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authorThe Android Open Source Project <initial-contribution@android.com>2012-07-11 10:15:24 -0700
committerThe Android Open Source Project <initial-contribution@android.com>2012-07-11 10:15:24 -0700
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tree57f3d390ebb0782cc0de0fb984c8ea7e45b4f386 /libAACenc/src/noisedet.cpp
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+
+/* -----------------------------------------------------------------------------------------------------------
+Software License for The Fraunhofer FDK AAC Codec Library for Android
+
+© Copyright 1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
+ All rights reserved.
+
+ 1. INTRODUCTION
+The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
+the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
+This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
+
+AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
+audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
+independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
+of the MPEG specifications.
+
+Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
+may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
+individually for the purpose of encoding or decoding bit streams in products that are compliant with
+the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
+these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
+software may already be covered under those patent licenses when it is used for those licensed purposes only.
+
+Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
+are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
+applications information and documentation.
+
+2. COPYRIGHT LICENSE
+
+Redistribution and use in source and binary forms, with or without modification, are permitted without
+payment of copyright license fees provided that you satisfy the following conditions:
+
+You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
+your modifications thereto in source code form.
+
+You must retain the complete text of this software license in the documentation and/or other materials
+provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
+You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
+modifications thereto to recipients of copies in binary form.
+
+The name of Fraunhofer may not be used to endorse or promote products derived from this library without
+prior written permission.
+
+You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
+software or your modifications thereto.
+
+Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
+and the date of any change. For modified versions of the FDK AAC Codec, the term
+"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
+"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
+
+3. NO PATENT LICENSE
+
+NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
+ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
+respect to this software.
+
+You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
+by appropriate patent licenses.
+
+4. DISCLAIMER
+
+This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
+"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
+of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
+including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
+or business interruption, however caused and on any theory of liability, whether in contract, strict
+liability, or tort (including negligence), arising in any way out of the use of this software, even if
+advised of the possibility of such damage.
+
+5. CONTACT INFORMATION
+
+Fraunhofer Institute for Integrated Circuits IIS
+Attention: Audio and Multimedia Departments - FDK AAC LL
+Am Wolfsmantel 33
+91058 Erlangen, Germany
+
+www.iis.fraunhofer.de/amm
+amm-info@iis.fraunhofer.de
+----------------------------------------------------------------------------------------------------------- */
+
+/******************************** MPEG Audio Encoder **************************
+
+ 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;
+
+ /***** 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;
+ }
+}