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Diffstat (limited to 'libFDK/src/FDK_trigFcts.cpp')
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diff --git a/libFDK/src/FDK_trigFcts.cpp b/libFDK/src/FDK_trigFcts.cpp new file mode 100644 index 0000000..2f8655c --- /dev/null +++ b/libFDK/src/FDK_trigFcts.cpp @@ -0,0 +1,330 @@ + +/* ----------------------------------------------------------------------------------------------------------- +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 +----------------------------------------------------------------------------------------------------------- */ + +/*************************** Fraunhofer IIS FDK Tools ********************** + + Author(s): Haricharan Lakshman, Manuel Jander + Description: Trigonometric functions fixed point fractional implementation. + +******************************************************************************/ + +#include "FDK_trigFcts.h" + +#include "fixpoint_math.h" + + + + +#define IMPROVE_ATAN2_ACCURACY 1 // 0 --> 59 dB SNR 1 --> 65 dB SNR +#define MINSFTAB 7 +#define MAXSFTAB 25 + +#if IMPROVE_ATAN2_ACCURACY +static const FIXP_DBL f_atan_expand_range[MAXSFTAB-(MINSFTAB-1)] = +{ + /***************************************************************************** + * + * Table holds fixp_atan() output values which are outside of input range + * of fixp_atan() to improve SNR of fixp_atan2(). + * + * This Table might also be used in fixp_atan() [todo] so there a wider input + * range can be covered, too. + * + * Matlab (generate table): + * for scl = 7:25 % MINSFTAB .. MAXSFTAB + * at=atan(0.5 *(2^scl)); % 0.5 because get in 'middle' area of current scale level 'scl' + * at/2 % div at by ATO_SCALE + * end + * + * Table divided by 2=ATO_SCALE <-- SF=ATO_SF + *****************************************************************************/ + FL2FXCONST_DBL(7.775862990872099e-001), FL2FXCONST_DBL(7.814919928673978e-001), FL2FXCONST_DBL(7.834450483314648e-001), + FL2FXCONST_DBL(7.844216021392089e-001), FL2FXCONST_DBL(7.849098823026687e-001), FL2FXCONST_DBL(7.851540227918509e-001), + FL2FXCONST_DBL(7.852760930873737e-001), FL2FXCONST_DBL(7.853371282415015e-001), FL2FXCONST_DBL(7.853676458193612e-001), + FL2FXCONST_DBL(7.853829046083906e-001), FL2FXCONST_DBL(7.853905340029177e-001), FL2FXCONST_DBL(7.853943487001828e-001), + FL2FXCONST_DBL(7.853962560488155e-001), FL2FXCONST_DBL(7.853972097231319e-001), FL2FXCONST_DBL(7.853976865602901e-001), + FL2FXCONST_DBL(7.853979249788692e-001), FL2FXCONST_DBL(7.853980441881587e-001), FL2FXCONST_DBL(7.853981037928035e-001), + FL2FXCONST_DBL(7.853981335951259e-001) + // pi/4 = 0.785398163397448 = pi/2/ATO_SCALE +}; +#endif + +FIXP_DBL fixp_atan2(FIXP_DBL y, FIXP_DBL x) +{ + FIXP_DBL q; + FIXP_DBL at; // atan out + FIXP_DBL at2; // atan2 out + FIXP_DBL ret = FL2FXCONST_DBL(-1.0f); + INT sf,sfo,stf; + + // --- division + + if (y > FL2FXCONST_DBL(0.0f)) + { + if (x > FL2FXCONST_DBL(0.0f)) { + q = fDivNormHighPrec( y, x, &sf); // both pos. + } + else if (x < FL2FXCONST_DBL(0.0f)) { + q = -fDivNormHighPrec( y,-x, &sf); // x neg. + } + else {//(x ==FL2FXCONST_DBL(0.0f)) + q = FL2FXCONST_DBL(+1.0f); // y/x = pos/zero = +Inf + sf = 0; + } + } + else if (y < FL2FXCONST_DBL(0.0f)) + { + if (x > FL2FXCONST_DBL(0.0f)) { + q = -fDivNormHighPrec(-y, x, &sf); // y neg. + } + else if (x < FL2FXCONST_DBL(0.0f)) { + q = fDivNormHighPrec(-y,-x, &sf); // both neg. + } + else {//(x ==FL2FXCONST_DBL(0.0f)) + q = FL2FXCONST_DBL(-1.0f); // y/x = neg/zero = -Inf + sf = 0; + } + } + else { // (y ==FL2FXCONST_DBL(0.0f)) + q = FL2FXCONST_DBL(0.0f); + sf = 0; + } + sfo = sf; + + // --- atan() + + if ( sfo > ATI_SF ) { + // --- could not calc fixp_atan() here