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diff --git a/libSBRdec/src/transcendent.h b/libSBRdec/src/transcendent.h new file mode 100644 index 0000000..f0ee21e --- /dev/null +++ b/libSBRdec/src/transcendent.h @@ -0,0 +1,355 @@ + +/* ----------------------------------------------------------------------------------------------------------- +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 +----------------------------------------------------------------------------------------------------------- */ + +/*! + \file + \brief FDK Fixed Point Arithmetic Library Interface +*/ + +#ifndef __TRANSCENDENT_H +#define __TRANSCENDENT_H + +#include "sbrdecoder.h" +#include "sbr_rom.h" + +/************************************************************************/ +/*! + \brief Get number of octaves between frequencies a and b + + The Result is scaled with 1/8. + The valid range for a and b is 1 to LOG_DUALIS_TABLE_SIZE. + + \return ld(a/b) / 8 +*/ +/************************************************************************/ +static inline FIXP_SGL FDK_getNumOctavesDiv8(INT a, /*!< lower band */ + INT b) /*!< upper band */ +{ + return ( (SHORT)((LONG)(CalcLdInt(b) - CalcLdInt(a))>>(FRACT_BITS-3)) ); +} + + +/************************************************************************/ +/*! + \brief Add two values given by mantissa and exponent. + + Mantissas are in fract format with values between 0 and 1. <br> + The base for exponents is 2. Example: \f$ a = a\_m * 2^{a\_e} \f$<br> +*/ +/************************************************************************/ +inline void FDK_add_MantExp(FIXP_SGL a_m, /*!< Mantissa of 1st operand a */ + SCHAR a_e, /*!< Exponent of 1st operand a */ + FIXP_SGL b_m, /*!< Mantissa of 2nd operand b */ + SCHAR b_e, /*!< Exponent of 2nd operand b */ + FIXP_SGL *ptrSum_m, /*!< Mantissa of result */ + SCHAR *ptrSum_e) /*!< Exponent of result */ +{ + FIXP_DBL accu; + int shift; + int shiftAbs; + + FIXP_DBL shiftedMantissa; + FIXP_DBL otherMantissa; + + /* Equalize exponents of the summands. + For the smaller summand, the exponent is adapted and + for compensation, the mantissa is shifted right. */ + + shift = (int)(a_e - b_e); + + shiftAbs = (shift>0)? shift : -shift; + shiftAbs = (shiftAbs < DFRACT_BITS-1)? shiftAbs : DFRACT_BITS-1; + shiftedMantissa = (shift>0)? (FX_SGL2FX_DBL(b_m) >> shiftAbs) : (FX_SGL2FX_DBL(a_m) >> shiftAbs); + otherMantissa = (shift>0)? FX_SGL2FX_DBL(a_m) : FX_SGL2FX_DBL(b_m); + *ptrSum_e = (shift>0)? a_e : b_e; + + accu = (shiftedMantissa >> 1) + (otherMantissa >> 1); + /* shift by 1 bit to avoid overflow */ + + if ( (accu >= (FL2FXCONST_DBL(0.5f) - (FIXP_DBL)1)) || (accu <= FL2FXCONST_DBL(-0.5f)) ) + *ptrSum_e += 1; + else + accu = (shiftedMantissa + otherMantissa); + + *ptrSum_m = FX_DBL2FX_SGL(accu); + +} + +inline void FDK_add_MantExp(FIXP_DBL a, /*!< Mantissa of 1st operand a */ + SCHAR a_e, /*!< Exponent of 1st operand a */ + FIXP_DBL b, /*!< Mantissa of 2nd operand b */ + SCHAR b_e, /*!< Exponent of 2nd operand b */ + FIXP_DBL *ptrSum, /*!< Mantissa of result */ + SCHAR *ptrSum_e) /*!< Exponent of result */ +{ + FIXP_DBL accu; + int shift; + int shiftAbs; + + FIXP_DBL shiftedMantissa; + FIXP_DBL otherMantissa; + + /* Equalize exponents of the summands. + For the smaller summand, the exponent is adapted and + for compensation, the mantissa is shifted right. */ + + shift = (int)(a_e - b_e); + + shiftAbs = (shift>0)? shift : -shift; + shiftAbs = (shiftAbs < DFRACT_BITS-1)? shiftAbs : DFRACT_BITS-1; + shiftedMantissa = (shift>0)? (b >> shiftAbs) : (a >> shiftAbs); + otherMantissa = (shift>0)? a : b; + *ptrSum_e = (shift>0)? a_e : b_e; + + accu = (shiftedMantissa >> 1) + (otherMantissa >> 1); + /* shift by 1 bit to avoid overflow */ + + if ( (accu >= (FL2FXCONST_DBL(0.5f) - (FIXP_DBL)1)) || (accu <= FL2FXCONST_DBL(-0.5f)) ) + *ptrSum_e += 1; + else + accu = (shiftedMantissa + otherMantissa); + + *ptrSum = accu; + +} + +/************************************************************************/ +/*! + \brief Divide two values given by mantissa and exponent. + + Mantissas are in fract format with values between 0 and 1. <br> + The base for exponents is 2. Example: \f$ a = a\_m * 2^{a\_e} \f$<br> + + For performance reasons, the division is based on a table lookup + which limits accuracy. +*/ +/************************************************************************/ +static inline void FDK_divide_MantExp(FIXP_SGL a_m, /*!