1、声明必要的变量

  hWndC : THandle;
  CapturingAVI : bool;

2、定义消息

const WM_CAP_START = WM_USER;
const WM_CAP_STOP = WM_CAP_START + 68;
const WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10;
const WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11;
const WM_CAP_SAVEDIB = WM_CAP_START + 25;
const WM_CAP_GRAB_FRAME = WM_CAP_START + 60;
const WM_CAP_SEQUENCE = WM_CAP_START + 62;
const WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20;
const WM_CAP_SEQUENCE_NOFILE =WM_CAP_START+  63 ;
const WM_CAP_SET_OVERLAY =WM_CAP_START+  51 ;
const WM_CAP_SET_PREVIEW =WM_CAP_START+  50 ;
const WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START +6;
const WM_CAP_SET_CALLBACK_ERROR=WM_CAP_START +2;
const WM_CAP_SET_CALLBACK_STATUSA= WM_CAP_START +3;
const WM_CAP_SET_CALLBACK_FRAME= WM_CAP_START +5;
const WM_CAP_SET_SCALE=WM_CAP_START+  53 ;
const WM_CAP_SET_PREVIEWRATE=WM_CAP_START+  52 ;

3、声明函数

function capCreateCaptureWindowA(lpszWindowName : PCHAR;
dwStyle : longint;
x : integer;
y : integer;
nWidth : integer;
nHeight : integer;
ParentWin : HWND;
nId : integer): HWND;
STDCALL EXTERNAL 'AVICAP32.DLL';

4、FormCreate

CapturingAVI := false;
hWndC := 0;
SaveDialog1.Options :=
[ofHideReadOnly, ofNoChangeDir, ofPathMustExist]

5、开始显示OpenVideo

hWndC := capCreateCaptureWindowA('My Own Capture Window',
WS_CHILD or WS_VISIBLE ,
Panel1.Left,
Panel1.Top,
Panel1.Width,
Panel1.Height,
Form1.Handle,
0);
if hWndC <> 0 then
SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, 0, 0);
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);
OpenVideo.Enabled :=false;

6、CloseVideo

if hWndC <> 0 then begin
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
hWndC := 0;
OpenVideo.Enabled :=true;
end;

7、SaveBMP

if hWndC <> 0 then begin
SaveDialog1.DefaultExt := 'bmp';
SaveDialog1.Filter := 'Bitmap files (*.bmp)|*.bmp';
if SaveDialog1.Execute then
SendMessage(hWndC,
WM_CAP_SAVEDIB,
0,
longint(pchar(SaveDialog1.FileName)));
end;

8、StartAVI

if hWndC <> 0 then begin
SaveDialog1.DefaultExt := 'avi';
SaveDialog1.Filter := 'AVI files (*.avi)|*.avi';
if SaveDialog1.Execute then begin
CapturingAVI := true;
SendMessage(hWndC,
WM_CAP_FILE_SET_CAPTURE_FILEA,
0,
Longint(pchar(SaveDialog1.FileName)));
SendMessage(hWndC, WM_CAP_SEQUENCE, 0, 0);
end;
end;

9、StopAVI

if hWndC <> 0 then begin
SendMessage(hWndC, WM_CAP_STOP, 0, 0);
CapturingAVI := false;
end;

10、FormClose
CloseVideo;

注意上面的前提是需要安装摄像头的驱动程序。

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