ftconv.csd Written by Iain McCurdy, 2012 -iadc -odac -dm0 sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 ;MAXIMUM AMPLITUDE ; IMPULSE RESPONSES STORED AS STEREO GEN01 FUNCTION TABLES giStairwell ftgen 1, 0, 131072, 1, "Stairwell.wav", 0, 0, 0 giDish ftgen 2, 0, 131072, 1, "dish.wav", 0, 0, 0 giWood ftgen 3, 0, 131072, 1, "Wood.wav", 0, 0, 0 ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255,255,255 FLcolor2 0, 0, 0 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "ftconv", 500, 550, 0, 0 ; ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | IDUR gkOnOff,ihOnOff FLbutton "On/Off", 1, 0, 22, 100, 25, 5, 5, -1;0, 1, 0, -1 ;WINDOWS BUG WORKAROUND FLsetColor2 255, 255, 50, ihOnOff ;SET SECONDARY COLOUR TO YELLOW gkDelay2Zero,ih FLbutton "To Zero", 1, 0, 21, 70, 18, 425,425, 0, 99, 0, 0 ;VALUE DISPLAY BOXES WIDTH | HEIGHT | X | Y idGain FLvalue " ", 60, 20, 5, 75 idMix FLvalue " ", 60, 20, 5, 125 idirlen FLvalue " ", 60, 20, 5, 325 idskipsamples FLvalue " ", 60, 20, 5, 375 idDelayOS FLvalue " ", 60, 20, 5, 425 idCompRat FLvalue " ", 60, 20, 5, 475 idCurve FLvalue " ", 60, 20, 5, 525 ; MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkGain,ihGain FLslider "Gain", 0.01, 50, 0, 23, idGain, 490, 25, 5, 50 gkMix,ihMix FLslider "Dry/Wet Mix", 0, 1, 0, 23, idMix, 490, 25, 5, 100 gkirlen,ihirlen FLslider "Impulse Response Length", 0.001, 1, 0, 23, idirlen, 490, 25, 5, 300 gkskipsamples,ihskipsamples FLslider "Skip Samples", 0, 1, 0, 23, idskipsamples, 490, 25, 5, 350 gkDelayOS,gihDelayOS FLslider "Dry Signal Delay Offset", -0.5, 0.5, 0, 23, idDelayOS, 490, 25, 5, 400 gkCompRat,ihCompRat FLslider "Table Compression Ratio", 0.1, 1, 0, 23, idCompRat, 490, 25, 5, 450 gkCurve,ihCurve FLslider "Amp. Env. Curve", -8, 8, 0, 23, idCurve, 490, 25, 5, 500 ;COUNTERS MIN | MAX | STEP1 | STEP2 | TYPE | WIDTH | HEIGHT | X | Y | OPCODE gkiplenpwr, ihiplenpwr FLcount "Partition Length (Power of 2)", 1, 15, 1, 10, 2, 120, 22, 5, 240, -1 ;VALUE BOXES MIN | MAX | STEP | TYPE | WIDTH | HEIGHT | X | Y gkiplen, gihiplen FLtext "Partition Length (display only)", 0, 1048576, 0, 1, 110, 22, 130, 240 ;BORDERS TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " ", 6, 9, 15, 160, 60, 5, 170 ;BORDER AROUND INPUT SELECTOR ih FLbox " ", 6, 9, 15, 300, 60, 170, 170 ;BORDER AROUND CONVOLUTION FILE SELECTOR ;LABELS MADE INVISIBLE FLlabel 13, 1, 1, 255,255,255 FLcolor2 255, 255, 50 ;SET SECONDARY COLOUR TO YELLOW ;BUTTON BANKS TYPE | NUMX | NUMY | WIDTH | HEIGHT | X | Y | OPCODE gkinput, ihinput FLbutBank 12, 1, 2, 25, 50, 55,175, -1 gkfile, ihfile FLbutBank 12, 1, 3, 25, 50, 320,175, -1 gkFwdBwd, ihFwdBwd FLbutBank 12, 1, 4, 25, 13*4, 250,240, -1 ;LABELS MADE VISIBLE AGAIN FLlabel 13, 5, 4, 0, 0, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox "Sound File", 1, 5, 12, 74, 25, 80, 175 ih FLbox "Live Input", 1, 5, 12, 74, 25, 80, 200 ih FLbox "Stairwell", 1, 5, 12, 70, 50/3, 350, 175 ih FLbox "Dish ", 1, 5, 12, 70, 50/3, 350, 175+50/3 ih FLbox "Wood ", 1, 5, 12, 70, 50/3, 350, 175+100/3 ih FLbox "Input", 1, 4, 14, 30, 20, 15, 