}
    ASSERT(!m_bRealizing);

    // Should we realise our palette again

    if ((Message == WM_QUERYNEWPALETTE || hwnd != m_hwnd)) {
        //  It seems that even if we're invisible that we can get asked
        //  to realize our palette and this can cause really ugly side-effects
        //  Seems like there's another bug but this masks it a least for the
        //  shutting down case.
        if (!IsWindowVisible(m_hwnd)) {
            DbgLog((LOG_TRACE, 1, TEXT("Realizing when invisible!")));
            return (LRESULT) 0;
        }

        // Avoid recursion with multiple graphs in the same app
#ifdef DEBUG
        m_bRealizing = TRUE;
#endif
        DoRealisePalette(Message != WM_QUERYNEWPALETTE);
#ifdef DEBUG
        m_bRealizing = FALSE;
#endif

        // Should we redraw the window with the new palette
        if (Message == WM_PALETTECHANGED) {
            InvalidateRect(m_hwnd,NULL,FALSE);
        }
    }

    return (LRESULT) 1;
}


// Determine if the window exists.

bool CBaseWindow::WindowExists()
{
    return !!IsWindow(m_hwnd);
}


// Return the default window rectangle

RECT CBaseWindow::GetDefaultRect()
{
    RECT DefaultRect = {0,0,DEFWIDTH,DEFHEIGHT};
    ASSERT(m_hwnd);
    // ASSERT(m_hdc);
    return DefaultRect;
}


// Return the current window width

LONG CBaseWindow::GetWindowWidth()
{
    ASSERT(m_hwnd);
    // ASSERT(m_hdc);
    return m_Width;
}


// Return the current window height

LONG CBaseWindow::GetWindowHeight()
{
    ASSERT(m_hwnd);
    // ASSERT(m_hdc);
    return m_Height;
}


// Return the window handle

HWND CBaseWindow::GetWindowHWND()
{
    ASSERT(m_hwnd);
    // ASSERT(m_hdc);
    return m_hwnd;
}


// Return the window drawing device context

HDC CBaseWindow::GetWindowHDC()
{
    ASSERT(m_hwnd);
    ASSERT(m_hdc);
    return m_hdc;
}


// Return the offscreen window drawing device context

HDC CBaseWindow::GetMemoryHDC()
{
    ASSERT(m_hwnd);
    ASSERT(m_MemoryDC);
    return m_MemoryDC;
}


#ifdef DEBUG
HPALETTE CBaseWindow::GetPalette()
{
    // The palette lock should always be held when accessing
    // m_hPalette.
    ASSERT(CritCheckIn(&m_PaletteLock));
    return m_hPalette;
}
#endif // DEBUG


// This is available to clients who want to change the window visiblity. It's
// little more than an indirection to the Win32 ShowWindow although these is
// some benefit in going through here as this function may change sometime

HRESULT CBaseWindow::DoShowWindow(LONG ShowCmd)
{
    ShowWindow(m_hwnd,ShowCmd);
    return NOERROR;
}


// Generate a WM_PAINT message for the video window

void CBaseWindow::PaintWindow(BOOL bErase)
{
    InvalidateRect(m_hwnd,NULL,bErase);
}


// Allow an application to have us set the video window in the foreground. We
// have this because it is difficult for one thread to do do this to a window
// owned by another thread. Rather than expose the message we use to execute
// the inter thread send message we provide the interface function. All we do
// is to SendMessage to the video window renderer thread with a WM_SHOWSTAGE

void CBaseWindow::DoSetWindowForeground(BOOL bFocus)
{
    SendMessage(m_hwnd,m_ShowStageMessage,(WPARAM) bFocus,(LPARAM) 0);
}


// Constructor initialises the owning object pointer. Since we are a worker
// class for the main window object we have relatively few state variables to
// look after. We are given device context handles to use later on as well as
// the source and destination rectangles (but reset them here just in case)

