IVideoWindow Interface

The IVideoWindow interface supports the video window properties of a video renderer. It is a dual interface (accessible through Microsoft® Visual Basic® and Visual C++®) that controls a generic video window. Generally, this is a video renderer that draws video into a window on the display. The IVideoWindow interface supports both properties and methods. Properties are more easily accessible from many Automation controllers (such as Microsoft Visual Basic). However, some operations require several properties to be changed simultaneously; for this reason, methods are provided that allow a number of related properties to be changed simultaneously. For example, setting the window's position and size can be done by four individual put_[property name] calls or by the single method SetWindowPosition.

The methods require only that the video renderer be connected. If it is not connected, all the interface functions return VFW_E_NOT_CONNECTED. Properties set on a video renderer persist between successive connections and disconnections. All applications should ensure that they reset the renderer properties before starting a presentation.

Because this interface is Automation-compatible, there are two important aspects to remember about parameters accepted by these methods. First, all Boolean returns are OAFALSE (0) or OATRUE (–1), which is different from the C or C++ definition. Second, all strings are defined as being of type BSTR. All strings sent to the interface should be allocated through the Automation SysAllocString function, and similarly all strings returned from the interface should be freed by using the Automation SysFreeString function.

When to Implement

The video renderer filter supplied with Microsoft DirectShow™ implements this interface. It is also implemented by the filter graph manager (via a plug-in distributor) to pass method calls from the application to the video renderer filter's implementation of the interface.

Implement this interface if you are writing a replacement video renderer filter. You can use the CBaseVideoWindow class, which handles the IDispatch implementation for Automation, to help implement this interface.

When to Use

This interface is used by applications or other filters that must control the video window's properties.

Methods in Vtable Order

IUnknown methods	Description
QueryInterface	Returns pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.

IDispatch methods	Description
GetTypeInfoCount	Determines whether there is type information available for this dispinterface.
GetTypeInfo	Retrieves the type information for this dispinterface if GetTypeInfoCount returned successfully.
GetIDsOfNames	Converts text names of properties and methods (including arguments) to their corresponding DISPIDs.
Invoke	Calls a method or accesses a property in this dispinterface if given a DISPID and any other necessary parameters.

IVideoWindow methods	Description
put_Caption	Sets the text caption on the playback window.
get_Caption	Retrieves the text caption on the playback window.
put_WindowStyle	Sets the playback window style.
get_WindowStyle	Retrieves the playback window style.
put_WindowStyleEx	Sets the style of the control window.
get_WindowStyleEx	Retrieves the playback window's extended style bits.
put_AutoShow	Specifies if the window will be automatically shown on the first state change.
get_AutoShow	Returns if the window will be automatically shown on the first state change.
put_WindowState	Sets the current window state (such as visible or minimized).
get_WindowState	Retrieves the current window state (such as visible or minimized).
put_BackgroundPalette	Informs the renderer to realize its palette in the background.
get_BackgroundPalette	Returns whenever the renderer realizes its palette in the background.
put_Visible	Sets the visibility of the window.
get_Visible	Retrieves the visibility of the window.
put_Left	Sets the x-axis coordinate for the video window.
get_Left	Retrieves the x-axis coordinate for the video window.
put_Width	Sets the width of the video window.
get_Width	Retrieves the width of the video window.
put_Top	Sets the y-axis coordinates for the video window.
get_Top	Retrieves the y-axis coordinates for the video window.
put_Height	Sets the height of the video window.
get_Height	Retrieves the height of the video window.
put_Owner	Sets the owning parent window for the video playback window.
get_Owner	Retrieves the owning parent window for the video playback window.
put_MessageDrain	Specifies a window to which the video window will post messages.
get_MessageDrain	Retrieves the window set to receive messages from the video window.
get_BorderColor	Retrieves the border color for the video window.
put_BorderColor	Sets the border color for the video window.
get_FullScreenMode	Returns the full-screen rendering mode of the video renderer filter supporting this interface.
put_FullScreenMode	Sets the full-screen mode for the video renderer filter supporting this interface.
SetWindowForeground	Tells the renderer filter to become the foreground window.
NotifyOwnerMessage	Forwards messages that have been received by a parent window to a child window owned by a filter.
SetWindowPosition	Sets the video window position on the display.
GetWindowPosition	Retrieves the video window position.
GetMinIdealImageSize	Retrieves the ideal minimum image size for the video image playback (client) area.
GetMaxIdealImageSize	Retrieves the ideal maximum image size for the video image playback (client) area.
GetRestorePosition	Returns the normal restored window dimensions.
HideCursor	Hides the cursor.
IsCursorHidden	Determines if the cursor is hidden or showing.

