Article: Q126742
Product(s): Microsoft Visual Basic for Windows
Version(s): 3.0
Operating System(s):
Keyword(s): kbcode kbWndw
Last Modified: 02-NOV-2001
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Visual Basic Standard Edition for Windows, version 3.0
- Microsoft Visual Basic Professional Edition for Windows, version 3.0
-------------------------------------------------------------------------------
SUMMARY
=======
To size a picture box to fit an AVI image at run time, you must first get the
dimensions of the AVI file. This article shows you how to do it.
MORE INFORMATION
================
The example uses the mciSendCommand function to get the dimensions of the AVI
file currently referenced by an MCI control.
Step-by-Step Example Demonstrates How to Get the Dimensions of an AVI file
--------------------------------------------------------------------------
1. Start a new project in Visual Basic. Add a module (.BAS) file, and make sure
the MCI control is included in the project. Add a MCI control (MMControl1), a
Command Button (Command1), and a Picture box (Picture1) to Form1. Set Form1's
ScaleMode property to Pixels (3).
2. In the General declarations section of the .BAS file, add this code:
Type RECT
left As Integer
top As Integer
right As Integer
bottom As Integer
End Type
Type MCI_OVLY_RECT_PARMS
dwCallback As Long
rc As RECT
End Type
Global Const MCI_OVLY_WHERE_SOURCE = &H20000
Global Const MCI_OVLY_WHERE_DESTINATION = &H40000
Global Const MCI_WHERE = &H843
' Enter the following Declare statement on one, single line:
Declare Function mciSendCommand Lib "mmsystem" (ByVal udeviceid As
Integer, ByVal uMessage As Integer, ByVal dwParam1 As Long, dwParam2
As Any) As Long
' Enter the following Declare statement on one, single line:
Declare Function mciGetErrorString Lib "mmsystem" (ByVal wError As
Long, ByVal lpstrBuffer As String, ByVal uLength As Integer) As
Integer
3. In the Command1_Click() method for the command button on Form1, enter this
code:
Sub Command1_Click ()
Const MB_OK = 0
Const MB_ICONSTOP = 16
Dim Retval&, Buffer$
Dim dwParam2 As MCI_OVLY_RECT_PARMS
MMControl1.Command = "Close"
MMControl1.Filename = "WndSurf1.avi" ' Sample AVI file to be played.
' Get the MCI control to display the video in Picture1:
MMControl1.hWndDisplay = Picture1.hWnd
MMControl1.Command = "Open"
' Initialize the structure being passed with mciSendCommand, and
' set it in case you want to use the Notify property:
dwParam2.dwCallback = MMControl1.hWnd
dwParam2.rc.left = 0
dwParam2.rc.top = 0
dwParam2.rc.right = 0
dwParam2.rc.bottom = 0
' Send the message:
' Enter the following two lines as one, single line of code:
Retval& = mciSendCommand(MMControl1.DeviceID, MCI_WHERE,
MCI_OVLY_WHERE_SOURCE, dwParam2)
If Retval& <> 0 Then ' An error occurred.
Buffer$ = Space$(100)
' Get a description of the error:
Retval& = mciGetErrorString(Retval&, Buffer$, Len(Buffer$))
MsgBox Trim$(Buffer$), MB_OK + MB_ICONSTOP, "ERROR"
Else
' Resize the picture box:
Picture1.Width = dwParam2.rc.right - dwParam2.rc.left
Picture1.Height = dwParam2.rc.bottom - dwParam2.rc.top
' Play the video:
MMControl1.Wait = True ' Wait for the next command to complete
MMControl1.Command = "play" 'Play the video clip
MMControl1.Command = "close"
End If
End Sub
4. Test the program. Press F5 to run it, and click the command button. The AVI
file will play back in the picture box, which will have been resized to fit
the video clip exactly.
Additional query words: 3.00 MCI AVI
======================================================================
Keywords : kbcode kbWndw
Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB300Search kbVB300
Version : :3.0
=============================================================================