Ans: #define WM_CAP_START 0x0400 #define WM_CAP_DRIVER_CONNECT (WM_CAP_START + 10) #define WM_CAP_DRIVER_DISCONNECT (WM_CAP_START + 11) #define WM_CAP_EDIT_COPY (WM_CAP_START + 30) #define WM_CAP_GRAB_FRAME (WM_CAP_START + 60) #define WM_CAP_SET_SCALE (WM_CAP_START + 53) #define WM_CAP_SET_PREVIEWRATE (WM_CAP_START + 52) #define WM_CAP_SET_PREVIEW (WM_CAP_START + 50) #define WM_CAP_DLG_VIDEOSOURCE (WM_CAP_START + 42) #define WM_CAP_STOP (WM_CAP_START+ 68) #include #include LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM); PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp); void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC); LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM); PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp); void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC); char szAppName [] = TEXT(\"WebCam\"); HWND camhwnd; HDC hdc ; HDC hdcMem; PAINTSTRUCT ps; HBITMAP hbm; RECT rc; //WinMain -- Main Window int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow ) { HWND hwnd; MSG msg; WNDCLASS wc; wc.style = CS_HREDRAW|CS_VREDRAW; wc.lpfnWndProc = WindowProc; wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = hInstance; wc.hIcon = LoadIcon(GetModuleHandle(NULL), IDI_APPLICATION); wc.hCursor = LoadCursor (NULL, IDC_ARROW); wc.hbrBackground = (HBRUSH) (COLOR_WINDOW+1); wc.lpszMenuName = NULL; wc.lpszClassName = szAppName; RegisterClass (&wc); // Create the window hwnd = CreateWindow (szAppName,szAppName,WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU| WS_MINIMIZEBOX,CW_USEDEFAULT,CW_USEDEFAULT,300,600,0,0,hInstance,0); ShowWindow (hwnd,SW_SHOW); UpdateWindow (hwnd); while (GetMessage(&msg,0,0,0)) { if(!IsDialogMessage(hwnd, &msg)) { TranslateMessage (&msg); DispatchMessage (&msg); } } return msg.wParam; } //Main Window Procedure WindowProc LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { HINSTANCE hInstance = GetModuleHandle(NULL); //some buttons HWND hButtStartCam; HWND hButtStopCam; HWND hButtGrabFrame; switch (message) /* handle the messages */ { case WM_CTLCOLORSTATIC: SetBkMode(hdc,TRANSPARENT); return (LRESULT)CreateSolidBrush(0xFFFFFF); case WM_CREATE: { hButtStartCam = CreateWindowEx(0,\"BUTTON\",\"Start Camera\",WS_CHILD | WS_VISIBLE, 0,0,100,20,hwnd,(HMENU)1,hInstance, 0); hButtStopCam = CreateWindowEx(0,\"BUTTON\",\"Stop Camera\",WS_CHILD | WS_VISIBLE, 0,25,100,20,hwnd,(HMENU)2,hInstance, 0); hButtGrabFrame = CreateWindowEx(0,\"BUTTON\",\"Grab Frame\",WS_CHILD | WS_VISIBLE, 0,50,100,20,hwnd,(HMENU)3,hInstance, 0); camhwnd = capCreateCaptureWindow (\"camera window\", WS_CHILD , 0, 100, 300, 300, hwnd, 0); SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0); SendMessage(camhwnd,WM_CAP_DLG_VIDEOSOURCE,0,0); break; } case WM_COMMAND: { switch(LOWORD(wParam)) { case 1: { ShowWindow(camhwnd,SW_SHOW); SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0); SendMessage(camhwnd, WM_CA.