---

IVideoWindow::get_AutoShow

IVideoWindow Interface

Retrieves information about whether the window will be automatically shown.

HRESULT get_AutoShow(
  long *AutoShow
  );

Parameters

AutoShow

[out] OATRUE indicates that the window will be made visible when the state is changed to the paused or running state.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_BackgroundPalette

IVideoWindow Interface

Retrieves information about whether any palette required will be realized in the background.

HRESULT get_BackgroundPalette(
  long *pBackgroundPalette
  );

Parameters

pBackgroundPalette

[out] OATRUE indicates that the palette will be realized in the background.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_BorderColor

IVideoWindow Interface

Retrieves the border color for the video window.

HRESULT get_BorderColor(
  long *pColor
  );

Parameters

pColor

[out] Retrieved border color as a COLORREF value.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_Caption

IVideoWindow Interface

Retrieves the textual title string for the video window.

HRESULT get_Caption(
  BSTR *strCaption
  );

Parameters

strCaption

[out] Retrieved window title caption.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_FullScreenMode

IVideoWindow Interface

Returns the full-screen rendering capabilities of the renderer filter supporting this interface.

HRESULT get_FullScreenMode(
  long *FullScreenMode
  );

Parameters

FullScreenMode

[out] OATRUE if supporting full-screen video, or OAFALSE if not.

Return Values

Returns an HRESULT value.

Remarks

This method is called by the filter graph manager when asked to render the video to full-screen size. If the renderer does not have inherent support for full-screen playback, it should return E_NOTIMPL. Otherwise, it should return NOERROR. If the renderer does support full-screen playback, this method determines if it is currently switched on or off.

---

IVideoWindow::get_Height

IVideoWindow Interface

Sets the height of the video window.

HRESULT get_Height(
  long *pHeight
  );

Parameters

pHeight

[out] Retrieved vertical dimension of the video window.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_Left

IVideoWindow Interface

Retrieves the x-axis coordinate for the video window.

HRESULT get_Left(
  long *pLeft
  );

Parameters

pLeft

[out] The x-axis coordinate to be retrieved.

Return Values

Returns an HRESULT value.

---

IVideoWindow::GetMaxIdealImageSize

IVideoWindow Interface

Retrieves the ideal maximum image size for the video image playback (client) area.

HRESULT GetMaxIdealImageSize(
  long *pWidth,
  long *pHeight
  );

Parameters

pWidth

[out] Image width.

pHeight

[out] Image height.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_MessageDrain

IVideoWindow Interface

Retrieves the window set to receive messages from the video window.

HRESULT get_MessageDrain(
  OAHWND *Drain
  );

Parameters

Drain

[in] Window currently assigned to receive messages from the video window.

Return Values

Returns an HRESULT value.

Remarks

The IVideoWindow::put_MessageDrain description contains a list of the Microsoft Win32® messages passed to the window that is specified as a message drain.

---

IVideoWindow::GetMinIdealImageSize

IVideoWindow Interface

Retrieves the ideal minimum image size for the video image playback (client) area.

HRESULT GetMinIdealImageSize(
  long *pWidth,
  long *pHeight
  );

Parameters

pWidth

[out] Image width.

pHeight

[out] Image height.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_Owner

IVideoWindow Interface

Retrieves the owning parent for the video window.

HRESULT get_Owner(
  OAHWND * pOwner
  );

Parameters

pOwner

[out] Retrieved window handle.

Return Values

Returns an HRESULT value.

---

IVideoWindow::GetRestorePosition

IVideoWindow Interface

Returns the normal restored window dimensions.

HRESULT GetRestorePosition(
  long *pLeft,
  long *pTop,
  long *pWidth,
  long *pHeight
  );

Parameters

pLeft

[out] Left x-axis coordinate of the window.

pTop

[out] Top y-axis coordinate of the window.

pWidth

[out] Width of the window in pixels.

pHeight

[out] Height of the window in pixels.

Return Values

Returns an HRESULT value.

