Fix nrgGain_e update in equalizeFiltBufferExp(). Prevents negative shift exponents in calculateSbrEnvelope().

Bug: 131430997
Test: atest DecoderTestXheAac ; atest DecoderTestAacDrc
Change-Id: I66ad54dae0fa1d414d8b2b9a9e0b6145cce4042d

1 files changed, 4 insertions, 3 deletions

diff --git a/libSBRdec/src/env_calc.cpp b/libSBRdec/src/env_calc.cpp
index c34ce96..5cfd56c 100644
--- a/libSBRdec/src/env_calc.cpp
+++ b/libSBRdec/src/env_calc.cpp
@@ -1831,7 +1831,8 @@ static void equalizeFiltBufferExp(
     diff = (int)(nrgGain_e[band] - filtBuffer_e[band]);
     if (diff > 0) {
       filtBuffer[band] >>=
-          diff; /* Compensate for the scale change by shifting the mantissa. */
+          fMin(diff, DFRACT_BITS - 1); /* Compensate for the scale change by
+                                          shifting the mantissa. */
       filtBuffer_e[band] += diff; /* New gain is bigger, use its exponent */
     } else if (diff < 0) {
       /* The buffered gains seem to be larger, but maybe there
@@ -1851,8 +1852,8 @@ static void equalizeFiltBufferExp(
         filtBuffer_e[band] -= reserve; /* Compensate in the exponent: */
 
         /* For the remaining difference, change the new gain value */
-        diff = fixMin(-(reserve + diff), DFRACT_BITS - 1);
-        nrgGain[band] >>= diff;
+        diff = -(reserve + diff);
+        nrgGain[band] >>= fMin(diff, DFRACT_BITS - 1);
         nrgGain_e[band] += diff;
       }
     }