DISTRHO
/
DISTRHO-Ports-Extra
mirror of https://github.com/DISTRHO/DISTRHO-Ports-Extra


			
							LiveSndwarp.csd
Iain McCurdy (2012)

Description and Instructions
----------------------------

This instrument implements live granulation of an audio input stream using the sndwarp opcode.                         

Live audio from the first input channel (left input if stereo) is written into a function table from which sndwarp reads 
audio. (If 'stereo in/out' is chosen from 'In/Out Mode' then audio from the second/right channel is written into a second 
table.) The key is that manual pointer read mode is used with sndwarp (as opposed to time-stretch mode) and that the read 
pointer follows on behind the pointer which is used to write audio into the function table(s). Some care is needed to ensure 
that the read pointer does not 'overtake' the write pointer (which would result in dicontinuities in the audio it reads). 
This could be possible if pitch transposition upwards of grains is used as the grain pointer is then moving faster than the 
write pointer. This example prevents this from happening internally so the user does not need to worry. The user can also 
define a random offset for the grain read pointer using the 'Grain Delay' settings. Delay times are randomly chosen 
according to a 'betarand' distribution the 'beta' of which the user can set: if distribution shape is 1 the distribution is 
uniform, if it is 2 the distribution is linear and beyond 2 it is increasingly exponential.

Note that 'Size' (grain size) and 'Size Rnd.' (random grain size) are i-rate variables so that changing them requires 
reinitialisation in the orchestra. For this reason discontinuity in the audio output can be heard when they are modified.
Grain Size and Size Random (bandwith) are in sample frames. Divide by sample rate to derive a value in seconds.

Pitch transposition can be set using either the 'Pitch' knob (ratio multiplier) or 'Semis' (transposition in semitones).
Changes made to 'Semis' will be reflected in the setting of the 'Pitch' knob, but not vice versa.
Pitch can also be controlled through MIDI input (in which case 'Pitch' and 'Semis' will be ignored). Using MIDI will 
polyphony will be possible. If you intend to use MIDI to start and stop sndwarp instances, turn 'On/Off [MIDI]' off.
You can also adjust the MIDI note at which unison (no transposition) will occur using the 'Uni.Note' knob.

Sound output from sndwarp can be fed back into the input to be mixed with the live audio in. The amount of feedback can be 
controlled using the 'Feedback' slider. Using high levels of feedback can result in overloading but this will also be 
dependent upon other factors such as random delay time, grain size (window size), density and transposition so user caution 
is advised. If the 'clip' button is activated the feedback signal will be clipped at the clip level set (a ratio of then 
maximum amplitude) providing at least some control over a runaway feedback loop. Note that 'Clip Lev.' defines the amplitude 
at which clipping begins, therefore lower settings will result in the signal being clipped sooner. The feedback signal can 
also be filtered by a lowpass filter.

If 'balance' is activated the output of sndwarp is dynamically balanced with the input signal. This can be useful for 
compensating for increases in amplitude caused when 'Number of Overlaps' (grain density) is increased. There are 3 
mono/stereo modes: 'mono in - mono out (x2)', 'mono in - stereo out' (stereo effect is created using sndwarp's built-in 
window/grain size randomisation, and 'stereo in - stereo out' mode.

The buffer size used in the example is just under 23 seconds long (function table size 1048576 at sr=44100). This could be 
enlarged if required but bear in mind that sndwarp needs a power of two table size.        

Activating 'Freeze' will pause writing of live audio to the function table and allow the user to manually navigate through 
the buffered audio. The feedback loop will also be deactivated when 'freeze' is active.