175 ih FLbox "Convolution File", 1, 4, 14, 130, 20, 180, 175 ih FLbox "Forwards ", 1, 5, 12, 140, 12, 277, 240 FLsetTextSize 11,ih ih FLbox "Backwards ", 1, 5, 12, 140, 12, 277, 253 FLsetTextSize 11,ih ih FLbox "Forwards Compressed ", 1, 5, 12, 140, 12, 277, 266 FLsetTextSize 11,ih ih FLbox "Backwards Compressed", 1, 5, 12, 140, 12, 277, 279 FLsetTextSize 11,ih ;SET INITIAL VALUES FOR SLIDERS |VALUE | HANDLE FLsetVal_i 0.7, ihGain FLsetVal_i 0.17, ihMix FLsetVal_i 0, ihinput FLsetVal_i 1, ihirlen FLsetVal_i 10, ihiplenpwr FLsetVal_i 0, ihskipsamples FLsetVal_i 0, gihDelayOS FLsetVal_i 1, ihCompRat FLsetVal_i 0, ihCurve FLpanel_end ;INSTRUCTIONS AND INFO PANEL WIDTH | HEIGHT | X | Y FLpanel " ", 515, 500, 512, 0 FLscroll 515, 500,0,0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " ftconv ", 1, 5, 14, 490, 20, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 20, 5, 20 ih FLbox "ftconv implements efficient low latency multichannel ", 1, 5, 14, 490, 20, 5, 40 ih FLbox "convolution using GEN01 function tables as input (deferred ", 1, 5, 14, 490, 20, 5, 60 ih FLbox "table size not permitted). This example uses stereo impulse ", 1, 5, 14, 490, 20, 5, 80 ih FLbox "files but files of up to 8 channels can be used. ", 1, 5, 14, 490, 20, 5, 100 ih FLbox "Convolution is calculated in chunks called 'partitions'. The ", 1, 5, 14, 490, 20, 5, 120 ih FLbox "latency induced by the opcode is related to the partition ", 1, 5, 14, 490, 20, 5, 140 ih FLbox "size (but not ksmps as with some other convolution opcodes). ", 1, 5, 14, 490, 20, 5, 160 ih FLbox "Latency in seconds will be partition size (in sample frames) ", 1, 5, 14, 490, 20, 5, 180 ih FLbox "divided by the sample rate. If the dry signal is to be mixed ", 1, 5, 14, 490, 20, 5, 200 ih FLbox "with the convoluted signal, the dry signal shoulod be delayed", 1, 5, 14, 490, 20, 5, 220 ih FLbox "according to this latency value. As partition size must ", 1, 5, 14, 490, 20, 5, 240 ih FLbox "always be a power of two, in this GUI the user specifies the ", 1, 5, 14, 490, 20, 5, 260 ih FLbox "index. The resulting partition size is displayed for the ", 1, 5, 14, 490, 20, 5, 280 ih FLbox "user. Smaller partition sizes (and therefore lower latencies)", 1, 5, 14, 490, 20, 5, 300 ih FLbox "demand more from the CPU and can result in buffer underruns. ", 1, 5, 14, 490, 20, 5, 320 ih FLbox "By default ftconv uses the entire function table for the ", 1, 5, 14, 490, 20, 5, 340 ih FLbox "impulse file but the user can specify a value shorter value, ", 1, 5, 14, 490, 20, 5, 360 ih FLbox "in which case the reverb effect will be abbreviated. In this ", 1, 5, 14, 490, 20, 5, 380 ih FLbox "example Impulse Response Length is specified as a fraction of", 1, 5, 14, 490, 20, 5, 400 ih FLbox "the entire file. This feature can be used to remove silence ", 1, 5, 14, 490, 20, 5, 420 ih FLbox "from the end of the impulse file (and therefore improve ", 1, 5, 14, 490, 20, 5, 440 ih FLbox "efficiency) or to produce special effects like gated ", 1, 5, 14, 490, 20, 5, 460 ih FLbox "reverbs. ", 1, 5, 14, 490, 