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Diffstat (limited to 'fdk-aac/libFDK/src/FDK_trigFcts.cpp')
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diff --git a/fdk-aac/libFDK/src/FDK_trigFcts.cpp b/fdk-aac/libFDK/src/FDK_trigFcts.cpp new file mode 100644 index 0000000..4bb6262 --- /dev/null +++ b/fdk-aac/libFDK/src/FDK_trigFcts.cpp @@ -0,0 +1,340 @@ +/* ----------------------------------------------------------------------------- +Software License for The Fraunhofer FDK AAC Codec Library for Android + +© Copyright 1995 - 2018 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 +----------------------------------------------------------------------------- */ + +/******************* Library for basic calculation routines ******************** + + 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() so there a wider input + * range can be covered, too. + * + *****************************************************************************/ + 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 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; + } + FDK_ASSERT(FL2FXCONST_DBL(1.0 / 64.0) == Q(Q_ATANINP)); + /* calc of arctan */ + if (x < FL2FXCONST_DBL(1.0 / 64.0)) + /* + Chebyshev polynomial approximation of atan(x) + 5th-order approximation: atan(x) = a1*x + a2*x^3 + a3*x^5 = x(a1 + x^2*(a2 + + a3*x^2)); a1 = 0.9949493661166540f, a2 = 0.2870606355326520f, a3 = + 0.0780371764464410f; 7th-order approximation: atan(x) = a1*x + a2*x^3 + + a3*x^5 + a3*x^7 = x(a1 + x^2*(a2 + x^2*(a3 + a4*x^2))); a1 = + 0.9991334482227801, a2 = -0.3205332923816640, a3 = 0.1449824901444650, a4 = + -0.0382544649702990; 7th-order approximation in use (the most accurate + solution) + */ + { + x <<= ATI_SF; + FIXP_DBL x2 = fPow2(x); + temp = fMultAddDiv2((FL2FXCONST_DBL(0.1449824901444650f) >> 1), x2, + FL2FXCONST_DBL(-0.0382544649702990)); + temp = fMultAddDiv2((FL2FXCONST_DBL(-0.3205332923816640f) >> 2), x2, temp); + temp = fMultAddDiv2((FL2FXCONST_DBL(0.9991334482227801f) >> 3), x2, temp); + result = fMult(x, (temp << 2)); + } 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 { + /* Other approximation for |x| > 1.28 */ + 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); + +#ifdef SINETABLE_16BIT + return cosine - error; +#else + /* Undo downscaling by 1 which was done at fixp_sin_cos_residual_inline */ + return SATURATE_LEFT_SHIFT(cosine - error, 1, DFRACT_BITS); +#endif +} + +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); + +#ifdef SINETABLE_16BIT + return sine + error; +#else + return SATURATE_LEFT_SHIFT(sine + error, 1, DFRACT_BITS); +#endif +} + +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); + +#ifdef SINETABLE_16BIT + *cos = cosine - error0; + *sin = sine + error1; +#else + *cos = SATURATE_LEFT_SHIFT(cosine - error0, 1, DFRACT_BITS); + *sin = SATURATE_LEFT_SHIFT(sine + error1, 1, DFRACT_BITS); +#endif +} |