diff options
Diffstat (limited to 'libFDK/include/fixpoint_math.h')
| -rw-r--r-- | libFDK/include/fixpoint_math.h | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/libFDK/include/fixpoint_math.h b/libFDK/include/fixpoint_math.h new file mode 100644 index 0000000..ae554cb --- /dev/null +++ b/libFDK/include/fixpoint_math.h @@ -0,0 +1,466 @@ + +/* ----------------------------------------------------------------------------------------------------------- +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): M. Gayer + Description: Fixed point specific mathematical functions + +******************************************************************************/ + +#ifndef __fixpoint_math_H +#define __fixpoint_math_H + + +#include "common_fix.h" + + +#define LD_DATA_SCALING (64.0f) +#define LD_DATA_SHIFT 6 /* pow(2, LD_DATA_SHIFT) = LD_DATA_SCALING */ + +/** + * \brief deprecated. Use fLog2() instead. + */ +FIXP_DBL CalcLdData(FIXP_DBL op); + +void LdDataVector(FIXP_DBL *srcVector, FIXP_DBL *destVector, INT number); + +FIXP_DBL CalcInvLdData(FIXP_DBL op); + + +void InitLdInt(); +FIXP_DBL CalcLdInt(INT i); + +extern const USHORT sqrt_tab[49]; + +inline FIXP_DBL sqrtFixp_lookup(FIXP_DBL x) +{ + UINT y = (INT)x; + UCHAR is_zero=(y==0); + INT zeros=fixnormz_D(y) & 0x1e; + y<<=zeros; + UINT idx=(y>>26)-16; + USHORT frac=(y>>10)&0xffff; + USHORT nfrac=0xffff^frac; + UINT t=nfrac*sqrt_tab[idx]+frac*sqrt_tab[idx+1]; + t=t>>(zeros>>1); + return(is_zero ? 0 : t); +} + +inline FIXP_DBL sqrtFixp_lookup(FIXP_DBL x, INT *x_e) +{ + UINT y = (INT)x; + INT e; + + if (x == (FIXP_DBL)0) { + return x; + } + + /* Normalize */ + e=fixnormz_D(y); + y<<=e; + e = *x_e - e + 2; + + /* Correct odd exponent. */ + if (e & 1) { + y >>= 1; + e ++; + } + /* Get square root */ + UINT idx=(y>>26)-16; + USHORT frac=(y>>10)&0xffff; + USHORT nfrac=0xffff^frac; + UINT t=nfrac*sqrt_tab[idx]+frac*sqrt_tab[idx+1]; + + /* Write back exponent */ + *x_e = e >> 1; + return (FIXP_DBL)(LONG)(t>>1); +} + + + +FIXP_DBL sqrtFixp(FIXP_DBL op); + +void InitInvSqrtTab(); + +FIXP_DBL invSqrtNorm2(FIXP_DBL op, INT *shift); + +/***************************************************************************** + + functionname: invFixp + description: delivers 1/(op) + +*****************************************************************************/ +inline FIXP_DBL invFixp(FIXP_DBL op) +{ + INT tmp_exp ; + FIXP_DBL tmp_inv = invSqrtNorm2(op, &tmp_exp) ; + FDK_ASSERT((31-(2*tmp_exp+1))>=0) ; + return ( fPow2Div2( (FIXP_DBL)tmp_inv ) >> (31-(2*tmp_exp+1)) ) ; +} + + + +#if defined(__mips__) && (__GNUC__==2) + +#define FUNCTION_schur_div +inline FIXP_DBL schur_div(FIXP_DBL num,FIXP_DBL denum, INT count) +{ + INT result, tmp ; + __asm__ ("srl %1, %2, 15\n" + "div %3, %1\n" : "=lo" (result) + : "%d" (tmp), "d" (denum) , "d" (num) + : "hi" ) ; + return result<<16 ; +} + +/*###########################################################################################*/ +#elif defined(__mips__) && (__GNUC__==3) + +#define FUNCTION_schur_div +inline FIXP_DBL schur_div(FIXP_DBL num,FIXP_DBL denum, INT count) +{ + INT result, tmp; + + __asm__ ("srl %[tmp], %[denum], 15\n" + "div %[result], %[num], %[tmp]\n" + : [tmp] "+r" (tmp), [result]"=r"(result) + : [denum]"r"(denum), [num]"r"(num) + : "hi", "lo"); + return result << (DFRACT_BITS-16); +} + +/*###########################################################################################*/ +#elif defined(SIMULATE_MIPS_DIV) + +#define FUNCTION_schur_div +inline FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count) +{ + FDK_ASSERT (count<=DFRACT_BITS-1); + FDK_ASSERT (num>=(FIXP_DBL)0); + FDK_ASSERT (denum>(FIXP_DBL)0); + FDK_ASSERT (num <= denum); + + INT tmp = denum >> (count-1); + INT result = 0; + + while (num > tmp) + { + num -= tmp; + result++; + } + + return result << (DFRACT_BITS-count); +} + +/*###########################################################################################*/ +#endif /* target architecture selector */ + +#if !defined(FUNCTION_schur_div) +/** + * \brief Divide two FIXP_DBL values with given precision. + * \param num dividend + * \param denum divisor + * \param count amount of significant bits of the result (starting to the MSB) + * \return num/divisor + */ +FIXP_DBL schur_div(FIXP_DBL num,FIXP_DBL denum, INT count); +#endif + + + +FIXP_DBL mul_dbl_sgl_rnd (const FIXP_DBL op1, + const FIXP_SGL op2); + +/** + * \brief multiply two values with normalization, thus max precision. + * Author: Robert Weidner + * + * \param f1 first factor + * \param f2 secod factor + * \param result_e pointer to an INT where the exponent of the result is stored into + * \return mantissa of the product f1*f2 + */ +FIXP_DBL fMultNorm( + FIXP_DBL f1, + FIXP_DBL f2, + INT *result_e + ); + +inline FIXP_DBL fMultNorm(FIXP_DBL f1, FIXP_DBL f2) +{ + FIXP_DBL m; + INT e; + + m = fMultNorm(f1, f2, &e); + + m = scaleValueSaturate(m, e); + + return m; +} + +/** + * \brief Divide 2 FIXP_DBL values with normalization of input values. + * \param num numerator + * \param denum denomintator + * \return num/denum with exponent = 0 + */ +FIXP_DBL fDivNorm(FIXP_DBL num, FIXP_DBL denom, INT *result_e); + +/** + * \brief Divide 2 FIXP_DBL values with normalization of input values. + * \param num numerator + * \param denum denomintator + * \param result_e pointer to an INT where the exponent of the result is stored into + * \return num/denum with exponent = *result_e + */ +FIXP_DBL fDivNorm(FIXP_DBL num, FIXP_DBL denom); + +/** + * \brief Divide 2 FIXP_DBL values with normalization of input values. + * \param num numerator + * \param denum denomintator + * \return num/denum with exponent = 0 + */ +FIXP_DBL fDivNormHighPrec(FIXP_DBL L_num, FIXP_DBL L_denum, INT *result_e); + +/** + * \brief Calculate log(argument)/log(2) (logarithm with base 2). deprecated. Use fLog2() instead. + * \param arg mantissa of the argument + * \param arg_e exponent of the argument + * \param result_e pointer to an INT to store the exponent of the result + * \return the mantissa of the result. + * \param + */ +FIXP_DBL CalcLog2(FIXP_DBL arg, INT arg_e, INT *result_e); + +/** + * \brief return 2 ^ (exp * 2^exp_e) + * \param exp_m mantissa of the exponent to 2.0f + * \param exp_e exponent of the exponent to 2.0f + * \param result_e pointer to a INT where the exponent of the result will be stored into + * \return mantissa of the result + */ +FIXP_DBL f2Pow(const FIXP_DBL exp_m, const INT exp_e, INT *result_e); + +/** + * \brief return 2 ^ (exp_m * 2^exp_e). This version returns only the mantissa with implicit exponent of zero. + * \param exp_m mantissa of the exponent to 2.0f + * \param exp_e exponent of the exponent to 2.0f + * \return mantissa of the result + */ +FIXP_DBL f2Pow(const FIXP_DBL exp_m, const INT exp_e); + +/** + * \brief return x ^ (exp * 2^exp_e), where log2(x) = baseLd_m * 2^(baseLd_e). This saves + * the need to compute log2() of constant values (when x is a constant). + * \param ldx_m mantissa of log2() of x. + * \param ldx_e exponent of log2() of x. + * \param exp_m mantissa of the exponent to 2.0f + * \param exp_e exponent of the exponent to 2.0f + * \param result_e pointer to a INT where the exponent of the result will be stored into + * \return mantissa of the