Method Notify

common/baseclasses/renbase.cpp:2130–2178

} // SetSink

STDMETHODIMP CBaseVideoRenderer::Notify(IBaseFilter *pSelf, Quality q)
{
    // NOTE:  We are NOT getting any locks here.  We could be called
    // asynchronously and possibly even on a time critical thread of
    // someone else's - so we do the minumum.  We only set one state
    // variable (an integer) and if that happens to be in the middle
    // of another thread reading it they will just get either the new
    // or the old value.  Locking would achieve no more than this.

    // It might be nice to check that we are being called from m_pGraph, but
    // it turns out to be a millisecond or so per throw!

    // This is heuristics, these numbers are aimed at being "what works"
    // rather than anything based on some theory.
    // We use a hyperbola because it's easy to calculate and it includes
    // a panic button asymptote (which we push off just to the left)
    // The throttling fits the following table (roughly)
    // Proportion   Throttle (msec)
    //     >=1000         0
    //        900         3
    //        800         7
    //        700        11
    //        600        17
    //        500        25
    //        400        35
    //        300        50
    //        200        72
    //        125       100
    //        100       112
    //         50       146
    //          0       200

    // (some evidence that we could go for a sharper kink - e.g. no throttling
    // until below the 750 mark - might give fractionally more frames on a
    // P60-ish machine).  The easy way to get these coefficients is to use
    // Renbase.xls follow the instructions therein using excel solver.

    if (q.Proportion >= 1000)
    {
        m_trThrottle = 0;
    }
    else
    {
        // The DWORD is to make quite sure I get unsigned arithmetic
        // as the constant is between 2**31 and 2**32
        m_trThrottle = -330000 + (388880000 / (q.Proportion + 167));
    }
    return NOERROR;
} // Notify

// Send a message to indicate what our supplier should do about quality.
// Theory: