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Diffstat (limited to 'libFDK/src/dct.cpp')
| -rw-r--r-- | libFDK/src/dct.cpp | 139 |
1 files changed, 83 insertions, 56 deletions
diff --git a/libFDK/src/dct.cpp b/libFDK/src/dct.cpp index 6a267cf..5dc9e78 100644 --- a/libFDK/src/dct.cpp +++ b/libFDK/src/dct.cpp @@ -1,27 +1,89 @@ -/**************************************************************************** - (C) copyright Fraunhofer IIS (2004) - 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. +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. - $Id$ +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 dct.cpp - \brief DCT Implementations $Revision: 37444 $ + \brief DCT Implementations Library functions to calculate standard DCTs. This will most likely be replaced by hand-optimized functions for the specific target processor. @@ -47,28 +109,6 @@ #endif -/*! - * - * \brief Perform dct type 3 - * The dct 3 is calculated by a inverse real fft, with - * some pre twiddeling before the inverse real fft, as discribed by Takuya OOURA. - * (http://momonga.t.u-tokyo.ac.jp/~ooura/fftman/ftmn2_32.html#sec2_3_2) - * The real inverse fft is calculated by a inverse complex fft, as described - * in numerical recipes in C, Cambridge University press - * the auxiliary function is built by reversing the odd samples - * - * Instead of doing 2 times the conjugation to calculate the - * inverse cfft with the cfft, one can also swap elements before - * calling the cfft to get the same result: - * swap - * r(1),i(1) with r(n-1),i(n-1), - * r(2),i(2) with r(n-2),i(n-2), ... - * r(n/2-1),i(n/2-1) with r(n/2+1),i(n/2+1) - * - * - * Scaling 1 shift in pre twiddeling, - * log2(L)-1 in cfft - */ #if !defined(FUNCTION_dct_III) void dct_III(FIXP_DBL *pDat, /*!< pointer to input/output */ FIXP_DBL *tmp, /*!< pointer to temporal working buffer */ @@ -142,19 +182,6 @@ void dct_III(FIXP_DBL *pDat, /*!< pointer to input/output */ } #endif -/*! - * - * \brief Perform dct type 2 - * The dct 2 is calculated by a real inverse fft, with - * some pre twiddeling after the fft, as discribed by Takuya OOURA. - * (http://momonga.t.u-tokyo.ac.jp/~ooura/fftman/ftmn2_32.html#sec2_3_2) - * The real inverse fft is calculated by a inverse complex fft, as described - * in numerical recipes in C, Cambridge University press - * the auxilery function is build by reversing the odd samples - * - * Scaling 1 shift in pre twiddeling, - * 5 in cfft - */ #if !defined(FUNCTION_dct_II) void dct_II(FIXP_DBL *pDat, /*!< pointer to input/output */ FIXP_DBL *tmp, /*!< pointer to temporal working buffer */ @@ -347,14 +374,14 @@ void dct_IV(FIXP_DBL *pDat, pDat_0[0] = (pDat_0[0]>>1); - /* 28 cycles for ARM926 */ + /* 28 cycles for ARM926 */ for (idx = sin_step,i=1; i<(M+1)>>1; i++, idx+=sin_step) { FIXP_STP twd = sin_twiddle[idx]; cplxMultDiv2(&accu3, &accu4, accu1, accu2, twd); pDat_0[1] = accu3; pDat_1[0] = accu4; - + pDat_0+=2; pDat_1-=2; @@ -417,22 +444,22 @@ void dst_IV(FIXP_DBL *pDat, #ifdef FUNCTION_dst_IV_func1 if ( (M>=4) && ((M&3) == 0) ) { dst_IV_func1(M, twiddle, &pDat[0], &pDat[L]); - } else + } else #endif { FIXP_DBL *RESTRICT pDat_0 = &pDat[0]; FIXP_DBL *RESTRICT pDat_1 = &pDat[L - 2]; - + register int i; /* 34 cycles on ARM926 */ - for (i = 0; i < M-1; i+=2,pDat_0+=2,pDat_1-=2) + for (i = 0; i < M-1; i+=2,pDat_0+=2,pDat_1-=2) { register FIXP_DBL accu1,accu2,accu3,accu4; accu1 = pDat_1[1]; accu2 = -pDat_0[0]; accu3 = pDat_0[1]; accu4 = -pDat_1[0]; - + cplxMultDiv2(&accu1, &accu2, accu1, accu2, twiddle[i]); cplxMultDiv2(&accu3, &accu4, accu4, accu3, twiddle[i+1]); @@ -444,7 +471,7 @@ void dst_IV(FIXP_DBL *pDat, register FIXP_DBL accu1,accu2; accu1 = pDat_1[1]; accu2 = -pDat_0[0]; - + cplxMultDiv2(&accu1, &accu2, accu1, accu2, twiddle[i]); pDat_0[0] = accu2; pDat_0[1] = accu1; |