DirectShow构建Windowless 模式
windowed mode 和 windowless mode
* windowed mode :renderer 创建它自己所属的窗口,简单的说你可以把他当作程序的子窗口。
* windowless mode:renderer 在程序窗口上直接绘图,这并不会创建子窗口
下面介绍windowsless mode的配置
1.创建filter graph manager.
2.创建VMR ,接着添加到过滤图层(filter graph)
3.调用IVMRFilterConfig::SetRenderingMode,参数设置成VMRMode_windowless
4.调用IVMRWindowlessControl::SetVideoClippingWindow,指定程序上的显示句柄(handle)
[CODE]
HRESULT InitWindowlessVMR( HWND hwndApp, // Window to hold the video. IGraphBuilder* pGraph, // Pointer to the Filter Graph Manager. IVMRWindowlessControl** ppWc ) // Receives a pointer to the VMR. { if (!pGraph || !ppWc) { return E_POINTER; } IBaseFilter* pVmr = NULL; IVMRWindowlessControl* pWc = NULL; // Create the VMR. HRESULT hr = CoCreateInstance(CLSID_VideoMixingRenderer, NULL, CLSCTX_INPROC, IID_IBaseFilter, (void**)&pVmr); if (FAILED(hr)) { return hr; } // Add the VMR to the filter graph. hr = pGraph->AddFilter(pVmr, L"Video Mixing Renderer"); if (FAILED(hr)) { pVmr->Release(); return hr; } // Set the rendering mode. IVMRFilterConfig* pConfig; hr = pVmr->QueryInterface(IID_IVMRFilterConfig, (void**)&pConfig); if (SUCCEEDED(hr)) { hr = pConfig->SetRenderingMode(VMRMode_Windowless); pConfig->Release(); } if (SUCCEEDED(hr)) { // Set the window. hr = pVmr->QueryInterface(IID_IVMRWindowlessControl, (void**)&pWc); if( SUCCEEDED(hr)) { hr = pWc->SetVideoClippingWindow(hwndApp); if (SUCCEEDED(hr)) { *ppWc = pWc; // Return this as an AddRef'd pointer. } else { // An error occurred, so release the interface. pWc->Release(); } } } pVmr->Release(); return hr; }