fuchsia / third_party / android / platform / external / aac / e8d354305f6a486d1abd142d292fd23b95fe1f5c / . / libFDK / src / fft_rad2.cpp

/* ----------------------------------------------------------------------------- | |

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 | |

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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 | |

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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): M. Lohwasser, M. Gayer | |

Description: | |

*******************************************************************************/ | |

#include "fft_rad2.h" | |

#include "scramble.h" | |

#define __FFT_RAD2_CPP__ | |

#if defined(__arm__) | |

#include "arm/fft_rad2_arm.cpp" | |

#elif defined(__GNUC__) && defined(__mips__) && defined(__mips_dsp) | |

#include "mips/fft_rad2_mips.cpp" | |

#endif | |

/***************************************************************************** | |

functionname: dit_fft (analysis) | |

description: dit-tukey-algorithm | |

scrambles data at entry | |

i.e. loop is made with scrambled data | |

returns: | |

input: | |

output: | |

*****************************************************************************/ | |

#ifndef FUNCTION_dit_fft | |

void dit_fft(FIXP_DBL *x, const INT ldn, const FIXP_STP *trigdata, | |

const INT trigDataSize) { | |

const INT n = 1 << ldn; | |

INT trigstep, i, ldm; | |

C_ALLOC_ALIGNED_CHECK(x); | |

scramble(x, n); | |

/* | |

* 1+2 stage radix 4 | |

*/ | |

for (i = 0; i < n * 2; i += 8) { | |

FIXP_DBL a00, a10, a20, a30; | |

a00 = (x[i + 0] + x[i + 2]) >> 1; /* Re A + Re B */ | |

a10 = (x[i + 4] + x[i + 6]) >> 1; /* Re C + Re D */ | |

a20 = (x[i + 1] + x[i + 3]) >> 1; /* Im A + Im B */ | |

a30 = (x[i + 5] + x[i + 7]) >> 1; /* Im C + Im D */ | |

x[i + 0] = a00 + a10; /* Re A' = Re A + Re B + Re C + Re D */ | |

x[i + 4] = a00 - a10; /* Re C' = Re A + Re B - Re C - Re D */ | |

x[i + 1] = a20 + a30; /* Im A' = Im A + Im B + Im C + Im D */ | |

x[i + 5] = a20 - a30; /* Im C' = Im A + Im B - Im C - Im D */ | |

a00 = a00 - x[i + 2]; /* Re A - Re B */ | |

a10 = a10 - x[i + 6]; /* Re C - Re D */ | |

a20 = a20 - x[i + 3]; /* Im A - Im B */ | |

a30 = a30 - x[i + 7]; /* Im C - Im D */ | |

x[i + 2] = a00 + a30; /* Re B' = Re A - Re B + Im C - Im D */ | |

x[i + 6] = a00 - a30; /* Re D' = Re A - Re B - Im C + Im D */ | |

x[i + 3] = a20 - a10; /* Im B' = Im A - Im B - Re C + Re D */ | |

x[i + 7] = a20 + a10; /* Im D' = Im A - Im B + Re C - Re D */ | |

} | |

for (ldm = 3; ldm <= ldn; ++ldm) { | |

INT m = (1 << ldm); | |

INT mh = (m >> 1); | |

INT j, r; | |

trigstep = ((trigDataSize << 2) >> ldm); | |

FDK_ASSERT(trigstep > 0); | |

/* Do first iteration with c=1.0 and s=0.0 separately to avoid loosing to | |

much precision. Beware: The impact on the overal FFT precision is rather | |

large. */ | |

{ /* block 1 */ | |

j = 0; | |

for (r = 0; r < n; r += m) { | |

INT t1 = (r + j) << 1; | |

INT t2 = t1 + (mh << 1); | |

FIXP_DBL vr, vi, ur, ui; | |

// cplxMultDiv2(&vi, &vr, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0); | |

vi = x[t2 + 1] >> 1; | |

vr = x[t2] >> 1; | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui + vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui - vi; | |

t1 += mh; | |

t2 = t1 + (mh << 1); | |

// cplxMultDiv2(&vr, &vi, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0); | |

vr = x[t2 + 1] >> 1; | |

vi = x[t2] >> 1; | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui - vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui + vi; | |

} | |

} /* end of block 1 */ | |

for (j = 1; j < mh / 4; ++j) { | |

FIXP_STP cs; | |

cs = trigdata[j * trigstep]; | |

for (r = 0; r < n; r += m) { | |

INT t1 = (r + j) << 1; | |

INT t2 = t1 + (mh << 1); | |

FIXP_DBL vr, vi, ur, ui; | |

cplxMultDiv2(&vi, &vr, x[t2 + 1], x[t2], cs); | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui + vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui - vi; | |

t1 += mh; | |

t2 = t1 + (mh << 1); | |

cplxMultDiv2(&vr, &vi, x[t2 + 1], x[t2], cs); | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui - vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui + vi; | |

/* Same as above but for t1,t2 with j>mh/4 and thus cs swapped */ | |

t1 = (r + mh / 2 - j) << 1; | |

t2 = t1 + (mh << 1); | |

cplxMultDiv2(&vi, &vr, x[t2], x[t2 + 1], cs); | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui - vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui + vi; | |

t1 += mh; | |

t2 = t1 + (mh << 1); | |

cplxMultDiv2(&vr, &vi, x[t2], x[t2 + 1], cs); | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur - vr; | |

x[t1 + 1] = ui - vi; | |

x[t2] = ur + vr; | |

x[t2 + 1] = ui + vi; | |

} | |

} | |

{ /* block 2 */ | |

j = mh / 4; | |

for (r = 0; r < n; r += m) { | |

INT t1 = (r + j) << 1; | |

INT t2 = t1 + (mh << 1); | |

FIXP_DBL vr, vi, ur, ui; | |

cplxMultDiv2(&vi, &vr, x[t2 + 1], x[t2], STC(0x5a82799a), | |

STC(0x5a82799a)); | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui + vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui - vi; | |

t1 += mh; | |

t2 = t1 + (mh << 1); | |

cplxMultDiv2(&vr, &vi, x[t2 + 1], x[t2], STC(0x5a82799a), | |

STC(0x5a82799a)); | |

ur = x[t1] >> 1; | |

ui = x[t1 + 1] >> 1; | |

x[t1] = ur + vr; | |

x[t1 + 1] = ui - vi; | |

x[t2] = ur - vr; | |

x[t2 + 1] = ui + vi; | |

} | |

} /* end of block 2 */ | |

} | |

} | |

#endif |