For a list of device-type
constants, see Constants: Device Types.
If the
MCI_OPEN_SHAREABLE flag is not specified when a device or file is initially
opened, all subsequent MCI_OPEN commands to the device or file will
fail. If the device or file is already open and this flag is not specified, the
call will fail even if the first open command specified MCI_OPEN_SHAREABLE.
Files opened for the MCISEQ.DRV and MCIWAVE.DRV devices are nonshareable.
Case is
ignored in the device name, but there cannot be leading or trailing blanks.
To use
automatic type selection (via the entries in the registry), assign the filename
and file extension to the lpstrElementName member of the structure
identified by lpOpen, set the lpstrDeviceType member to NULL, and
set the MCI_OPEN_ELEMENT flag.
The following
additional flags apply to all devices supporting MCI_OPEN:
MCI_OPEN_ALIAS
An alias is
included in the lpstrAlias member of the structure identified by lpOpen.
MCI_OPEN_SHAREABLE
The device or
file should be opened as shareable.
MCI_OPEN_TYPE
A device type
name or constant is included in the lpstrDeviceType member of the
structure identified by lpOpen.
MCI_OPEN_TYPE_ID
The low-order
word of the lpstrDeviceType member of the structure identified by lpOpen
contains a standard MCI device type identifier and the high-order word
optionally contains the ordinal index for the device. Use this flag with the
MCI_OPEN_TYPE flag.
The following
additional flags apply to compound devices:
MCI_OPEN_ELEMENT
A filename is
included in the lpstrElementName member of the structure identified by lpOpen.
MCI_OPEN_ELEMENT_ID
The lpstrElementName
member of the structure identified by lpOpen is interpreted as a
doubleword value and has meaning internal to the device. Use this flag with the
MCI_OPEN_ELEMENT flag.
The following
additional flags are used with the digitalvideo device type:
MCI_DGV_OPEN_NOSTATIC
The device
should reduce the number of static (system) colors in the palette. This
increases the number of colors available for rendering the video stream. This
flag applies only to devices that share a palette with Windows.
MCI_DGV_OPEN_PARENT
The parent
window handle is specified in the hWndParent member of the structure
identified by lpOpen.
MCI_DGV_OPEN_WS
A window
style is specified in the dwStyle member of the structure identified by lpOpen.
MCI_DGV_OPEN_16BIT
Indicates a
preference for 16-bit MCI device support.
MCI_DGV_OPEN_32BIT
Indicates a
preference for 32-bit MCI device support.
For
digital-video devices, the lpOpen parameter points to an MCI_DGV_OPEN_PARMS structure.
The following
additional flags are used with the overlay device type:
MCI_OVLY_OPEN_PARENT
The parent
window handle is specified in the hWndParent member of the structure
identified by lpOpen.
MCI_OVLY_OPEN_WS
A window
style is specified in the dwStyle member of the structure identified by lpOpen.
The dwStyle value specifies the style of the window that the driver will
create and display if the application does not provide one. The style parameter
takes an integer that defines the window style. These constants are the same as
the standard window styles (such as WS_CHILD, WS_OVERLAPPEDWINDOW, or
WS_POPUP).
For
video-overlay devices, the lpOpen parameter points to an MCI_OVLY_OPEN_PARMS structure.
The following
additional flag is used with the waveaudio device type:
MCI_WAVE_OPEN_BUFFER
A buffer
length is specified in the dwBufferSeconds member of the structure
identified by lpOpen.
For
waveform-audio devices, the lpOpen parameter points to an MCI_WAVE_OPEN_PARMS structure. The MCIWAVE
driver requires an asychronous waveform-audio device.
See Also