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/*****************************************************************************
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* beat_detect.c: basic beat detection algorithm
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*****************************************************************************
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* Copyright (C) 2004 the VideoLAN team
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* $Id: 583d307cd631735c4d7ef510694070abaa85c88b $
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* Authors: Cyril Deguet <asmax@videolan.org>
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* code from projectM http://xmms-projectm.sourceforge.net
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
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*****************************************************************************/
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//Takes sound data from wherever and returns beat detection values
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//Uses statistical Energy-Based methods. Very simple
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//Some stuff was taken from Frederic Patin's beat-detection article, you'll find it online
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#include "engine_vars.h"
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double beat_buffer[32][80],beat_instant[32],beat_history[32];
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double *beat_val,*beat_att,*beat_variance;
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double vol_buffer[80],vol_instant,vol_history;
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beat_val=(double *)malloc(32*sizeof(double));
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beat_att=(double *)malloc(32*sizeof(double));
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beat_variance=(double *)malloc(32*sizeof(double));
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void getBeatVals(double *vdataL,double *vdataR, double *vol)
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for ( y=linear*2;y<(linear+8+x)*2;y++)
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beat_instant[x]+=((vdataL[y]*vdataL[y])+(vdataR[y]*vdataR[y]))*(1.0/(8+x));
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vol_instant+=((vdataL[y]*vdataL[y])+(vdataR[y]*vdataR[y]))*(1.0/512.0);
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beat_history[x]-=(beat_buffer[x][beat_buffer_pos])*.0125;
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beat_buffer[x][beat_buffer_pos]=beat_instant[x];
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beat_history[x]+=(beat_instant[x])*.0125;
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beat_val[x]=(beat_instant[x])/(beat_history[x]);
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beat_att[x]+=(beat_instant[x])/(beat_history[x]);
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vol_history-=(vol_buffer[beat_buffer_pos])*.0125;
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vol_buffer[beat_buffer_pos]=vol_instant;
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vol_history+=(vol_instant)*.0125;
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mid+=(beat_instant[x]);
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temp2+=(beat_history[x]);
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treb+=(beat_instant[x]);
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temp2+=(beat_history[x]);
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treb=treb/(1.5*temp2);
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*vol=vol_instant/(1.5*vol_history);
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bass=(beat_instant[0])/(1.5*beat_history[0]);
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treb_att=.6 * treb_att + .4 * treb;
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mid_att=.6 * mid_att + .4 * mid;
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bass_att=.6 * bass_att + .4 * bass;
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//printf("%f %f %f %f\n",bass,mid,treb,*vol);
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// *vol=(beat_instant[3])/(beat_history[3]);
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if( beat_buffer_pos>79)beat_buffer_pos=0;
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void freeBeatDetect()