fdk-aac/libFDK/include/fft_rad2.h

/* -----------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android

© Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
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 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
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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
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Commercially-licensed AAC software libraries, including floating-point versions
with enhanced sound quality, are also available from Fraunhofer. Users are
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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
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
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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:

*******************************************************************************/

#ifndef FFT_RAD2_H
#define FFT_RAD2_H

#include "common_fix.h"

/**
 * \brief Performe an inplace  complex valued FFT of 2^n length
 *
 * \param x Input/Output data buffer. The input data must have at least 1 bit
 * scale headroom. The values are interleaved, real/imag pairs.
 * \param ldn log2 of FFT length
 * \param trigdata Pointer to a sinetable of a length of at least (2^ldn)/2 sine
 * values.
 * \param trigDataSize length of the sinetable "trigdata".
 */
void dit_fft(FIXP_DBL *x, const INT ldn, const FIXP_STP *trigdata,
             const INT trigDataSize);

#endif /* FFT_RAD2_H */