From fc4d7b0e73a87042f87ab847cfbe60e4d2dddf71 Mon Sep 17 00:00:00 2001
From: Jean-Michel Trivi <jmtrivi@google.com>
Date: Thu, 8 Aug 2013 17:47:33 -0700
Subject: SBR encoder improvement

SBR encoder: Introduce coupling energy ratio limitation to prevent undesirable SBR band
     amplification while decoding.

Bug 9428126

Change-Id: I18a77cd1a178fff7531b490779a29a0df7d993af
---
 libSBRenc/src/env_est.cpp | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

(limited to 'libSBRenc/src/env_est.cpp')

diff --git a/libSBRenc/src/env_est.cpp b/libSBRenc/src/env_est.cpp
index e441cbd..9924348 100644
--- a/libSBRenc/src/env_est.cpp
+++ b/libSBRenc/src/env_est.cpp
@@ -817,22 +817,22 @@ calculateSbrEnvelope (FIXP_DBL **RESTRICT YBufferLeft,  /*! energy buffer left *
       }
 
       /* ld64 to integer conversion */
-      nrgLeft = fixMin(fixMax(nrgLeft,FL2FXCONST_DBL(0.0f)),FL2FXCONST_DBL(0.5f));
+      nrgLeft = fixMin(fixMax(nrgLeft,FL2FXCONST_DBL(0.0f)),(FL2FXCONST_DBL(0.5f)>>oneBitLess));
       nrgLeft = (FIXP_DBL)(LONG)nrgLeft >> (DFRACT_BITS-1-LD_DATA_SHIFT-1-oneBitLess-1);
       sfb_nrgLeft[m] = ((INT)nrgLeft+1)>>1; /* rounding */
 
       if (stereoMode == SBR_COUPLING) {
         FIXP_DBL scaleFract;
+        int sc0, sc1;
 
-        if (nrgRight != FL2FXCONST_DBL(0.0f)) {
-          int sc0 = CountLeadingBits(nrgLeft2);
-          int sc1 = CountLeadingBits(nrgRight);
+        nrgLeft2 = fixMax((FIXP_DBL)0x1, nrgLeft2);
+        nrgRight = fixMax((FIXP_DBL)0x1, nrgRight);
 
-          scaleFract = ((FIXP_DBL)(sc0-sc1)) << (DFRACT_BITS-1-LD_DATA_SHIFT); /* scale value in ld64 representation */
-          nrgRight = CalcLdData(nrgLeft2<<sc0) - CalcLdData(nrgRight<<sc1) - scaleFract;
-        }
-        else
-          nrgRight =  FL2FXCONST_DBL(0.5f);   /* ld64(4294967296.0f) */
+        sc0 = CountLeadingBits(nrgLeft2);
+        sc1 = CountLeadingBits(nrgRight);
+
+        scaleFract = ((FIXP_DBL)(sc0-sc1)) << (DFRACT_BITS-1-LD_DATA_SHIFT); /* scale value in ld64 representation */
+        nrgRight = CalcLdData(nrgLeft2<<sc0) - CalcLdData(nrgRight<<sc1) - scaleFract;
 
         /* ld64 to integer conversion */
         nrgRight = (FIXP_DBL)(LONG)(nrgRight) >> (DFRACT_BITS-1-LD_DATA_SHIFT-1-oneBitLess);
-- 
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