DES Error Logging: Example Code

Microsoft DirectShow 9.0

DES Error Logging: Example Code

The following sample code presents a complete console application that loads and previews an XML project file, using the error logging class described in this section. (See Logging Errors.) The name of the project file is hard-coded into the application.

To make the code shorter, the console application uses ATL smart pointers, which removes the need to call QueryInterface and Release. If you prefer, you can modify the sample application in Loading and Previewing a Project. Simply add the code shown in the previous section.

#include <atlbase.h>
#include <dshow.h>
#include <qedit.h>
#include <stdio.h>

// Declare error logging class.
class CErrReporter;

// (The implementation of CErrReporter was given previously.)

void __cdecl main(void)
{
    HRESULT hr = CoInitialize(NULL);

    if (FAILED(hr))
    {
        // Error handling is omitted for clarity.
    }

    { // Scope for smart pointers.

    CComPtr<IAMTimeline>   pTL;
    CComPtr<IRenderEngine> pRenderEngine; 
    CComPtr<IXml2Dex>      pXML; 
    CComPtr<IGraphBuilder> pGraph;

    hr = CoCreateInstance(CLSID_AMTimeline, NULL, CLSCTX_INPROC_SERVER, 
                IID_IAMTimeline, (void**) &pTL);
    hr = CoCreateInstance(CLSID_Xml2Dex, NULL, CLSCTX_INPROC_SERVER, 
                IID_IXml2Dex, (void**) &pXML);
    hr = CoCreateInstance(CLSID_RenderEngine, NULL, CLSCTX_INPROC_SERVER,
                IID_IRenderEngine, (void**) &pRenderEngine);

    // Set the error log.
    CComQIPtr<IAMSetErrorLog, &IID_IAMSetErrorLog> pSetLog(pTL);
    if (pSetLog)
    {
        IAMErrorLog *pLog = new CErrReporter;    
        pSetLog->put_ErrorLog(pLog);
    }
   
    // Load and preview the project.
    CComBSTR bstrFile(OLESTR("C:\\example.xtl"));
    hr = pXML->ReadXMLFile(pTL, bstrFile); 
    if (SUCCEEDED(hr))
    {
        hr = pRenderEngine->SetTimelineObject(pTL);
        hr = pRenderEngine->ConnectFrontEnd( );
        hr = pRenderEngine->RenderOutputPins( );
        hr = pRenderEngine->GetFilterGraph(&pGraph);

        CComQIPtr<IMediaControl, &IID_IMediaControl> pControl(pGraph);
        CComQIPtr<IMediaEvent, &IID_IMediaEvent> pEvent(pGraph);
        pControl->Run();

        long evCode;
        hr = pEvent->WaitForCompletion(INFINITE, &evCode);
        pControl->Stop();
    }
    // Clean up.
    pRenderEngine->ScrapIt();
    }
    CoUninitialize();
}