教你如何利用vfw控制摄像头
操作摄像头我想主要有以下几点。启动摄像头；将摄像头的视频流转为图片或视频文件保存；一些设置。
启动摄像头
包括创建捕捉窗口，连接硬件设备，显示图像以及一些基本设置。view plaincopy to clipboardprint?
Dim lpszName As String * 100
Dim lpszVer As String * 100
Dim Caps As CAPDRIVERCAPS
'//Create Capture Window
capGetDriverDescriptionA 0, lpszName, 100, lpszVer, 100 '// Retrieves driver info
lwndC = capCreateCaptureWindowA(lpszName, WS_CAPTION Or WS_THICKFRAME Or WS_VISIBLE Or WS_CHILD, 0, 0, 160, 120, Me.hWnd, 0)
'// Set title of window to name of driver
SetWindowText lwndC, lpszName
'// Set the video stream callback function
'capSetCallbackOnStatus lwndC, AddressOf MyStatusCallback
'capSetCallbackOnError lwndC, AddressOf MyErrorCallback
'// Connect the capture window to the driver
If capDriverConnect(lwndC, 0) Then
'/////
'// Only do the following if the connect was successful.
'// if it fails, the error will be reported in the call
'// back function.
'/////
'// Get the capabilities of the capture driver
capDriverGetCaps lwndC, VarPtr(Caps), Len(Caps)
'// If the capture driver does not support a dialog, grey it out
'// in the menu bar.
If Caps.fHasDlgVideoSource = 0 Then mnuSource.Enabled = False
If Caps.fHasDlgVideoFormat = 0 Then mnuFormat.Enabled = False
If Caps.fHasDlgVideoDisplay = 0 Then mnuDisplay.Enabled = False
'// Turn Scale on
capPreviewScale lwndC, True
'// Set the preview rate in milliseconds
capPreviewRate lwndC, 66
'// Start previewing the image from the camera
capPreview lwndC, True
'// Resize the capture window to show the whole image
ResizeCaptureWindow lwndC
End If
Dim lpszName As String * 100
Dim lpszVer As String * 100
Dim Caps As CAPDRIVERCAPS
'//Create Capture Window
capGetDriverDescriptionA 0, lpszName, 100, lpszVer, 100 '// Retrieves driver info
lwndC = capCreateCaptureWindowA(lpszName, WS_CAPTION Or WS_THICKFRAME Or WS_VISIBLE Or WS_CHILD, 0, 0, 160, 120, Me.hWnd, 0)
'// Set title of window to name of driver
SetWindowText lwndC, lpszName
'// Set the video stream callback function
'capSetCallbackOnStatus lwndC, AddressOf MyStatusCallback
'capSetCallbackOnError lwndC, AddressOf MyErrorCallback
'// Connect the capture window to the driver
If capDriverConnect(lwndC, 0) Then
'/////
'// Only do the following if the connect was successful.
'// if it fails, the error will be reported in the call
'// back function.
'/////
'// Get the capabilities of the capture driver
capDriverGetCaps lwndC, VarPtr(Caps), Len(Caps)
'// If the capture driver does not support a dialog, grey it out
'// in the menu bar.
If Caps.fHasDlgVideoSource = 0 Then mnuSource.Enabled = False
If Caps.fHasDlgVideoFormat = 0 Then mnuFormat.Enabled = False
If Caps.fHasDlgVideoDisplay = 0 Then mnuDisplay.Enabled = False
'// Turn Scale on
capPreviewScale lwndC, True
'// Set the preview rate in milliseconds
capPreviewRate lwndC, 66
'// Start previewing the image from the camera
capPreview lwndC, True
'// Resize the capture window to show the whole image
ResizeCaptureWindow lwndC
End If
将视频流转为图片或文件保存
关于保存为图片好像没有什么直接方法，我用的是在窗体中加入了一个picture控件来搞定的。
view plaincopy to clipboardprint?
SendMessage(lwnd, WM_CAP_EDIT_COPY, 0, 0)
Picture1.Picture = Clipboard.GetData
SavePicture Picture1.Picture, "c:\test.jpg"
SendMessage(lwnd, WM_CAP_EDIT_COPY, 0, 0)
Picture1.Picture = Clipboard.GetData
SavePicture Picture1.Picture, "c:\test.jpg"
保存到视频文件
view plaincopy to clipboardprint?