1. Ans:
#define WM_CAP_START 0x0400
#define WM_CAP_DRIVER_CONNECT (WM_CAP_START + 10)
#define WM_CAP_DRIVER_DISCONNECT (WM_CAP_START + 11)
#define WM_CAP_EDIT_COPY (WM_CAP_START + 30)
#define WM_CAP_GRAB_FRAME (WM_CAP_START + 60)
#define WM_CAP_SET_SCALE (WM_CAP_START + 53)
#define WM_CAP_SET_PREVIEWRATE (WM_CAP_START + 52)
#define WM_CAP_SET_PREVIEW (WM_CAP_START + 50)
#define WM_CAP_DLG_VIDEOSOURCE (WM_CAP_START + 42)
#define WM_CAP_STOP (WM_CAP_START+ 68)
#include
#include
LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM);
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp);
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC);
LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM);
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp);
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC);
char szAppName [] = TEXT("WebCam");
HWND camhwnd;
HDC hdc ;
HDC hdcMem;
PAINTSTRUCT ps;
HBITMAP hbm;
RECT rc;
//WinMain -- Main Window
int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow )
{
HWND hwnd;
MSG msg;
WNDCLASS wc;

2. wc.style = CS_HREDRAW|CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(GetModuleHandle(NULL), IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) (COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = szAppName;
RegisterClass (&wc);
// Create the window
hwnd = CreateWindow
(szAppName,szAppName,WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|
WS_MINIMIZEBOX,CW_USEDEFAULT,CW_USEDEFAULT,300,600,0,0,hInstance,0);
ShowWindow (hwnd,SW_SHOW);
UpdateWindow (hwnd);
while (GetMessage(&msg,0,0,0))
{
if(!IsDialogMessage(hwnd, &msg))
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
return msg.wParam;
}
//Main Window Procedure WindowProc
LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
//some buttons
HWND hButtStartCam;
HWND hButtStopCam;
HWND hButtGrabFrame;

3. switch (message) /* handle the messages */
{
case WM_CTLCOLORSTATIC:
SetBkMode(hdc,TRANSPARENT);
return (LRESULT)CreateSolidBrush(0xFFFFFF);
case WM_CREATE:
{
hButtStartCam = CreateWindowEx(0,"BUTTON","Start Camera",WS_CHILD |
WS_VISIBLE,
0,0,100,20,hwnd,(HMENU)1,hInstance, 0);
hButtStopCam = CreateWindowEx(0,"BUTTON","Stop Camera",WS_CHILD |
WS_VISIBLE,
0,25,100,20,hwnd,(HMENU)2,hInstance, 0);
hButtGrabFrame = CreateWindowEx(0,"BUTTON","Grab Frame",WS_CHILD |
WS_VISIBLE,
0,50,100,20,hwnd,(HMENU)3,hInstance, 0);
camhwnd = capCreateCaptureWindow ("camera window", WS_CHILD , 0, 100, 300, 300,
hwnd, 0);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
}
case WM_COMMAND:
{
switch(LOWORD(wParam))
{
case 1:
{
ShowWindow(camhwnd,SW_SHOW);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
case 2:

4. {
ShowWindow(camhwnd,SW_HIDE);
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
break;
}
case 3:
{
//Grab a Frame
SendMessage(camhwnd, WM_CAP_GRAB_FRAME, 0, 0);
//Copy the frame we have just grabbed to the clipboard
SendMessage(camhwnd, WM_CAP_EDIT_COPY,0,0);
//Copy the clipboard image data to a HBITMAP object called hbm
hdc = BeginPaint(camhwnd, &ps);
hdcMem = CreateCompatibleDC(hdc);
if (hdcMem != NULL)
{
if (OpenClipboard(camhwnd))
{
hbm = (HBITMAP) GetClipboardData(CF_BITMAP);
SelectObject(hdcMem, hbm);
GetClientRect(camhwnd, &rc);
CloseClipboard();
}
}
//Save hbm to a .bmp file called Frame.bmp
PBITMAPINFO pbi = CreateBitmapInfoStruct(hwnd, hbm);
CreateBMPFile(hwnd, "Frame.bmp", pbi, hbm, hdcMem);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
}
break;
}

5. case WM_DESTROY:
{
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
}
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC)
{
HANDLE hf; // file handle
BITMAPFILEHEADER hdr; // bitmap file-header
PBITMAPINFOHEADER pbih; // bitmap info-header
LPBYTE lpBits; // memory pointer
DWORD dwTotal; // total count of bytes
DWORD cb; // incremental count of bytes
BYTE *hp; // byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits)
{
MessageBox(hwnd,"GlobalAlloc","Error", MB_OK );
}
// Retrieve the color table (RGBQUAD array) and the bits
// (array of palette indices) from the DIB.
if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi,DIB_RGB_COLORS))
{
MessageBox(hwnd,"GetDIBits","Error",MB_OK );
}
// Create the .BMP file.
hf = CreateFile(pszFile,GENERIC_READ | GENERIC_WRITE,(DWORD)

