DelayDoppler.csd Written by Iain McCurdy, 2008 -iadc -odac -dm0 sr = 44100 ;SAMPLE RATE ksmps = 1 ;NUMBER OF AUDIO SAMPLES IN EACH CONTROL CYCLE (MAY NEED TO BE LOW WHEN WORKING WITH SHORT DELAY TIMES DEFINED INITIALLY AT KRATE) nchnls = 2 ;NUMBER OF CHANNELS (2=STEREO) 0dbfs = 1 ;MAXIMUM AMPLITUDE ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255, 255, 255, 0, 0, 0 ;SETUP BASIC COLOURS ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "Doppler Effect", 500, 450, 0, 0 ;SWITCHES ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | DUR gkOnOff,ihOnOff FLbutton "On/Off", 1, 0, 22, 100, 25, 5, 5, 0, 1, 0, -1 FLsetColor2 255, 255, 50, ihOnOff ;SET SECONDARY COLOUR TO YELLOW ;VALUE DISPLAY BOXES iwidth iheight ix, iy idfreq FLvalue " ", 70, 20, 5, 75 idAmpDepth FLvalue " ", 70, 20, 5, 125 idAmpPhase FLvalue " ", 70, 20, 5, 175 idPanDepth FLvalue " ", 70, 20, 5, 225 idDopDep FLvalue " ", 70, 20, 5, 275 idRvbScaling FLvalue " ", 70, 20, 5, 325 idRvbTime FLvalue " ", 50, 20, 5, 375 idRvbFilt FLvalue " ", 50, 20, 255, 375 idOutGain FLvalue " ", 70, 20, 5, 425 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkfreq, ihfreq FLslider "Frequency of Rotation (Hertz)",-5, 5, 0, 23, idfreq, 490, 25, 5, 50 gkAmpDepth, ihAmpDepth FLslider "Central/Edge", 0, 1, 0, 23, idAmpDepth, 490, 25, 5, 100 gkAmpPhase, ihAmpPhase FLslider "Orientation (radians)", 0, 1, 0, 23, idAmpPhase, 490, 25, 5, 150 gkPanDepth, ihPanDepth FLslider "Panning Width", 0, 1, 0, 23, idPanDepth, 490, 25, 5, 200 gkDopDep, ihDopDep FLslider "Doppler Depth", 0, .1, 0, 23, idDopDep, 490, 25, 5, 250 gkRvbScaling, ihRvbScaling FLslider "Reverb Scaling", 0, 1, 0, 23, idRvbScaling, 490, 25, 5, 300 gkRvbTime, ihRvbTime FLslider "Reverb Time", 0.3,0.99, 0, 23, idRvbTime, 240, 25, 5, 350 gkRvbFilt, ihRvbFilt FLslider "Reverb Damping", 20,20000, 0, 23, idRvbFilt, 240, 25, 255, 350 gkOutGain, ihOutGain FLslider "Output Gain", 0, 1, 0, 23, idOutGain, 490, 25, 5, 400 gkInGain, ihInGain FLslider "Live Input Gain", 0, 1, 0, 23, -1, 195, 12, 300, 20 ;GENERAL_TEXT_SETTINGS SIZE | FONT | ALIGN | RED | GREEN | BLUE FLlabel 13, 1, 1, 255, 255, 255 ; NUMBERS MADE INVISIBLE ; FLBUTBANK TYPE | NUMX | NUMY | WIDTH | HEIGHT | X | Y | OPCODE gkinput, ihinput FLbutBank 4, 1, 2, 18, 36, 200, 1, -1 ;GENERAL_TEXT_SETTINGS SIZE | FONT | ALIGN | RED | GREEN | BLUE FLlabel 13, 5, 4, 0, 0, 0 ;LABELS MADE VISIBLE AGAIN ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox "Input:", 1, 5, 12, 48, 12, 150, 2 ih FLbox "Noisy Tone", 1, 5, 12, 70, 15, 220, 2 ih FLbox "Live Input", 1, 5, 12, 70, 15, 220, 19 ;INITIALISATION FLsetVal_i 0.2, ihfreq FLsetVal_i .7, ihAmpDepth FLsetVal_i 0.5, ihAmpPhase FLsetVal_i 1, ihPanDepth FLsetVal_i .003, ihDopDep FLsetVal_i 0.3, ihRvbScaling FLsetVal_i 0.7, ihRvbTime FLsetVal_i 4000, ihRvbFilt FLsetVal_i 