20, 5, 480 ih FLbox "Reversed versions of all the function tables are also created", 1, 5, 14, 490, 20, 5, 500 ih FLbox "which can be accessed by choosing 'Backwards Reverb' from the", 1, 5, 14, 490, 20, 5, 520 ih FLbox "button bank. When this mode is chosen the dry signal is ", 1, 5, 14, 490, 20, 5, 540 ih FLbox "delayed to coincide with the end od the impulse file thereby ", 1, 5, 14, 490, 20, 5, 560 ih FLbox "creating a classic backwards reverb sound. ", 1, 5, 14, 490, 20, 5, 580 ih FLbox "Compressed versions of the forwards and backwards versions of", 1, 5, 14, 490, 20, 5, 600 ih FLbox "the impulse files are also created. The effect produced is ", 1, 5, 14, 490, 20, 5, 620 ih FLbox "similar to reducing the 'Impulse Response Length' except that", 1, 5, 14, 490, 20, 5, 640 ih FLbox "the Impulse file is enveloped, the curve of which can be ", 1, 5, 14, 490, 20, 5, 660 ih FLbox "adjusted. Envelope curves are created using GEN16. ", 1, 5, 14, 490, 20, 5, 680 ih FLbox "'Delay Offset' allows the user to fine tune the delay that is", 1, 5, 14, 490, 20, 5, 700 ih FLbox "used to synchronise ther dry signal with the convoluted ", 1, 5, 14, 490, 20, 5, 720 ih FLbox "signal. Normally this should be zero. ", 1, 5, 14, 490, 20, 5, 740 FLscroll_end FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; reverse function table UDO opcode tab_reverse,i,i ifn xin iTabLen = nsamp(ifn) iTableRev ftgen ifn+100,0,-iTabLen,-2, 0 icount = 0 loop: ival table iTabLen-icount-1, ifn tableiw ival,icount,iTableRev loop_lt icount,1,iTabLen,loop xout iTableRev endop ; compress function table UDO opcode tab_compress,i,iii ifn,iCompRat,iCurve xin iTabLen = nsamp(ifn) iTabLenComp = int(nsamp(ifn)*iCompRat) iTableComp ftgen ifn+200,0,-iTabLenComp,-2, 0 iAmpScaleTab ftgen ifn+300,0,-iTabLenComp,-16, 1,iTabLenComp,iCurve,0 icount = 0 loop: ival table icount, ifn iAmpScale table icount, iAmpScaleTab tableiw ival*iAmpScale,icount,iTableComp loop_lt icount,1,iTabLenComp,loop xout iTableComp endop ; compress reverse function table UDO opcode tab_compress_rev,i,iii ifn,iCompRat,iCurve xin iTabLen = nsamp(ifn) iTabLenComp = int(nsamp(ifn)*iCompRat) iTableComp ftgen ifn+400,0,-iTabLenComp,-2, 0 iAmpScaleTab ftgen ifn+500,0,-iTabLenComp,-16, 1,iTabLenComp,iCurve,0 icount = 0 loop: ival table icount, ifn iAmpScale table icount, iAmpScaleTab tableiw ival*iAmpScale, iTabLenComp-icount-1,iTableComp loop_lt icount,1,iTabLenComp,loop xout iTableComp endop instr OnOff ktrigOn trigger gkOnOff,0.5,0 ktrigOff trigger gkOnOff,0.5,1 if ktrigOn==1 then event "i",1,0,-1 elseif ktrigOff==1 then turnoff2 1,0,0 endif endin instr 1 ;GENERATE INPUT AUDIO INDEPENDENTLY OF REVERBERATING INSTRUMENT ;if gkOnOff==0 then ;IF ON/OFF SWITCH IS OFF... ;WINDOWS BUG WORKAROUND ; turnoff ;TURN THIS INSTRUMENT OFF ;WINDOWS BUG WORKAROUND ;endif ;END OF CONDITIONAL BRANCHING ;WINDOWS BUG WORKAROUND if gkinput=0 then ;IF 'Sound File' IS SELECTED... gasig diskin2 "808LoopMono.wav", 1, 0, 1 ;READ AUDIO FROM SOUND FILE ON HARD DISC elseif gkinput=1 then ;IF 'Live Input' IS SELECTED gasig inch 