[x265] [PATCH] analysis: bidir/inter choice using sa8dCost

[deepthi at multicorewareinc.com]

# HG changeset patch
# User Deepthi Nandakumar <deepthi at multicorewareinc.com>
# Date 1426065176 -19800
#      Wed Mar 11 14:42:56 2015 +0530
# Node ID 7d8f7aadfb6d0af071d804a3eec1511cd00818c5
# Parent  37ec8002eba15ec3b7bf2b16a792af572b099078
analysis: bidir/inter choice using sa8dCost

diff -r 37ec8002eba1 -r 7d8f7aadfb6d source/encoder/analysis.cpp
--- a/source/encoder/analysis.cpp	Wed Mar 11 14:31:57 2015 +0530
+++ b/source/encoder/analysis.cpp	Wed Mar 11 14:42:56 2015 +0530
@@ -749,7 +749,7 @@
         /* Compute Merge Cost */
         md.pred[PRED_MERGE].cu.initSubCU(parentCTU, cuGeom);
         md.pred[PRED_SKIP].cu.initSubCU(parentCTU, cuGeom);
-        checkMerge2Nx2N_rd0_4(md.pred[PRED_SKIP], md.pred[PRED_MERGE], cuGeom);
+        checkMerge2Nx2N_rd0_4(md.pred[PRED_SKIP], md.pred[PRED_MERGE], cuGeom); /* writes into md.bestMode */
 
         bool earlyskip = false;
         if (m_param->rdLevel)
@@ -822,24 +822,26 @@
 
             if (m_param->rdLevel >= 3)
             {
-                /* Calculate RD cost of best inter option */
-                if (!m_bChromaSa8d) /* When m_bChromaSa8d is enabled, chroma MC has already been done */
-                {
-                    for (uint32_t puIdx = 0; puIdx < bestInter->cu.getNumPartInter(); puIdx++)
-                    {
-                        PredictionUnit pu(bestInter->cu, cuGeom, puIdx);
-                        motionCompensation(bestInter->cu, pu, bestInter->predYuv, false, true);
-                    }
-                }
-                encodeResAndCalcRdInterCU(*bestInter, cuGeom);
-                checkBestMode(*bestInter, depth);
-
-                /* If BIDIR is available and within 17/16 of best inter option, choose by RDO */
+                /* If BIDIR is available and within 17/16 of best inter option, choose bidir */
                 if (m_slice->m_sliceType == B_SLICE && md.pred[PRED_BIDIR].sa8dCost != MAX_INT64 &&
                     md.pred[PRED_BIDIR].sa8dCost * 16 <= bestInter->sa8dCost * 17)
                 {
                     encodeResAndCalcRdInterCU(md.pred[PRED_BIDIR], cuGeom);
-                    checkBestMode(md.pred[PRED_BIDIR], depth);
+                    checkBestMode(md.pred[PRED_BIDIR], depth); /* compare against Merge by RDO*/
+                }
+                else
+                {
+                    /* Calculate RD cost of best inter option */
+                    if (!m_bChromaSa8d) /* When m_bChromaSa8d is enabled, chroma MC has already been done */
+                    {
+                        for (uint32_t puIdx = 0; puIdx < bestInter->cu.getNumPartInter(); puIdx++)
+                        {
+                            PredictionUnit pu(bestInter->cu, cuGeom, puIdx);
+                            motionCompensation(bestInter->cu, pu, bestInter->predYuv, false, true);
+                        }
+                    }
+                    encodeResAndCalcRdInterCU(*bestInter, cuGeom);
+                    checkBestMode(*bestInter, depth);
                 }
 
                 if ((bTryIntra && md.bestMode->cu.getQtRootCbf(0)) ||