<Cabbage>
form caption("Live Sndwarp") size(530, 465), pluginID("lwrp")

groupbox bounds(  0,  0, 300,100), text("Master"), colour(30, 30, 40), fontcolour(255,125,125){
checkbox bounds( 10, 28, 110, 20), colour("yellow"), channel("OnOff"),  value(1), text("On/Off [MIDI]"), trackercolour("red")
label    bounds( 22, 53,  80, 13), text("In/Out Mode")
combobox bounds( 10, 69, 100, 20), channel("monostereo"), value(2), text("mono","stereo out","stereo in/out")
rslider  bounds(115, 30,  60, 60), text("In Gain"), channel("InGain"), range(0, 2.00, 1, 0.5), trackercolour("red")
rslider  bounds(175, 30,  60, 60), text("Out Gain"), channel("amp"), range(0, 2.00, 1, 0.5), trackercolour("red")
rslider  bounds(235, 30,  60, 60), text("Mix"), channel("mix"), range(0, 1.00, 1), trackercolour("red")
}

groupbox bounds(300,  0, 230,100), text("Feedback - CAUTION!"), colour(25, 25, 35), fontcolour(250,120,120){
rslider  bounds(305, 30,  60, 60), text("Amount"), channel("feedback"), range(0, 1.00, 0), trackercolour("red")
checkbox bounds(365, 35,  70, 20), colour("yellow"), channel("clip"),  value(1), text("Clip"), trackercolour("red")
checkbox bounds(365, 65,  70, 20), colour("yellow"), channel("LPF_On"),  value(0), text("LPF"), trackercolour("red")
rslider  bounds(410, 30,  60, 60), text("Clip Lev."), channel("ClipLev"), range(0.01, 1, 0.5, 0.5), trackercolour("red")
rslider  bounds(465, 30,  60, 60), text("LPF"), channel("Cutoff"), range(20, 20000,  4000, 0.5), trackercolour("red")
}

groupbox bounds(  0,100, 530,100), text("Grains"), colour(35, 35, 45), fontcolour(255,130,130){
rslider  bounds(  5,130,  60, 60), text("Size"), channel("wsize"), range(1, 88200, 7000, 0.25), trackercolour("red")
rslider  bounds( 65,130,  60, 60), text("Size Rnd."), channel("rnd"), range(0, 30000, 1000, 0.375), trackercolour("red")
rslider  bounds(125,130,  60, 60), text("Pitch"), channel("pch"), range(0.01, 8, 1, 0.5), trackercolour("red")
rslider  bounds(185,130,  60, 60), text("Semis"), channel("semis"), range(-48, 48, 0,1,1), trackercolour("red")
rslider  bounds(245,130,  60, 60), text("Density"), channel("olaps"), range(1, 100, 10, 1, 1), trackercolour("red")
label    bounds(305,125, 100, 13), text("Grain Envelope")
combobox bounds(305,141, 100, 20), channel("wfn"), value(1), text("Half Sine","Perc. 1","Perc. 2","Gate","Rev. Perc. 1 ","Rev. Perc. 2")
checkbox bounds(315,170, 100, 20), colour("yellow"), channel("balance"),  value(0), text("Balance")
rslider  bounds(405,130,  60, 60), text("Delay"), channel("dly"), range(0, 5, 0.01, 0.5), trackercolour("red")
rslider  bounds(465,130,  60, 60), text("Distr."), channel("beta"), range(1, 16.0, 1, 0.5), trackercolour("red")
}

groupbox bounds(  0,200,530,135), text("Freeze"), colour(45, 45, 55), fontcolour(255,100,100){
label    bounds(234,230, 80, 17), text("FREEZE"), fontcolour("LightBlue")
label    bounds(233,231, 80, 17), text("FREEZE"), fontcolour(105,105,255)
checkbox bounds(225,249, 80, 30), colour(115,115,255), channel("freeze"),  value(0)
rslider  bounds( 10,227, 60, 60), text("Port.Time"), channel("ManPtrPort"), range(0, 1.00, 0.5), trackercolour("red")
hslider  bounds( 10,280,510, 40), channel("ManPtr"), range(-1.00, 0, 0, 1, 0.001), trackercolour("red")
label    bounds(220,315,100, 13), text("Manual Pointer")
}

groupbox bounds(  0,335, 80,100), text("MIDI"), colour(30, 30, 40), fontcolour(255,100,100){
rslider  bounds( 10,365, 60, 60), text("Uni.Note"), channel("UniNote"), range(0, 127, 72,1,1), trackercolour("red")
keyboard bounds( 80,335,450,100)
}

image bounds( 5, 440, 215, 20), colour(75, 85, 90, 100), plant("credit"), line(0){
label bounds(0.03, 0.1, .9, .7), text("Author: Iain McCurdy |2012|"), colour("white")

