Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

                                                 ◄Contents► ◄Index► ◄Back►
────────────────────────────────────────────────────────────────────────────
MCI_OPEN
 
        This MCI command message initializes a device or device element.
        All devices respond to this message. The parameters and flags
        available for this message depend on the selected device.
 
Parameters
        DWORD dwFlags
            The following flags apply to all devices:
 
            MCI_NOTIFY
                Specifies that MCI should post the MM_MCINOTIFY message
                when this command completes. The window to receive this
                message is specified in the dwCallback field of the data
                structure identified by lpOpen.
 
            MCI_WAIT
                Specifies that the open operation should finish before
                MCI returns control to the application.
 
            MCI_OPEN_ALIAS
                Specifies that an alias is included in the lpstrAlias
                field of the data structure identified by lpOpen.
 
            MCI_OPEN_SHAREABLE
                Specifies that the device or device element should be
                opened as shareable.
 
            MCI_OPEN_TYPE
                Specifies that a device type name or constant is
                included in the lpstrDeviceType field of the data
                structure identified by lpOpen.
 
            MCI_OPEN_TYPE_ID
                Specifies that the low-order word of the
                lpstrDeviceType field of the associated data structure
                contains a standard MCI device type ID and the
                high-order word optionally contains the ordinal index
                for the device. Use this flag with the MCI_OPEN_TYPE
                flag.
 
        LPMCI_OPEN_PARMS lpOpen
            Specifies a far pointer to the MCI_OPEN_PARMS data
            structure. (Devices with extended command sets might replace
            this data structure with a device-specific data structure.)
 
        Flags for Compound Devices
 
        DWORD dwFlags
            The following additional flags apply to compound devices:
 
            MCI_OPEN_ELEMENT
                Specifies that an element name is included in the
                lpstrElementName field of the data structure identified
                by lpOpen.
 
            MCI_OPEN_ELEMENT_ID
                Specifies that the lpstrElementName field of the data
                structure identified by lpOpen is interpreted as a DWORD
                and has meaning internal to the device. Use this flag
                with the MCI_OPEN_ELEMENT flag.
 
        LPMCI_OPEN_PARMS lpOpen
            Specifies a far pointer to the MCI_OPEN_PARMS data
            structure. (Devices with additional parameters might replace
            this data structure with a device-specific data structure.)
 
        Animation Extensions
 
        DWORD dwFlags
            The following flags apply to animation devices:
 
            MCI_ANIM_OPEN_EXPANDDIBS
                Specifies that the device should expand bitmaps while
                loading the animation rather than while playing.
 
            MCI_ANIM_OPEN_NOSTATIC
                Specifies that the device should reduce the number of
                static (system) colors in the palette to two.
 
            MCI_ANIM_OPEN_PARENT
                Indicates the parent window handle is specified in the
                hWndParent field of the data structure identified by
                lpOpen. The parent window handle is required for some
                window styles.
 
            MCI_ANIM_OPEN_WS
                Indicates a window style is specified in the dwStyle
                field of the data structure identified by lpOpen. The
                dwStyle field 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
                which defines the window style. These constants are the
                same as the ones in WINDOWS.H (such as WS_CHILD,
                WS_OVERLAPPEDWINDOW, or WS_POPUP).
 
        LPMCI_ANIM_OPEN_PARMS lpOpen
            Specifies a far pointer to the MCI_ANIM_OPEN_PARMS data
            structure.
 
        Video Overlay Extensions
 
        DWORD dwFlags
            The following flags apply to video overlay devices:
 
            MCI_OVLY_OPEN_PARENT
                Indicates the parent window handle is specified in the
                hWndParent field of the data structure identified by
                lpOpen.
 
            MCI_OVLY_OPEN_WS
                Indicates a window style is specified in the dwStyle
                field of the data structure identified by lpOpen. The
                dwStyle field 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 those in WINDOWS.H (for example, WS_CHILD,
                WS_OVERLAPPEDWINDOW, or WS_POPUP).
 
        LPMCI_OVLY_OPEN_PARMS lpOpen
            Specifies a far pointer to the MCI_OVLY_OPEN_PARMS data
            structure.
 
        Waveform Audio Extensions
 
        The MCIWAVE device included with Inwdows requires
        asynchronous waveform driver. It does not work with
        synchronous drivers like the PC speaker driver.
 
        DWORD dwFlags
            The following flags apply to waveform audio devices:
 
            MCI_WAVE_OPEN_BUFFER
                Indicates a buffer length is specified in the
                dwBufferSeconds field of the data structure identified
                by lpOpen. The default size of the buffer is set when the
                waveform audio device is installed or configured. Typically
                the buffer size is set to 4 seconds. With the MCIWAVE
                device, the minimum size is 2 seconds and the maximum size
                is 9 seconds.
 
        LPMCI_WAVE_OPEN_PARMS lpOpen
            Specifies a far pointer to the MCI_WAVE_OPEN_PARMS data
            structure. (Devices with extended command sets might replace
            this data structure with a device-specific data structure.)
 
Return value
        Returns zero if the open is successful. If an error occurs, it
        returns the following values:
 
        MCIERR_CANNOT_LOAD_DRIVER
            Error loading media device driver.
 
        MCIERR_DEVICE_OPEN
            The device name is in use by this task. Use a unique alias.
 
        MCIERR_DUPLICATE_ALIAS
            The specified alias is an open device in this task.
 
        MCIERR_EXTENSION_NOT_FOUND
            Cannot deduce a device type from the given extension.
 
        MCIERR_FILENAME_REQUIRED
            A valid filename is required.
 
        MCIERR_MISSING_PARAMETER
            Required parameter is missing.
 
        MCIERR_MUST_USE_SHAREABLE
            The device is already open; use the shareable flag with each
            open.
 
        MCIERR_NO_ELEMENT_ALLOWED
            An element name cannot be used with this device.
 
Comments
        If MCI_OPEN_SHAREABLE is not specified when a device or device
        element is initially opened, then all subsequent MCI_OPEN
        messages to the device or device element will fail. If the
        device or device element is already open, and this flag is not
        specified, the call will fail even if the first open command
        specified MCI_OPEN_SHAREABLE. Files for the MCISEQ and MCIWAVE
        devices are nonshareable.
 
        Case is ignored in the device name, but there must not be any
        leading or trailing blanks.
 
        To use automatic type selection (via the [mci extensions]
        section of the WIN.INI file), assign the file name (including
        file extension) to the lpstrElementName field, assign a NULL
        pointer to the lpstrDeviceType field, and set the
        MCI_OPEN_ELEMENT flag.
 
See also
        MCI_CLOSE
 
                                       -♦-