Aegisub/aegisub/src/fft.h

// Copyright (c) 2005, Rodrigo Braz Monteiro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
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//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
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// Aegisub Project http://www.aegisub.org/
//
// $Id$

/// @file fft.h
/// @see fft.cpp
/// @ingroup utility
///




#ifndef AGI_PRE
#include <stdlib.h> // size_t
#endif


/// DOCME
/// @class FFT
/// @brief DOCME
///
/// DOCME
class FFT {
private:
	void DoTransform(size_t n_samples,float *input,float *output_r,float *output_i,bool inverse);

public:
	void Transform(size_t n_samples,float *input,float *output_r,float *output_i);
	void InverseTransform(size_t n_samples,float *input,float *output_r,float *output_i);
	bool IsPowerOfTwo(unsigned int x);
	unsigned int NumberOfBitsNeeded(unsigned int n_samples);
	unsigned int ReverseBits(unsigned int index, unsigned int bits);
	float FrequencyAtIndex(unsigned int baseFreq, unsigned int n_samples, unsigned int index);
};