result + */ +FIXP_DBL fLdPow( + FIXP_DBL baseLd_m, + INT baseLd_e, + FIXP_DBL exp_m, INT exp_e, + INT *result_e + ); + +/** + * \brief return x ^ (exp * 2^exp_e), where log2(x) = baseLd_m * 2^(baseLd_e). This saves + * the need to compute log2() of constant values (when x is a constant). This version + * does not return an exponent, which is implicitly 0. + * \param ldx_m mantissa of log2() of x. + * \param ldx_e exponent of log2() of x. + * \param exp_m mantissa of the exponent to 2.0f + * \param exp_e exponent of the exponent to 2.0f + * \return mantissa of the result + */ +FIXP_DBL fLdPow( + FIXP_DBL baseLd_m, INT baseLd_e, + FIXP_DBL exp_m, INT exp_e + ); + +/** + * \brief return (base * 2^base_e) ^ (exp * 2^exp_e). Use fLdPow() instead whenever possible. + * \param base_m mantissa of the base. + * \param base_e exponent of the base. + * \param exp_m mantissa of power to be calculated of the base. + * \param exp_e exponent of power to be calculated of the base. + * \param result_e pointer to a INT where the exponent of the result will be stored into. + * \return mantissa of the result. + */ +FIXP_DBL fPow(FIXP_DBL base_m, INT base_e, FIXP_DBL exp_m, INT exp_e, INT *result_e); + +/** + * \brief return (base * 2^base_e) ^ N + * \param base mantissa of the base + * \param base_e exponent of the base + * \param power to be calculated of the base + * \param result_e pointer to a INT where the exponent of the result will be stored into + * \return mantissa of the result + */ +FIXP_DBL fPowInt(FIXP_DBL base_m, INT base_e, INT N, INT *result_e); + +/** + * \brief calculate logarithm of base 2 of x_m * 2^(x_e) + * \param x_m mantissa of the input value. + * \param x_e exponent of the input value. + * \param pointer to an INT where the exponent of the result is returned into. + * \return mantissa of the result. + */ +FIXP_DBL fLog2(FIXP_DBL x_m, INT x_e, INT *result_e); + +/** + * \brief calculate logarithm of base 2 of x_m * 2^(x_e) + * \param x_m mantissa of the input value. + * \param x_e exponent of the input value. + * \return mantissa of the result with implicit exponent of LD_DATA_SHIFT. + */ +FIXP_DBL fLog2(FIXP_DBL x_m, INT x_e); + +/** + * \brief Add with saturation of the result. + * \param a first summand + * \param b second summand + * \return saturated sum of a and b. + */ +inline FIXP_SGL fAddSaturate(const FIXP_SGL a, const FIXP_SGL b) +{ + LONG sum; + + sum = (LONG)(SHORT)a + (LONG)(SHORT)b; + sum = fMax(fMin((INT)sum, (INT)MAXVAL_SGL), (INT)MINVAL_SGL); + return (FIXP_SGL)(SHORT)sum; +} + +/** + * \brief Add with saturation of the result. + * \param a first summand + * \param b second summand + * \return saturated sum of a and b. + */ +inline FIXP_DBL fAddSaturate(const FIXP_DBL a, const FIXP_DBL b) +{ + LONG sum; + + sum = (LONG)(a>>1) + (LONG)(b>>1); + sum = fMax(fMin((INT)sum, (INT)(MAXVAL_DBL>>1)), (INT)(MINVAL_DBL>>1)); + return (FIXP_DBL)(LONG)(sum<<1); +} + +//#define TEST_ROUNDING + + + + +/***************************************************************************** + + array for 1/n, n=1..50 + +****************************************************************************/ + + extern const FIXP_DBL invCount[50]; + + LNK_SECTION_INITCODE + inline void InitInvInt(void) {} + + +/** + * \brief Calculate the value of 1/i where i is a integer value. It supports + * input values from 1 upto 50. + * \param intValue Integer input value. + * \param FIXP_DBL representation of 1/intValue + */ +inline FIXP_DBL GetInvInt(int intValue) +{ + FDK_ASSERT((intValue > 0) && (intValue < 50)); + FDK_ASSERT(intValue<50); + return invCount[intValue]; +} + + +#endif + |