C / C++ / MFC

30-Nov-07 4:40

hello , i've tryed to capture snapshots on yahoo webcam with bitblt to make a yahoo webcam recorder, i managed to do it but with some problems. on my webcam it works perfectly the image captured is clear but if i try to snapshot another webcam window(some work some don't) the image is scrambled. i will post the entire source code it's not too long and a sample snapshot to see the problem.

http://rapidshare.com/files/73346892/frame_2.bmp.html

<br />
   HWND frame,mainwin,last=NULL;<br />
<br />
<br />
bool writebmpfile(int bitmap_dx,int bitmap_dy,int bytes, BYTE *memory,BITMAPFILEHEADER fileHeader,BITMAPINFOHEADER infoHeader,int frame);<br />
<br />
<br />
typedef struct cadre<br />
{<br />
    char cadru[200];<br />
}cadre;<br />
<br />
<br />
cadre cadre[10000];<br />
<br />
<br />
<br />
BOOL CALLBACK findchildweb(HWND hwnd,LPARAM lParam)<br />
{<br />
    char clasa[100]={0};<br />
    char text[150]={0};<br />
<br />
<br />
    GetClassName(hwnd,clasa,100);<br />
<br />
    if(!strcmp(clasa,"ATL:0B39D378")|| !strcmp(clasa,"#32770"))<br />
    {    <br />
        frame=hwnd;<br />
<br />
    <br />
    }<br />
<br />
    GetWindowText(hwnd,text,150);<br />
<br />
    if(strstr(text,"Last")!=NULL || strstr(text,"Broadcast")!=NULL)<br />
    {<br />
        last=hwnd;<br />
<br />
    }<br />
<br />
<br />
<br />
    <br />
    if(last!=NULL && frame!=NULL)<br />
        return false;<br />
    else<br />
        return true;<br />
<br />
}<br />
<br />
<br />
<br />
//----------------------------------------------------------<br />
BOOL CALLBACK findwebwnd(HWND hwnd,LPARAM lParam)<br />
{<br />
    char clasa[100]={0};<br />
<br />
    GetClassName(hwnd,clasa,100);<br />
<br />
    if(!strcmp(clasa,"WebcamClass"))<br />
    {<br />
        mainwin=hwnd;<br />
        EnumChildWindows(hwnd,findchildweb,0);<br />
        return false;<br />
<br />
    }<br />
<br />
<br />
<br />
<br />
<br />
    return true;<br />
}<br />
<br />
<br />
<br />
//--------------------------------------------------------<br />
<br />
bool findandcapture()<br />
{<br />
     frame=NULL;<br />
     HDC devcnt=NULL,devc=NULL,cmpdc=NULL;<br />
     RECT dim={0};<br />
     HBITMAP bmp=NULL;<br />
     BYTE *memory=0;<br />
<br />
    BITMAPFILEHEADER fileHeader;<br />
    BITMAPINFOHEADER infoHeader;<br />
    BITMAPINFO info;<br />
    int numframe=-1;<br />
<br />
    char cur[150]={0},prev[150]={0};<br />
    <br />
<br />
<br />
    <br />
<br />
<br />
    EnumWindows(findwebwnd,0);<br />
<br />
<br />
    <br />
    <br />
    if(frame!=NULL)<br />
    devcnt=GetWindowDC(frame);<br />
    else<br />
        return false;<br />
<br />
    GetWindowRect(frame,&dim);<br />
<br />
    int bitmap_dx = dim.right - dim.left;<br />
    int bitmap_dy = dim.bottom - dim.top;<br />
<br />
//------------headerul bitmap----------------------<br />
    fileHeader.bfType      = 0x4d42;<br />
         fileHeader.bfSize      = 0;<br />
         fileHeader.bfReserved1 = 0;<br />
