andrew@0: /*
andrew@0: 	 Copyright (C) 2003 Paul Brossier
andrew@0: 
andrew@0: 	 This program is free software; you can redistribute it and/or modify
andrew@0: 	 it under the terms of the GNU General Public License as published by
andrew@0: 	 the Free Software Foundation; either version 2 of the License, or
andrew@0: 	 (at your option) any later version.
andrew@0: 
andrew@0: 	 This program is distributed in the hope that it will be useful,
andrew@0: 	 but WITHOUT ANY WARRANTY; without even the implied warranty of
andrew@0: 	 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
andrew@0: 	 GNU General Public License for more details.
andrew@0: 
andrew@0: 	 You should have received a copy of the GNU General Public License
andrew@0: 	 along with this program; if not, write to the Free Software
andrew@0: 	 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
andrew@0: 
andrew@0: */
andrew@0: 
andrew@0: /** @file
andrew@0:  *  various math functions
andrew@0:  *
andrew@0:  *  \todo multichannel (each function should return -or set- an array sized to
andrew@0:  *  the number of channel in the input vector)
andrew@0:  *
andrew@0:  *  \todo appropriate switches depending on types.h content
andrew@0:  */
andrew@0: 
andrew@0: #ifndef MATHUTILS_H
andrew@0: #define MATHUTILS_H
andrew@0: 
andrew@0: /** Window types 
andrew@0:  * 
andrew@0:  * inspired from 
andrew@0:  *
andrew@0:  *  - dafx : http://profs.sci.univr.it/%7Edafx/Final-Papers/ps/Bernardini.ps.gz
andrew@0:  *  - freqtweak : http://freqtweak.sf.net/
andrew@0:  *  - extace : http://extace.sf.net/
andrew@0:  */
andrew@0: 
andrew@0: #ifdef __cplusplus
andrew@0: extern "C" {
andrew@0: #endif
andrew@0: 
andrew@0: typedef enum {
andrew@0: 	aubio_win_rectangle,          
andrew@0: 	aubio_win_hamming,
andrew@0: 	aubio_win_hanning,
andrew@0: 	aubio_win_hanningz,
andrew@0: 	aubio_win_blackman,
andrew@0: 	aubio_win_blackman_harris,
andrew@0: 	aubio_win_gaussian,
andrew@0: 	aubio_win_welch,
andrew@0: 	aubio_win_parzen
andrew@0: } aubio_window_type;
andrew@0: 
andrew@0: /** create window */
andrew@0: void aubio_window(smpl_t *w, ba_uint_t size, aubio_window_type wintype);
andrew@0: 
andrew@0: /** principal argument
andrew@0:  *
andrew@0:  * mod(phase+PI,-TWO_PI)+PI 
andrew@0:  */
andrew@0: smpl_t aubio_unwrap2pi (smpl_t phase);
andrew@0: 
andrew@0: /** calculates the mean of a vector
andrew@0:  *
andrew@0:  * \bug mono 
andrew@0:  */
andrew@0: smpl_t vec_mean(fvec_t *s);
andrew@0: /** returns the max of a vector
andrew@0:  *
andrew@0:  * \bug mono 
andrew@0:  */
andrew@0: smpl_t vec_max(fvec_t *s);
andrew@0: /** returns the min of a vector
andrew@0:  *
andrew@0:  * \bug mono 
andrew@0:  */
andrew@0: smpl_t vec_min(fvec_t *s);
andrew@0: /** returns the index of the min of a vector
andrew@0:  *
andrew@0:  * \bug mono 
andrew@0:  */
andrew@0: ba_uint_t vec_min_elem(fvec_t *s);
andrew@0: /** returns the index of the max of a vector
andrew@0:  *
andrew@0:  * \bug mono 
andrew@0:  */
andrew@0: ba_uint_t vec_max_elem(fvec_t *s);
andrew@0: /** implement 'fftshift' like function
andrew@0:  * 
andrew@0:  * a[0]...,a[n/2],a[n/2+1],...a[n]
andrew@0:  * 
andrew@0:  * becomes
andrew@0:  * 
andrew@0:  * a[n/2+1],...a[n],a[0]...,a[n/2]
andrew@0:  */
andrew@0: void vec_shift(fvec_t *s);
andrew@0: /** returns sum */
andrew@0: smpl_t vec_sum(fvec_t *s);
andrew@0: /** returns energy 
andrew@0:  *
andrew@0:  * \bug mono 
andrew@0:  */
andrew@0: smpl_t vec_local_energy(fvec_t * f);
andrew@0: /** returns High Frequency Energy Content
andrew@0:  *
andrew@0:  * \bug mono */
andrew@0: smpl_t vec_local_hfc(fvec_t * f);
andrew@0: /** return alpha norm.
andrew@0:  *
andrew@0:  * alpha=2 means normalise variance. 
andrew@0:  * alpha=1 means normalise abs value. 
andrew@0:  * as alpha goes large, tends to normalisation 
andrew@0:  * by max value.
