TapTempoAudio.csd Written by Iain McCurdy 2012. -odac -iadc -dm0 sr = 44100 ksmps = 8 nchnls = 1 ;MONO 0dbfs = 1 ;MAXIMUM AMPLITUDE ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255,255,255 FLcolor2 0, 0, 0 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "Tap Tempo (Audio)", 500, 210, 0, 0 ;VALUE DISPLAY BOXES WIDTH | HEIGHT | X | Y idthreshold FLvalue " ", 60, 20, 5, 35 idInGain FLvalue " ", 60, 20, 5, 135 idMetroGain FLvalue " ", 60, 20, 5, 185 ; MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkthreshold,ihthreshold FLslider "Threshold", 0, 1, 0, 23, idthreshold, 490, 25, 5, 10 gkInGain,ihInGain FLslider "Audio Input Gain", 0, 1, 0, 23, idInGain, 490, 25, 5, 110 gkMetroGain,ihMetroGain FLslider "Metronome Gain", 0, 1, 0, 23, idMetroGain, 490, 25, 5, 160 ; MIN | MAX | STEP | TYPE | WIDTH | HEIGHT | X | Y gktempo, gihtempo FLtext "Tempo", 0, 2000, 0, 1, 100, 20, 5, 60 gkbeatduration, gihbeatduration FLtext "Beat Duration",0, 2000, 0, 1, 100, 20, 110, 60 ;SET INITIAL VALUES FOR SLIDERS |VALUE | HANDLE FLsetVal_i 0.2, ihthreshold FLsetVal_i 1, ihInGain FLsetVal_i 1, ihMetroGain FLpanel_end ;INSTRUCTIONS AND INFO PANEL WIDTH | HEIGHT | X | Y FLpanel " ", 500, 340, 512, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " Tap Tempo (Audio) ", 1, 5, 14, 490, 15, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 15, 5, 20 ih FLbox "This example uses tapping of a microphone to derive a tempo. ", 1, 5, 14, 490, 15, 5, 40 ih FLbox "The tempo deduced and beat duration are printed to the ", 1, 5, 14, 490, 15, 5, 60 ih FLbox "relevant FLTK widgets each time the microphone is struck. An ", 1, 5, 14, 490, 15, 5, 80 ih FLbox "audio metronome provides audible confirmation of the current ", 1, 5, 14, 490, 15, 5, 100 ih FLbox "tempo value. Tempo is calculated by measuring the time gap ", 1, 5, 14, 490, 15, 5, 120 ih FLbox "between successive tappings of the microphone and by then ", 1, 5, 14, 490, 15, 5, 140 ih FLbox "regarding this measurement as a beat duration. Beat duration ", 1, 5, 14, 490, 15, 5, 160 ih FLbox "is actually calculated by averaging the previous two time ", 1, 5, 14, 490, 15, 5, 180 ih FLbox "gaps. It is necessary to tap the microphone at least four ", 1, 5, 14, 490, 15, 5, 200 ih FLbox "times at a particular tempo to arrive at an accurate ", 1, 5, 14, 490, 15, 5, 220 ih FLbox "calculation of that tempo. Tempo and beat duration are ", 1, 5, 14, 490, 15, 5, 240 ih FLbox "provided as global variables so that the code for this ", 1, 5, 14, 490, 15, 5, 260 ih FLbox "instrument could easily be transplanted into another ", 1, 5, 14, 490, 15, 5, 280 ih FLbox "orchestra. Encapsulating all code within a single instrument ", 1, 5, 14, 490, 15, 5, 300 ih FLbox "block also assists in achieving this. ", 1, 5, 14, 490, 15, 5, 320 FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; instr taptempo prints "Tap the microphone bar repeatedly...