Delphi利用avicap32.dll编程控制摄像头实现拍照、录制视频
项目需求：平板电脑（Windows系统）一维/二维码扫描功能；
需求分析：
需要扫描一维/二维码时，分两步实现。
第一步，avicap32.dll或者dspack技术实现静默打开摄像头拍照、保存BMP图片。
第二步，ZXing技术实现对一维/二维码的解析，最终获取到码值。
本篇是利用avicap32.dll技术实现拍照/录制视频的测试Demo。
请看代码：
unit uMain; interface uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls, RzPanel, RzButton; type
TFrmMain = class(TForm)
gbScreen: TRzGroupBox;
gbOperation: TRzGroupBox;
btnStart: TRzBitBtn;
btnStop: TRzBitBtn;
btnSaveBMP: TRzBitBtn;
btnStartR: TRzBitBtn;
btnSaveAVI: TRzBitBtn;
pMain: TPanel;
procedure btnStartClick(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure btnStopClick(Sender: TObject);
procedure btnSaveBMPClick(Sender: TObject);
procedure btnStartRClick(Sender: TObject);
procedure btnSaveAVIClick(Sender: TObject);
private
{ Private declarations }
hWndC: THandle;
public
{ Public declarations }
end; var
FrmMain: TFrmMain;
const WM_CAP_START = WM_USER;
const WM_CAP_STOP = WM_CAP_START + ;
const WM_CAP_DRIVER_CONNECT = WM_CAP_START + ;
const WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + ;
const WM_CAP_SAVEDIB = WM_CAP_START + ;
const WM_CAP_GRAB_FRAME = WM_CAP_START + ;
const WM_CAP_SEQUENCE = WM_CAP_START + ;
const WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + ;
const WM_CAP_SEQUENCE_NOFILE = WM_CAP_START + ;
const WM_CAP_SET_OVERLAY = WM_CAP_START + ;
const WM_CAP_SET_PREVIEW = WM_CAP_START + ;
const WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START + ;
const WM_CAP_SET_CALLBACK_ERROR = WM_CAP_START + ;
const WM_CAP_SET_CALLBACK_STATUSA = WM_CAP_START + ;
const WM_CAP_SET_CALLBACK_FRAME = WM_CAP_START + ;
const WM_CAP_SET_SCALE = WM_CAP_START + ;
const WM_CAP_SET_PREVIEWRATE = WM_CAP_START + ; function capCreateCaptureWindowA(lpszWindowName: PCHAR;
dwStyle: longint; x: integer; y: integer; nWidth: integer;
nHeight: integer; ParentWin: HWND; nId: integer): HWND;
STDCALL EXTERNAL 'AVICAP32.DLL'; implementation {$R *.dfm} procedure TFrmMain.btnStartClick(Sender: TObject);
begin
//开始拍摄
hWndC := capCreateCaptureWindowA('My Own Capture Window', WS_CHILD or WS_VISIBLE, pMain.Left, pMain.Top, pMain.Width, pMain.Height, FrmMain.Handle, );
if hWndC <> then
begin
SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, , );
SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, , );
SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, , );
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, , );
SendMessage(hWndC, WM_CAP_SET_SCALE, , );
SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, , );
SendMessage(hWndC, WM_CAP_SET_OVERLAY, , );
SendMessage(hWndC, WM_CAP_SET_PREVIEW, , );
end;
end; procedure TFrmMain.FormClose(Sender: TObject; var Action: TCloseAction);
begin
//程序退出时，自动关闭摄像头
if hWndC <> then
begin
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, , );
end;
end; procedure TFrmMain.btnStopClick(Sender: TObject);
begin
//关闭摄像头
if hWndC <> then
begin
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, , );
hWndC := ;
end;
end; procedure TFrmMain.btnSaveBMPClick(Sender: TObject);
begin
//保存BMP
if hWndC <> then
begin
SendMessage(hWndC, WM_CAP_SAVEDIB, , longint(pchar('D:/1.bmp')));
end;
end; procedure TFrmMain.btnStartRClick(Sender: TObject);
begin
//开始录制AVI视频
if hWndC <> then
begin
SendMessage(hWndC, WM_CAP_FILE_SET_CAPTURE_FILEA, , Longint(pchar('c:/test.avi')));
SendMessage(hWndC, WM_CAP_SEQUENCE, , );
end;
end; procedure TFrmMain.btnSaveAVIClick(Sender: TObject);
begin
//停止录制并保存AVI视频
if hWndC <> then
begin
SendMessage(hWndC, WM_CAP_STOP, , );
end;
end; end.
运行效果：
作者：Jeremy.Wu
出处：https://www.cnblogs.com/jeremywucnblog/
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。