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Diffstat (limited to 'libFDK/include/fft.h')
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diff --git a/libFDK/include/fft.h b/libFDK/include/fft.h deleted file mode 100644 index 616f350..0000000 --- a/libFDK/include/fft.h +++ /dev/null @@ -1,253 +0,0 @@ - -/* ----------------------------------------------------------------------------------------------------------- -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 ------------------------------------------------------------------------------------------------------------ */ - -/*************************** Fraunhofer IIS FDK Tools ********************** - - Author(s): Josef Hoepfl, DSP Solutions - Description: Fix point FFT - -******************************************************************************/ - -#ifndef __FFT_H__ -#define __FFT_H__ - -#include "common_fix.h" - -/** - * \brief Perform an inplace complex valued FFT of length 2^n - * - * \param length Length of the FFT to be calculated. - * \param pInput Input/Output data buffer. The input data must have at least 1 bit scale headroom. - * The values are interleaved, real/imag pairs. - * \param scalefactor Pointer to an INT, which contains the current scale of the input data, - * which is updated according to the FFT scale. - */ -void fft(int length, FIXP_DBL *pInput, INT *scalefactor); - -/** - * \brief Perform an inplace complex valued IFFT of length 2^n - * - * \param length Length of the FFT to be calculated. - * \param pInput Input/Output data buffer. The input data must have at least 1 bit scale headroom. - * The values are interleaved, real/imag pairs. - * \param scalefactor Pointer to an INT, which contains the current scale of the input data, - * which is updated according to the IFFT scale. - */ -void ifft(int length, FIXP_DBL *pInput, INT *scalefactor); - - -/* - * Frequently used and fixed short length FFTs. - */ - -LNK_SECTION_CODE_L1 -static void FORCEINLINE fft_4(FIXP_DBL *x) -{ - FIXP_DBL a00, a10, a20, a30, tmp0, tmp1; - - a00 = (x[0] + x[4])>>1; /* Re A + Re B */ - a10 = (x[2] + x[6])>>1; /* Re C + Re D */ - a20 = (x[1] + x[5])>>1; /* Im A + Im B */ - a30 = (x[3] + x[7])>>1; /* Im C + Im D */ - - x[0] = a00 + a10; /* Re A' = Re A + Re B + Re C + Re D */ - x[1] = a20 + a30; /* Im A' = Im A + Im B + Im C + Im D */ - - tmp0 = a00 - x[4]; /* Re A - Re B */ - tmp1 = a20 - x[5]; /* Im A - Im B */ - - x[4] = a00 - a10; /* Re C' = Re A + Re B - Re C - Re D */ - x[5] = a20 - a30; /* Im C' = Im A + Im B - Im C - Im D */ - - a10 = a10 - x[6]; /* Re C - Re D */ - a30 = a30 - x[7]; /* Im C - Im D */ - - x[2] = tmp0 + a30; /* Re B' = Re A - Re B + Im C - Im D */ - x[6] = tmp0 - a30; /* Re D' = Re A - Re B - Im C + Im D */ - x[3] = tmp1 - a10; /* Im B' = Im A - Im B - Re C + Re D */ - x[7] = tmp1 + a10; /* Im D' = Im A - Im B + Re C - Re D */ -} - -LNK_SECTION_CODE_L1 -static void FORCEINLINE fft_8(FIXP_DBL *x) -{ - #define W_PiFOURTH STC(0x5a82799a) - - FIXP_DBL a00, a10, a20, a30; - FIXP_DBL y[16]; - - a00 = (x[0] + x[8])>>1; - a10 = x[4] + x[12]; - a20 = (x[1] + x[9])>>1; - a30 = x[5] + x[13]; - - y[0] = a00 + (a10>>1); - y[4] = a00 - (a10>>1); - y[1] = a20 + (a30>>1); - y[5] = a20 - (a30>>1); - - a00 = a00 - x[8]; - a10 = (a10>>1) - x[12]; - a20 = a20 - x[9]; - a30 = (a30>>1) - x[13]; - - y[2] = a00 + a30; - y[6] = a00 - a30; - y[3] = a20 - a10; - y[7] = a20 + a10; - - a00 = (x[2] + x[10])>>1; - a10 = x[6] + x[14]; - a20 = (x[3] + x[11])>>1; - a30 = x[7] + x[15]; - - y[8] = a00 + (a10>>1); - y[12] = a00 - (a10>>1); - y[9] = a20 + (a30>>1); - y[13] = a20 - (a30>>1); - - a00 = a00 - x[10]; - a10 = (a10>>1) - x[14]; - a20 = a20 - x[11]; - a30 = (a30>>1) - x[15]; - - y[10] = a00 + a30; - y[14] = a00 - a30; - y[11] = a20 - a10; - y[15] = a20 + a10; - - FIXP_DBL vr, vi, ur, ui; - - ur = y[0]>>1; - ui = y[1]>>1; - vr = y[8]; - vi = y[9]; - x[0] = ur + (vr>>1); - x[1] = ui + (vi>>1); - x[8] = ur - (vr>>1); - x[9] = ui - (vi>>1); - - ur = y[4]>>1; - ui = y[5]>>1; - vi = y[12]; - vr = y[13]; - x[4] = ur + (vr>>1); - x[5] = ui - (vi>>1); - x[12] = ur - (vr>>1); - x[13] = ui + (vi>>1); - - ur = y[10]; - ui = y[11]; - vr = fMultDiv2(ui+ur,W_PiFOURTH); - vi = fMultDiv2(ui-ur,W_PiFOURTH); - ur = y[2]; - ui = y[3]; - x[2] = (ur>>1) + vr; - x[3] = (ui>>1) + vi; - x[10] = (ur>>1) - vr; - x[11] = (ui>>1) - vi; - - ur = y[14]; - ui = y[15]; - vr = fMultDiv2(ui-ur,W_PiFOURTH); - vi = fMultDiv2(ui+ur,W_PiFOURTH); - ur = y[6]; - ui = y[7]; - x[6] = (ur>>1) + vr; - x[7] = (ui>>1) - vi; - x[14] = (ur>>1) - vr; - x[15] = (ui>>1) + vi; -} - -/** - * \brief FFT of fixed length 16 - */ -inline void fft_16(FIXP_DBL *x); - -/** - * \brief FFT of fixed length 32 - */ -inline void fft_32(FIXP_DBL *x); - - -#endif |