%n" ;PRINT INSTRUCTION TO THE TERMINAL ;SET SOME INITIAL VALUES AND CREATE FUNCTION TABLES kTimer init 1 ;TIMER THAT MEASURES THE TIME GAP BETWEEN ADJACENT NOTES gkBeatDur init 1 ;AVERAGE OF ALL TIME GAPS STORED IN TABLE gkTempo init 60 ;CURRENT TEMPO iTabLoc init 0 ;TABLE LOCATION COUNTER iTimes ftgentmp 0,0,-2,-2,1,1 ;TABLE TO STORE TIME GAPS isine ftgentmp 0,0,4096,10,1 ;A SINE WAVE ;SENSE TEMPO a1 inch 1 ;READ LIVE AUDIO INPUT FROM INPUT CHANNEL 1 krms rms a1*gkInGain ;DERIVE RMS VALUE FROM AUDIO STREAM ktrig trigger krms,gkthreshold,0 ;IF RMS THRESHOLD HAS BEEN CROSS (IN THE UPWARDS DIRECTION) ktrig EQUALS '1' FOR ONE 'K' CYCLE if ktrig=1 then ;IF THERE HAS BEEN A RMS THRESHOLD CROSSING... reinit TAP ;BEGIN A REINITIALISATION PAS FROM LABEL 'TAP' endif ;END OF CONDITIONAL BRANCH TAP: ;LABEL CALLED 'TAP'. REINITIALISATION BEGINS FROM HERE AFTER AN RMS THRESHOLD CROSSING HAS BEEN DETECTED. kNoteOnFlag init 1 ;NOTE ON FLAG IS SET TO ON (WILL BE RESET TO ZERO IN INSTR 3) iTimeGap init i(kTimer) ;READ TIME GAP BETWEEN PREVIOUS NOTE AND THIS ONE iTimeGap = (iTimeGap>2?i(gkBeatDur):iTimeGap) ;DON'T ALLOW EXCESSIVELY LONG TIME GAPS - I.E. AFTER A LONG WAIT WHICH IS PROBABLY NOT INTENDED AS AN INDICATION OF TEMPO - INSTEAD REPLACE READING WITH THE CURRENT TEMPO tablew iTimeGap,iTabLoc,iTimes ;WRITE TIME GAP READING TO FUNCTION TABLE iNumVals = ftlen(iTimes) ;DEDUCE NUMBER OF TIMER READING LOCATIONS IN THE TABLE iTabLoc wrap iTabLoc+1,0,iNumVals ;INCREMENT THE TABLE LOCATION COUNTER. WRAP AROUND BACK TO ZERO IF REQUIRED iSumVals init 0 ;INITIALISE AND CLEAR SUM OF ALL TIME GAP READINGS STORED IN giTimes TABLE iLoopCount init 0 ;INITIALISE LOOP COUNTER LOOP_BEGIN: ;LABEL. LOOP BEGINS HERE ival table iLoopCount,iTimes ;READ TIME GAP READING FROM TABLE iSumVals = iSumVals+ival ;ADD TIME GAP READING FROM TABLE TO THE ACCUMULATING VARIABLE iSumVals loop_lt iLoopCount,1,iNumVals,LOOP_BEGIN ;LOOP BACK TO THE BEGINNING OF THE LOOP IF THERE ARE STILL MORE TIME GAP READINGS TO BE READ gkBeatDur init iSumVals/iNumVals ;FIND THE AVERAGE OF THE TABLE gkTempo init 60/i(gkBeatDur) ;DEDUCE TEMPO prints "tempo:%5.2f%tbeat duration:%5.3f%n",gkTempo,gkBeatDur ;PRINT TEMPO AND BEAT DURATION TO THE TERMINAL FLsetVal_i i(gkTempo), gihtempo FLsetVal_i i(gkBeatDur), gihbeatduration kTimer timeinsts ;TIMER READS THE TIME SINCE THIS NOTE BEGAN rireturn ;AUDIO METRONOME kmetro metro gkTempo/60 ;CREATE A TRAIN OF METRONOME TRIGGER ACCORDING TO CURRENT TEMPO if kmetro=1 then ;IF A METRONOME BEAT HAS BEEN RECEIVED reinit RESTART_CLICK ;REINITIALISE THE METRONOME endif ;END OF CONDITIONAL BRANCH RESTART_CLICK: ;A LABEL. REINTIALISATION OF THE METRONOME ENVELOPES (AMPLITUDE AND PITCH) BEGINS HERE. aenv linseg 0,0.001,1,0.005-0.001,0 ;PERCUSSIVE AMPLITUDE ENVELOPE afreq expseg 4000,0.005,200,1,200 ;PITCH OF TONE (VERY FAST GLISS DOWN TO A HELD VALUE) rireturn ;RETURN FROM REINITIALISATION PASS asig oscili 0.5*aenv*gkMetroGain,afreq,isine;CREATE AUDIO FOR METRONOME 'CLICK' out asig ;SEND AUDIO TO OUPUT endin i "taptempo" 0 3600