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/******************************** MPEG Audio Encoder **************************
(C) Copyright Fraunhofer IIS (2001)
All Rights Reserved
Please be advised that this software and/or program delivery is
Confidential Information of Fraunhofer and subject to and covered by the
Fraunhofer IIS Software Evaluation Agreement
between Google Inc. and Fraunhofer
effective and in full force since March 1, 2012.
You may use this software and/or program only under the terms and
conditions described in the above mentioned Fraunhofer IIS Software
Evaluation Agreement. Any other and/or further use requires a separate agreement.
This software and/or program is protected by copyright law and international
treaties. Any reproduction or distribution of this software and/or program,
or any portion of it, may result in severe civil and criminal penalties, and
will be prosecuted to the maximum extent possible under law.
$Id$
Initial author: M. Lohwasser
contents/description: noisedet.c
Routines for Noise Detection
******************************************************************************/
#include "noisedet.h"
#include "aacenc_pns.h"
#include "pnsparam.h"
/*****************************************************************************
functionname: FDKaacEnc_fuzzyIsSmaller
description: Fuzzy value calculation for "testVal is smaller than refVal"
returns: fuzzy value
input: test and ref Value,
low and high Lim
output: return fuzzy value
*****************************************************************************/
static FIXP_SGL FDKaacEnc_fuzzyIsSmaller( FIXP_DBL testVal,
FIXP_DBL refVal,
FIXP_DBL loLim,
FIXP_DBL hiLim )
{
if (refVal <= FL2FXCONST_DBL(0.0))
return( FL2FXCONST_SGL(0.0f) );
else if (testVal >= fMult((hiLim>>1)+(loLim>>1), refVal))
return( FL2FXCONST_SGL(0.0f) );
else return( (FIXP_SGL)MAXVAL_SGL );
}
/*****************************************************************************
functionname: FDKaacEnc_noiseDetect
description: detect tonal sfb's; two tests
Powerdistribution:
sfb splittet in four regions,
compare the energy in all sections
PsychTonality:
compare tonality from chaosmeasure with reftonality
returns:
input: spectrum of one large mdct
number of sfb's
pointer to offset of sfb's
pointer to noiseFuzzyMeasure (modified)
noiseparams struct
pointer to sfb energies
pointer to tonality calculated in chaosmeasure
output: noiseFuzzy Measure
*****************************************************************************/
void FDKaacEnc_noiseDetect(FIXP_DBL *RESTRICT mdctSpectrum,
INT *RESTRICT sfbMaxScaleSpec,
INT sfbActive,
const INT *RESTRICT sfbOffset,
FIXP_SGL *RESTRICT noiseFuzzyMeasure,
NOISEPARAMS *np,
FIXP_SGL *RESTRICT sfbtonality )
{
int i, k, sfb, sfbWidth;
FIXP_SGL fuzzy, fuzzyTotal;
FIXP_DBL refVal, testVal;
#define ALL_SFB_TONAL 0
#define ALL_SFB_NONTONAL 0
/***** Start detection phase *****/
/* Start noise detection for each band based on a number of checks */
for (sfb=0; sfb<sfbActive; sfb++) {
fuzzyTotal = (FIXP_SGL)MAXVAL_SGL;
sfbWidth = sfbOffset[sfb+1] - sfbOffset[sfb];
/* Reset output for lower bands or too small bands */
if (sfb < np->startSfb || sfbWidth < np->minSfbWidth) {
noiseFuzzyMeasure[sfb] = FL2FXCONST_SGL(0.0f);
continue;
}
if ( (np->detectionAlgorithmFlags & USE_POWER_DISTRIBUTION) && (fuzzyTotal > FL2FXCONST_SGL(0.5f)) ) {
FIXP_DBL fhelp1, fhelp2, fhelp3, fhelp4, maxVal, minVal;
INT leadingBits = fixMax(0,(sfbMaxScaleSpec[sfb] - 3)); /* max sfbWidth = 96/4 ; 2^5=32 => 5/2 = 3 (spc*spc) */
/* check power distribution in four regions */
fhelp1 = fhelp2 = fhelp3 = fhelp4 = FL2FXCONST_DBL(0.0f);
k = sfbWidth >>2; /* Width of a quarter band */
for (i=sfbOffset[sfb]; i<sfbOffset[sfb]+k; i++) {
fhelp1 = fPow2AddDiv2(fhelp1, mdctSpectrum[i]<<leadingBits);
fhelp2 = fPow2AddDiv2(fhelp2, mdctSpectrum[i+k]<<leadingBits);
fhelp3 = fPow2AddDiv2(fhelp3, mdctSpectrum[i+2*k]<<leadingBits);
fhelp4 = fPow2AddDiv2(fhelp4, mdctSpectrum[i+3*k]<<leadingBits);
}
/* get max into fhelp: */
maxVal = fixMax(fhelp1, fhelp2);
maxVal = fixMax(maxVal, fhelp3);
maxVal = fixMax(maxVal, fhelp4);
/* get min into fhelp1: */
minVal = fixMin(fhelp1, fhelp2);
minVal = fixMin(minVal, fhelp3);
minVal = fixMin(minVal, fhelp4);
/* Normalize min and max Val */
leadingBits = CountLeadingBits(maxVal);
testVal = maxVal << leadingBits;
refVal = minVal << leadingBits;
/* calculate fuzzy value for power distribution */
testVal = fMultDiv2(testVal, np->powDistPSDcurve[sfb]);
fuzzy = FDKaacEnc_fuzzyIsSmaller(testVal, /* 1/2 * maxValue * PSDcurve */
refVal, /* 1 * minValue */
FL2FXCONST_DBL(0.495), /* 1/2 * loLim (0.99f/2) */
FL2FXCONST_DBL(0.505)); /* 1/2 * hiLim (1.01f/2) */
fuzzyTotal = fixMin(fuzzyTotal, fuzzy);
}
if ( (np->detectionAlgorithmFlags & USE_PSYCH_TONALITY) && (fuzzyTotal > FL2FXCONST_SGL(0.5f)) ) {
/* Detection with tonality-value of psych. acoustic (here: 1 is tonal!)*/
testVal = FX_SGL2FX_DBL(sfbtonality[sfb])>>1; /* 1/2 * sfbTonality */
refVal = np->refTonality;
fuzzy = FDKaacEnc_fuzzyIsSmaller(testVal,
refVal,
FL2FXCONST_DBL(0.45f), /* 1/2 * loLim (0.9f/2) */
FL2FXCONST_DBL(0.55f)); /* 1/2 * hiLim (1.1f/2) */
fuzzyTotal = fixMin(fuzzyTotal, fuzzy);
}
/* Output of final result */
noiseFuzzyMeasure[sfb] = fuzzyTotal;
}
}
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