VSynth effects

[Simon ArmstrongParticipant]

Early days but the new effects section in my VSynth arpeggiator project are turning out to be a lot of fun.

Save to wav is now working (24 bit only) , uploaded sample output here.

The reverb implementation is too slow for Debug so not quite ready for prime time.

Monkey

Class Distortion Implements Effect Const DistortionControls:=New String[]("Overdrive","Gain") Method ControlNames:String[]() Return DistortionControls End Method EffectAudio(samples:V Ptr,sampleCount:Int,control:V[][]) Local overdrive:=control[0] Local gain:=control[1] For Local s:=0 Until sampleCount*2 Local i:=s/2 Local v:=samples[s] v*=overdrive[i] If v>0 v=1-Exp(-v) Else v=-1+Exp(v) Endif v*=gain[i] samples[s]=v Next End End Class Reverb Implements Effect Const Controls:=New String[]("Wet","Dry","Effect") Struct Pole Field distance:M Field dampen:V Method New(meters:M,gain:V) distance=meters dampen=gain End End Field poles:=New List<Pole> Field future:V[] Field removeSource:=True Method New() poles.Add(New Pole(510,0.5)) End Method ControlNames:String[]() Return Controls End Method EffectAudio(samples:V Ptr,sampleCount:Int,control:V[][]) Local wetness:=control[0] Local dryness:=control[1] Local falloff:=control[2] Local n1:=math.Min(future.Length,sampleCount*2) For Local i:=0 Until n1 samples[i]+=future[i]*falloff[i/2] Next For Local pole:=Eachin poles Local seconds:=pole.distance/SpeedOfSound Local offset:=Int(AudioFrequency*seconds) Local maxOffset:Int=(sampleCount+offset)*2 If future.Length<maxOffset future=future.Resize(maxOffset) Local dampen:=pole.dampen For Local i:=0 Until sampleCount Local l:=samples[i*2+0] Local r:=samples[i*2+1] future[(offset+i)*2+0]+=l*dampen future[(offset+i)*2+1]+=r*dampen Next Next Local n2:=math.Min(future.Length,sampleCount*2) For Local i:=0 Until n2 Local wet:=wetness[i/2] Local dry:=dryness[i/2] samples[i]=wet*future[i]+dry*(samples[i]-future[i]) Next future=future.Slice(sampleCount*2) End End

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Class Distortion Implements Effect Const DistortionControls:=New String[]("Overdrive","Gain") Method ControlNames:String[]() Return DistortionControls End Method EffectAudio(samples:V Ptr,sampleCount:Int,control:V[][]) Local overdrive:=control[0] Local gain:=control[1] For Local s:=0 Until sampleCount*2 Local i:=s/2 Local v:=samples[s] v*=overdrive[i] If v>0 v=1-Exp(-v) Else v=-1+Exp(v) Endif v*=gain[i] samples[s]=v Next End End   Class Reverb Implements Effect Const Controls:=New String[]("Wet","Dry","Effect")   Struct Pole Field distance:M Field dampen:V Method New(meters:M,gain:V) distance=meters dampen=gain End End Field poles:=New List<Pole> Field future:V[] Field removeSource:=True Method New() poles.Add(New Pole(510,0.5)) End Method ControlNames:String[]() Return Controls End Method EffectAudio(samples:V Ptr,sampleCount:Int,control:V[][])   Local wetness:=control[0] Local dryness:=control[1] Local falloff:=control[2] Local n1:=math.Min(future.Length,sampleCount*2) For Local i:=0 Until n1 samples[i]+=future[i]*falloff[i/2] Next   For Local pole:=Eachin poles Local seconds:=pole.distance/SpeedOfSound Local offset:=Int(AudioFrequency*seconds) Local maxOffset:Int=(sampleCount+offset)*2 If future.Length<maxOffset future=future.Resize(maxOffset) Local dampen:=pole.dampen For Local i:=0 Until sampleCount Local l:=samples[i*2+0] Local r:=samples[i*2+1] future[(offset+i)*2+0]+=l*dampen future[(offset+i)*2+1]+=r*dampen Next Next   Local n2:=math.Min(future.Length,sampleCount*2) For Local i:=0 Until n2 Local wet:=wetness[i/2] Local dry:=dryness[i/2] samples[i]=wet*future[i]+dry*(samples[i]-future[i]) Next future=future.Slice(sampleCount*2) End End

[AdamStrangeParticipant]

You might want to think about effects busses.

in essence. you have a buss – which is a buffer the same size as the output.

for each ‘sound’ you have a float from 0 to 1 for each bus.

at 0 the ‘sound’ will not go to the buss, at 1 it will be full volume to the bus. so you have a volume that sets the amount gong to the bus.

 

For each buffer loop. (once filled) you will have some audio in the bus buffer. You then just do your effect on this buffer.

 

The result is the output buffer plus the effect bus buffer

[Simon ArmstrongParticipant]

Thanks Adam, I can see the reason for bussing when multiple instruments are involved but not too clear on any benefit to what I suppose I would classify as a standalone synth project.

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