class COutputQueue : public CCritSec
{
public:
    //  Constructor
    COutputQueue(IPin      *pInputPin,          //  Pin to send stuff to
                 HRESULT   *phr,                //  'Return code'
                 BOOL       bAuto = TRUE,       //  Ask pin if blocks
                 BOOL       bQueue = TRUE,      //  Send through queue (ignored if
                                                //  bAuto set)
                 LONG       lBatchSize = 1,     //  Batch
                 BOOL       bBatchExact = FALSE,//  Batch exactly to BatchSize
                 LONG       lListSize =         //  Likely number in the list
                                DEFAULTCACHE,
                 DWORD      dwPriority =        //  Priority of thread to create
                                THREAD_PRIORITY_NORMAL,
                 bool       bFlushingOpt = false // flushing optimization
                );
    ~COutputQueue();

    // enter flush state - discard all data
    void BeginFlush();      // Begin flushing samples

    // re-enable receives (pass this downstream)
    void EndFlush();        // Complete flush of samples - downstream
                            // pin guaranteed not to block at this stage

    void EOS();             // Call this on End of stream

    void SendAnyway();      // Send batched samples anyway (if bBatchExact set)

    void NewSegment(
            REFERENCE_TIME tStart,
            REFERENCE_TIME tStop,
            double dRate);

    HRESULT Receive(IMediaSample *pSample);

    // do something with these media samples
    HRESULT ReceiveMultiple (
        IMediaSample **pSamples,
        long nSamples,
        long *nSamplesProcessed);

    void Reset();           // Reset m_hr ready for more data

    //  See if its idle or not
    BOOL IsIdle();

    // give the class an event to fire after everything removed from the queue
    void SetPopEvent(HANDLE hEvent);

protected:
    static DWORD WINAPI InitialThreadProc(LPVOID pv);
    DWORD ThreadProc();
    BOOL  IsQueued()
    {
        return m_List != NULL;
    }

    //  The critical section MUST be held when this is called
    void QueueSample(IMediaSample *pSample);

    BOOL IsSpecialSample(IMediaSample *pSample)
    {
        return (DWORD_PTR)pSample > (DWORD_PTR)(LONG_PTR)(-16);
    }

    //  Remove and Release() batched and queued samples
    void FreeSamples();

    //  Notify the thread there is something to do
    void NotifyThread();

protected:
    //  Queue 'messages'
    #define SEND_PACKET      ((IMediaSample *)(LONG_PTR)(-2))  // Send batch
    #define EOS_PACKET       ((IMediaSample *)(LONG_PTR)(-3))  // End of stream
    #define RESET_PACKET     ((IMediaSample *)(LONG_PTR)(-4))  // Reset m_hr
    #define NEW_SEGMENT      ((IMediaSample *)(LONG_PTR)(-5))  // send NewSegment

    // new segment packet is always followed by one of these
    struct NewSegmentPacket {
        REFERENCE_TIME tStart;
        REFERENCE_TIME tStop;
        double dRate;
    };