Dim sFileName As String
Dim CAP_PARAMS As CAPTUREPARMS
capCaptureGetSetup lwndC, VarPtr(CAP_PARAMS), Len(CAP_PARAMS)
CAP_PARAMS.dwRequestMicroSecPerFrame = (1 * (10 ^ 6)) / 30 ' 30 Frames per second
CAP_PARAMS.fMakeUserHitOKToCapture = True
CAP_PARAMS.fCaptureAudio = False
capCaptureSetSetup lwndC, VarPtr(CAP_PARAMS), Len(CAP_PARAMS)
sFileName = "C:\myvideo.avi"
capCaptureSequence lwndC ' Start Capturing!
capFileSaveAs lwndC, sFileName ' Copy video from swap file into a real file.
Dim sFileName As String
Dim CAP_PARAMS As CAPTUREPARMS
capCaptureGetSetup lwndC, VarPtr(CAP_PARAMS), Len(CAP_PARAMS)
CAP_PARAMS.dwRequestMicroSecPerFrame = (1 * (10 ^ 6)) / 30 ' 30 Frames per second
CAP_PARAMS.fMakeUserHitOKToCapture = True
CAP_PARAMS.fCaptureAudio = False
capCaptureSetSetup lwndC, VarPtr(CAP_PARAMS), Len(CAP_PARAMS)
sFileName = "C:\myvideo.avi"
capCaptureSequence lwndC ' Start Capturing!
capFileSaveAs lwndC, sFileName ' Copy video from swap file into a real file.
一些设置
设置格式
view plaincopy to clipboardprint?
Dim CAPSTATUS As CAPSTATUS
Dim lCaptionHeight As Long
Dim lX_Border As Long
Dim lY_Border As Long
SendMessage(lwnd, WM_CAP_DLG_VIDEOFORMAT, 0, 0)
lCaptionHeight = GetSystemMetrics(SM_CYCAPTION)
lX_Border = GetSystemMetrics(SM_CXFRAME)
lY_Border = GetSystemMetrics(SM_CYFRAME)
'// Get the capture window attributes .. width and height
If capGetStatus(lwnd, VarPtr(CAPSTATUS), Len(CAPSTATUS)) Then
'// Resize the capture window to the capture sizes
SetWindowPos lwnd, HWND_BOTTOM, 0, 0, _
CAPSTATUS.uiImageWidth + (lX_Border * 2), _
CAPSTATUS.uiImageHeight + lCaptionHeight + (lY_Border * 2), _
SWP_NOMOVE Or SWP_NOZORDER
End If
Dim CAPSTATUS As CAPSTATUS
Dim lCaptionHeight As Long
Dim lX_Border As Long
Dim lY_Border As Long
SendMessage(lwnd, WM_CAP_DLG_VIDEOFORMAT, 0, 0)
lCaptionHeight = GetSystemMetrics(SM_CYCAPTION)
lX_Border = GetSystemMetrics(SM_CXFRAME)
lY_Border = GetSystemMetrics(SM_CYFRAME)
'// Get the capture window attributes .. width and height
If capGetStatus(lwnd, VarPtr(CAPSTATUS), Len(CAPSTATUS)) Then
'// Resize the capture window to the capture sizes
SetWindowPos lwnd, HWND_BOTTOM, 0, 0, _
CAPSTATUS.uiImageWidth + (lX_Border * 2), _
CAPSTATUS.uiImageHeight + lCaptionHeight + (lY_Border * 2), _
SWP_NOMOVE Or SWP_NOZORDER
End If
设置视频源
view plaincopy to clipboardprint?
SendMessage(lwnd, WM_CAP_DLG_VIDEOSOURCE, 0, 0)
SendMessage(lwnd, WM_CAP_DLG_VIDEOSOURCE, 0, 0)
设置压缩选项
view plaincopy to clipboardprint?
SendMessage(lwnd, WM_CAP_DLG_VIDEOCOMPRESSION, 0, 0)
SendMessage(lwnd, WM_CAP_DLG_VIDEOCOMPRESSION, 0, 0)
以上就是主要源代码，当然自己运用的时候还要进行api的申明，结构体的申明等等。