server/plugins/BeatTrack2.h

   1 /*
   2         SuperCollider real time audio synthesis system
   3     Copyright (c) 2002 James McCartney. All rights reserved.
   4         http://www.audiosynth.com
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  19 */
  20
  21
  22 //N feature stream inputs, cross correlation with template on each channel
  23
  24 //templates- search 120 tempi * 2 groove types (really just /2 and /3 subdivision) and no metrical discernment * a different numbers of phases depending on tempo
  25
  26 //assume 4 features * 120 tempi * 2 groove * 20 phase = 19200 per calculation time; say you calculate each 0.5 sec, amortise over (44100/64*0.5 >344.5) control blocks;
  27 //calculate over 240 blocks
  28
  29 #include "SC_PlugIn.h"
  30
  31 struct BeatTrack2 : Unit {
  32
  33         //adjust for any sampling rate by calculating factors; runs off of k rate inputs
  34         float m_srate;
  35         float m_phaseaccuracy;  //probably 8 control blocks!
  36         int m_numtempi; //= 120;
  37         //float * m_tempi;
  38         int * m_numphases;
  39         //float ** m_phases;
  40
  41         int m_numfeatures;
  42         float * m_features; //pointer to control bus, assumes contiguous busnum for each consecutive feature
  43
  44         //
  45         float m_temporalwindowsize; //typically small, 2 seconds for fast reactions compared to 6 secs for BeatTrack
  46         float m_fullwindowsize;
  47         float m_krlength;
  48         int m_buffersize; //in control blocks
  49
  50         float ** m_pastfeatures;  //for each feature, a trail of last m_workingmemorysize values
  51
  52         int m_counter, m_startcounter;
  53
  54         //time positions
  55         float m_calculationschedule;
  56         float m_calculationperiod;
  57
  58         //tempo
  59         float m_period;
  60         int m_groove;
  61         float m_currtempo;
  62
  63         //phase
  64         float m_currphase;
  65
  66         //phasor, trigger beat and modulo when >1.0
  67         float m_phase, m_phaseperblock;
  68
  69         //phasor output separate so can have it lock and keep going when don't want to track
  70         float m_outputphase, m_outputtempo, m_outputgroove, m_outputphaseperblock;
  71
  72         float m_predictphase, m_predictperiod;
  73
  74         //amortization - more complex structure to support different rates of work
  75         int m_amortisationstate;
  76         int m_amortcount;
  77         int m_amortlength;
  78         int m_amortisationsteps;
  79
  80         //efficiency trick
  81         float * m_scores;
  82
  83         //tracking best results for each feature
  84         //also storing second best and previous best and second best?
  85         //thus keep best from previous round too for additional vote/consistency check
  86         float * bestscore;
  87         int * bestphase;
  88         int * besttempo;
  89         int * bestgroove;
  90
  91         //or store all scores and resolve later?
  92
  93         int halftrig;
  94     int q1trig;
  95         int q2trig;
  96
  97         SndBuf * m_tempoweights;
  98         int m_weightingscheme;
  99 };
 100
 101
 102
 103 extern "C"
 104 {
 105         //required interface functions
 106         void BeatTrack2_next(BeatTrack2 *unit, int wrongNumSamples);
 107         void BeatTrack2_Ctor(BeatTrack2 *unit);
 108         void BeatTrack2_Dtor(BeatTrack2 *unit);
 109 }