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https://github.com/LMMS/lmms.git
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7227c89847
This PR places all LMMS symbols into namespaces to eliminate any potential future name collisions between LMMS and third-party modules.
Also, this PR changes back `LmmsCore` to `Engine`, reverting c519921306 .
Co-authored-by: allejok96 <allejok96@gmail.com>
113 lines
3.5 KiB
C++
113 lines
3.5 KiB
C++
/*
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* fft_helpers.h - some functions around FFT analysis
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*
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* Copyright (c) 2008-2012 Tobias Doerffel <tobydox/at/users.sourceforge.net>
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* Copyright (c) 2019 Martin Pavelek <he29.HS/at/gmail.com>
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*
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* This file is part of LMMS - https://lmms.io
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program (see COPYING); if not, write to the
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* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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* Boston, MA 02110-1301 USA.
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*
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*/
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#ifndef FFT_HELPERS_H
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#define FFT_HELPERS_H
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#include "lmms_export.h"
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#include <vector>
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#include <fftw3.h>
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namespace lmms
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{
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// NOTE: FFT_BUFFER_SIZE should be considered deprecated!
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// It is used by Eq plugin and some older code here, but this should be a user
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// switchable parameter, not a constant. Use a value from FFT_BLOCK_SIZES
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const unsigned int FFT_BUFFER_SIZE = 2048;
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// Allowed FFT block sizes. Ranging from barely useful to barely acceptable
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// because of performance and latency reasons.
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const std::vector<unsigned int> FFT_BLOCK_SIZES = {256, 512, 1024, 2048, 4096, 8192, 16384};
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// List of FFT window functions supported by precomputeWindow()
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enum FFT_WINDOWS
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{
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RECTANGULAR = 0,
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BLACKMAN_HARRIS,
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HAMMING,
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HANNING
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};
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/** Returns biggest value from abs_spectrum[spec_size] array.
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*
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* @return -1 on error, 0 on success
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*/
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float LMMS_EXPORT maximum(const float *abs_spectrum, unsigned int spec_size);
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float LMMS_EXPORT maximum(const std::vector<float> &abs_spectrum);
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/** Normalize the abs_spectrum array of absolute values to a 0..1 range
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* based on supplied energy and stores it in the norm_spectrum array.
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*
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* @return -1 on error
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*/
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int LMMS_EXPORT normalize(const float *abs_spectrum, float *norm_spectrum, unsigned int bin_count, unsigned int block_size);
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int LMMS_EXPORT normalize(const std::vector<float> &abs_spectrum, std::vector<float> &norm_spectrum, unsigned int block_size);
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/** Check if the spectrum contains any non-zero value.
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*
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* @return 1 if spectrum contains any non-zero value
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* @return 0 otherwise
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*/
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int LMMS_EXPORT notEmpty(const std::vector<float> &spectrum);
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/** Precompute a window function for later real-time use.
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* Set normalized to false if you do not want to apply amplitude correction.
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*
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* @return -1 on error
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*/
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int LMMS_EXPORT precomputeWindow(float *window, unsigned int length, FFT_WINDOWS type, bool normalized = true);
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/** Compute absolute values of complex_buffer, save to absspec_buffer.
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* Take care that - compl_len is not bigger than complex_buffer!
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* - absspec buffer is big enough!
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*
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* @return 0 on success, else -1
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*/
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int LMMS_EXPORT absspec(const fftwf_complex *complex_buffer, float *absspec_buffer,
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unsigned int compl_length);
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/** Build fewer subbands from many absolute spectrum values.
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* Take care that - compressedbands[] array num_new elements long
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* - num_old > num_new
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*
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* @return 0 on success, else -1
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*/
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int LMMS_EXPORT compressbands(const float * _absspec_buffer, float * _compressedband,
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int _num_old, int _num_new, int _bottom, int _top);
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} // namespace lmms
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#endif
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