0.7, ihOutGain FLsetVal_i 0.1, ihInGain FLpanel_end ;END OF PANEL CONTENTS ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 515, 700, 512, 0 FLscroll 515, 700, 0, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " Circular Motion Doppler Effect (vdelayxw) ", 1, 5, 14, 490, 20, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 20, 5, 20 ih FLbox "This example uses three LFOs to create the effect of a sound ", 1, 5, 14, 490, 20, 5, 40 ih FLbox "moving in a circle around the listener. The three parameters ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "controlled by these LFOs are amplitude, panning and delay ", 1, 5, 14, 490, 20, 5, 80 ih FLbox "time. The modulation of the delay time also results in a ", 1, 5, 14, 490, 20, 5, 100 ih FLbox "modulation of pitch which is sometimes referred to as the ", 1, 5, 14, 490, 20, 5, 120 ih FLbox "Doppler effect. ", 1, 5, 14, 490, 20, 5, 140 ih FLbox "Note that in this example the 'vdelayxw' opcode is used to ", 1, 5, 14, 490, 20, 5, 160 ih FLbox "implement the delay and doppler shift. This opcode is unique ", 1, 5, 14, 490, 20, 5, 180 ih FLbox "in that the delay time of the write pointer rather than the ", 1, 5, 14, 490, 20, 5, 200 ih FLbox "read pointer is modulated. This is appropriate here as it is ", 1, 5, 14, 490, 20, 5, 220 ih FLbox "the sound source that is moving, not the listener. ", 1, 5, 14, 490, 20, 5, 240 ih FLbox "Crucial to this effect is that that all three LFOs share the ", 1, 5, 14, 490, 20, 5, 260 ih FLbox "same frequency value. Negative frequency values are also ", 1, 5, 14, 490, 20, 5, 280 ih FLbox "allowed - this would represent a change in direction of the ", 1, 5, 14, 490, 20, 5, 300 ih FLbox "source sounds motion around us. ", 1, 5, 14, 490, 20, 5, 320 ih FLbox "Also of crucial importance is the phase relationship between ", 1, 5, 14, 490, 20, 5, 340 ih FLbox "the three LFOs as this defines exactly where the sound source", 1, 5, 14, 490, 20, 5, 360 ih FLbox "is in relation to the listener. ", 1, 5, 14, 490, 20, 5, 380 ih FLbox "The panning LFO should be at its points of minimum rate of ", 1, 5, 14, 490, 20, 5, 400 ih FLbox "change when the sound source is moving parallel to the ", 1, 5, 14, 490, 20, 5, 420 ih FLbox "direction in which the listener is facing, i.e. directly to ", 1, 5, 14, 490, 20, 5, 440 ih FLbox "the left or to the right of the listener. ", 1, 5, 14, 490, 20, 5, 460 ih FLbox "The delay time LFO (pitch modulation/doppler) should be at ", 1, 5, 14, 490, 20, 5, 480 ih FLbox "its points of minimum rate of change when the sound source is", 1, 5, 14, 490, 20, 5, 500 ih FLbox "moving perpendicular to the direction in which the listener ", 1, 5, 14, 490, 20, 5, 520 ih FLbox "is facing, i.e. directly in front of or behind the listener. ", 1, 5, 14, 490, 20, 5, 540 ih FLbox "The phase