6. 0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,(HANDLE) NULL);
if (hf == INVALID_HANDLE_VALUE)
{
MessageBox( hwnd,"CreateFile","Error", MB_OK);
}
hdr.bfType = 0x4d42; // File type designator "BM" 0x42 = "B" 0x4d = "M"
// Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed *
sizeof(RGBQUAD) + pbih->biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
// Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed
* sizeof (RGBQUAD);
// Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp,
NULL) )
{
MessageBox(hwnd,"WriteFileHeader","Error",MB_OK );
}
// Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof
(RGBQUAD), (LPDWORD) &dwTmp, NULL))
{
MessageBox(hwnd,"WriteInfoHeader","Error",MB_OK );
}
// Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL))
{
MessageBox(hwnd,"WriteFile","Error",MB_OK );
}
// Close the .BMP file.
if (!CloseHandle(hf))
{

7. MessageBox(hwnd,"CloseHandle","Error",MB_OK );
}
// Free memory.
GlobalFree((HGLOBAL)lpBits);
}
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp)
{
BITMAP bmp;
PBITMAPINFO pbmi;
WORD cClrBits;
// Retrieve the bitmap color format, width, and height.
if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp))
{
MessageBox(hwnd,"GetObject","Error",MB_OK );
}
// Convert the color format to a count of bits.
cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;
else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;
// Allocate memory for the BITMAPINFO structure. (This structure
// contains a BITMAPINFOHEADER structure and an array of RGBQUAD
// data structures.)
if (cClrBits != 24)
{
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1<< cClrBits));
}

8. // There is no RGBQUAD array for the 24-bit-per-pixel format.
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));
// Initialize the fields in the BITMAPINFO structure.
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
{
pbmi->bmiHeader.biClrUsed = (1<bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color
// indices and store the result in biSizeImage.
// For Windows NT, the width must be DWORD aligned unless
// the bitmap is RLE compressed. This example shows this.
// For Windows 95/98/Me, the width must be WORD aligned unless the
// bitmap is RLE compressed.
pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 *
pbmi->bmiHeader.biHeight;
// Set biClrImportant to 0, indicating that all of the
// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;
return pbmi; //return BITMAPINFO
}
//Setup some defines you need to connect to a webcam
//You can put these in a header
//If you are using Microsoft Visual Studio you wont need them as they
//Are included in Microsoft's version of vfw.h
#define WM_CAP_START 0x0400
#define WM_CAP_DRIVER_CONNECT (WM_CAP_START + 10)
#define WM_CAP_DRIVER_DISCONNECT (WM_CAP_START + 11)
#define WM_CAP_EDIT_COPY (WM_CAP_START + 30)
#define WM_CAP_GRAB_FRAME (WM_CAP_START + 60)
#define WM_CAP_SET_SCALE (WM_CAP_START + 53)
#define WM_CAP_SET_PREVIEWRATE (WM_CAP_START + 52)

9. #define WM_CAP_SET_PREVIEW (WM_CAP_START + 50)
#define WM_CAP_DLG_VIDEOSOURCE (WM_CAP_START + 42)
#define WM_CAP_STOP (WM_CAP_START+ 68)
//End of defines
#include
#include
//Remember to Link to vfw32 Library, gdi32 Library
LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM);
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp);
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC);
char szAppName [] = TEXT("WebCam");
HWND camhwnd;
HDC hdc ;
HDC hdcMem;
PAINTSTRUCT ps;
HBITMAP hbm;
RECT rc;
//WinMain -- Main Window
int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow )
{
HWND hwnd;
MSG msg;
WNDCLASS wc;
wc.style = CS_HREDRAW|CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(GetModuleHandle(NULL), IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) (COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = szAppName;

