Method DoBufferProcessingLoop

common/baseclasses/source.cpp:480–553

DoBufferProcessingLoop Grabs a buffer and calls the users processing function. Overridable, so that different delivery styles can be catered for.

// Grabs a buffer and calls the users processing function.
// Overridable, so that different delivery styles can be catered for.
HRESULT CSourceStream::DoBufferProcessingLoop(void)
{

    Command com;

    OnThreadStartPlay();

    do
    {
        while (!CheckRequest(&com))
        {

            IMediaSample *pSample;

            HRESULT hr = GetDeliveryBuffer(&pSample, NULL, NULL, 0);
            if (FAILED(hr))
            {
                Sleep(1);
                continue; // go round again. Perhaps the error will go away
                          // or the allocator is decommited & we will be asked to
                          // exit soon.
            }

            // Virtual function user will override.
            hr = FillBuffer(pSample);

            if (hr == S_OK)
            {
                hr = Deliver(pSample);
                pSample->Release();

                // downstream filter returns S_FALSE if it wants us to
                // stop or an error if it's reporting an error.
                if (hr != S_OK)
                {
                    DbgLog((LOG_TRACE, 2, TEXT("Deliver() returned %08x; stopping"), hr));
                    return S_OK;
                }
            }
            else if (hr == S_FALSE)
            {
                // derived class wants us to stop pushing data
                pSample->Release();
                DeliverEndOfStream();
                return S_OK;
            }
            else
            {
                // derived class encountered an error
                pSample->Release();
                DbgLog((LOG_ERROR, 1, TEXT("Error %08lX from FillBuffer!!!"), hr));
                DeliverEndOfStream();
                m_pFilter->NotifyEvent(EC_ERRORABORT, hr, 0);
                return hr;
            }

            // all paths release the sample
        }