Why dows my window get stuck when using #WM_CAP_EDIT_COPY ?

AndyMK · Post by **AndyMK** » Tue Jul 25, 2006 10:28 pm

You will need a webcam or a capture card to run this. Wen i run it, the window seems busy and wont move or respond to the mouse. Ive managed to pin it down to #WM_CAP_EDIT_COPY which seems take control from the window. If i call #WM_CAP_EDIT_COPY every 100ms or higher, the window is ok but the final update is slow (10fps@100ms) Is this something to do with overlay mode? I need to use overlay as using preview stops the image update when the preview video is covered by another application. Overlay is on the left and jpeg stream on the right.

Code: Select all

InitSprite()
UseJPEGImageEncoder()
UseJPEGImageDecoder()

#WM_CAP_START = #WM_USER 
#WM_CAP_DRIVER_CONNECT = #WM_CAP_START + 10 
#WM_CAP_DRIVER_DISCONNECT = #WM_CAP_START + 11 
#WM_CAP_DRIVER_GET_CAPS = #WM_CAP_START + 14
#WM_CAP_EDIT_COPY = #WM_CAP_START + 30
#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_OVERLAY = #WM_CAP_START + 51
#WM_CAP_GRAB_FRAME_NOSTOP = #WM_CAP_START + 61 
#WM_CAP_STOP = #WM_CAP_START + 68 

  OpenWindow(0, 0, 0, 700, 270, "Server Preview", #PB_Window_SystemMenu|#PB_Window_ScreenCentered) 
  SetWindowColor(0,RGB($00,$00,$00))
  OpenWindowedScreen(WindowID(0),365,15,685,255,0,0,0)
  If OpenLibrary(0, "avicap32.dll") 
    *capAddress = GetFunction(0, "capCreateCaptureWindowA") 
    hWndC.l = CallFunctionFast(*capAddress, "My Capture Window",#WS_CHILD | #WS_VISIBLE , 15, 15, 320, 240, WindowID(0),0) 
    SendMessage_(hWndC, #WM_CAP_DRIVER_CONNECT, 0, 0) 
    SendMessage_(hWndC, #WM_CAP_SET_OVERLAY, #True, 0) 
  EndIf 

Repeat
  event=WaitWindowEvent(1)
  SendMessage_(hWndC, #WM_CAP_EDIT_COPY, 0, 0)
  img = GetClipboardImage(#PB_Any)
  If img
  SaveImage(img,"c:\1.jpg",#PB_ImagePlugin_JPEG,5)
  FreeImage(img)
  Sprite = LoadSprite(#PB_Any, "c:\1.jpg"); 
  DisplaySprite(Sprite,0,0)
  FreeSprite(sprite)
  EndIf
  FlipBuffers()
Until event=#PB_Event_CloseWindow

*EDIT*
If i hide the overlay window by removing "#WS_VISIBLE", it seems to work ok but i only get the resultant jpeg and not the overlay itself so it would seem, using overlay is the problem and not #WM_CAP_EDIT_COPY... my knowledge is too limited

and it is so frustrating

Jan Vooijs · Post by **Jan Vooijs** » Thu Jul 27, 2006 1:45 pm

This is the result of the dutch jury:

Code: Select all

InitSprite()
UseJPEGImageEncoder()
UseJPEGImageDecoder()

#WM_CAP_START = #WM_USER
#WM_CAP_DRIVER_CONNECT = #WM_CAP_START + 10
#WM_CAP_DRIVER_DISCONNECT = #WM_CAP_START + 11
#WM_CAP_DRIVER_GET_CAPS = #WM_CAP_START + 14
#WM_CAP_EDIT_COPY = #WM_CAP_START + 30
#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_OVERLAY = #WM_CAP_START + 51
#WM_CAP_GRAB_FRAME_NOSTOP = #WM_CAP_START + 61
#WM_CAP_STOP = #WM_CAP_START + 68