10. RegisterClass (&wc);
// Create the window
hwnd = CreateWindow
(szAppName,szAppName,WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|
WS_MINIMIZEBOX,CW_USEDEFAULT,CW_USEDEFAULT,300,600,0,0,hInstance,0);
ShowWindow (hwnd,SW_SHOW);
UpdateWindow (hwnd);
while (GetMessage(&msg,0,0,0))
{
if (!IsDialogMessage(hwnd, &msg))
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
return msg.wParam;
}
//Main Window Procedure WindowProc
LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
//some buttons
HWND hButtStartCam;
HWND hButtStopCam;
HWND hButtGrabFrame;
switch (message) /* handle the messages */
{
case WM_CTLCOLORSTATIC:
SetBkMode(hdc,TRANSPARENT);
return (LRESULT)CreateSolidBrush(0xFFFFFF);
case WM_CREATE:
{
hButtStartCam = CreateWindowEx(0,"BUTTON","Start Camera",WS_CHILD |
WS_VISIBLE,
0,0,100,20,hwnd,(HMENU)1,hInstance, 0);

11. hButtStopCam = CreateWindowEx(0,"BUTTON","Stop Camera",WS_CHILD |
WS_VISIBLE,
0,25,100,20,hwnd,(HMENU)2,hInstance, 0);
hButtGrabFrame = CreateWindowEx(0,"BUTTON","Grab Frame",WS_CHILD |
WS_VISIBLE,
0,50,100,20,hwnd,(HMENU)3,hInstance, 0);
camhwnd = capCreateCaptureWindow ("camera window", WS_CHILD , 0, 100, 300, 300,
hwnd, 0);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
}
case WM_COMMAND:
{
switch (LOWORD(wParam))
{
case 1:
{
ShowWindow(camhwnd,SW_SHOW);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
case 2:
{
ShowWindow(camhwnd,SW_HIDE);
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
break;
}
case 3:
{
//Grab a Frame
SendMessage(camhwnd, WM_CAP_GRAB_FRAME, 0, 0);
//Copy the frame we have just grabbed to the clipboard

12. SendMessage(camhwnd, WM_CAP_EDIT_COPY,0,0);
//Copy the clipboard image data to a HBITMAP object called hbm
hdc = BeginPaint(camhwnd, &ps);
hdcMem = CreateCompatibleDC(hdc);
if (hdcMem != NULL)
{
if (OpenClipboard(camhwnd))
{
hbm = (HBITMAP) GetClipboardData(CF_BITMAP);
SelectObject(hdcMem, hbm);
GetClientRect(camhwnd, &rc);
CloseClipboard();
}
}
//Save hbm to a .bmp file called Frame.bmp
PBITMAPINFO pbi = CreateBitmapInfoStruct(hwnd, hbm);
CreateBMPFile(hwnd, "Frame.bmp", pbi, hbm, hdcMem);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
}
break;
}
case WM_DESTROY:
{
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
}
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;

13. }
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC)
{
HANDLE hf; // file handle
BITMAPFILEHEADER hdr; // bitmap file-header
PBITMAPINFOHEADER pbih; // bitmap info-header
LPBYTE lpBits; // memory pointer
DWORD dwTotal; // total count of bytes
DWORD cb; // incremental count of bytes
BYTE *hp; // byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits)
{
MessageBox(hwnd,"GlobalAlloc","Error", MB_OK );
}
// Retrieve the color table (RGBQUAD array) and the bits
// (array of palette indices) from the DIB.
if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi,DIB_RGB_COLORS))
{
MessageBox(hwnd,"GetDIBits","Error",MB_OK );
}
// Create the .BMP file.
hf = CreateFile(pszFile,GENERIC_READ | GENERIC_WRITE,(DWORD)
0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,(HANDLE)
NULL);
if (hf == INVALID_HANDLE_VALUE)
{
MessageBox( hwnd,"CreateFile","Error", MB_OK);
}
hdr.bfType = 0x4d42; // File type designator "BM" 0x42 = "B" 0x4d = "M"
// Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed *
sizeof(RGBQUAD) + pbih-