Remarks

When the window is maximized or minimized, the window position methods return the actual window size. This method returns the dimensions that the window would be when restored. It is useful for applications that want to save a window state while the window is maximized or minimized.

---

IVideoWindow::get_Top

IVideoWindow Interface

Retrieves the y-axis coordinate of the video window.

HRESULT get_Top(
  long *pTop
  );

Parameters

pTop

[out] The y-axis origin to be retrieved.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_Visible

IVideoWindow Interface

Retrieves the visibility of the video window.

HRESULT get_Visible(
  long *pVisible
  );

Parameters

pVisible

[out] OATRUE if the window is shown; otherwise, the window is hidden.

Return Values

Returns an HRESULT value.

---

IVideoWindow::get_Width

IVideoWindow Interface

Retrieves the width of the video window.

HRESULT get_Width(
  long *pWidth
  );

Parameters

pWidth

[out] Width to be retrieved.

Return Values

Returns an HRESULT value.

---

IVideoWindow::GetWindowPosition

IVideoWindow Interface

Retrieves the current window rectangle (not the client rectangle) in device coordinates.

HRESULT GetWindowPosition(
  long *pLeft,
  long *pTop,
  long *pWidth,
  long *pHeight
  );

Parameters

pLeft

[out] The x-axis origin of the window.

pTop

[out] The y-axis origin of the window.

pWidth

[out] Width of the window in pixels.

pHeight

[out] Height of the window in pixels.

Return Values

Returns an HRESULT value.

Remarks

This method has the same effect as individually calling the IVideoWindow::get_Left, IVideoWindow::get_Top, IVideoWindow::get_Width, and IVideoWindow::get_Height methods.

---

IVideoWindow::get_WindowState

IVideoWindow Interface

Returns the state of the video window.

HRESULT get_WindowState(
  long *WindowState
  );

Parameters

WindowState

[out] Flags indicating the state of the video window.

Return Values

Returns an HRESULT value.

Remarks

This method retrieves a subset of the properties of the window state, specifically SW_MINIMIZE, SW_MAXIMIZE, SW_SHOW, or SW_HIDE. These have the same definitions as the Microsoft Win32 ShowWindow function.

---

IVideoWindow::get_WindowStyle

IVideoWindow Interface

Changes the style parameters for the video window.

HRESULT get_WindowStyle(
  long *pWindowStyle
  );

Parameters

pWindowStyle

[out] Set of flags that matches a subset of the flags that can be set by the GWL_STYLE value of the Microsoft Win32 GetWindowLong function.

Return Values

Returns an HRESULT value.

Remarks

For a complete list of window styles, see the CreateWindow function in the Microsoft Win32 Software Development Kit (SDK).

---

IVideoWindow::get_WindowStyleEx

IVideoWindow Interface

Changes the style parameters for the video window.

HRESULT get_WindowStyleEx(
  long * pWindowStyleEx
  );

Parameters

pWindowStyleEx

[out] Set of flags that matches a subset of the flags that can be set by the GWL_STYLE value of the Microsoft Win32 GetWindowLong function.

Return Values

Returns an HRESULT value.

Remarks

This function uses extended window styles. For a complete list of window styles, see the CreateWindow function in the Microsoft Win32 Software Development Kit (SDK).

---

IVideoWindow::HideCursor

IVideoWindow Interface

Hides the cursor.

HRESULT HideCursor(
  long HideCursor
  );

Parameters

HideCursor

[in] If OATRUE, do not display the cursor; if OAFALSE, display the cursor.

Return Values

Returns an HRESULT value.

Remarks

This method is typically used when the video renderer is in full-screen mode, where cursor display might be unwanted.

---

IVideoWindow::IsCursorHidden

IVideoWindow Interface

Determines if the cursor is hidden or showing.

HRESULT IsCursorHidden(
  long * CursorHidden
  );

Parameters

CursorHidden

[out] If OATRUE, cursor is hidden; if OAFALSE, cursor is displayed.

Return Values

Returns an HRESULT value.

Remarks

This method is typically used when the video renderer is in full-screen mode, where cursor display might be unwanted.

---

IVideoWindow::NotifyOwnerMessage

IVideoWindow Interface

Forwards messages that have been received by a parent window to a child window owned by a filter.

