下面介绍如何在视频文件中加入自己的水印图片及LOGO
typedef struct _VMRALPHABITMAP {
DWORD dwFlags; //指明从哪儿获取位图
HDC hdc; //指定的设备上下文DC。如果指定为NULL，则位图是从一个DirectDraw surface上获取。
LPDIRECTDRAWSURFACE7 pDDS; // 指向 DirectDraw surface的一个指针。如果指定为NULL则,位图是从GDI DC中获取。
RECT rSrc; //指明源矩形
NORMALIZEDRECT rDest; //指定目标矩形
FLOAT fAlpha; //指定alpha混合值，必须有一个在0.0到1.0之间的值（含） 。
COLORREF clrSrcKey; //指定需要取消图片的背景颜色
} VMRALPHABITMAP;typedef struct _VMRALPHABITMAP *PVMRALPHABITMAP;
dwFlags应为以下值
| VMRBITMAP_DISABLE (0x00000001) | 现在不需要位图 |
| VMRBITMAP_HDC (0x00000002) | 从HDC中获取位图 |
| VMRBITMAP_ENTIREDDS (0x00000004) | 从整个DirectDraw surface获取位图.当这个被指定时, 指定rSrc没有用. |
| VMRBITMAP_SRCCOLORKEY (0x00000008) | clrSrcKey 值可用，当在混合运算渲染位图时，这个值将被用到 |
| VMRBITMAP_SRCRECT (0x00000010) |
HRESULT CVMRPlayMovive::BlendApplicationImage(HWND hwndApp)
{
LONG cx, cy;
HRESULT hr;
RECT rc={0};
hr = pWC->GetNativeVideoSize(&cx, &cy, NULL, NULL);
if (FAILED(hr))
return hr;
HINSTANCE hInstance = (HINSTANCE)GetWindowLong(m_hwnd,GWL_HINSTANCE);
HBITMAP hbm = LoadBitmap(hInstance, MAKEINTRESOURCE(IDB_BITMAP3));
//加载位图
BITMAP bm;
HBITMAP hbmOld;
HDC hdc = GetDC(hwndApp);
HDC hdcBmp = CreateCompatibleDC(hdc);
ReleaseDC(hwndApp, hdc);
GetObject(hbm, sizeof(bm), &bm);
hbmOld = (HBITMAP)SelectObject(hdcBmp, hbm);
VMRALPHABITMAP bmpInfo;
ZeroMemory(&bmpInfo, sizeof(bmpInfo) );
bmpInfo.dwFlags = VMRBITMAP_HDC;
bmpInfo.hdc = hdcBmp;
g_nBitmapWidth = bm.bmWidth;
g_nImageWidth = bm.bmWidth / NUM_IMAGES_IN_BITMAP;
SetRect(&rc,0,0,g_nBitmapWidth, bm.bmHeight);
bmpInfo.rSrc = rc;
// rDest specifies the destination rectangle in composition space (0.0f to 1.0f)
bmpInfo.rDest.left = (float)(cx - g_nImageWidth) / (float)cx - EDGE_BUFFER;
bmpInfo.rDest.top = (float)(cy - bm.bmHeight) / (float)cy - EDGE_BUFFER;
bmpInfo.rDest.right = 1.0f - EDGE_BUFFER;
bmpInfo.rDest.bottom = 1.0f - EDGE_BUFFER;
g_rDest = bmpInfo.rDest;
g_rSrc = bmpInfo.rSrc;
g_fBitmapCompWidth = (float)g_nImageWidth / (float)cx;
bmpInfo.fAlpha = 0.0;
SetColorRef(bmpInfo);
hr = pBMP->SetAlphaBitmap(&bmpInfo);
if (FAILED(hr))
Msg(TEXT("SetAlphaBitmap FAILED! Bitmap operations will fail. hr=0x%x\r\n"), hr);
// Clean up GDI resources
DeleteObject(SelectObject(hdcBmp, hbmOld));
DeleteObject(hbm);
DeleteDC(hdcBmp);
// If setting the alpha bitmap succeeded, update its parameters
if (SUCCEEDED(hr))
{
SetRect(&rc, 0, 0, g_nImageWidth, bm.bmHeight);
bmpInfo.rSrc = rc;
g_rSrcSingle = rc;
bmpInfo.dwFlags = VMRBITMAP_SRCRECT | VMRBITMAP_SRCCOLORKEY;
bmpInfo.fAlpha = TRANSPARENCY_VALUE;
hr = pBMP->UpdateAlphaBitmapParameters(&bmpInfo);
if (FAILED(hr))
Msg(TEXT("UpdateAlphaBitmapParameters FAILED! hr=0x%x\r\n"), hr);
}
return hr;
}
void CVMRPlayMovive::SetColorRef(VMRALPHABITMAP& bmpInfo)
{
bmpInfo.clrSrcKey = RGB(255, 0, 0);
bmpInfo.dwFlags |= VMRBITMAP_SRCCOLORKEY;
}