CDrawImage::CDrawImage(CBaseWindow *pBaseWindow) :
    m_pBaseWindow(pBaseWindow),
    m_hdc(NULL),
    m_MemoryDC(NULL),
    m_bStretch(FALSE),
    m_pMediaType(NULL),
    m_bUsingImageAllocator(FALSE)
{
    ASSERT(pBaseWindow);
    ResetPaletteVersion();
    SetRectEmpty(&m_TargetRect);
    SetRectEmpty(&m_SourceRect);

    m_perfidRenderTime = MSR_REGISTER(TEXT("Single Blt time"));
}


// Overlay the image time stamps on the picture. Access to this method is
// serialised by the caller. We display the sample start and end times on
// top of the video using TextOut on the device context we are handed. If
// there isn't enough room in the window for the times we don't show them

void CDrawImage::DisplaySampleTimes(IMediaSample *pSample)
{
#ifdef DEBUG
    //
    // Only allow the "annoying" time messages if the users has turned the
    // logging "way up"
    //
    BOOL bAccept = DbgCheckModuleLevel(LOG_TRACE, 5);
    if (bAccept == FALSE) {
        return;
    }
#endif

    TCHAR szTimes[TIMELENGTH];      // Time stamp strings
    ASSERT(pSample);                // Quick sanity check
    RECT ClientRect;                // Client window size
    SIZE Size;                      // Size of text output

    // Get the time stamps and window size

    pSample->GetTime((REFERENCE_TIME*)&m_StartSample, (REFERENCE_TIME*)&m_EndSample);
    HWND hwnd = m_pBaseWindow->GetWindowHWND();
    EXECUTE_ASSERT(GetClientRect(hwnd,&ClientRect));

    // Format the sample time stamps

    wsprintf(szTimes,TEXT("%08d : %08d"),
             m_StartSample.Millisecs(),
             m_EndSample.Millisecs());

    ASSERT(lstrlen(szTimes) < TIMELENGTH);

    // Put the times in the middle at the bottom of the window

    GetTextExtentPoint32(m_hdc,szTimes,lstrlen(szTimes),&Size);
    INT XPos = ((ClientRect.right - ClientRect.left) - Size.cx) / 2;
    INT YPos = ((ClientRect.bottom - ClientRect.top) - Size.cy) * 4 / 5;

    // Check the window is big enough to have sample times displayed

    if ((XPos > 0) && (YPos > 0)) {
        TextOut(m_hdc,XPos,YPos,szTimes,lstrlen(szTimes));
    }
}


// This is called when the drawing code sees that the image has a down level
// palette cookie. We simply call the SetDIBColorTable Windows API with the
// palette that is found after the BITMAPINFOHEADER - we return no errors

void CDrawImage::UpdateColourTable(HDC hdc,BITMAPINFOHEADER *pbmi)
{
    ASSERT(pbmi->biClrUsed);
    RGBQUAD *pColourTable = (RGBQUAD *)(pbmi+1);

    // Set the new palette in the device context

    UINT uiReturn = SetDIBColorTable(hdc,(UINT) 0,
                                     pbmi->biClrUsed,
                                     pColourTable);

    // Should always succeed but check in debug builds
    ASSERT(uiReturn == pbmi->biClrUsed);
}


// No source rectangle scaling is done by the base class

RECT CDrawImage::ScaleSourceRect(const RECT *pSource)
{
    ASSERT(pSource);
    return *pSource;
}


// This is called when the funky output pin uses our allocator. The samples we
// allocate are special because the memory is shared between us and GDI thus
// removing one copy when we ask for the image to be rendered. The source type
// information is in the main renderer m_mtIn field which is initialised when
// the media type is agreed in SetMediaType, the media type may be changed on
// the fly if, for example, the source filter needs to change the palette

void CDrawImage::FastRender(IMediaSample *pMediaSample)
{
    BITMAPINFOHEADER *pbmi;     // Image format data
    DIBDATA *pDibData;          // Stores DIB information
    BYTE *pImage;               // Pointer to image data
    HBITMAP hOldBitmap;         // Store the old bitmap
    CImageSample *pSample;      // Pointer to C++ object

    ASSERT(m_pMediaType);

    // From the untyped source format block get the VIDEOINFO and subsequently
    // the BITMAPINFOHEADER structure. We can cast the IMediaSample interface
    // to a CImageSample object so we can retrieve it's DIBSECTION details

    pbmi = HEADER(m_pMediaType->Format());
    pSample = (CImageSample *) pMediaSample;
    pDibData = pSample->GetDIBData();
    hOldBitmap = (HBITMAP) SelectObject(m_MemoryDC,pDibData->hBitmap);

