Bitmap Screenshots.

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Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 03 Oct 2011, 16:28

Hello everyone, does anybody have example how to take bmp screenshots and save it to file and/or display it on window ? Thanks.

03 Oct 2011, 16:28

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 03 Oct 2011, 17:05

edit:
OK, I have done this (found in google.) but I don't know how to save it or display.. anyone help ?

Code:

        invoke CreateDC,<"DISPLAY",0>,0,0,0
        mov [hScreenDC],eax
        invoke CreateCompatibleDC,[hScreenDC]
        mov [hMemDC],eax
        invoke GetDeviceCaps,[hScreenDC],8 ;HORZRES
        mov [x],eax
        invoke GetDeviceCaps,[hScreenDC],10 ;VERTRES
        mov [y],eax
        invoke CreateCompatibleBitmap,[hScreenDC],[x],[y]
        mov [hBitmap],eax
        invoke SelectObject,[hMemDC],[hBitmap]
        mov [hOldBitmap],eax
        invoke BitBlt,[hMemDC],0,0,[x],[y],[hScreenDC],0,0,SRCCOPY
        invoke SelectObject,[hMemDC],[hOldBitmap]
        mov [hBitmap],eax
        invoke DeleteDC,[hMemDC]
        invoke DeleteDC,[hScreenDC]
        ret

03 Oct 2011, 17:05

cod3b453

Joined: 25 Aug 2004
Posts: 618

cod3b453 03 Oct 2011, 17:11

I did this back in the days of Win98 to make blended windows/menus in VB6 Laughing

Use:

Code:

    scrDC = CreateDCA("DISPLAY", "", "", 0)

to get the screen and then create a bitmap:

Code:

SystemParametersInfoA (SPI_GETWORKAREA, 0, rScreen, 0)
...
    bmTransDC = CreateCompatibleDC(scrDC)
    bmHTrans = CreateCompatibleBitmap(scrDC, tbSize.X, tbSize.Y)
    SelectObject(bmTransDC, bmHTrans)

and then copy using:

Code:

BitBlt bmTransDC, 0, 0, tbSize.X, tbSize.Y, scrDC, tbPos.X, tbPos.Y, vbSrcCopy

You can also change the destination DC to a window instead of a bitmap in memory.

03 Oct 2011, 17:11

dancho

Joined: 06 Mar 2011
Posts: 74

dancho 03 Oct 2011, 17:29

Capturing an Image :
http://msdn.microsoft.com/en-us/library/dd183402(v=VS.85).aspx

Storing an Image :
http://msdn.microsoft.com/en-us/library/dd145119(v=VS.85).aspx

03 Oct 2011, 17:29

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 03 Oct 2011, 18:42

Here is a virtual screen app i made, should help you out.

Description:		Download
Filename:	V-screen.zip
Filesize:	15.32 KB
Downloaded:	1125 Time(s)

03 Oct 2011, 18:42

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 03 Oct 2011, 18:49

Thank you guys! I'm going to study now.

03 Oct 2011, 18:49

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 07 Oct 2011, 09:41

tried, tried but unsuccessful. I found some example written in CPP. but I don't understand how to parse this line..

Code:

 DWORD dwBmpSize = ((bmpScreen.bmWidth * bi.biBitCount + 31) / 32) * 4 * bmpScreen.bmHeight;

Here's MSDN src.
http://msdn.microsoft.com/en-us/library/dd183402
Thanks.

07 Oct 2011, 09:41

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 07 Oct 2011, 10:40

I give up. I was trying to capture screen+save to disk but everytime unsucessful. I lost my 3 days without luck. FUCK!

07 Oct 2011, 10:40

dancho

Joined: 06 Mar 2011
Posts: 74

dancho 07 Oct 2011, 11:20

found this , maybe will help you :

http://win32assembly.online.fr/files/CapScreen.txt

07 Oct 2011, 11:20

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 07 Oct 2011, 12:23

Thank you dancho, that will help me a lot! Smile

07 Oct 2011, 12:23

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 07 Oct 2011, 14:41

Quote:

tried, tried but unsuccessful. I found some example written in CPP. but I don't understand how to parse this line..

