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Diffstat (limited to 'extern/audaspace/include/util/FFTPlan.h')
-rw-r--r-- | extern/audaspace/include/util/FFTPlan.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/extern/audaspace/include/util/FFTPlan.h b/extern/audaspace/include/util/FFTPlan.h new file mode 100644 index 00000000000..7d533ca8773 --- /dev/null +++ b/extern/audaspace/include/util/FFTPlan.h @@ -0,0 +1,120 @@ +/******************************************************************************* +* Copyright 2015-2016 Juan Francisco Crespo Galán +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +******************************************************************************/ + +#pragma once + +/** +* @file FFTPlan.h +* @ingroup util +* The FFTPlan class. +*/ + +#include <complex> +#include <fftw3.h> +#include "Audaspace.h" + +#include <memory> +#include <vector> + +/**Default FFT size.*/ +#define DEFAULT_N 4096 + +AUD_NAMESPACE_BEGIN + +/** +* Thas class represents an plan object that allows to calculate FFTs and IFFTs. +*/ +class AUD_API FFTPlan +{ +private: + /** + * The size of the FFT plan. + */ + int m_N; + + /** + * The plan to transform the input to the frequency domain. + */ + fftwf_plan m_fftPlanR2C; + + /** + * The plan to transform the input to the time domain again. + */ + fftwf_plan m_fftPlanC2R; + + /** + * The size of a buffer for its use with the FFT plan (in bytes). + */ + unsigned int m_bufferSize; + + // delete copy constructor and operator= + FFTPlan(const FFTPlan&) = delete; + FFTPlan& operator=(const FFTPlan&) = delete; + +public: + /** + * Creates a new FFTPlan object with DEFAULT_N size (4096). + * \param measureTime The aproximate amount of seconds that FFTW will spend searching for the optimal plan, + * which means faster FFTs and IFFTs while using this plan. If measureTime is negative, it will take all the time it needs. + */ + FFTPlan(double measureTime = 0); + + /** + * Creates a new FFTPlan object with a custom size. + * \param n The size of the FFT plan. Values that are a power of two are faster. + * The useful range usually is between 2048 and 8192, but bigger values can be useful + * in certain situations (when using the StreamBuffer class per example). + * Generally, low values use more CPU power and are a bit faster than large ones, + * there is also a huge decrease in efficiency when n is lower than 2048. + * \param measureTime The aproximate amount of seconds that FFTW will spend searching for the optimal plan, + * which means faster FFTs while using this plan. If measureTime is negative, it will take all the time it needs. + */ + FFTPlan(int n, double measureTime = 0); + ~FFTPlan(); + + /** + * Retrieves the size of the FFT plan. + * \return The size of the plan. + */ + int getSize(); + + /** + * Calculates the FFT of an input buffer with the current plan. + * \param[in,out] buffer A buffer with the input data an in which the output data will be written. + */ + void FFT(void* buffer); + + /** + * Calculates the IFFT of an input buffer with the current plan. + * \param[in,out] buffer A buffer with the input data an in which the output data will be written. + */ + void IFFT(void* buffer); + + /** + * Reserves memory for a buffer that can be used for inplace transformations with this plan. + * \return A pointer to a buffer of size ((N/2)+1)*2*sizeof(fftwf_complex). + * \warning The returned buffer must be freed with the freeBuffer method of this class. + */ + void* getBuffer(); + + /** + * Frees one of the buffers reserved with the getRealOnlyBuffer(), getComplexOnlyBuffer() or getInplaceBuffer() method. + * \param buffer A pointer to the buufer taht must be freed. + */ + void freeBuffer(void* buffer); +}; + +AUD_NAMESPACE_END |