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author | Fraunhofer IIS FDK <audio-fdk@iis.fraunhofer.de> | 2019-03-08 16:09:45 +0100 |
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committer | Jean-Michel Trivi <jmtrivi@google.com> | 2019-05-14 09:53:45 -0700 |
commit | 69a5c189ad088715d1fac7140c57248d747d6a2a (patch) | |
tree | 8528dcb05a51c14173957c4c193642652f591218 | |
parent | e51063ca54212efa9a2074ec02626999ced2fb74 (diff) | |
download | fdk-aac-69a5c189ad088715d1fac7140c57248d747d6a2a.tar.gz fdk-aac-69a5c189ad088715d1fac7140c57248d747d6a2a.tar.bz2 fdk-aac-69a5c189ad088715d1fac7140c57248d747d6a2a.zip |
Improve accuracy of division in calcSubbandGain().
Bug: 132641988
Test: atest DecoderTestXheAac ; atest DecoderTestAacDrc
Change-Id: I3beeda23355ae1200d9f55c9e8cd1cc6bc899153
-rw-r--r-- | libSBRdec/src/env_calc.cpp | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/libSBRdec/src/env_calc.cpp b/libSBRdec/src/env_calc.cpp index cb1474f..11b7eca 100644 --- a/libSBRdec/src/env_calc.cpp +++ b/libSBRdec/src/env_calc.cpp @@ -1,7 +1,7 @@ /* ----------------------------------------------------------------------------- Software License for The Fraunhofer FDK AAC Codec Library for Android -© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten +© Copyright 1995 - 2019 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. All rights reserved. 1. INTRODUCTION @@ -2325,7 +2325,15 @@ static void calcSubbandGain( } /* gain = nrgRef / B */ - FDK_divide_MantExp(nrgRef, nrgRef_e, b, b_e, ptrNrgGain, ptrNrgGain_e); + INT result_exp = 0; + *ptrNrgGain = fDivNorm(nrgRef, b, &result_exp); + *ptrNrgGain_e = (SCHAR)result_exp + (nrgRef_e - b_e); + + /* There could be a one bit diffs. This is important to compensate, + because later in the code values are compared by exponent only. */ + int headroom = CountLeadingBits(*ptrNrgGain); + *ptrNrgGain <<= headroom; + *ptrNrgGain_e -= headroom; } } |