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git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9345 d0543943-73ff-0310-b7d9-9358b9ac24b2
140 lines
3.6 KiB
C++
140 lines
3.6 KiB
C++
/*****************************************************************************
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* *
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* DIGITAL SIGNAL PROCESSING TOOLS *
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* Version 1.03, 2001/06/15 *
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* (c) 1999 - Laurent de Soras *
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* *
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* FFTReal.h *
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* Fourier transformation of real number arrays. *
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* Portable ISO C++ *
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* *
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* Tab = 3 *
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*****************************************************************************/
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#if defined (FFTReal_CURRENT_HEADER)
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#error Recursive inclusion of FFTReal header file.
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#endif
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#define FFTReal_CURRENT_HEADER
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#if ! defined (FFTReal_HEADER_INCLUDED)
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#define FFTReal_HEADER_INCLUDED
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#if defined (_MSC_VER)
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#pragma pack (push, 8)
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#endif // _MSC_VER
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class FFTReal
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{
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/*\\\ PUBLIC \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/
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public:
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/* Change this typedef to use a different floating point type in your FFTs
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(i.e. float, double or long double). */
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typedef float flt_t;
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explicit FFTReal (const long length);
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~FFTReal ();
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void do_fft (flt_t f [], const flt_t x []) const;
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void do_ifft (const flt_t f [], flt_t x []) const;
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void rescale (flt_t x []) const;
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/*\\\ PRIVATE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/
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private:
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/* Bit-reversed look-up table nested class */
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class BitReversedLUT
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{
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public:
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explicit BitReversedLUT (const int nbr_bits);
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~BitReversedLUT ();
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const long * get_ptr () const
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{
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return (_ptr);
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}
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private:
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long * _ptr;
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};
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/* Trigonometric look-up table nested class */
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class TrigoLUT
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{
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public:
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explicit TrigoLUT (const int nbr_bits);
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~TrigoLUT ();
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const flt_t * get_ptr (const int level) const
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{
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return (_ptr + (1L << (level - 1)) - 4);
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};
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private:
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flt_t * _ptr;
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};
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const BitReversedLUT _bit_rev_lut;
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const TrigoLUT _trigo_lut;
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const flt_t _sqrt2_2;
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const long _length;
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const int _nbr_bits;
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flt_t * _buffer_ptr;
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/*\\\ FORBIDDEN MEMBER FUNCTIONS \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/
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private:
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FFTReal (const FFTReal &other);
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const FFTReal& operator = (const FFTReal &other);
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int operator == (const FFTReal &other);
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int operator != (const FFTReal &other);
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};
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#if defined (_MSC_VER)
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#pragma pack (pop)
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#endif // _MSC_VER
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#endif // FFTReal_HEADER_INCLUDED
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#undef FFTReal_CURRENT_HEADER
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/*****************************************************************************
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LEGAL
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Source code may be freely used for any purpose, including commercial
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applications. Programs must display in their "About" dialog-box (or
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documentation) a text telling they use these routines by Laurent de Soras.
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Modified source code can be distributed, but modifications must be clearly
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indicated.
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CONTACT
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Laurent de Soras
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92 avenue Albert 1er
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92500 Rueil-Malmaison
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France
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ldesoras@club-internet.fr
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*****************************************************************************/
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/*\\\ EOF \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/
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