</Cabbage>

<CsoundSynthesizer>

<CsOptions>
;-d -n
-dm0 -n -+rtmidi=null -M0
</CsOptions>

<CsInstruments>

sr 		= 	44100	;SAMPLE RATE
ksmps 		= 	32	;NUMBER OF AUDIO SAMPLES IN EACH CONTROL CYCLE
nchnls 		= 	2	;NUMBER OF CHANNELS (2=STEREO)
0dbfs		=	1
massign	0,2

gibuffer	ftgen	0, 0, 1048576, 2, 0	;Buffer table. Roughly 23 seconds duration.
gibufferR	ftgen	0, 0, 1048576, 2, 0	;right channel

;GRAIN ENVELOPE WINDOW FUNCTION TABLES:
giwfn1	ftgen	0,  0, 131072,  9,   .5, 1, 	0 				; HALF SINE
giwfn2	ftgen	0,  0, 131072,  7,    0, 3072,  1, 128000,     0		; PERCUSSIVE - STRAIGHT SEGMENTS
giwfn3	ftgen	0,  0, 131072,  5, .001, 3072,  1, 128000, 0.001		; PERCUSSIVE - EXPONENTIAL SEGMENTS
giwfn4	ftgen	0,  0, 131072,  7,    0, 1536,  1, 128000,     1, 1536, 0	; GATE - WITH ANTI-CLICK RAMP UP AND RAMP DOWN SEGMENTS
giwfn5	ftgen	0,  0, 131072,  7,    0, 128000,1, 3072,       0		; REVERSE PERCUSSIVE - STRAIGHT SEGMENTS
giwfn6	ftgen	0,  0, 131072,  5, .001, 128000,1, 3072,   0.001		; REVERSE PERCUSSIVE - EXPONENTIAL SEGMENTS

instr	1
	gkOnOff		chnget	"OnOff"
	ktrigger	trigger	gkOnOff,0.5,0
	schedkwhen	ktrigger,0,0,2,0,-1

	ginsamp		=	ftlen(gibuffer)-1			;index of the final sample in the function table

	gkamp		chnget	"amp"
	gkInGain	chnget	"InGain"
	gkmix		chnget	"mix"
	gkbalance	chnget	"balance"
	gkmonostereo	chnget	"monostereo"
	gkfback		chnget	"feedback"
	gkclip  	chnget	"clip"
	gkClipLev  	chnget	"ClipLev"
	gkCutoff	chnget	"Cutoff"
	gkpch		chnget	"pch"
	gkLPF_On  	chnget	"LPF_On"
	gkwsize		chnget	"wsize"
	gkrnd		chnget	"rnd"
	gkolap		chnget	"olaps"
	gkwfn		chnget	"wfn"
	gkdly		chnget	"dly"
	gkbeta		chnget	"beta"
	gkfreeze	chnget	"freeze"
	gkManPtrPort	chnget	"ManPtrPort"
	gkManPtr	chnget	"ManPtr"
	gkUniNote	chnget	"UniNote"

	ktrigger	trigger	gkfreeze,0.5,1				;if 'freeze' switch is turned off...
	if ktrigger==1 then						
	 chnset	1-ktrigger,"ManPtr"					;reset Manual Pointer slider to its default (maximum) position
	endif

	ain	inch	1						;read audio input from the left input channel
	ain	=	ain*gkInGain					;scale input signal according to 'In Gain' control position
		outch	1,ain*(1-gkmix)					;send some dry signal to output according to dry/wet 'Mix' control position
	gaFBackSig,gaFBackSigR	init	0				;audio feedback signal (initialised for first performance iteration)
	
	/*dc offset filter feedback signal*/
	aFBackSig	dcblock2	gaFBackSig			;filter dc offset from left channel feedback signal
	if gkmonostereo==3 then						;if 'stereo in' mode is active...
	 aFBackSigR	dcblock2	gaFBackSigR			;filter dc offset from right channel feedback signal
	endif
	