difference between these two LFOs is either 90 or ", 1, 5, 14, 490, 20, 5, 560 ih FLbox "270 degrees, depending on whether the source sound is moving ", 1, 5, 14, 490, 20, 5, 580 ih FLbox "in a clockwise or anticlockwise direction around us. ", 1, 5, 14, 490, 20, 5, 600 ih FLbox "Amplitude modulation comes into play whenever we are not ", 1, 5, 14, 490, 20, 5, 620 ih FLbox "listening from the centre of the circle of motion. The closer", 1, 5, 14, 490, 20, 5, 640 ih FLbox "to the edge of the circle we are the greater the amount of ", 1, 5, 14, 490, 20, 5, 660 ih FLbox "amplitude modulation we will experience. If the amplitude ", 1, 5, 14, 490, 20, 5, 680 ih FLbox "modulation is extreme then the circle of the source sound's ", 1, 5, 14, 490, 20, 5, 700 ih FLbox "motion must be extremely large. The phase of the amplitude ", 1, 5, 14, 490, 20, 5, 720 ih FLbox "modulation LFO is also adjustable ('Orientation' slider - ", 1, 5, 14, 490, 20, 5, 740 ih FLbox "this define which edge of the circle we are closest to, e.g. ", 1, 5, 14, 490, 20, 5, 760 ih FLbox "upper, lower, left, right etc. It is probably best to always ", 1, 5, 14, 490, 20, 5, 780 ih FLbox "include at least a small amount of amplitude modulation as we", 1, 5, 14, 490, 20, 5, 800 ih FLbox "perceive sounds directly to our left or to our right to be ", 1, 5, 14, 490, 20, 5, 820 ih FLbox "louder, even if they remain equidistant from us. In this case", 1, 5, 14, 490, 20, 5, 840 ih FLbox "the amplitude LFO phase ('Orientation') should be 0.5 ", 1, 5, 14, 490, 20, 5, 860 ih FLbox "(radians). ", 1, 5, 14, 490, 20, 5, 880 ih FLbox "The waveform for all three LFOs is a sine wave. This defines ", 1, 5, 14, 490, 20, 5, 900 ih FLbox "The object's motion as being circular. If we were to use a ", 1, 5, 14, 490, 20, 5, 920 ih FLbox "different waveform this would model non-circular motion. ", 1, 5, 14, 490, 20, 5, 940 ih FLbox "There is interesting potential in experimentation in this ", 1, 5, 14, 490, 20, 5, 960 ih FLbox "direction with this example. ", 1, 5, 14, 490, 20, 5, 980 ih FLbox "Finally as the moving signal becomes more distant, i.e. when ", 1, 5, 14, 490, 20, 5,1000 ih FLbox "the amplitude scaling function is at its minimum, a ", 1, 5, 14, 490, 20, 5,1020 ih FLbox "reverberated version of the signal can become more evident. ", 1, 5, 14, 490, 20, 5,1040 ih FLbox "The degree to which this is present can be scaled using the ", 1, 5, 14, 490, 20, 5,1060 ih FLbox "'Reverb Scaling' slider. ", 1, 5, 14, 490, 20, 5,1080 FLscrollEnd FLpanel_end FLrun ;RUN THE WIDGET THREAD gisine ftgen 0, 0, 4096, 10, 1 ;A SINE WAVE FUNCTION TABLE IS DEFINED instr 1 if gkOnOff=0 then ;...IF 'On/Off' BUTTON IS 'OFF'... turnoff ;...TURNOFF THIS INSTRUMENT IMMEDIATLEY endif ;END OF CONDIIONAL BRANCHING kporttime linseg 0,0.001,0.1 ;CREATE 'PORTAMENTO