Use Delphi programming to control the camera (figure)

Does your computer have a camera? Will you think about how to achieve it when you see someone playing the video screen with QQ? Here we will introduce how to use MS in Delphi
Avicap32.dll can easily program the camera. If you add your network programming level, it is no problem to implement a video screen chat.

Look at the generation below
Code:

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 Function Capcreatecapture0000wa (lpszwindowname: pchar; dwstyle: longint; X: Integer; Y: integer; nwidth: integer; nheight: integer; parentwin: Hwnd; NID: integer): hwnd; stdcall external 'avicap32. dll ';

　
The above code is the definition of a function and constant that we mainly use.

Okay. Open your Delphi, create a project, and add the above definition.

　
Create a new window, place a panel, and add a button. Set caption to "start". A global variable, VAR hwndc: thandle, must be defined here;
The code for the start button is as follows:

Begin Hwndc: = capcreatecapturew.wa ('my own capture Window ', ws_child or ws_visible , Panel1.left, panel1.top, panel1.width, panel1.height, form1.handle, 0 ); Hwndc : = Capcreatecapturew.wa ('my own capture Window', ws_child or Ws_visible , Panel1.left, panel1.top, panel1.width, panel1.height, form1.handle, 0 ); If Hwndc <> 0 then Begin 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 ); End; Run F9. How can I see the camera's video screen? So how to stop? Set the button caption" Stop ". The Code is as follows: If hwndc <> 0 then begin Sendmessage (hwndc, Wm_cap_driver_disconnect, 0, 0 ); Hwndc: = 0; End;

　
When the video is captured, how can we save it? The following are saved in two ways: BMP static graph and AVI animation.

Put three buttons on the form.
Go and set caption to "save BMP", "Start video", and "Stop video" respectively. The code for the three buttons is as follows:

// Save BMP If hwndc <> 0 then begin Sendmessage (hwndc, wm_cap_savedib, 0, longint (pchar ('C:/test.bmp '))); End; // Start recording If hwndc <> 0 then Begin Sendmessage (hwndc, wm_cap_file_set_capture_filea, 0, Longint (pchar ('C:/test. avi '))); Sendmessage (hwndc, wm_cap_sequence, 0, 0 ); End; // Stop recording If hwndc <> 0 then begin Sendmessage (hwndc, Wm_cap_stop, 0, 0 ); End;

Run it again ..
You can save several images to see, or you can record them as avi and then enjoy them slowly.

Program running effect:

The complete program code is as follows:

Unit unit1; Interface Uses Windows, messages, Sysutils, variants, classes, graphics, controls, forms, Dialogs, Stdctrls, extctrls; Type Tform1 = Class (tform) Panel1: Tpanel; Button1: tbutton; Button2: tbutton; Button3: tbutton; Button4: Tbutton; Button5: tbutton; Procedure button1click (Sender: Tobject ); Procedure button2click (Sender: tobject ); Procedure Button3click (Sender: tobject ); Procedure button4click (Sender: Tobject ); Procedure button5click (Sender: tobject ); Procedure Formclose (Sender: tobject; var action: tcloseaction ); Private Hwndc : Thandle; Public {Public declarations} End; VaR Form1: Tform1; 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 Function Capcreatecapture0000wa (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 tform1.button1click (Sender: tobject ); Begin Hwndc : = Capcreatecapturew.wa ('my own capture Window', ws_child or Ws_visible , Panel1.left, panel1.top, panel1.width, panel1.height, form1.handle, 0 ); Hwndc : = Capcreatecapturew.wa ('my own capture Window', ws_child or Ws_visible , Panel1.left, panel1.top, panel1.width, panel1.height, form1.handle, 0 ); If Hwndc <> 0 then Begin 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 ); End; End; Procedure tform1.button2click (Sender: Tobject ); Begin If hwndc <> 0 then begin Sendmessage (hwndc, Wm_cap_driver_disconnect, 0, 0 ); Hwndc: = 0; End; End; Procedure Tform1.button3click (Sender: tobject ); Begin If hwndc <> 0 Then begin Sendmessage (hwndc, wm_cap_savedib, 0, longint (pchar ('C:/test.bmp '))); End; End; Procedure Tform1.button4click (Sender: tobject ); Begin If hwndc <> 0 Then Begin Sendmessage (hwndc, wm_cap_file_set_capture_filea, 0, Longint (pchar ('C:/test. avi '))); Sendmessage (hwndc, wm_cap_sequence, 0, 0 ); End; End; Procedure tform1.button5click (Sender: Tobject ); Begin If hwndc <> 0 then begin Sendmessage (hwndc, Wm_cap_stop, 0, 0 ); End; End; Procedure Tform1.formclose (Sender: tobject; var action: tcloseaction ); Begin If Hwndc <> 0 then begin Sendmessage (hwndc, Wm_cap_driver_disconnect, 0, 0 ); End; End; End.

　
If the computer does not have a camera, but you want to see the effect of the program, can you?

Of course, you can find a virtual camera. You can try softcam.
It is a real software camera that can be simulated as a "real" camera. I would like to remind you that you may not use this camera to cheat mm or Gg on chat software such as QQ or MSN.

　
For camera programming, you can also look at this set of VCL components: dspack, dspack is a set
Show and DirectX technology classes and components, designed for DirectX 9, support system Win9x, me, 2000 and Windows XP.

　
Now, let's talk about this. As for how to implement video-screen chat, it's up to you to compress the data and display it to the other party. However, it seems simple to come back, it is still difficult to implement.