diff options
| -rw-r--r-- | libFDK/src/autocorr2nd.cpp | 43 |
1 files changed, 21 insertions, 22 deletions
diff --git a/libFDK/src/autocorr2nd.cpp b/libFDK/src/autocorr2nd.cpp index 718a555..8c5673c 100644 --- a/libFDK/src/autocorr2nd.cpp +++ b/libFDK/src/autocorr2nd.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 - 2020 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. All rights reserved. 1. INTRODUCTION @@ -102,11 +102,6 @@ amm-info@iis.fraunhofer.de #include "autocorr2nd.h" -/* If the accumulator does not provide enough overflow bits, - products have to be shifted down in the autocorrelation below. */ -#define SHIFT_FACTOR (5) -#define SHIFT >> (SHIFT_FACTOR) - /*! * * \brief Calculate second order autocorrelation using 2 accumulators @@ -126,45 +121,49 @@ INT autoCorr2nd_real( const FIXP_DBL *realBuf = reBuffer; + const int len_scale = fMax(DFRACT_BITS - fNormz((FIXP_DBL)(len / 2)), 1); /* r11r,r22r r01r,r12r r02r */ pReBuf = realBuf - 2; - accu5 = ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3])) - SHIFT); + accu5 = + ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3])) >> + len_scale); pReBuf++; /* len must be even */ - accu1 = fPow2Div2(pReBuf[0]) SHIFT; - accu3 = fMultDiv2(pReBuf[0], pReBuf[1]) SHIFT; + accu1 = fPow2Div2(pReBuf[0]) >> len_scale; + accu3 = fMultDiv2(pReBuf[0], pReBuf[1]) >> len_scale; pReBuf++; for (j = (len - 2) >> 1; j != 0; j--, pReBuf += 2) { - accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pReBuf[1])) SHIFT); + accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pReBuf[1])) >> len_scale); - accu3 += ((fMultDiv2(pReBuf[0], pReBuf[1]) + - fMultDiv2(pReBuf[1], pReBuf[2])) SHIFT); + accu3 += + ((fMultDiv2(pReBuf[0], pReBuf[1]) + fMultDiv2(pReBuf[1], pReBuf[2])) >> + len_scale); - accu5 += ((fMultDiv2(pReBuf[0], pReBuf[2]) + - fMultDiv2(pReBuf[1], pReBuf[3])) SHIFT); + accu5 += + ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3])) >> + len_scale); } - accu2 = (fPow2Div2(realBuf[-2]) SHIFT); + accu2 = (fPow2Div2(realBuf[-2]) >> len_scale); accu2 += accu1; - accu1 += (fPow2Div2(realBuf[len - 2]) SHIFT); + accu1 += (fPow2Div2(realBuf[len - 2]) >> len_scale); - accu4 = (fMultDiv2(realBuf[-1], realBuf[-2]) SHIFT); + accu4 = (fMultDiv2(realBuf[-1], realBuf[-2]) >> len_scale); accu4 += accu3; - accu3 += (fMultDiv2(realBuf[len - 1], realBuf[len - 2]) SHIFT); + accu3 += (fMultDiv2(realBuf[len - 1], realBuf[len - 2]) >> len_scale); mScale = CntLeadingZeros( (accu1 | accu2 | fAbs(accu3) | fAbs(accu4) | fAbs(accu5))) - 1; - autoCorrScaling = mScale - 1 - SHIFT_FACTOR; /* -1 because of fMultDiv2*/ + autoCorrScaling = mScale - 1 - len_scale; /* -1 because of fMultDiv2*/ /* Scale to common scale factor */ ac->r11r = accu1 << mScale; @@ -190,7 +189,7 @@ INT autoCorr2nd_cplx( const FIXP_DBL *imBuffer, /*!< Pointer to imag part of input samples */ const int len /*!< Number of input samples (should be smaller than 128) */ ) { - int j, autoCorrScaling, mScale, len_scale; + int j, autoCorrScaling, mScale; FIXP_DBL accu0, accu1, accu2, accu3, accu4, accu5, accu6, accu7, accu8; @@ -199,7 +198,7 @@ INT autoCorr2nd_cplx( const FIXP_DBL *realBuf = reBuffer; const FIXP_DBL *imagBuf = imBuffer; - (len > 64) ? (len_scale = 6) : (len_scale = 5); + const int len_scale = fMax(DFRACT_BITS - fNormz((FIXP_DBL)len), 1); /* r00r, r11r,r22r |