HRESULT NotifyOwnerMessage(
  long hwnd,
  long uMsg,
  long wParam,
  long lParam
  );

Parameters

hwnd

[in] Window handle.

uMsg

[in] Message being sent.

wParam

[in] Message's wParam passed in.

lParam

[in] Message's lParam passed in.

Return Values

Returns an HRESULT value.

Remarks

This method should be used by windows that make a renderer window a child window. It forwards significant messages to the child window that the child window would not otherwise receive. This includes the following messages.

WM_ACTIVATEAPP

WM_DEVMODECHANGE

WM_DISPLAYCHANGE

WM_PALETTECHANGED

WM_PALETTEISCHANGING

WM_QUERYNEWPALETTE

WM_SYSCOLORCHANGE

---

IVideoWindow::put_AutoShow

IVideoWindow Interface

Determines whether or not the window will be automatically shown.

HRESULT put_AutoShow(
  long AutoShow
  );

Parameters

AutoShow

[in] OATRUE (–1) means the window will be visible when the state changes; OAFALSE (0) means the window remains hidden until explicitly shown.

Return Values

Returns an HRESULT value.

Remarks

Many simple applications require a displayed window when a filter graph is set to the running state. AutoShow defaults to OATRUE so that when the graph changes state to paused or running, the window is visible (it also is set as the foreground window). It will remain visible on all subsequent state changes to paused or running. If you close the window while the stream is running, the window will not automatically reappear. If you stop and restart the stream, however, the window will automatically reappear.

See Also

IVideoWindow::put_Visible

---

IVideoWindow::put_BackgroundPalette

IVideoWindow Interface

Determines whether any palette required will be realized in the background.

HRESULT put_BackgroundPalette(
  long BackgroundPalette
  );

Parameters

BackgroundPalette

[in] OATRUE to realize the palette in the background; otherwise, OAFALSE.

Return Values

Returns an HRESULT value.

Remarks

If this is OATRUE (–1), any palette required by the video is realized by the renderer in the background. This means that any colors the palette uses will change to their closest match in the display palette prior to drawing. This ensures that an application will not have its palette disturbed when playing a video. It does, however, impose severe performance penalties on the video and should not be used unless absolutely necessary. The default value for this property is OAFALSE.

---

IVideoWindow::put_BorderColor

IVideoWindow Interface

Sets the border color for the video window.

HRESULT put_BorderColor(
  long Color
  );

Parameters

Color

[in] New border color as a COLORREF type.

Return Values

Returns an HRESULT value.

Remarks

When a destination rectangle that is set differs from the visible client area of the window, a border is exposed around the edge. This method allows an application to change the border color. It is set to black by default. Any nonsystem color passed in is converted to its closest match according to the current palette before being used (this is not an issue on true color devices). Setting this causes the window border to be repainted in the new color automatically.

---

IVideoWindow::put_Caption

IVideoWindow Interface

Sets the textual title string for the video window.

HRESULT put_Caption(
  BSTR strCaption
  );

Parameters

strCaption

[in] Window title caption.

Return Values

Returns an HRESULT value.

---

IVideoWindow::put_FullScreenMode

IVideoWindow Interface

Sets the full-screen mode for the video renderer filter supporting this interface.

HRESULT put_FullScreenMode(
  long FullScreenMode
  );

Parameters

FullScreenMode

[in] OATRUE if supporting full-screen video, or OAFALSE if not.

Return Values

Returns E_NOTIMPL if the video renderer doesn't support full-screen mode or NOERROR if it does.

Remarks

This method allows an application to switch a full-screen renderer into and out of full-screen mode. The renderer's behavior when switched out of full-screen mode is implementation-dependent. The Microsoft full-screen renderer, for example, switches back to a window.

The IVideoWindow plug-in distributor in the filter graph manager implements full-screen renderer switching. It looks to see if any renderer in the graph supports a full-screen mode and, if not, will temporarily replace the renderer with the default DirectShow full-screen renderer. It calls IVideoWindow::GetMaxIdealImageSize to determine if a window can be made a topmost window and resized to the entire display. This is preferred to swapping renderers, because the filter graph might be using DirectDraw® overlays or a hardware decoder filter.

---

IVideoWindow::put_Height

IVideoWindow Interface

Sets the height of the video window.

HRESULT put_Height(
  long Height
  );

Parameters

Height

[in] New vertical dimension of the video window.

Return Values

Returns an HRESULT value.

Remarks

Calling this method does not affect the y-axis coordinate of the video window.