14. >biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
// Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed
* sizeof (RGBQUAD);
// Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp,
NULL) )
{
MessageBox(hwnd,"WriteFileHeader","Error",MB_OK );
}
// Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof
(RGBQUAD), (LPDWORD) &dwTmp,
NULL))
{
MessageBox(hwnd,"WriteInfoHeader","Error",MB_OK );
}
// Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL))
{
MessageBox(hwnd,"WriteFile","Error",MB_OK );
}
// Close the .BMP file.
if (!CloseHandle(hf))
{
MessageBox(hwnd,"CloseHandle","Error",MB_OK );
}
// Free memory.
GlobalFree((HGLOBAL)lpBits);
}
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp)
{

15. BITMAP bmp;
PBITMAPINFO pbmi;
WORD cClrBits;
// Retrieve the bitmap color format, width, and height.
if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp))
{
MessageBox(hwnd,"GetObject","Error",MB_OK );
}
// Convert the color format to a count of bits.
cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;
else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;
// Allocate memory for the BITMAPINFO structure. (This structure
// contains a BITMAPINFOHEADER structure and an array of RGBQUAD
// data structures.)
if (cClrBits != 24)
{
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1<< cClrBits));
}
// There is no RGBQUAD array for the 24-bit-per-pixel format.
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));
// Initialize the fields in the BITMAPINFO structure.
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;

16. pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
{
pbmi->bmiHeader.biClrUsed = (1<bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color
// indices and store the result in biSizeImage.
// For Windows NT, the width must be DWORD aligned unless
// the bitmap is RLE compressed. This example shows this.
// For Windows 95/98/Me, the width must be WORD aligned unless the
// bitmap is RLE compressed.
pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 *
pbmi->bmiHeader.biHeight;
// Set biClrImportant to 0, indicating that all of the
// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;
return pbmi; //return BITMAPINFO
}
Solution
Ans:
#define WM_CAP_START 0x0400
#define WM_CAP_DRIVER_CONNECT (WM_CAP_START + 10)
#define WM_CAP_DRIVER_DISCONNECT (WM_CAP_START + 11)
#define WM_CAP_EDIT_COPY (WM_CAP_START + 30)
#define WM_CAP_GRAB_FRAME (WM_CAP_START + 60)
#define WM_CAP_SET_SCALE (WM_CAP_START + 53)
#define WM_CAP_SET_PREVIEWRATE (WM_CAP_START + 52)
#define WM_CAP_SET_PREVIEW (WM_CAP_START + 50)
#define WM_CAP_DLG_VIDEOSOURCE (WM_CAP_START + 42)
#define WM_CAP_STOP (WM_CAP_START+ 68)
#include
#include
LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM);
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp);

17. void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC);
LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM);
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp);
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC);
char szAppName [] = TEXT("WebCam");
HWND camhwnd;
HDC hdc ;
HDC hdcMem;
PAINTSTRUCT ps;
HBITMAP hbm;
RECT rc;
//WinMain -- Main Window
int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow )
{
HWND hwnd;
MSG msg;
WNDCLASS wc;
wc.style = CS_HREDRAW|CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(GetModuleHandle(NULL), IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) (COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = szAppName;
RegisterClass (&wc);
// Create the window
hwnd = CreateWindow
(szAppName,szAppName,WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|
WS_MINIMIZEBOX,CW_USEDEFAULT,CW_USEDEFAULT,300,600,0,0,hInstance,0);
ShowWindow (hwnd,SW_SHOW);

18. UpdateWindow (hwnd);
while (GetMessage(&msg,0,0,0))
{
if(!IsDialogMessage(hwnd, &msg))
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
return msg.wParam;
}
//Main Window Procedure WindowProc
LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
//some buttons
HWND hButtStartCam;
HWND hButtStopCam;
HWND hButtGrabFrame;
switch (message) /* handle the messages */
{
case WM_CTLCOLORSTATIC:
SetBkMode(hdc,TRANSPARENT);
return (LRESULT)CreateSolidBrush(0xFFFFFF);
case WM_CREATE:
{
hButtStartCam = CreateWindowEx(0,"BUTTON","Start Camera",WS_CHILD |
WS_VISIBLE,
0,0,100,20,hwnd,(HMENU)1,hInstance, 0);
hButtStopCam = CreateWindowEx(0,"BUTTON","Stop Camera",WS_CHILD |
WS_VISIBLE,
0,25,100,20,hwnd,(HMENU)2,hInstance, 0);
hButtGrabFrame = CreateWindowEx(0,"BUTTON","Grab Frame",WS_CHILD |
WS_VISIBLE,
0,50,100,20,hwnd,(HMENU)3,hInstance, 0);

19. camhwnd = capCreateCaptureWindow ("camera window", WS_CHILD , 0, 100, 300, 300,
hwnd, 0);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
}
case WM_COMMAND:
{
switch(LOWORD(wParam))
{
case 1:
{
ShowWindow(camhwnd,SW_SHOW);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
case 2:
{
ShowWindow(camhwnd,SW_HIDE);
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
break;
}
case 3:
{
//Grab a Frame
SendMessage(camhwnd, WM_CAP_GRAB_FRAME, 0, 0);
//Copy the frame we have just grabbed to the clipboard
SendMessage(camhwnd, WM_CAP_EDIT_COPY,0,0);
//Copy the clipboard image data to a HBITMAP object called hbm
hdc = BeginPaint(camhwnd, &ps);
hdcMem = CreateCompatibleDC(hdc);
if (hdcMem != NULL)
{

20. if (OpenClipboard(camhwnd))
{
hbm = (HBITMAP) GetClipboardData(CF_BITMAP);
SelectObject(hdcMem, hbm);
GetClientRect(camhwnd, &rc);
CloseClipboard();
}
}
//Save hbm to a .bmp file called Frame.bmp
PBITMAPINFO pbi = CreateBitmapInfoStruct(hwnd, hbm);
CreateBMPFile(hwnd, "Frame.bmp", pbi, hbm, hdcMem);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
}
break;
}
case WM_DESTROY:
{
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
}
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC)
{
HANDLE hf; // file handle
BITMAPFILEHEADER hdr; // bitmap file-header

21. PBITMAPINFOHEADER pbih; // bitmap info-header
LPBYTE lpBits; // memory pointer
DWORD dwTotal; // total count of bytes
DWORD cb; // incremental count of bytes
BYTE *hp; // byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits)
{
MessageBox(hwnd,"GlobalAlloc","Error", MB_OK );
}
// Retrieve the color table (RGBQUAD array) and the bits
// (array of palette indices) from the DIB.
if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi,DIB_RGB_COLORS))
{
MessageBox(hwnd,"GetDIBits","Error",MB_OK );
}
// Create the .BMP file.
hf = CreateFile(pszFile,GENERIC_READ | GENERIC_WRITE,(DWORD)
0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,(HANDLE) NULL);
if (hf == INVALID_HANDLE_VALUE)
{
MessageBox( hwnd,"CreateFile","Error", MB_OK);
}
hdr.bfType = 0x4d42; // File type designator "BM" 0x42 = "B" 0x4d = "M"
// Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed *
sizeof(RGBQUAD) + pbih->biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
// Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed
* sizeof (RGBQUAD);
// Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp,

22. NULL) )
{
MessageBox(hwnd,"WriteFileHeader","Error",MB_OK );
}
// Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof
(RGBQUAD), (LPDWORD) &dwTmp, NULL))
{
MessageBox(hwnd,"WriteInfoHeader","Error",MB_OK );
}
// Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL))
{
MessageBox(hwnd,"WriteFile","Error",MB_OK );
}
// Close the .BMP file.
if (!CloseHandle(hf))
{
MessageBox(hwnd,"CloseHandle","Error",MB_OK );
}
// Free memory.
GlobalFree((HGLOBAL)lpBits);
}
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp)
{
BITMAP bmp;
PBITMAPINFO pbmi;
WORD cClrBits;
// Retrieve the bitmap color format, width, and height.
if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp))
{
MessageBox(hwnd,"GetObject","Error",MB_OK );
}
// Convert the color format to a count of bits.

23. cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;
else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;
// Allocate memory for the BITMAPINFO structure. (This structure
// contains a BITMAPINFOHEADER structure and an array of RGBQUAD
// data structures.)
if (cClrBits != 24)
{
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1<< cClrBits));
}
// There is no RGBQUAD array for the 24-bit-per-pixel format.
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));
// Initialize the fields in the BITMAPINFO structure.
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
{
pbmi->bmiHeader.biClrUsed = (1<bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color
// indices and store the result in biSizeImage.
// For Windows NT, the width must be DWORD aligned unless
// the bitmap is RLE compressed. This example shows this.