bec of input data out of range + // ==> therefore give back boundary values + + #if IMPROVE_ATAN2_ACCURACY + if (sfo > MAXSFTAB) sfo = MAXSFTAB; + #endif + + if ( q > FL2FXCONST_DBL(0.0f) ) { + #if IMPROVE_ATAN2_ACCURACY + at = +f_atan_expand_range[sfo-ATI_SF-1]; + #else + at = FL2FXCONST_DBL( +M_PI/2 / ATO_SCALE); + #endif + } + else if ( q < FL2FXCONST_DBL(0.0f) ) { + #if IMPROVE_ATAN2_ACCURACY + at = -f_atan_expand_range[sfo-ATI_SF-1]; + #else + at = FL2FXCONST_DBL( -M_PI/2 / ATO_SCALE); + #endif + } + else { // q== FL2FXCONST_DBL(0.0f) + at = FL2FXCONST_DBL( 0.0f ); + } + }else{ + // --- calc of fixp_atan() is possible; input data within range + // ==> set q on fixed scale level as desired from fixp_atan() + stf = sfo - ATI_SF; + if (stf > 0) q = q << (INT)fMin( stf,DFRACT_BITS-1); + else q = q >> (INT)fMin(-stf,DFRACT_BITS-1); + at = fixp_atan(q); // ATO_SF + } + + // --- atan2() + + at2 = at >> (AT2O_SF - ATO_SF); // now AT2O_SF for atan2 + if ( x > FL2FXCONST_DBL(0.0f) ) { + ret = at2; + } + else if ( x < FL2FXCONST_DBL(0.0f) ) { + if ( y >= FL2FXCONST_DBL(0.0f) ) { + ret = at2 + FL2FXCONST_DBL( M_PI / AT2O_SCALE); + } else { + ret = at2 - FL2FXCONST_DBL( M_PI / AT2O_SCALE); + } + } + else { + // x == 0 + if ( y > FL2FXCONST_DBL(0.0f) ) { + ret = FL2FXCONST_DBL( +M_PI/2 / AT2O_SCALE); + } + else if ( y < FL2FXCONST_DBL(0.0f) ) { + ret = FL2FXCONST_DBL( -M_PI/2 / AT2O_SCALE); + } + else if ( y == FL2FXCONST_DBL(0.0f) ) { + ret = FL2FXCONST_DBL(0.0f); + } + } + return ret; +} + + +FIXP_DBL fixp_atan(FIXP_DBL x) +{ + INT sign; + FIXP_DBL result, temp; + + // SNR of fixp_atan() = 56 dB + FIXP_DBL ONEBY3P56 = (FIXP_DBL)0x26800000; // 1.0/3.56 in q31 + FIXP_DBL P281 = (FIXP_DBL)0x00013000; // 0.281 in q18 + FIXP_DBL ONEP571 = (FIXP_DBL)0x6487ef00; // 1.571 in q30 + + if (x < FIXP_DBL(0)) { + sign = 1; + x = - x ; + } else { + sign = 0; + } + + /* calc of arctan */ + if(x < ( Q(Q_ATANINP)-FL2FXCONST_DBL(0.00395)) ) + { + INT res_e; + + temp = fPow2(x); // q25 * q25 - (DFRACT_BITS-1) = q19 + temp = fMult(temp, ONEBY3P56); // q19 * q31 - (DFRACT_BITS-1) = q19 + temp = temp + Q(19); // q19 + q19 = q19 + result = fDivNorm(x, temp, &res_e); + result = scaleValue(result, (Q_ATANOUT-Q_ATANINP+19-DFRACT_BITS+1) + res_e ); + } + else if( x < FL2FXCONST_DBL(1.28/64.0) ) + { + FIXP_DBL delta_fix; + FIXP_DBL PI_BY_4 = FL2FXCONST_DBL(3.1415926/4.0) >> 1; /* pi/4 in q30 */ + + delta_fix = (x - FL2FXCONST_DBL(1.0/64.0)) << 5; /* q30 */ + result = PI_BY_4 + (delta_fix >> 1) - (fPow2Div2(delta_fix)); + } + else + { + INT res_e; + + temp = fPow2Div2(x); // q25 * q25 - (DFRACT_BITS-1) - 1 = q18 + temp = temp + P281; // q18 + q18 = q18 + result = fDivNorm(x, temp, &res_e); + result = scaleValue(result, (Q_ATANOUT-Q_ATANINP+18-DFRACT_BITS+1) + res_e ); + result = ONEP571 - result; // q30 + q30 = q30 + } + if (sign) { + result = -result; + } + + return(result); +} + + + +#include "FDK_tools_rom.h" + +FIXP_DBL fixp_cos(FIXP_DBL x, int scale) +{ + FIXP_DBL residual, error, sine, cosine; + + residual = fixp_sin_cos_residual_inline(x, scale, &sine, &cosine); + error = fMult(sine, residual); + + return cosine - error; +} + +FIXP_DBL fixp_sin(FIXP_DBL x, int scale) +{ + FIXP_DBL residual, error, sine, cosine; + + residual = fixp_sin_cos_residual_inline(x, scale, &sine, &cosine); + error = fMult(cosine, residual); + + return sine + error; +} + +void fixp_cos_sin (FIXP_DBL x, int scale, FIXP_DBL *cos, FIXP_DBL *sin) +{ + FIXP_DBL residual, error0, error1, sine, cosine; + + residual = fixp_sin_cos_residual_inline(x, scale, &sine, &cosine); + error0 = fMult(sine, residual); + error1 = fMult(cosine, residual); + *cos = cosine - error0; + *sin = sine + error1; +} + + + + + |