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Diffstat (limited to 'libFDK/src/fft.cpp')
| -rw-r--r-- | libFDK/src/fft.cpp | 150 |
1 files changed, 79 insertions, 71 deletions
diff --git a/libFDK/src/fft.cpp b/libFDK/src/fft.cpp index cd04b98..bbf3d99 100644 --- a/libFDK/src/fft.cpp +++ b/libFDK/src/fft.cpp @@ -1,34 +1,90 @@ -/*************************** Fraunhofer IIS FDK Tools ********************** - (C) Copyright Fraunhofer IIS (2001) - All Rights Reserved +/* ----------------------------------------------------------------------------------------------------------- +Software License for The Fraunhofer FDK AAC Codec Library for Android - Please be advised that this software and/or program delivery is - Confidential Information of Fraunhofer and subject to and covered by the +© Copyright 1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. + All rights reserved. - Fraunhofer IIS Software Evaluation Agreement - between Google Inc. and Fraunhofer - effective and in full force since March 1, 2012. + 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. - You may use this software and/or program only under the terms and - conditions described in the above mentioned Fraunhofer IIS Software - Evaluation Agreement. Any other and/or further use requires a separate agreement. +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. - $Id$ - Author(s): Josef Hoepfl, DSP Solutions - Description: Fix point FFT +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." - This software and/or program is protected by copyright law and international - treaties. Any reproduction or distribution of this software and/or program, - or any portion of it, may result in severe civil and criminal penalties, and - will be prosecuted to the maximum extent possible under law. +3. NO PATENT LICENSE - History: - 20-APR-2010 A. Tritthart replaced modulo operations with comparisons in fft15 - to avoid failures with ARM RVCT 4.0 compiler - Tuned fft15 by 18% (Cortex-A8) to 25% (ARM926) by reprogramming - with merged loops. +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 ******************************************************************************/ @@ -71,7 +127,6 @@ static FORCEINLINE void fft3(FIXP_DBL *RESTRICT pDat) } -//#define F5C(x) ((FIXP_DBL)x) #define F5C(x) STC(x) #define C51 (F5C(0x79bc3854)) /* FL2FXCONST_DBL( 0.95105652) */ @@ -148,10 +203,6 @@ static FORCEINLINE void fft5(FIXP_DBL *RESTRICT pDat) /* Performs the FFT of length 15. It is split into FFTs of length 3 and length 5. */ static inline void fft15(FIXP_DBL *pInput) { -#if FORCE_CRITICAL_CODE_FOR_RVCT4 - FIXP_DBL accu; - int j; -#endif FIXP_DBL aDst[2*N15]; FIXP_DBL aDst1[2*N15]; int i,k,l; @@ -162,48 +213,6 @@ static inline void fft15(FIXP_DBL *pInput) input3(6:8) = [input(6) input(11) input(1)]; input3(9:11) = [input(9) input(14) input(4)]; input3(12:14) = [input(12) input(2) input(7)]; */ -#if FORCE_CRITICAL_CODE_FOR_RVCT4 - /* This branch generate failures on RVCT 4.0 with ARM926/ARM1136/ARM1176/C-R4, but not on Cortex-A8 */ - pSrc = pInput; - pDst = aDst; - for(i=0,l=0,k=0; i<N5; i++) - { - for(j=0; j<N3; j++) - { - pDst[k] = pSrc[l]; - pDst[k+1] = pSrc[l+1]; - k += 2; - l += 2*N5; - if (l >= (2*N15)) - l -= (2*N15); - } - l += (2*N3); - if (l >= (2*N15)) - l -= (2*N15); - } - /* Perform 5 times the fft of length 3 - output3(0:2) = fft3(input3(0:2)); - output3(3:5) = fft3(input3(3:5)); - output3(6:8) = fft3(input3(6:8)); - output3(9:11) = fft3(input3(9:11)); - output3(12:14) = fft3(input3(12:14)); */ - pSrc=aDst; - for(i=0; i<N5; i++) - { - fft3(pSrc); - pSrc += (2*N3); - } - - /* Scaling of the input vector of the fft5 with the scale factor 0.125 */ - pSrc=aDst; - for(j=0; j<(2*N3*N5); j++) - { - accu = pSrc[j]; - /* 2 bit right shift */ - accu >>= 2; - pSrc[j] = accu; - } -#else { const FIXP_DBL *pSrc = pInput; FIXP_DBL *RESTRICT pDst = aDst; @@ -251,7 +260,6 @@ static inline void fft15(FIXP_DBL *pInput) pDst[k+5] = (s1 - r2)>>2; } } -#endif /* Sort input vector for fft's of length 5 input5(0:4) = [output3(0) output3(3) output3(6) output3(9) output3(12)]; input5(5:9) = [output3(1) output3(4) output3(7) output3(10) output3(13)]; |