TIME'. A FUNCTION THAT RISES QUICKLY FROM ZERO TO A HELD VALUE. kAmpPhase portk gkAmpPhase, kporttime ;APPLY PORTAMENTO TO gkAmpPhase. CREATE NEW OUTPUT VARIABLE kAmpPhase (GLOBAL VARIABLES CAN'T BE BOTH INPUT AND OUTPUT) kDopDep portk gkDopDep, kporttime ;APPLY PORTAMENTO TO gkDopDep. CREATE NEW OUTPUT VARIABLE kDopDep (GLOBAL VARIABLES CAN'T BE BOTH INPUT AND OUTPUT) if gkinput=0 then ;IF FIRST INPUT OPTION IS CHOSEN... asig pinkish 10 ;DEFINE SOUND SOURCE (PINK NOISE) FOR THIS EXAMPLE asig butbp asig, 500, 10 ;BANDPASS FILTER PINK NOISE TO GIVE asig A 'WHISTLING' CHARACTERISTIC. THIS FILTERING CAUSES A LOSS OF SIGNAL POWER WHICH MUST LATER BE COMPENSATED FOR else ;OTHERWISE... asig inch 1 ;READ AUDIO FROM INPPUT CHANNEL 1 asig = asig * gkInGain ;SCALE INPUT USING INPUT GAIN SLIDER endif ;END OF THIS CONDITIONAL BRANCH aAmp osciliktp gkfreq, gisine, kAmpPhase ;AN LFO DEFINES A VARIABLE USED TO MODULATE AMPLITUDE (NOTE: VARIABLE PHASE). THIS MODELS THE LOCATION WITHIN THE CIRCLE FROM WHICH WE ARE LISTENING. NO AMPLITUDE MODULATION REPRESENT REPRESENTS OUR LISTENING POSITION BEING EXACTLY CENTRAL, MAXIMUM MODULATION REPRESENTS US BEING NEAR TO THE EDGE OF A LARGE CIRCLE. THE CONTROL OVER PHASE OF THIS LFO REPRESENTS WHICH EDGE WE ARE CLOSER TO. aAmp = (aAmp * 0.5 * gkAmpDepth) + 0.5 ;RESCALE AND OFFSET AMPLITUDE MODULATION LFO aPan oscili (gkPanDepth * 0.5), gkfreq, gisine, 0.75 ;AN LFO DEFINES A VARIABLE FOR PANNING CONTROL - I.E. WHETHER SOUND IS CURRENTLY TO OUT LEFT OR TO OUT RIGHT. NOTE THAT PHASE IS 0.75 AND THEREFORE 0.75 RADIANS (OR 270 DEGREES OUT OF PHASE) WITH THE DELAY MODULATION aPan = aPan + 0.5 ;OFFSET PANNING LFO iMaxDelay = 1 ;DEFINE A VARIABLE THAT WILL BE USE FOR 'MAXIMUM DELAY TIME' (BUFFER LENGTH) aDelTim oscili kDopDep, gkfreq, gisine, 0 ;AN LFO DEFINES A VARIABLE FOR DELAY TIME (NOTE PHASE AT ZERO) aDelTim = aDelTim + kDopDep ;DELAY TIME VARIABLE 'aDelay' IS OFFSET TO STAY WITHIN THE POSITIVE DOMAIN ;vdelayxw IS USED FOR THE DELAY READ/WRITE AS IT MODULATES THE WRITE POINTER RATHER THAN THE READ POINTER. ;THIS IS MORE APPROPRIATE IN THIS EXAMPLE AS THE SOURCE IS MOVING BUT THE POINT OF LISTENING IS STATIONARY aDelTap vdelayxw asig, aDelTim, iMaxDelay, 16 aL, aR pan2 aDelTap, aPan, 1 ;APPLY PANNING TO SIGNAL OUTPUT FROM DELAY USING pan2 OPCODE. CREATE A NEW aDryL = aL * (aAmp^0.5) * gkOutGain ;APPLY AMPLITUDE MODULATION (CREATE A NEW AUDIO SIGNAL - DRY (UN-REVERBERATED) SIGNAL) aDryR = aR * (aAmp^0.5) * gkOutGain ;APPLY AMPLITUDE MODULATION (CREATE A NEW AUDIO SIGNAL - DRY (UN-REVERBERATED) SIGNAL) aRvbL, aRvbR reverbsc aL, aR, gkRvbTime, gkRvbFilt ;REVERB (UNAFFECTED BY AMPLITUDE MODULATION) outs aDryL+(aRvbL*gkRvbScaling), aDryR+(aRvbL*gkRvbScaling) ;SEND AUDIO TO OUTPUTS. MIX DRY AND REVERBERATED SIGNALS. endin f 0 3600 ;DUMMY SCORE EVENT