---

IVideoWindow::put_Left

IVideoWindow Interface

Sets the x-axis coordinate for the video window.

HRESULT put_Left(
  long Left
  );

Parameters

Left

[in] The x-axis coordinate to be set.

Return Values

Returns an HRESULT value.

Remarks

Calling this method does not affect the video window's width.

---

IVideoWindow::put_MessageDrain

IVideoWindow Interface

Specifies a window to which the video window will post messages.

HRESULT put_MessageDrain(
  OAHWND Drain
  );

Parameters

Drain

[in] Window to which messages will be posted.

Return Values

Returns an HRESULT value.

Remarks

The video renderer passes messages to the specified message drain by calling the Microsoft Win32 PostMessage function. These messages allow you to write applications that include user interaction, such as applications that require mouse clicks on specific areas of the video display. An application can have a close relationship with the video window and know at certain time points to look for user interaction. When the renderer passes a message to the drain, it sends the parameters, such as the client-area coordinates, exactly as generated.

DirectShow passes the following messages to the window specified by the Drain parameter, if and when the application generates them.

WM_KEYDOWN

WM_KEYUP

WM_LBUTTONDBLCLK

WM_LBUTTONDOWN

WM_LBUTTONUP

WM_MBUTTONDBLCLK

WM_MBUTTONDOWN

WM_MBUTTONUP

WM_MOUSEACTIVATE

WM_MOUSEMOVE

WM_NCLBUTTONDBLCLK

WM_NCLBUTTONDOWN

WM_NCLBUTTONUP

WM_NCMBUTTONDBLCLK

WM_NCMBUTTONDOWN

WM_NCMBUTTONUP

WM_NCMOUSEMOVE

WM_NCRBUTTONDBLCLK

WM_NCRBUTTONDOWN

WM_NCRBUTTONUP

WM_RBUTTONDBLCLK

WM_RBUTTONDOWN

WM_RBUTTONUP

Because this member function does not make the message drain window a child window, applications with full-screen capabilities can use it.

---

IVideoWindow::put_Owner

IVideoWindow Interface

Sets an owning parent for the video window.

HRESULT put_Owner(
  OAHWND Owner
  );

Parameters

Owner

[in] Handle of new owner window.

Return Values

Returns an HRESULT value.

Remarks

This method offers a way for applications to set the owner of the video window. This is often used when playing videos in compound documents. This method changes the parent of the renderer window and sets the WS_CHILD style for the video window.

To forward video window messages to the parent window, use the IVideoWindow::put_MessageDrain method, supplying the window handle of the parent window. This method does not post messages automatically.

After using this method to set the owner of a video window, you must reset the owner to NULL (by calling put_Owner(NULL)) before releasing the filter graph. Otherwise, messages will continue to be sent to this window and errors will likely occur when the application is terminated.

---

IVideoWindow::put_Top

IVideoWindow Interface

Sets the y-axis coordinate of the video window.

HRESULT put_Top(
  long Top
  );

Parameters

Top

[in] The y-axis origin of the video window.

Return Values

Returns an HRESULT value.

Remarks

Calling this method does not affect the height of the video window.

---

IVideoWindow::put_Visible

IVideoWindow Interface

Changes the visibility of the video window.

HRESULT put_Visible(
  long Visible
  );

Parameters

Visible

[in] Boolean flag that is compatible with Automation.

Return Values

Returns an HRESULT value.

Remarks

If the Visible parameter is set to OATRUE (–1), the window is shown. If it is set to OAFALSE (0), the window is hidden.

---

IVideoWindow::put_Width

IVideoWindow Interface

Sets the video window's width.

HRESULT put_Width(
  long Width
  );

Parameters

Width

[in] Width to be set.

Return Values

Returns an HRESULT value.

Remarks

Calling this method does not affect the video window's x-axis coordinate.

---

IVideoWindow::put_WindowState

IVideoWindow Interface

Sets the video window's state.

HRESULT put_WindowState(
  long WindowState
  );

Parameters

WindowState

[in] Describes the video window's state.

Return Values

Returns NOERROR.

Remarks

This method is a wrapper for the Microsoft Win32 ShowWindow function. IVideoWindow::put_WindowState passes the WindowState parameter on to CBaseWindow::DoShowWindow, which in turn passes it on to ShowWindow. Hence, WindowState can be any value that is valid for ShowWindow.

