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IStreamBuilder::Render

  • Artigo
 
Microsoft DirectShow 9.0

IStreamBuilder::Render

The Render method completes rendering of the stream originating with this pin. This can involve adding filters to the filter graph and connecting them.

Syntax

  HRESULT Render(
  IPin *ppinOut,
  IGraphBuilder *pGraph
);

Parameters

ppinOut

[in] Pointer to the IPin interface of this pin.

pGraph

[in] Pointer to the IGraphBuilder interface of the Filter Graph Manager.

Return Value

Returns an HRESULT value. A return code of S_OK indicates that the stream was successfully rendered.

Remarks

The following code illustrates how to implement this method on an output pin. This example assumes that the filter requires a custom renderer downstream from it.

STDMETHODIMP CMyOutputPin::Render(IPin *pPin, IGraphBuilder *pGraph)
{
    CheckPointer(pPin, E_POINTER);
    CheckPointer(pGraph, E_POINTER);

    // This filter needs a special renderer connected to it.
    IBaseFilter *pMyRenderer = NULL;

    // Create the renderer.
    HRESULT hr = CoCreateInstance(CLSID_MyRenderer, NULL, CLSCTX_INPROC,
        IID_IBaseFilter, (void **)&pMyRenderer);
    if (FAILED(hr))
    {
        return hr;
    }
    
    // Add my renderer to the filter graph.
    hr = pGraph->AddFilter(pMyRenderer, L"My Renderer");
    if (FAILED(hr))
    {
        pMyRenderer->Release();
        return hr;
    }

    IEnumPins *pEnumPins;
    IPin *pMyRendererInputPin = NULL;
    hr = pMyRenderer->EnumPins(&pEnumPins);
    if (SUCCEEDED(hr)) 
    {
        if (S_OK != pEnumPins->Next(1, &pMyRendererInputPin, 0))
        {
            hr = E_UNEXPECTED;
         }
    }
    if (SUCCEEDED(hr)) 
    {
        // Connect my renderer to my output pin.
        hr = pGraph->ConnectDirect(pPin, pMyRendererInputPin);
        pMyRendererInputPin->Release();
    }
    if (FAILED(hr)) 
    {
        // Could not connect to my renderer. Remove it from the graph.
        pGraph->RemoveFilter(pMyRenderer);
    }
    pMyRenderer->Release();
    return hr;
}

Requirements

Header: Declared in Strmif.h; include Dshow.h.

Library: Use Strmiids.lib.

See Also