    // Get a pointer to the real image data

    HRESULT hr = pMediaSample->GetPointer(&pImage);
    if (FAILED(hr)) {
        return;
    }

    // Do we need to update the colour table, we increment our palette cookie
    // each time we get a dynamic format change. The sample palette cookie is
    // stored in the DIBDATA structure so we try to keep the fields in sync
    // By the time we get to draw the images the format change will be done
    // so all we do is ask the renderer for what it's palette version is

    if (pDibData->PaletteVersion < GetPaletteVersion()) {
        ASSERT(pbmi->biBitCount <= iPALETTE);
        UpdateColourTable(m_MemoryDC,pbmi);
        pDibData->PaletteVersion = GetPaletteVersion();
    }

    // This allows derived classes to change the source rectangle that we do
    // the drawing with. For example a renderer may ask a codec to stretch
    // the video from 320x240 to 640x480, in which case the source we see in
    // here will still be 320x240, although the source we want to draw with
    // should be scaled up to 640x480. The base class implementation of this
    // method does nothing but return the same rectangle as we are passed in

    RECT SourceRect = ScaleSourceRect(&m_SourceRect);

    // Is the window the same size as the video

    if (m_bStretch == FALSE) {

        // Put the image straight into the window

        BitBlt(
            (HDC) m_hdc,                            // Target device HDC
            m_TargetRect.left,                      // X sink position
            m_TargetRect.top,                       // Y sink position
            m_TargetRect.right - m_TargetRect.left, // Destination width
            m_TargetRect.bottom - m_TargetRect.top, // Destination height
            m_MemoryDC,                             // Source device context
            SourceRect.left,                        // X source position
            SourceRect.top,                         // Y source position
            SRCCOPY);                               // Simple copy

    } else {

        // Stretch the image when copying to the window

        StretchBlt(
            (HDC) m_hdc,                            // Target device HDC
            m_TargetRect.left,                      // X sink position
            m_TargetRect.top,                       // Y sink position
            m_TargetRect.right - m_TargetRect.left, // Destination width
            m_TargetRect.bottom - m_TargetRect.top, // Destination height
            m_MemoryDC,                             // Source device HDC
            SourceRect.left,                        // X source position
            SourceRect.top,                         // Y source position
            SourceRect.right - SourceRect.left,     // Source width
            SourceRect.bottom - SourceRect.top,     // Source height
            SRCCOPY);                               // Simple copy
    }

    // This displays the sample times over the top of the image. This used to
    // draw the times into the offscreen device context however that actually
    // writes the text into the image data buffer which may not be writable

    #ifdef DEBUG
    DisplaySampleTimes(pMediaSample);
    #endif

    // Put the old bitmap back into the device context so we don't leak
    SelectObject(m_MemoryDC,hOldBitmap);
}


// This is called when there is a sample ready to be drawn, unfortunately the
// output pin was being rotten and didn't choose our super excellent shared
// memory DIB allocator so we have to do this slow render using boring old GDI
// SetDIBitsToDevice and StretchDIBits. The down side of using these GDI
// functions is that the image data has to be copied across from our address
// space into theirs before going to the screen (although in reality the cost
// is small because all they do is to map the buffer into their address space)

void CDrawImage::SlowRender(IMediaSample *pMediaSample)
{
    // Get the BITMAPINFOHEADER for the connection

    ASSERT(m_pMediaType);
    BITMAPINFOHEADER *pbmi = HEADER(m_pMediaType->Format());
    BYTE *pImage;

    // Get the image data buffer

    HRESULT hr = pMediaSample->GetPointer(&pImage);
    if (FAILED(hr)) {
        return;
    }

    // This allows derived classes to change the source rectangle that we do
    // the drawing with. For example a renderer may ask a codec to stretch
    // the video from 320x240 to 640x480, in which case the source we see in
    // here will still be 320x240, although the source we want to draw with
    // should be scaled up to 640x480. The base class implementation of this