#WM_CAP_SET_PREVIEW = #WM_CAP_START + 50
#WM_CAP_SET_PREVIEWRATE = #WM_CAP_START + 52

OpenWindow(0, 0, 0, 700, 270, "Server Preview", #PB_Window_SystemMenu|#PB_Window_ScreenCentered)
SetWindowColor(0,RGB($00,$cc,$00))
  OpenWindowedScreen(WindowID(0),365,15,685,255,0,0,0)
  If OpenLibrary(0, "avicap32.dll")
    *capAddress = GetFunction(0, "capCreateCaptureWindowA")
    hWndC.l = CallFunctionFast(*capAddress, "My Capture Window",#WS_CHILD | #WS_VISIBLE , 15, 15, 320, 240, WindowID(0),0)
    SendMessage_(hWndC, #WM_CAP_DRIVER_CONNECT, 0, 0)
    SendMessage_(hWndC, #WM_CAP_SET_OVERLAY, #True, 0)
		SendMessage_( hWndC, #WM_CAP_SET_PREVIEW, #True, 0)
		SendMessage_( hWndC, #WM_CAP_SET_PREVIEWRATE, 1, 0)
  EndIf

Repeat
  event=WaitWindowEvent(10)
  SendMessage_(hWndC, #WM_CAP_EDIT_COPY, 0, 0)
  img = GetClipboardImage(#PB_Any)
  If img
  	SaveImage(img,"c:\1.jpg",#PB_ImagePlugin_JPEG,5)
  	FreeImage(img)
  	Sprite = LoadSprite(#PB_Any, "c:\1.jpg");
  	DisplaySprite(Sprite,0,0)
  	FreeSprite(sprite)
  EndIf
  FlipBuffers()
Until event=#PB_Event_CloseWindow

add these two:
#WM_CAP_SET_PREVIEW = #WM_CAP_START + 50
#WM_CAP_SET_PREVIEWRATE = #WM_CAP_START + 52

and in the sendmessage part these two:
SendMessage_( hWndC, #WM_CAP_SET_PREVIEW, #True, 0)
SendMessage_( hWndC, #WM_CAP_SET_PREVIEWRATE, 1, 0)

And it works.

Jan V.

AndyMK · Post by **AndyMK** » Thu Jul 27, 2006 2:08 pm

Excelent! this works BUT my webcam preview streams at 15 frames per second and if i move the window it also moves across the screen at 15 frames per second.. it moves but very jerky..

Jan Vooijs · Post by **Jan Vooijs** » Thu Jul 27, 2006 4:30 pm

AndyK,

Yes that is because wincap is writing to the screen via your window this has to do with pointers, so move the window and wincap needs to update its internal wizardry that takes time!!.

And 15 frames is not enough? MSN does it with 10 max and most of the time with 'only'5 frames.

Jan V.

AndyMK · Post by **AndyMK** » Fri Jul 28, 2006 1:04 pm

I understand what you are saying and im not really worried about the framerate of the webcam but surely there must be a way to make the window move smooth? is there any way i can temporarily stop the webcam while the window is moving? would this solve the problem? it does not look too professional when you are draggina an app and it stutters as its moving.

Jan Vooijs · Post by **Jan Vooijs** » Fri Jul 28, 2006 1:19 pm

AndyMk,

You have to test for #WM_MOVE in your message pump (being the PB or a callback). Than temporally stop the capture, after the #WM_MOVE stop you can capture again I believe there is a 'pause' constant to send to AviCap.

Oh and one tip make an image with somthing like 'No Video'To be placed instead of the capture if you drag.

And it is not 'professionel' look at all the dvd players drag THEM and they all stutter. It is inherent to DirectShow (aka Microsoft).

Something like this (from my own working code):

Code: Select all


;- MSG pump
			Repeat
				EventID  = WaitWindowEvent( Frame/2)		; Event twice EVERY frame..
				evGadget = EventGadget()
				evWindow = EventWindow()
				evType   = EventType() 
				;

.... snip of code ....


ElseIf EventID = #WM_MOVE
					; Debug "WindowEvent = #WM_MOVE"
					If evWindow = #hWnd
						; Main screen is moving, so 'rubberband' the control window..
						GetWindowRect_( hWnd, @Rect.RECT)
						ResizeWindow( #hWndRC, Rect\left, Rect\bottom, #PB_Ignore, #PB_Ignore)
					EndIf

Jan V.

AndyMK · Post by **AndyMK** » Fri Jul 28, 2006 3:16 pm

Thanks for your help. Much appreciated.