ref: cafb00ac8054cf7ef50fc29f2310fbcd95a21b74
dir: /src/pitchschmitt.c/
/* Copyright (C) 2004, 2005 Mario Lang <mlang@delysid.org> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* This file was taken from the tuneit project, in the file tuneit.c -- Detect fundamental frequency of a sound see http://delysid.org/tuneit.html */ #include "aubio_priv.h" #include "sample.h" #include "pitchschmitt.h" smpl_t aubio_schmittS16LE (aubio_pitchschmitt_t *p, uint_t nframes, signed short int *indata); struct _aubio_pitchschmitt_t { uint_t blockSize; uint_t rate; signed short int *schmittBuffer; signed short int *schmittPointer; }; aubio_pitchschmitt_t * new_aubio_pitchschmitt (uint_t size, uint_t samplerate) { aubio_pitchschmitt_t * p = AUBIO_NEW(aubio_pitchschmitt_t); p->blockSize = size; p->schmittBuffer = AUBIO_ARRAY(signed short int,p->blockSize); p->schmittPointer = p->schmittBuffer; p->rate = samplerate; return p; } smpl_t aubio_pitchschmitt_detect (aubio_pitchschmitt_t *p, fvec_t * input) { signed short int buf[input->length]; uint_t i; for (i=0; i<input->length; i++) { buf[i] = input->data[0][i]*32768.; } return aubio_schmittS16LE(p, input->length, buf); } smpl_t aubio_schmittS16LE (aubio_pitchschmitt_t *p, uint_t nframes, signed short int *indata) { uint_t i, j; uint_t blockSize = p->blockSize; signed short int *schmittBuffer = p->schmittBuffer; signed short int *schmittPointer = p->schmittPointer; smpl_t freq = 0., trigfact = 0.6; for (i=0; i<nframes; i++) { *schmittPointer++ = indata[i]; if (schmittPointer-schmittBuffer >= blockSize) { sint_t endpoint, startpoint, t1, t2, A1, A2, tc, schmittTriggered; schmittPointer = schmittBuffer; for (j=0,A1=0,A2=0; j<blockSize; j++) { if (schmittBuffer[j]>0 && A1<schmittBuffer[j]) A1 = schmittBuffer[j]; if (schmittBuffer[j]<0 && A2<-schmittBuffer[j]) A2 = -schmittBuffer[j]; } t1 = (sint_t)( A1 * trigfact + 0.5); t2 = - (sint_t)( A2 * trigfact + 0.5); startpoint=0; for (j=1; schmittBuffer[j]<=t1 && j<blockSize; j++); for (; !(schmittBuffer[j] >=t2 && schmittBuffer[j+1]< t2) && j<blockSize; j++); startpoint=j; schmittTriggered=0; endpoint=startpoint+1; for(j=startpoint,tc=0; j<blockSize; j++) { if (!schmittTriggered) { schmittTriggered = (schmittBuffer[j] >= t1); } else if (schmittBuffer[j]>=t2 && schmittBuffer[j+1]<t2) { endpoint=j; tc++; schmittTriggered = 0; } } if (endpoint > startpoint) { freq = ((smpl_t)p->rate*(tc/(smpl_t)(endpoint-startpoint))); } } } p->schmittBuffer = schmittBuffer; p->schmittPointer = schmittPointer; return freq; } void del_aubio_pitchschmitt (aubio_pitchschmitt_t *p) { AUBIO_FREE(p->schmittBuffer); AUBIO_FREE(p); }