         fileHeader.bfReserved2 = 0;<br />
         fileHeader.bfOffBits   = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);<br />
<br />
         infoHeader.biSize          = sizeof(infoHeader);<br />
         infoHeader.biWidth         = bitmap_dx;<br />
         infoHeader.biHeight        = bitmap_dy;<br />
         infoHeader.biPlanes        = 1;<br />
         infoHeader.biBitCount      = 24;<br />
         infoHeader.biCompression   = BI_RGB;<br />
         infoHeader.biSizeImage     = 0;<br />
         infoHeader.biXPelsPerMeter = 0;<br />
         infoHeader.biYPelsPerMeter = 0;<br />
         infoHeader.biClrUsed       = 0;<br />
         infoHeader.biClrImportant  = 0;<br />
         info.bmiHeader = infoHeader;<br />
<br />
<br />
//------------headerul bitmap----------------------<br />
<br />
             cmpdc=CreateCompatibleDC(devcnt);<br />
<br />
    bmp=CreateDIBSection(devcnt, &info, DIB_RGB_COLORS, (void**)&memory, 0, 0);<br />
    DWORD eror=GetLastError();<br />
    SelectObject(cmpdc,bmp);<br />
<br />
<br />
<br />
    while(1)<br />
    {<br />
        <br />
<br />
        if(strcmp(cur,prev) || strstr(prev,"Broad")!=NULL)<br />
        {<br />
                numframe++;<br />
<br />
        GetWindowText(last,cur,150);<br />
<br />
            BitBlt(cmpdc, 0, 0, bitmap_dx, bitmap_dy, devcnt, 0, 0, SRCCOPY);<br />
<br />
             int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy;<br />
<br />
<br />
<br />
              writebmpfile(bitmap_dx,bitmap_dy, bytes, memory,fileHeader,infoHeader,numframe);<br />
<br />
<br />
             DeleteObject(bmp);<br />
<br />
              if(UpdateWindow(mainwin)==false)<br />
                  break;<br />
<br />
              if(strstr(prev,"Broad")!=NULL)<br />
                  Sleep(500);<br />
<br />
        }<br />
        else<br />
            Sleep(1);<br />
<br />
<br />
        GetWindowText(last,prev,150);<br />
<br />
<br />
<br />
<br />
    Sleep(1);<br />
    }<br />
<br />
<br />
<br />
<br />
    DeleteDC(cmpdc);<br />
    ReleaseDC(frame, devcnt);<br />
<br />
<br />
<br />
<br />
<br />
    return true;<br />
}<br />
<br />
//---------------------------------------------------------------------------------------------<br />
<br />
bool writebmpfile(int bitmap_dx,int bitmap_dy,int bytes, BYTE *memory,BITMAPFILEHEADER fileHeader,BITMAPINFOHEADER infoHeader,int frame)<br />
{<br />
<br />
<br />
<br />
<br />
    FILE *fisier;<br />
    <br />
    <br />
    sprintf(cadre[frame].cadru,"%s_%d.%s","frame",frame,"bmp");<br />
<br />
        <br />
<br />
         fisier=fopen(cadre[frame].cadru,"w+");<br />
<br />
<br />
<br />
         fwrite((char*)&fileHeader,1,sizeof(fileHeader),fisier);<br />
<br />
         fwrite((char*)&infoHeader,1,sizeof(infoHeader),fisier);<br />
<br />
         fwrite(memory,1,bytes,fisier);<br />
<br />
    <br />
<br />
         fclose (fisier);<br />
<br />
<br />
<br />
<br />
    return true;<br />
}<br />
<br />
<br />
<br />