1 ;READ AUDIO FROM SOUND CARD'S FIRST (LEFT) INPUT endif gasig = gasig*gkGain ;SCALE AUDIO SIGNAL WITH GAIN CONTROL endin instr 2 ;CONVOLUTION REVERB INSTRUMENT ;CREATE REVERSED TABLES irev1 tab_reverse giStairwell irev2 tab_reverse giStairwell+1 irev3 tab_reverse giStairwell+2 kSwitch changed gkfile,gkirlen,gkskipsamples,gkiplenpwr,gkFwdBwd,gkDelayOS,gkCompRat,gkCurve ;GENERATE A MOMENTARY '1' PULSE IN OUTPUT 'kSwitch' IF ANY OF THE SCANNED INPUT VARIABLES CHANGE. (OUTPUT 'kSwitch' IS NORMALLY ZERO) if kSwitch=1 then ;IF I-RATE VARIABLE IS CHANGED... reinit UPDATE ;BEGIN A REINITIALISATION PASS IN ORDER TO EFFECT THIS CHANGE. BEGIN THIS PASS AT LABEL ENTITLED 'UPDATE' AND CONTINUE UNTIL rireturn OPCODE endif ;END OF CONDITIONAL BRANCHING UPDATE: ;LABEL ;CREATE COMPRESSED TABLES icomp1 tab_compress giStairwell,i(gkCompRat),i(gkCurve) icomp2 tab_compress giStairwell+1,i(gkCompRat),i(gkCurve) icomp3 tab_compress giStairwell+2,i(gkCompRat),i(gkCurve) ;CREATE COMPRESSED REVERSED TABLES icomprev1 tab_compress_rev giStairwell,i(gkCompRat),i(gkCurve) icomprev2 tab_compress_rev giStairwell+1,i(gkCompRat),i(gkCurve) icomprev3 tab_compress_rev giStairwell+2,i(gkCompRat),i(gkCurve) iplen = 2^i(gkiplenpwr) ;BUFFER LENGTH FLsetVal_i iplen,gihiplen ;WRITE ACTUAL BUFFER SIZE TO THE TEXT BOX itab = giStairwell+i(gkfile) ;DERIVE FUNCTION TABLE NUMBER OF CHOSEN TABLE FOR IMPULSE FILE iirlen = nsamp(itab)*0.5*i(gkirlen) ;DERIVE THE LENGTH OF THE IMPULSE RESPONSE IN SAMPLES. DIVIDE BY 2 AS TABLE IS STEREO. iskipsamples = nsamp(itab)*0.5*i(gkskipsamples) ;DERIVE INSKIP INTO IMPULSE FILE. DIVIDE BY 2 (MULTIPLY BY 0.5) AS ALL IMPULSE FILES ARE STEREO ;FORWARDS REVERB if gkFwdBwd==0 then aL,aR ftconv gasig, itab, iplen,iskipsamples, iirlen ;CONVOLUTE INPUT SOUND adel delay gasig, abs((iplen/sr)+i(gkDelayOS)) ;DELAY THE INPUT SOUND ACCORDING TO THE BUFFER SIZE ;BACKWARDS REVERB elseif gkFwdBwd==1 then aL,aR ftconv gasig, irev1+i(gkfile), iplen, iskipsamples, iirlen ;CONVOLUTE INPUT SOUND adel delay gasig,abs((iplen/sr)+(iirlen/sr)-(iskipsamples/sr)+i(gkDelayOS)) ;DELAY THE INPUT SOUND ACCORDING TO THE BUFFER SIZE AND THE DURATION OF THE IMPULSE FILE elseif gkFwdBwd==2 then aL,aR ftconv gasig, icomp1+i(gkfile), iplen,iskipsamples, iirlen*i(gkCompRat) ;CONVOLUTE INPUT SOUND adel delay gasig, abs((iplen/sr)+i(gkDelayOS)) ;DELAY THE INPUT SOUND ACCORDING TO THE BUFFER SIZE else aL,aR ftconv gasig, icomprev1+i(gkfile), iplen, iskipsamples, iirlen*i(gkCompRat) ;CONVOLUTE INPUT SOUND adel delay gasig,abs((iplen/sr)+((iirlen*i(gkCompRat))/sr)-(iskipsamples/sr)+i(gkDelayOS)) ;DELAY THE INPUT SOUND ACCORDING TO THE BUFFER SIZE AND THE DURATION OF THE IMPULSE FILE endif ; CREATE A DRY/WET MIX aMixL ntrpol adel,aL*0.1,gkMix aMixR ntrpol adel,aR*0.1,gkMix outs aMixL,aMixR gasig = 0 ;CLEAR GLOBAL AUDIO SIGNAL FROM INSTR 1 (LEFT CHANNEL) endin instr 99 FLsetVal_i 0,gihDelayOS endin i "OnOff" 0 3600 ;SENSE ON/OFF SWITCH (WORKAROUND FOR WINDOWS BUG i 2 0 3600 ;INSTRUMENT 2 (CONVOLUTION INSTRUMENT) RUNS FOR 1 HOUR (AND KEEPS REAL-TIME PERFORMANCE GOING) e