| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2013 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 |