Mark Salsbery30-Nov-07 9:46

30-Nov-07 9:46

What do you mean by "scrambled"?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

csmanul30-Nov-07 11:58

30-Nov-07 11:58

the picture has interference like an old tv or a cracked LCD display

Mark Salsbery30-Nov-07 12:12

30-Nov-07 12:12

I don't have an old TV or a cracked LCD display to compare to.
Can you post an example image somewhere?

If it works on some windows and not others, then I imagine it's
a problem with the way the video is being rendered (DirectX,
for example), you're scraping the screen out of sync with the video
refresh, or you're getting frames in between key frames.

Just guesses...
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

csmanul30-Nov-07 12:58

30-Nov-07 12:58

http://rapidshare.com/files/73346892/frame_2.bmp.html here is the sample image and i noticed that CreateDIBSection returns Not enough storage is available to process this command.

Mark Salsbery30-Nov-07 13:18

30-Nov-07 13:18

I couldn't see the image, but I've been trying to find something in the code.

Shouldn't the DeleteObject(bmp); call be outside/after the while() loop?

You should also select bmp out of the memory DC (by selecting its original bitmap back in)
before you delete it.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Mark Salsbery30-Nov-07 13:28

30-Nov-07 13:28

Does this work (changes marked in color)?

bool findandcapture()
{
    frame=NULL;
    HDC devcnt=NULL,devc=NULL,cmpdc=NULL;
    RECT dim={0};
    HBITMAP bmp=NULL;
    BYTE *memory=0;

    BITMAPFILEHEADER fileHeader;
    BITMAPINFOHEADER infoHeader;
    BITMAPINFO info;
    int numframe=-1;

    char cur[150]={0},prev[150]={0};


    EnumWindows(findwebwnd,0);


    if(frame!=NULL)
        devcnt=GetWindowDC(frame);
    else
        return false;

    GetWindowRect(frame,&dim);

    int bitmap_dx = dim.right - dim.left;
    int bitmap_dy = dim.bottom - dim.top;

    //------------headerul bitmap----------------------
    fileHeader.bfType = 0x4d42;
    fileHeader.bfSize = 0;
    fileHeader.bfReserved1 = 0;
    fileHeader.bfReserved2 = 0;
    fileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

    infoHeader.biSize = sizeof(infoHeader);
    infoHeader.biWidth = bitmap_dx;
    infoHeader.biHeight = bitmap_dy;
    infoHeader.biPlanes = 1;
    infoHeader.biBitCount = 24;
    infoHeader.biCompression = BI_RGB;
    infoHeader.biSizeImage = 0;
    infoHeader.biXPelsPerMeter = 0;
    infoHeader.biYPelsPerMeter = 0;
    infoHeader.biClrUsed = 0;
    infoHeader.biClrImportant = 0;
    info.bmiHeader = infoHeader;


    //------------headerul bitmap----------------------

    cmpdc=CreateCompatibleDC(devcnt);

    bmp=CreateDIBSection(devcnt, &info, DIB_RGB_COLORS, (void**)&memory, 0, 0);
    DWORD eror=GetLastError();
    <font color="Red">HGDIOBJ hOldBMP = </font>SelectObject(cmpdc,bmp);


    <font color="Green">// Moved out of while loop</font>
    <font color="Red">int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy;</font>

    while(1)
    {
        if(strcmp(cur,prev) || strstr(prev,"Broad")!=NULL)
        {
            numframe++;

            GetWindowText(last,cur,150);

            BitBlt(cmpdc, 0, 0, bitmap_dx, bitmap_dy, devcnt, 0, 0, SRCCOPY);

           
<font color="Green">            // Moved out of while loop</font>
            <font color="Red">//int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy;</font>



            writebmpfile(bitmap_dx,bitmap_dy, bytes, memory,fileHeader,infoHeader,numframe);
<font color="Green">

            // Moved out of while loop</font>             <font color="Red">
            //DeleteObject(bmp);</font>

            if(UpdateWindow(mainwin)==false)
                break;

            if(strstr(prev,"Broad")!=NULL)
                Sleep(500);

        }
        else
            Sleep(1);


        GetWindowText(last,prev,150);




        Sleep(1);
    }


    <font color="Red">SelectObject(cmpdc,hOldBMP);
    DeleteObject(bmp);</font>

    DeleteDC(cmpdc);
    ReleaseDC(frame, devcnt);


    return true;
}

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

csmanul30-Nov-07 13:38

30-Nov-07 13:38

nope same problem and getlasterror still returns Not enough storage after the CreateDIBsection func. i think there is the problem maybe i miscalculated something on the bitmap structures , what do you think ?

P.S : thanks for your kindness to help me

Mark Salsbery30-Nov-07 13:46

30-Nov-07 13:46

It looks ok to me - I'm not sure what I'm missing (obviously Smile | :)

)

CreateDIBSection is returning NULL and then GetLastError() returns what?
The only thing that should affect that is the width and height - what are those values?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

csmanul30-Nov-07 13:55