	/*lowpass filter feedback signal*/
	if gkLPF_On==1 then						;if lowpass filter button is on...
	 aFBackSig tone	aFBackSig,gkCutoff				;...filter left feedback channel
	 if gkmonostereo==3 then					;if 'stereo in' mode is active...
	  aFBackSigR tone	aFBackSigR,gkCutoff			;lowpass filter the right channel
	 endif
	endif

	/*clip feedback signal*/
	if gkclip==1 then						;if clip switch is on...
	 ktrig	changed	gkClipLev					;if clip level control is adjusted generate a trigger impulse (momentary '1')
	 if ktrig==1 then						;if a trigger impulse has been received...
	  reinit	UPDATE_CLIP_L					;reinitialise clip opcode (clip level is i-rate only)
	 endif
	 UPDATE_CLIP_L:
	 aFBackSig	clip	aFBackSig, 0, 0dbfs*i(gkClipLev)	;clip left feedback signal at maximum amplitude using bram de jong method
	 if gkmonostereo==3 then					;and if stereo in/out mode is also chosen
	  aFBackSigR	clip	aFBackSigR, 0, 0dbfs*i(gkClipLev)	;clip right channel feedback signal
	  rireturn
	 endif
	endif
	gaphsW	phasor	(sr*(1-gkfreeze))/ginsamp			;pointer 0 - 1	;create a moving phase value that will be used to point to locations in a function table where input audio signal will be written

	/*write audio from left input to function table*/
	if gkfreeze==0 then
		tablew	ain+aFBackSig,gaphsW,gibuffer,1			;write input audio to table
	endif
	
	/*if stereo in - stereo out mode*/
	if gkmonostereo==3 then						;if stereo in/out mode has been chosen...
	 aR	inch	2						;read right channel audio input
	 aR	=	aR*gkInGain					;rescale its amplitude with 'Input Gain' slider
	 if gkfreeze==0 then
		tablew	aR+aFBackSigR,gaphsW,gibufferR,1		;write right channel audio input audio to table
	 endif
		outch	2,aR*(1-gkmix)					;if 'stereo in' mode is selected, send some right channel dry signal to output according to dry/wet 'Mix' control position
	else
		outch	2,ain*(1-gkmix)					;otherwise not 'stereo in' mode so just send some left channel dry signal to output
	endif
		clear	gaFBackSig,gaFBackSigR				;clear feedback signals
endin

instr	2
	iMIDIActiveValue	=	1		;IF MIDI ACTIVATED
	iMIDIflag		=	0		;IF FLTK ACTIVATED
	mididefault	iMIDIActiveValue, iMIDIflag	;IF NOTE IS MIDI ACTIVATED REPLACE iMIDIflag WITH iMIDIActiveValue 
	kMIDIflag	init	iMIDIflag
	if gkOnOff==0&&iMIDIflag==0 then
	 turnoff
	endif

	if iMIDIflag==1 then
	 icps	cpsmidi
	 kpch	=	icps/cpsmidinn(gkUniNote)
	else
	 kpch		=	gkpch
	endif	
	
	kporttime	linseg	0,0.001,0.03				;portamento time. Rises quickly from zero to a held value.
	kpch		portk	kpch,kporttime				;Apply portamento smoothing to changes made to the pitch multiplier
	apch	interp	kpch						;interpolate pitch multiplier variable to create an a-rate version. This will produce higher quality results when pitch is modulated.
	
	kManPtr	portk	gkManPtr,kporttime*10*gkfreeze*gkManPtrPort

	ktrig	changed	gkwsize,gkrnd,gkolap,gkwfn			;if any of the list of input args. change, generate a trigger impulse (momentary '1'). The input args are all i-rate in sndwarp so reinitialisation will be required for their changes to register.
	if ktrig==1 then						;if a trigger hass been generated... 
	 reinit	UPDATE_SNDWARP						;... begin a reinitialisation pass from the given label
	endif
	UPDATE_SNDWARP:							;a label. Reinitialisation begins from here.
	imode	=	1						;sndwarp mode. (1=pointer mode, timestretch mode not so useful in a live audio in application)
	ibeg	=	0						;point in the function table from which to begin reading audio (0=beginning)
	iwsize	=	i(gkwsize)					;window (grain) size in samples
	irnd	=	i(gkrnd)					;window (grain) size randomisation bandwidth in samples
	iolap	=	i(gkolap)					;number of grain overlaps
	kRndDly	betarand	gkdly,1,gkbeta				;random grain delay time
	if gkmonostereo!=0 then
	 kRndDlyR	betarand	gkdly,1,gkbeta			;random grain delay time
	endif
	