---

IVideoWindow::put_WindowStyle

IVideoWindow Interface

Changes the style parameters for the video window.

HRESULT put_WindowStyle(
  long WindowStyle
  );

Parameters

WindowStyle

[in] Set of flags that matches a subset of the flags that can be set by the GWL_STYLE value of the Microsoft Win32 GetWindowLong function.

Return Values

Returns an HRESULT value.

Remarks

Use this property to change the overall style of the video window; for example, to remove the border and caption areas of the video window. It is a fairly thin wrapper on top of setting the GWL_STYLE value of the Microsoft Win32 GetWindowLong function and therefore must be treated with care. In particular, ensure that the current styles are first retrieved, and then the necessary bit fields are added or removed. With some exceptions (noted here), the acceptable flags are the same as those allowed by the Win32 CreateWindow function.

Do not use this method to affect the window size. For example, if the window is minimized, do not set the WS_MAXIMIZE style; doing so causes unpredictable results. Instead, use the IVideoWindow::put_WindowState method for maximizing or minimizing the window.

Any of the following styles return E_INVALIDARG.

WS_DISABLED

WS_HSCROLL

WS_ICONIC

WS_MAXIMIZE

WS_MINIMIZE

WS_VSCROLL

---

IVideoWindow::put_WindowStyleEx

IVideoWindow Interface

Sets the style of the control window.

HRESULT put_WindowStyleEx(
  long pWindowStyleEx
  );

Parameters

pWindowStyleEx

[in] Value that specifies the style of the control window.

Return Values

Returns NOERROR.

Remarks

This method uses EX window styles. For a complete list of extended window styles, see the CreateWindowEx function in the Microsoft Win32 Software Development Kit (SDK).

Use this property to change the overall style of the video window; for example, to remove the border and caption areas of the video window. It is a fairly thin wrapper on top of setting the GWL_STYLE value of the Microsoft Win32 GetWindowLong function and therefore must be treated with care. In particular, ensure that the current styles are first retrieved, and then the necessary bit fields are added or removed.

Note: Do not use the following window styles as they are not validated.

WS_DISABLED

WS_HSCROLL

WS_ICONIC

WS_MAXIMIZE

WS_MINIMIZE

WS_VSCROLL

With some exceptions (noted here), the acceptable flags are the same as those allowed by the Win32 CreateWindow function.

---

IVideoWindow::SetWindowForeground

IVideoWindow Interface

Moves the video window to the foreground and optionally gives it focus.

HRESULT SetWindowForeground(
  long Focus
  );

Parameters

Focus

Long value that specifies whether the video window will get focus. A value of –1 gives the window focus and 0 does not.

Return Values

Returns one of the following values.

Value	Meaning
NOERROR	The method succeeded.
E_INVALIDARG	Focus doesn't equal –1 or 0.
VFW_E_NOT_CONNECTED	The current filter isn't connected to a complete filter graph.

---

IVideoWindow::SetWindowPosition

IVideoWindow Interface

Sets the position of the video window (not the client rectangle position) in device coordinates.

HRESULT SetWindowPosition(
  long Left,
  long Top,
  long Width,
  long Height
  );

Parameters

Left

[in] The x-axis origin of the window.

Top

[in] The y-axis origin of the window.

Width

[in] Width of the window.

Height

[in] Height of the window.

Return Values

Returns an HRESULT value.

Remarks

This method has the same effect as individually calling the IVideoWindow::put_Left, IVideoWindow::put_Top, IVideoWindow::put_Width, and IVideoWindow::put_Height methods.

Specify, in window coordinates, where the video should appear. For example, setting a destination of (100,50,200,400) positions the video playback at an origin of 100 pixels from the left of the client area and 50 pixels from the top, with an overall size of 200 x 400 pixels. If the video is smaller than this (or a source rectangle has been specified that is smaller than the video), it will be stretched appropriately. Similarly, if the video is larger than the destination rectangle, the video is compressed into the visible rectangle. There are fairly severe performance penalties if an application does not keep the source and destination rectangles the same size.

Under typical circumstances, when no destination rectangle has been set, the video fills the entire visible client window area (regardless of how much the user has stretched the window). Also, the destination rectangle properties correctly return the size of the video window client area.

© 1998 Microsoft Corporation. All rights reserved. Terms of Use.

Top of Page