changed code

if (bufferFillCur < targetFill || sum > m_vbvMaxRate)
                {
                    q *= 1.01;
                    loopTerminate |= 1;
                    continue;
                }
                /* Try to get the buffer not more than 80% filled, but don't set an impossible goal. */
                targetFill = x265_clip3(m_bufferSize * (1 - 0.2 * finalDur), m_bufferSize, m_bufferFill - totalDuration * m_vbvMaxRate * 0.5);
                if (bufferFillCur > targetFill || sum < m_vbvMaxRate)
                {
                    q /= 1.01;
                    loopTerminate |= 2;
                    continue;
                }