[x265] [PATCH] rc: bug fix to avoid vbv predictor misprediction errors at scenecut

[aarthi at multicorewareinc.com]

# HG changeset patch
# User Aarthi Thirumalai
# Date 1443713129 -19800
#      Thu Oct 01 20:55:29 2015 +0530
# Branch stable
# Node ID 13cfec40af4fe67c3a82e3d82ea9d289822a4fbc
# Parent  33218e324fec6c0ea04499ebd6ac3b25d7dd91d1
rc: bug fix to avoid vbv predictor misprediction errors at scenecut

diff -r 33218e324fec -r 13cfec40af4f source/encoder/ratecontrol.cpp
--- a/source/encoder/ratecontrol.cpp	Tue Sep 22 13:41:11 2015 +0530
+++ b/source/encoder/ratecontrol.cpp	Thu Oct 01 20:55:29 2015 +0530
@@ -1583,8 +1583,9 @@
             rce->qpNoVbv = x265_qScale2qp(q);
             q = clipQscale(curFrame, rce, q);
             /*  clip qp to permissible range after vbv-lookahead estimation to avoid possible
-             * mispredictions by initial frame size predictors */
-            if (!m_2pass && m_isVbv && m_pred[m_predType].count == 1)
+             * mispredictions by initial frame size predictors, after each scenecut */
+            bool isFrameAfterScenecut = m_sliceType!= I_SLICE && m_curSlice->m_refPicList[0][0]->m_lowres.bScenecut;
+            if (!m_2pass && m_isVbv && isFrameAfterScenecut)
                 q = x265_clip3(lqmin, lqmax, q);
         }
         m_lastQScaleFor[m_sliceType] = q;