fenix/fdk-aac
1
0
Fork 0
mirror of https://github.com/mstorsjo/fdk-aac.git synced 2025-02-17 11:40:35 +01:00
Code Issues Projects Releases Wiki Activity

Improve accuracy of division in calcSubbandGain().

Browse Source 
am: 69a5c189ad

Change-Id: I2bc889856aa9b066ba5d1c2043a6864b2455733f
This commit is contained in:
Fraunhofer IIS FDK 2019-05-15 23:05:02 -07:00 committed by android-build-merger
commit c9fbf5a360
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
libSBRdec/src/env_calc.cpp
View File

@ -1,7 +1,7 @@
/* ----------------------------------------------------------------------------- /* -----------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android 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. Forschung e.V. All rights reserved.
1. INTRODUCTION 1. INTRODUCTION
@ -2325,7 +2325,15 @@ static void calcSubbandGain(
} }
/* gain = nrgRef / B */ /* 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;
} }
} }