< Mantissa of dividend a */ + SCHAR a_e, /*!< Exponent of dividend a */ + FIXP_SGL b_m, /*!< Mantissa of divisor b */ + SCHAR b_e, /*!< Exponent of divisor b */ + FIXP_SGL *ptrResult_m, /*!< Mantissa of quotient a/b */ + SCHAR *ptrResult_e) /*!< Exponent of quotient a/b */ + +{ + int preShift, postShift, index, shift; + FIXP_DBL ratio_m; + FIXP_SGL bInv_m = FL2FXCONST_SGL(0.0f); + + preShift = CntLeadingZeros(FX_SGL2FX_DBL(b_m)); + + /* + Shift b into the range from 0..INV_TABLE_SIZE-1, + + E.g. 10 bits must be skipped for INV_TABLE_BITS 8: + - leave 8 bits as index for table + - skip sign bit, + - skip first bit of mantissa, because this is always the same (>0.5) + + We are dealing with energies, so we need not care + about negative numbers + */ + + /* + The first interval has half width so the lowest bit of the index is + needed for a doubled resolution. + */ + shift = (FRACT_BITS - 2 - INV_TABLE_BITS - preShift); + + index = (shift<0)? (LONG)b_m << (-shift) : (LONG)b_m >> shift; + + + /* The index has INV_TABLE_BITS +1 valid bits here. Clear the other bits. */ + index &= (1 << (INV_TABLE_BITS+1)) - 1; + + /* Remove offset of half an interval */ + index--; + + /* Now the lowest bit is shifted out */ + index = index >> 1; + + /* Fetch inversed mantissa from table: */ + bInv_m = (index<0)? bInv_m : FDK_sbrDecoder_invTable[index]; + + /* Multiply a with the inverse of b: */ + ratio_m = (index<0)? FX_SGL2FX_DBL(a_m >> 1) : fMultDiv2(bInv_m,a_m); + + postShift = CntLeadingZeros(ratio_m)-1; + + *ptrResult_m = FX_DBL2FX_SGL(ratio_m << postShift); + *ptrResult_e = a_e - b_e + 1 + preShift - postShift; +} + +static inline void FDK_divide_MantExp(FIXP_DBL a_m, /*!< Mantissa of dividend a */ + SCHAR a_e, /*!< Exponent of dividend a */ + FIXP_DBL b_m, /*!< Mantissa of divisor b */ + SCHAR b_e, /*!< Exponent of divisor b */ + FIXP_DBL *ptrResult_m, /*!< Mantissa of quotient a/b */ + SCHAR *ptrResult_e) /*!< Exponent of quotient a/b */ + +{ + int preShift, postShift, index, shift; + FIXP_DBL ratio_m; + FIXP_SGL bInv_m = FL2FXCONST_SGL(0.0f); + + preShift = CntLeadingZeros(b_m); + + /* + Shift b into the range from 0..INV_TABLE_SIZE-1, + + E.g. 10 bits must be skipped for INV_TABLE_BITS 8: + - leave 8 bits as index for table + - skip sign bit, + - skip first bit of mantissa, because this is always the same (>0.5) + + We are dealing with energies, so we need not care + about negative numbers + */ + + /* + The first interval has half width so the lowest bit of the index is + needed for a doubled resolution. + */ + shift = (DFRACT_BITS - 2 - INV_TABLE_BITS - preShift); + + index = (shift<0)? (LONG)b_m << (-shift) : (LONG)b_m >> shift; + + + /* The index has INV_TABLE_BITS +1 valid bits here. Clear the other bits. */ + index &= (1 << (INV_TABLE_BITS+1)) - 1; + + /* Remove offset of half an interval */ + index--; + + /* Now the lowest bit is shifted out */ + index = index >> 1; + + /* Fetch inversed mantissa from table: */ + bInv_m = (index<0)? bInv_m : FDK_sbrDecoder_invTable[index]; + + /* Multiply a with the inverse of b: */ + ratio_m = (index<0)? (a_m >> 1) : fMultDiv2(bInv_m,a_m); + + postShift = CntLeadingZeros(ratio_m)-1; + + *ptrResult_m = ratio_m << postShift; + *ptrResult_e = a_e - b_e + 1 + preShift - postShift; +} + +/*! + \brief Calculate the squareroot of a number given by mantissa and exponent + + Mantissa is in fract format with values between 0 and 1. <br> + The base for the exponent is 2. Example: \f$ a = a\_m * 2^{a\_e} \f$<br> + The operand is addressed via pointers and will be overwritten with the result. + + For performance reasons, the square root is based on a table lookup + which limits accuracy. +*/ +static inline void FDK_sqrt_MantExp(FIXP_DBL *mantissa, /*!< Pointer to mantissa */ + SCHAR *exponent, + const SCHAR *destScale) +{ + FIXP_DBL input_m = *mantissa; + int input_e = (int) *exponent; + FIXP_DBL result = FL2FXCONST_DBL(0.0f); + int result_e = -FRACT_BITS; + + /* Call lookup square root, which does internally normalization. */ + result = sqrtFixp_lookup(input_m, &input_e); + result_e = input_e; + + /* Write result */ + if (exponent==destScale) { + *mantissa = result; + *exponent = result_e; + } else { + int shift = result_e - *destScale; + *mantissa = (shift>=0) ? result << (INT)fixMin(DFRACT_BITS-1,shift) + : result >> (INT)fixMin(DFRACT_BITS-1,-shift); + *exponent = *destScale; + } +} + + +#endif |