| /* ----------------------------------------------------------------------------- |
| 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): Manuel Jander |
| |
| Description: LPC related functions |
| |
| *******************************************************************************/ |
| |
| #ifndef FDK_LPC_H |
| #define FDK_LPC_H |
| |
| #include "common_fix.h" |
| |
| #define LPC_MAX_ORDER 24 |
| |
| /* |
| * Experimental solution for lattice filter substitution. |
| * LPC_SYNTHESIS_IIR macro must be activated in aacdec_tns.cpp. |
| * When LPC_SYNTHESIS_IIR enabled, there will be a substitution of the default |
| * lpc synthesis lattice filter by an IIR synthesis filter (with a conversionof |
| * the filter coefs). LPC_TNS related macros are intended to implement the data |
| * types used by the CLpc_Synthesis variant which is used for this solution. |
| * */ |
| |
| /* #define LPC_TNS_LOWER_PRECISION */ |
| |
| typedef FIXP_DBL FIXP_LPC_TNS; |
| #define FX_DBL2FX_LPC_TNS(x) (x) |
| #define FX_DBL2FXCONST_LPC_TNS(x) (x) |
| #define FX_LPC_TNS2FX_DBL(x) (x) |
| #define FL2FXCONST_LPC_TNS(val) FL2FXCONST_DBL(val) |
| #define MAXVAL_LPC_TNS MAXVAL_DBL |
| |
| typedef FIXP_SGL FIXP_LPC; |
| #define FX_DBL2FX_LPC(x) FX_DBL2FX_SGL((FIXP_DBL)(x)) |
| #define FX_DBL2FXCONST_LPC(x) FX_DBL2FXCONST_SGL(x) |
| #define FX_LPC2FX_DBL(x) FX_SGL2FX_DBL(x) |
| #define FL2FXCONST_LPC(val) FL2FXCONST_SGL(val) |
| #define MAXVAL_LPC MAXVAL_SGL |
| |
| /** |
| * \brief Obtain residual signal through LPC analysis. |
| * \param signal pointer to buffer holding signal to be analysed. Residual is |
| * returned there (in place) |
| * \param signal_size the size of the input data in pData |
| * \param lpcCoeff_m the LPC filter coefficient mantissas |
| * \param lpcCoeff_e the LPC filter coefficient exponent |
| * \param order the LPC filter order (size of coeff) |
| * \param filtState Pointer to state buffer of size order |
| * \param filtStateIndex pointer to state index storage |
| */ |
| void CLpc_Analysis(FIXP_DBL signal[], const int signal_size, |
| const FIXP_LPC lpcCoeff_m[], const int lpcCoeff_e, |
| const int order, FIXP_DBL *filtState, int *filtStateIndex); |
| |
| /** |
| * \brief Synthesize signal fom residual through LPC synthesis, using LP |
| * coefficients. |
| * \param signal pointer to buffer holding the residual signal. The synthesis is |
| * returned there (in place) |
| * \param signal_size the size of the input data in pData |
| * \param inc buffer traversal increment for signal |
| * \param coeff the LPC filter coefficients |
| * \param coeff_e exponent of coeff |
| * \param order the LPC filter order (size of coeff) |
| * \param state state buffer of size LPC_MAX_ORDER |
| * \param pStateIndex pointer to state index storage |
| */ |
| void CLpc_Synthesis(FIXP_DBL *signal, const int signal_size, const int signal_e, |
| const int inc, const FIXP_LPC_TNS *lpcCoeff_m, |
| const int lpcCoeff_e, const int order, FIXP_DBL *state, |
| int *pStateIndex); |
| void CLpc_Synthesis(FIXP_DBL *signal, const int signal_size, const int signal_e, |
| const int inc, const FIXP_LPC coeff[], const int coeff_e, |
| const int order, FIXP_DBL *filtState, int *pStateIndex); |
| |
| /** |
| * \brief Synthesize signal fom residual through LPC synthesis, using ParCor |
| * coefficients. The algorithm assumes a filter gain of max 1.0. If the filter |
| * gain is higher, this must be accounted into the values of signal_e |
| * and/or signal_e_out to avoid overflows. |
| * \param signal pointer to buffer holding the residual signal. The synthesis is |
| * returned there (in place) |
| * \param signal_size the size of the input data in pData |
| * \param inc buffer traversal increment for signal |
| * \param coeff the LPC filter coefficients |
| * \param coeff_e exponent of coeff |
| * \param order the LPC filter order (size of coeff) |
| * \param state state buffer of size LPC_MAX_ORDER |
| */ |
| void CLpc_SynthesisLattice(FIXP_DBL *signal, const int signal_size, |
| const int signal_e, const int signal_e_out, |
| const int inc, const FIXP_SGL *coeff, |
| const int order, FIXP_DBL *state); |
| |
| void CLpc_SynthesisLattice(FIXP_DBL *RESTRICT signal, const int signal_size, |
| const int signal_e, const int signal_e_out, |
| const int inc, const FIXP_DBL *RESTRICT coeff, |
| const int order, FIXP_DBL *RESTRICT state); |
| |
| /** |
| * \brief |
| */ |
| INT CLpc_ParcorToLpc(const FIXP_LPC_TNS reflCoeff[], FIXP_LPC_TNS LpcCoeff[], |
| INT numOfCoeff, FIXP_DBL workBuffer[]); |
| INT CLpc_ParcorToLpc(const FIXP_LPC reflCoeff[], FIXP_LPC LpcCoeff[], |
| const int numOfCoeff, FIXP_DBL workBuffer[]); |
| |
| /** |
| * \brief Calculate ParCor (Partial autoCorrelation, reflection) coefficients |
| * from autocorrelation coefficients using the Schur algorithm (instead of |
| * Levinson Durbin). |
| * \param acorr order+1 autocorrelation coefficients |
| * \param reflCoeff output reflection /ParCor coefficients. The first |
| * coefficient which is always 1.0 is ommitted. |
| * \param order number of acorr / reflCoeff coefficients. |
| * \param pPredictionGain_m prediction gain mantissa |
| * \param pPredictionGain_e prediction gain exponent |
| */ |
| void CLpc_AutoToParcor(FIXP_DBL acorr[], const int acorr_e, |
| FIXP_LPC reflCoeff[], const int order, |
| FIXP_DBL *pPredictionGain_m, INT *pPredictionGain_e); |
| |
| #endif /* FDK_LPC_H */ |