	iMaxDur	=	(iwsize+irnd)/sr				;maximum grain duration in seconds
	kTransComp	limit	iMaxDur*(kpch-1),0,ginsamp/sr
	kdelay	=	(kTransComp+kRndDly) / (ginsamp/sr)		;delay time required when reading grains from the function table
	if gkmonostereo!=0 then
	 kdelayR	=	(kTransComp+kRndDlyR) / (ginsamp/sr)		;delay time required when reading grains from the function table
	endif
	if gkfreeze==1 then
	 kdelay		=	kdelay + (sr/(ginsamp)*1.75*iwsize/sr)	;if freeze mode is active regress the read pointer a small amount
	 if gkmonostereo!=0 then
	  kdelayR	=	kdelayR + (sr/(ginsamp)*1.75*iwsize/sr)	;if freeze mode is active regress the read pointer a small amount
	 endif
	endif
	aphsR	wrap	(gaphsW-kdelay+kManPtr)*(ginsamp/sr),0,(ginsamp-iwsize-irnd)/sr	;location from which to read grain. This is always directly related to the poistion of the write pointer.
	aphsR_R	wrap	(gaphsW-kdelayR+kManPtr)*(ginsamp/sr),0,(ginsamp-iwsize-irnd)/sr	;location from which to read grain. This is always directly related to the poistion of the write pointer.
	iwfn	=	giwfn1+i(gkwfn)-1					;Grain amplitude windowing shape
	
	/*sndwarp*/
	asig,ac	sndwarp 1, aphsR, apch, gibuffer, ibeg, iwsize, irnd, iolap, iwfn, imode
	if gkbalance==1 then							;if 'balance switch is on...
	 asig	balance	asig,ac							;... amplitude balance the signal
	endif
	if gkmonostereo==1 then							;if 'mono' mode seleced...
	 gaFBackSig	=	gaFBackSig+(asig*gkfback)			;create feedback signal for next iteration. (This will be written into the function table along with the live audio in.)
	 aR	=	asig
	elseif gkmonostereo==2 then						;or if 'stereo out' mode
	 aR,acR	sndwarp 1, aphsR_R, apch, gibuffer, ibeg, iwsize, irnd, iolap, iwfn, imode
	 if gkbalance==1 then
	  aR	balance	aR,acR
	 endif
	 gaFBackSig	=	gaFBackSig+((asig+aR)*gkfback)			;create feedback signal, a mixture of the left and right sndwarp output channels
	else									;otherwise 'stereo in/out' mode
	 aR,acR	sndwarp 1, aphsR_R, apch, gibufferR, ibeg, iwsize, irnd, iolap, iwfn, imode
	 if gkbalance==1 then
	  aR	balance	aR,acR
	 endif
	 gaFBackSig	=	gaFBackSig+(asig*gkfback)			;left channel feedback signal
	 gaFBackSig	=	gaFBackSig+(aR*gkfback)				;right channel feedback signal
	endif	
	rireturn								;return from reinitialisation
	aAntiClick	linsegr	0,0.03,1,0.03,0
		outs	asig*gkamp*gkmix*aAntiClick, aR*gkamp*gkmix*aAntiClick	;send audio to outputs
endin

instr	UpdateWidgets
	ksemis	chnget	"semis"			;read in 'semis' widget
	ktrig1	changed	ksemis			;if 'semis' knob is moved...
	if ktrig1==1 then			
	 chnset	semitone(ksemis), "pch"		;update 'Pitch' knob with the value of semis (converted to a ratio)
	endif
endin

</CsInstruments>

<CsScore>
i 1 0 [3600*24*7]
;i 2 0 [3600*24*7]
i "UpdateWidgets" 0 [3600*24*7]
</CsScore>


</CsoundSynthesizer>