That "mess"is just to ensure that each scanline will have a physical length multiple of four. Since in the example by Microsoft biBitCount is set to 32, the expression could be simplified:

Code:

 DWORD dwBmpSize = bmpScreen.bmWidth * 4 * bmpScreen.bmHeight;

But note that for others bit counts you'll need the original expression.

07 Oct 2011, 14:41

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 07 Oct 2011, 21:41

LocoDelAssembly
Thanks, I'll try that.
-------
I have still problem here, I'm trying to do it with CreateCompatibleBitmap() function instead of CreateDIBSection().. Here's my code but it fails.. What I have missed ?

Code:

format PE GUI 4.0
include 'WIN32AX.INC'
entry main
section '.data' data readable writeable

hdc             dd ?
memdc           dd ?
hFile           dd ?
dwBytes         dd ?
bfilehdr        BITMAPFILEHEADER
binfohdr        BITMAPINFOHEADER
hBitmap         dd ?
dwWidth         dd ?
dwHeight        dd ?
bmpScreen       dd ?
ColorSize       dd ?

section '.text' code readable executable

main:
        invoke GetDC,0
        mov [hdc],eax
        invoke GetSystemMetrics,0
        mov [dwWidth],eax
        invoke GetSystemMetrics,1
        mov [dwHeight],eax
        invoke CreateCompatibleDC,[hdc]
        mov [memdc],eax
        invoke CreateCompatibleBitmap,[hdc],[dwWidth],[dwHeight]
        mov [hBitmap],eax
        invoke SelectObject,[memdc],[hBitmap]
        push eax
        invoke BitBlt,[memdc],0,0,[dwWidth],[dwHeight],[hdc],0,0,SRCCOPY
        mov [ColorSize],eax
        invoke GetObject,[hBitmap],sizeof.BITMAP,bmpScreen
        mov [bfilehdr.bfType],0x4D42
        mov eax,[dwWidth]
        mov edx,[dwHeight]
        mul edx
        mov edx,32
        mul edx
        xor edx,edx
        mul [ColorSize]
        shr eax,3
        add eax,sizeof.BITMAPFILEHEADER
        add eax,sizeof.BITMAPINFOHEADER
        mov [bfilehdr.bfSize],eax
        mov [bfilehdr.bfReserved1],0
        mov [bfilehdr.bfReserved2],0
        mov eax,[ColorSize]
        add eax,sizeof.BITMAPINFOHEADER
        add eax,sizeof.BITMAPFILEHEADER
        mov [bfilehdr.bfOffBits],eax
        mov [binfohdr.biSize],sizeof.BITMAPINFOHEADER
        mov eax,[dwWidth]
        mov [binfohdr.biWidth],eax
        mov eax,[dwHeight]
        mov [binfohdr.biHeight],eax
        mov [binfohdr.biPlanes],1
        mov [binfohdr.biBitCount],32
        mov [binfohdr.biCompression],BI_RGB
        mov [binfohdr.biSizeImage],0
        mov [binfohdr.biXPelsPerMeter],0
        mov [binfohdr.biYPelsPerMeter],0
        mov [binfohdr.biClrUsed],0
        mov [binfohdr.biClrImportant],0
        invoke CreateFile,<"test.bmp",0>,GENERIC_WRITE,0,0,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0
        mov [hFile],eax
        invoke WriteFile,[hFile],binfohdr,sizeof.BITMAPINFOHEADER,dwBytes,0
        invoke WriteFile,[hFile],bfilehdr,sizeof.BITMAPFILEHEADER,dwBytes,0
        mov eax,[dwWidth]
        mov edx,[dwHeight]
        mul edx
        shr eax,3
        pop ecx
        invoke WriteFile,[hFile],ecx,eax,dwBytes,0
        invoke CloseHandle,[hFile]
        invoke DeleteObject,[hBitmap]
        invoke DeleteDC,[memdc]
        invoke DeleteDC,[hdc]
ret

section '.idata' import data readable
library user32,'user32.dll',\
        kernel32,'kernel32.dll',\
        shell32,'shell32.dll',\
        gdi32,'gdi32.dll'
        include 'API\USER32.INC'
        include 'API\KERNEL32.INC'
        include 'API\SHELL32.INC'
        include 'API\GDI32.INC'

07 Oct 2011, 21:41

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 08 Oct 2011, 20:36

bump.. nobody can help ?..

08 Oct 2011, 20:36

dancho

Joined: 06 Mar 2011
Posts: 74

dancho 09 Oct 2011, 08:56

this
invoke GetObject,[hBitmap],sizeof.BITMAP,bmpScreen
fails ( return 0 )...

edit
hm,it only fails when I add fileName variable to data section to raplace
raw name in CreateFile function,
strange...

09 Oct 2011, 08:56

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 09 Oct 2011, 18:41

Here's a screen-shot app i made, in fasm.

Description:		Download
Filename:	DexShot.zip
Filesize:	292.09 KB
Downloaded:	435 Time(s)

09 Oct 2011, 18:41

Overflowz

Joined: 03 Sep 2010
Posts: 1046

Overflowz 09 Oct 2011, 20:40

Hi Dex, thanks for that example, it works fine but I have little problem. When trying something like this, it gives me access violation, not valid address at EAX+0x14 ;EAX=0

Code:

section '.data' data readable writeable
input GdiplusStartupInput
token dd ?
encoders_count dd ?
encoders_size dd ?
...
section '.text' code readable executable
        invoke  GdiplusStartup,token,input,NULL
        test    eax,eax
        jnz     exit

        invoke  GdipGetImageEncodersSize,encoders_count,encoders_size; <--- HERE!

is there any way to do it without encoders ? or to get encoder clsid with different way ? Thank you!

EDIT:
strange, it worked when I tried "input GdiStartupInput 1". But what exactly that 1 does ?
EDIT:
Also, I found this one! Smile

http://board.flatassembler.net/topic.php?t=10427

09 Oct 2011, 20:40

wht36

Joined: 18 Sep 2005
Posts: 106

wht36 09 May 2016, 08:14

Try this

Code:

include 'win32ax.inc'

.data

struct RGBQUAD
        rgbBlue db ?
        rgbGreen db ?
        rgbRed db ?
        rgbReserved db ?
ends

struct BITMAPINFO
        bmiHeader BITMAPINFOHEADER 40,800,600,1,24,0
        bmiColors RGBQUAD ?
ends

bmpHeader:              ; 54 bytes
        Signature       db 0x42,0x4D,0xC6,0x5F,0x01,00,00,00,00,00,0x36,00,00,00        ; 14 bytes
        bi24BitInfo     BITMAPINFO                                                      ; 40 bytes
pbits   dd ?

memDC   dd ?
winDC   dd ?
hDIB    dd ?
hFile   dd ?
bWritten dd ?

.code

start:
        ; Initialize bitmapinfo
;       mov [bi24BitInfo.bmiHeader.biSize], 40
;       mov [bi24BitInfo.bmiHeader.biWidth], 800
;       mov [bi24BitInfo.bmiHeader.biHeight], 600
;       mov [bi24BitInfo.bmiHeader.biPlanes], 1
;       mov [bi24BitInfo.bmiHeader.biBitCount],24
;       mov [bi24BitInfo.bmiHeader.biCompression], 0

        invoke CreateCompatibleDC, 0
        mov [memDC], eax
        invoke CreateDIBSection, eax, bi24BitInfo, 0, pbits, 0, 0
        mov [hDIB], eax
        invoke SelectObject, [memDC], eax

        invoke GetDC, 0
        mov [winDC],eax
        invoke StretchBlt, [memDC], 0, 0, 800, 600, eax, 0, 0, 1152, 864, 0xCC0020

        invoke CreateFile, 'cap.bmp', GENERIC_WRITE, 0, 0, CREATE_ALWAYS, 0, 0
        mov [hFile], eax
        invoke WriteFile, eax, bmpHeader, 54, bWritten, 0
        invoke WriteFile, [hFile], [pbits], 1440000, bWritten, 0        ; 1440000 = 800 * 600 * 3
        invoke CloseHandle, [hFile]

        invoke DeleteDC, [memDC]
        invoke DeleteObject, [hDIB]
        invoke ReleaseDC,HWND_DESKTOP,[winDC]
        invoke ExitProcess, 0

.end start

09 May 2016, 08:14

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