24. // For Windows 95/98/Me, the width must be WORD aligned unless the
// bitmap is RLE compressed.
pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 *
pbmi->bmiHeader.biHeight;
// Set biClrImportant to 0, indicating that all of the
// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;
return pbmi; //return BITMAPINFO
}
//Setup some defines you need to connect to a webcam
//You can put these in a header
//If you are using Microsoft Visual Studio you wont need them as they
//Are included in Microsoft's version of vfw.h
#define WM_CAP_START 0x0400
#define WM_CAP_DRIVER_CONNECT (WM_CAP_START + 10)
#define WM_CAP_DRIVER_DISCONNECT (WM_CAP_START + 11)
#define WM_CAP_EDIT_COPY (WM_CAP_START + 30)
#define WM_CAP_GRAB_FRAME (WM_CAP_START + 60)
#define WM_CAP_SET_SCALE (WM_CAP_START + 53)
#define WM_CAP_SET_PREVIEWRATE (WM_CAP_START + 52)
#define WM_CAP_SET_PREVIEW (WM_CAP_START + 50)
#define WM_CAP_DLG_VIDEOSOURCE (WM_CAP_START + 42)
#define WM_CAP_STOP (WM_CAP_START+ 68)
//End of defines
#include
#include
//Remember to Link to vfw32 Library, gdi32 Library
LRESULT CALLBACK WindowProc (HWND, UINT, WPARAM, LPARAM);
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp);
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC);
char szAppName [] = TEXT("WebCam");
HWND camhwnd;
HDC hdc ;
HDC hdcMem;

25. PAINTSTRUCT ps;
HBITMAP hbm;
RECT rc;
//WinMain -- Main Window
int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow )
{
HWND hwnd;
MSG msg;
WNDCLASS wc;
wc.style = CS_HREDRAW|CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(GetModuleHandle(NULL), IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) (COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = szAppName;
RegisterClass (&wc);
// Create the window
hwnd = CreateWindow
(szAppName,szAppName,WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|
WS_MINIMIZEBOX,CW_USEDEFAULT,CW_USEDEFAULT,300,600,0,0,hInstance,0);
ShowWindow (hwnd,SW_SHOW);
UpdateWindow (hwnd);
while (GetMessage(&msg,0,0,0))
{
if (!IsDialogMessage(hwnd, &msg))
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
return msg.wParam;

26. }
//Main Window Procedure WindowProc
LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
//some buttons
HWND hButtStartCam;
HWND hButtStopCam;
HWND hButtGrabFrame;
switch (message) /* handle the messages */
{
case WM_CTLCOLORSTATIC:
SetBkMode(hdc,TRANSPARENT);
return (LRESULT)CreateSolidBrush(0xFFFFFF);
case WM_CREATE:
{
hButtStartCam = CreateWindowEx(0,"BUTTON","Start Camera",WS_CHILD |
WS_VISIBLE,
0,0,100,20,hwnd,(HMENU)1,hInstance, 0);
hButtStopCam = CreateWindowEx(0,"BUTTON","Stop Camera",WS_CHILD |
WS_VISIBLE,
0,25,100,20,hwnd,(HMENU)2,hInstance, 0);
hButtGrabFrame = CreateWindowEx(0,"BUTTON","Grab Frame",WS_CHILD |
WS_VISIBLE,
0,50,100,20,hwnd,(HMENU)3,hInstance, 0);
camhwnd = capCreateCaptureWindow ("camera window", WS_CHILD , 0, 100, 300, 300,
hwnd, 0);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
}
case WM_COMMAND:
{
switch (LOWORD(wParam))
{