andrew@0:  *
andrew@0:  * \bug should not use POW :(
andrew@0:  */
andrew@0: smpl_t vec_alpha_norm(fvec_t * DF, smpl_t alpha);
andrew@0: /**  dc(min) removal */
andrew@0: void vec_dc_removal(fvec_t * mag);
andrew@0: /**  alpha normalisation */
andrew@0: void vec_alpha_normalise(fvec_t * mag, ba_uint_t alpha);
andrew@0: /** add a constant to all members of a vector */
andrew@0: void vec_add(fvec_t * mag, smpl_t threshold);
andrew@0: 
andrew@0: /** compute adaptive threshold of input vector */ 
andrew@0: void vec_adapt_thres(fvec_t * vec, fvec_t * tmp, 
andrew@0:     ba_uint_t win_post, ba_uint_t win_pre);
andrew@0: /**  adaptative thresholding 
andrew@0:  *
andrew@0:  * y=fn_thresh(fn,x,post,pre)
andrew@0:  * compute adaptive threshold at each time 
andrew@0:  *    fn : a function name or pointer, eg 'median'
andrew@0:  *    x:   signal vector
andrew@0:  *    post: window length, causal part
andrew@0:  *    pre: window length, anti-causal part
andrew@0:  * Returns:
andrew@0:  *    y:   signal the same length as x
andrew@0:  *
andrew@0:  * Formerly median_thresh, used compute median over a 
andrew@0:  * window of post+pre+1 samples, but now works with any
andrew@0:  * function that takes a vector or matrix and returns a
andrew@0:  * 'representative' value for each column, eg
andrew@0:  *    medians=fn_thresh(median,x,8,8)  
andrew@0:  *    minima=fn_thresh(min,x,8,8)  
andrew@0:  * see SPARMS for explanation of post and pre
andrew@0:  */
andrew@0: smpl_t vec_moving_thres(fvec_t * vec, fvec_t * tmp, 
andrew@0:     ba_uint_t win_post, ba_uint_t win_pre, ba_uint_t win_pos);
andrew@0: 
andrew@0: /** returns the median of the vector 
andrew@0:  *
andrew@0:  *  This Quickselect routine is based on the algorithm described in
andrew@0:  *  "Numerical recipes in C", Second Edition,
andrew@0:  *  Cambridge University Press, 1992, Section 8.5, ISBN 0-521-43108-5
andrew@0:  *
andrew@0:  *  This code by Nicolas Devillard - 1998. Public domain,
andrew@0:  *  available at http://ndevilla.free.fr/median/median/
andrew@0:  */
andrew@0: smpl_t vec_median(fvec_t * input);
andrew@0: 
andrew@0: /** finds exact maximum position by quadratic interpolation*/
andrew@0: smpl_t vec_quadint(fvec_t * x,ba_uint_t pos);
andrew@0: 
andrew@0: /** finds exact minimum position by quadratic interpolation*/
andrew@0: smpl_t vec_quadint_min(fvec_t * x,ba_uint_t pos, ba_uint_t span);
andrew@0: 
andrew@0: /** Quadratic interpolation using Lagrange polynomial.
andrew@0:  *
andrew@0:  * inspired from ``Comparison of interpolation algorithms in real-time sound
andrew@0:  * processing'', Vladimir Arnost, 
andrew@0:  * 
andrew@0:  * estimate = s0 + (pf/2.)*((pf-3.)*s0-2.*(pf-2.)*s1+(pf-1.)*s2);
andrew@0:  *    where 
andrew@0:  *    \param s0,s1,s2 are 3 known points on the curve,
andrew@0:  *    \param pf is the floating point index [0;2]
andrew@0:  */
andrew@0: smpl_t aubio_quadfrac(smpl_t s0, smpl_t s1, smpl_t s2, smpl_t pf);
andrew@0: 
andrew@0: /** returns 1 if X1 is a peak and positive */
andrew@0: ba_uint_t vec_peakpick(fvec_t * input, ba_uint_t pos);
andrew@0: 
andrew@0: /** convert frequency bin to midi value */
andrew@0: smpl_t aubio_bintomidi(smpl_t bin, smpl_t samplerate, smpl_t fftsize);
andrew@0: /** convert midi value to frequency bin */
andrew@0: smpl_t aubio_miditobin(smpl_t midi, smpl_t samplerate, smpl_t fftsize);
andrew@0: /** convert frequency bin to frequency (Hz) */
andrew@0: smpl_t aubio_bintofreq(smpl_t bin, smpl_t samplerate, smpl_t fftsize);
andrew@0: /** convert frequency (Hz) to frequency bin */
andrew@0: smpl_t aubio_freqtobin(smpl_t freq, smpl_t samplerate, smpl_t fftsize);
andrew@0: /** convert frequency (Hz) to midi value (0-128) */
andrew@0: smpl_t aubio_freqtomidi(smpl_t freq);
andrew@0: /** convert midi value (0-128) to frequency (Hz) */
andrew@0: smpl_t aubio_miditofreq(smpl_t midi);
andrew@0: 
andrew@0: /** check if current buffer level is under a given threshold */
andrew@0: ba_uint_t aubio_silence_detection(fvec_t * ibuf, smpl_t threshold);
andrew@0: /** get the current buffer level */
andrew@0: smpl_t aubio_level_detection(fvec_t * ibuf, smpl_t threshold);
andrew@0: /** 
andrew@0:  * calculate normalised autocorrelation function
andrew@0:  */
andrew@0: void aubio_autocorr(fvec_t * input, fvec_t * output);
andrew@0: /**
andrew@0:  * clean up cached memory at the end of program
andrew@0:  *
andrew@0:  * use this function at the end of programs to purge all
andrew@0:  * cached memory. so far this function is only used to clean
andrew@0:  * fftw cache.
andrew@0:  */
andrew@0: void aubio_cleanup(void);
andrew@0: 
andrew@0: #ifdef __cplusplus
andrew@0: }
andrew@0: #endif
andrew@0: 
andrew@0: #endif
andrew@0: