C Win32: save .bmp image from HBITMAP

Question

I am working with a framegrabber and need to get the images from computer memory and save them on an image file. after trying for couple of days I end up with the following 2 fu

Answer 1

FORMAT_INFO sFormat;
mvfg_getparam( MVFGPAR_DATAFORMAT, &sFormat, giCurrentGrabberID);
long lFrameSize     = sFormat.lFrameSize;

BYTE *pBitmap = (BYTE*)malloc(FrameSize);
memcpy( pBitmap, CamGetPicture(), FrameSize );
writeBitmapToFile(pBitmap, FrameSize, "tmp.bmp");

/*
 * write our raw data into a bitmap file
 * adding the correct header and put it all
 * together in a single file
 */
int
writeBitmapToFile(void *data, unsigned long size, const char *filename)
{
    bmpFileHeader_t header;
    bmpInfoHeader_t info;
    bmpRGBQuad_t rgb = { 0, 0, 0, 0};
    FILE *out;
    size_t len;
    int i;


    header.type = 0x4d42; // magic sequence 'BM'
    header.size = 0;
    header.res0 = 0;
    header.res1 = 0;
    /* 256 different colors, each is defined by an bmpRBQuad type */
    header.offset = 256 * sizeof(bmpRGBQuad_t) + 
                    sizeof(bmpInfoHeader_t) + sizeof(bmpFileHeader_t);
    info.size = sizeof(bmpInfoHeader_t);
    info.width = WIDTH;
    info.height = HEIGHT;
    info.planes = 1;
    info.cDepth = 8; /* 8 Bit */
    info.compression = 0;
    info.rawSize = size;
    info.hRes = 0;
    info.vRes = 0;
    info.nrColors = 0x100;
    info.impColors = 0;

    out = fopen(filename, "wb");
    if (out == NULL) {
        printf("error cannot open %s for writing\n", filename);
        return -1;
    }
    len = fwrite(&header, 1, sizeof(header), out);
    if (len != sizeof(header)) {
        printf("error while writing header\n");
        return -1;
    }
    len = fwrite(&info, 1, sizeof(info), out);
    if (len != sizeof(info)) {
        printf("error while writing info header\n");
        return -1;
    }
    /* stupid try and error programming leads to this */
    for (i = 0; i < 256; i++) {
        rgb.red = i;
        rgb.green = i;
        rgb.blue = i;
        len = fwrite(&rgb, 1, sizeof(rgb), out);
        if (len != sizeof(rgb)) {
            printf("error while writing rgb header\n");
            return -1;
        }
    }

    len = fwrite(data, 1, size, out);
    if (len != size ) {
        printf("error while writing bitmap data\n");
        return -1;
    }
    return 0;
}

Reference - mikrotron

Reference - write bitmap