27. case 1:
{
ShowWindow(camhwnd,SW_SHOW);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
case 2:
{
ShowWindow(camhwnd,SW_HIDE);
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
break;
}
case 3:
{
//Grab a Frame
SendMessage(camhwnd, WM_CAP_GRAB_FRAME, 0, 0);
//Copy the frame we have just grabbed to the clipboard
SendMessage(camhwnd, WM_CAP_EDIT_COPY,0,0);
//Copy the clipboard image data to a HBITMAP object called hbm
hdc = BeginPaint(camhwnd, &ps);
hdcMem = CreateCompatibleDC(hdc);
if (hdcMem != NULL)
{
if (OpenClipboard(camhwnd))
{
hbm = (HBITMAP) GetClipboardData(CF_BITMAP);
SelectObject(hdcMem, hbm);
GetClientRect(camhwnd, &rc);
CloseClipboard();
}
}
//Save hbm to a .bmp file called Frame.bmp
PBITMAPINFO pbi = CreateBitmapInfoStruct(hwnd, hbm);

28. CreateBMPFile(hwnd, "Frame.bmp", pbi, hbm, hdcMem);
SendMessage(camhwnd,WM_CAP_DRIVER_CONNECT,0,0);
SendMessage(camhwnd, WM_CAP_SET_SCALE, true , 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(camhwnd, WM_CAP_SET_PREVIEW, true , 0);
break;
}
}
break;
}
case WM_DESTROY:
{
SendMessage(camhwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
}
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP,
HDC hDC)
{
HANDLE hf; // file handle
BITMAPFILEHEADER hdr; // bitmap file-header
PBITMAPINFOHEADER pbih; // bitmap info-header
LPBYTE lpBits; // memory pointer
DWORD dwTotal; // total count of bytes
DWORD cb; // incremental count of bytes
BYTE *hp; // byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits)
{

29. MessageBox(hwnd,"GlobalAlloc","Error", MB_OK );
}
// Retrieve the color table (RGBQUAD array) and the bits
// (array of palette indices) from the DIB.
if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi,DIB_RGB_COLORS))
{
MessageBox(hwnd,"GetDIBits","Error",MB_OK );
}
// Create the .BMP file.
hf = CreateFile(pszFile,GENERIC_READ | GENERIC_WRITE,(DWORD)
0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,(HANDLE)
NULL);
if (hf == INVALID_HANDLE_VALUE)
{
MessageBox( hwnd,"CreateFile","Error", MB_OK);
}
hdr.bfType = 0x4d42; // File type designator "BM" 0x42 = "B" 0x4d = "M"
// Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed *
sizeof(RGBQUAD) + pbih-
>biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
// Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed
* sizeof (RGBQUAD);
// Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp,
NULL) )
{
MessageBox(hwnd,"WriteFileHeader","Error",MB_OK );
}
// Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof
(RGBQUAD), (LPDWORD) &dwTmp,
NULL))

30. {
MessageBox(hwnd,"WriteInfoHeader","Error",MB_OK );
}
// Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL))
{
MessageBox(hwnd,"WriteFile","Error",MB_OK );
}
// Close the .BMP file.
if (!CloseHandle(hf))
{
MessageBox(hwnd,"CloseHandle","Error",MB_OK );
}
// Free memory.
GlobalFree((HGLOBAL)lpBits);
}
PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp)
{
BITMAP bmp;
PBITMAPINFO pbmi;
WORD cClrBits;
// Retrieve the bitmap color format, width, and height.
if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp))
{
MessageBox(hwnd,"GetObject","Error",MB_OK );
}
// Convert the color format to a count of bits.
cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;

31. else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;
// Allocate memory for the BITMAPINFO structure. (This structure
// contains a BITMAPINFOHEADER structure and an array of RGBQUAD
// data structures.)
if (cClrBits != 24)
{
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1<< cClrBits));
}
// There is no RGBQUAD array for the 24-bit-per-pixel format.
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));
// Initialize the fields in the BITMAPINFO structure.
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
{
pbmi->bmiHeader.biClrUsed = (1<bmiHeader.biCompression = BI_RGB;
// Compute the number of bytes in the array of color
// indices and store the result in biSizeImage.
// For Windows NT, the width must be DWORD aligned unless
// the bitmap is RLE compressed. This example shows this.
// For Windows 95/98/Me, the width must be WORD aligned unless the
// bitmap is RLE compressed.
pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 *
pbmi->bmiHeader.biHeight;
// Set biClrImportant to 0, indicating that all of the
// device colors are important.
pbmi->bmiHeader.biClrImportant = 0;

32. return pbmi; //return BITMAPINFO
}