delphi and webcamera catching picture

[martinchrzan]

Hello! For my program I want to download pictures from webcam.I work in Delphi 7 and I(dont know where) red about unit AVICAP32.dll whitch contain this function. So I tried create simple program which by step show 100 pictures from webcam after I click button :

unit Main2;

interface

{-----------------------------------------------------------------------------}

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;

{-----------------------------------------------------------------------------}

const
WM_USER = 1024;
WM_CAP_DRIVER_CONNECT = 1034;
WM_CAP_DRIVER_DISCONNECT = 1035;
WM_CAP_GET_FRAME = 1084;
WM_CAP_COPY = 1054;

WM_CAP_START = WM_USER;
WM_CAP_DLG_VIDEOFORMAT = WM_CAP_START + 41;
WM_CAP_DLG_VIDEOSOURCE = WM_CAP_START + 42;
WM_CAP_DLG_VIDEODISPLAY = WM_CAP_START + 43;
WM_CAP_GET_VIDEOFORMAT = WM_CAP_START + 44;
WM_CAP_SET_VIDEOFORMAT = WM_CAP_START + 45;
WM_CAP_DLG_VIDEOCOMPRESSION = WM_CAP_START + 46;
WM_CAP_SET_PREVIEW = WM_CAP_START + 50;

PICWIDTH = 640;
PICHEIGHT = 480;

{-----------------------------------------------------------------------------}

type
TfmMain = class(TForm)
Panel1 : TPanel;
Button2 : TButton;
procedure FormDestroy (Sender: TObject);
procedure FormCreate (Sender: TObject);
procedure Button2Click (Sender: TObject);
private
FCapHandle : THandle;
public

end;

{*****************************************************************************}

var
fmMain: TfmMain;

{*****************************************************************************}

implementation

{$R *.dfm}


{-----------------------------------------------------------------------------}

function capCreateCaptureWindow(lpszWindowName: LPCSTR; dwStyle: DWORD;
x, y, nWidth, nHeight: integer; hwndParent: HWND; nID: integer): HWND; stdcall;
external 'AVICAP32.DLL' name 'capCreateCaptureWindowA';

//------------------------------------------------------------------------------

procedure TfmMain.FormCreate(Sender: TObject);
begin
FCapHandle:= capCreateCaptureWindow('Video', WS_CHILD or WS_VISIBLE, 0, 0, PICWIDTH, PICHEIGHT, panel1.Handle, 1);

SendMessage(FCapHandle, WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(FCapHandle, WM_CAP_DLG_VIDEOSOURCE,0,0);
SendMessage(FCapHandle, WM_CAP_DLG_VIDEOFORMAT,0,0);

end;

{-----------------------------------------------------------------------------}

procedure TfmMain.FormDestroy(Sender: TObject);
begin
SendMessage(FCapHandle,WM_CAP_DRIVER_DISCONNECT, 0, 0);
end;

{-----------------------------------------------------------------------------}

procedure TfmMain.Button2Click(Sender: TObject);
Var i:integer;
begin
For i:=1 to 100 do begin //Only for testing
SendMessage(FCapHandle,WM_CAP_GET_FRAME, 0, 0); end;
end;

end.



Program is running but is it too slow. Per 1 second it show just about 5 pictures. Does is something wrong in my program or is it error of Delphi ? In the aggregate all this system of catching pictures to panel dont conform me. I need just read single pixels in picture and a dont need to show this picture. It will be the best if the picture are saveing to some memory (canvas) – maybe it will be faster...
Thanks for advice

 

[DelphiAaron]

if its a usb webcam on the same pc as the program your developing then you can capture images with twain.

http://delphi.about.com/gi/dynamic/offsite.htm?site=http://delphitwain.sourceforge.net/

Aaron

 

[whosrdaddy]

here is a video for windows example, play with it and learn. It contains a preview function...

http://www.nldelphi.nl/Forum/attachment.php?attachmentid=2953&d=1132754067

//Daddy

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