There is also s_pinknoise in rjlib which uses rpole filters. Not sure how accurate it is, but then again, I’ve never really needed that much accuracy for what I do :)
Dan Wilcox @danomatika https://twitter.com/danomatika danomatika.com http://danomatika.com/ robotcowboy.com http://robotcowboy.com/
On Nov 14, 2015, at 2:38 PM, pd-list-request@lists.iem.at wrote:
From: Alexandre Torres Porres <porres@gmail.com mailto:porres@gmail.com> Date: November 14, 2015 at 2:09:54 PM MST To: Matt Barber <brbrofsvl@gmail.com mailto:brbrofsvl@gmail.com> Cc: "pd-list@lists.iem.at mailto:pd-list@lists.iem.at" <pd-list@lists.iem.at mailto:pd-list@lists.iem.at> Subject: Re: [PD] brown/grey noise in pd
was looking for a substitute/parallel object to BrownNoise in Sc, which is described just as "Generates noise whose spectrum falls off in power by 6 dB per octave."
Another one would be GreyNoise, described as "Generates noise which results from flipping random bits in a word. This type of noise has a high RMS level relative to its peak to peak level. The spectrum is emphasized towards lower frequencies."
thanks
The nice thing about supercollider is that you have the code available, so you can try to replicate it. See code and attached patches below. Looks like SC's GrayNoise is not about color but rather generates something akin to a random Gray code. https://en.wikipedia.org/wiki/Gray_code
void BrownNoise_next(BrownNoise *unit, int inNumSamples) { float *out = ZOUT(0); RGET f loat z = unit->mLevel; LOOP1(inNumSamples, z += frand8(s1, s2, s3); // random sample between -0.125 and +0.124999
if (z > 1.f) z = 2.f - z; else if (z < -1.f) z = -2.f - z; ZXP(out) = z; ); unit->mLevel = z; RPUT }
void BrownNoise_Ctor(BrownNoise* unit) { SETCALC(BrownNoise_next); unit->mLevel = unit->mParent->mRGen->frand2(); ZOUT0(0) = unit->mLevel; }
On Sat, Nov 14, 2015 at 4:53 PM, Dan Wilcox danomatika@gmail.com wrote:
There is also s_pinknoise in rjlib which uses rpole filters. Not sure how accurate it is, but then again, I’ve never really needed that much accuracy for what I do :)
Dan Wilcox @danomatika https://twitter.com/danomatika danomatika.com robotcowboy.com
On Nov 14, 2015, at 2:38 PM, pd-list-request@lists.iem.at wrote:
*From: *Alexandre Torres Porres porres@gmail.com *Date: *November 14, 2015 at 2:09:54 PM MST *To: *Matt Barber brbrofsvl@gmail.com *Cc: *"pd-list@lists.iem.at" pd-list@lists.iem.at *Subject: **Re: [PD] brown/grey noise in pd*
was looking for a substitute/parallel object to BrownNoise in Sc, which is described just as "Generates noise whose spectrum falls off in power by 6 dB per octave."
Another one would be GreyNoise, described as "Generates noise which results from flipping random bits in a word. This type of noise has a high RMS level relative to its peak to peak level. The spectrum is emphasized towards lower frequencies."
thanks
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Here's GrayNoise. SC's version flips random bits of a 32-bit integer and then outputs the result. Since we don't have 32-bit integers in Pd, it has to be done with 24 bits. No matter, though, because the range between -1 and +1 has what, 25-bit resolution? So not much difference.
Source:
void GrayNoise_next(GrayNoise *unit, int inNumSamples) { float *out = ZOUT(0); RGET int counter = unit->mCounter; LOOP1(inNumSamples, counter ^= 1L << (trand(s1,s2,s3) & 31); ZXP(out) = counter * 4.65661287308e-10f; ); unit->mCounter = counter; RPUT }
void GrayNoise_Ctor(GrayNoise* unit) { SETCALC(GrayNoise_next); unit->mCounter = 0; GrayNoise_next(unit, 1); }
On Sat, Nov 14, 2015 at 6:15 PM, Matt Barber brbrofsvl@gmail.com wrote:
The nice thing about supercollider is that you have the code available, so you can try to replicate it. See code and attached patches below. Looks like SC's GrayNoise is not about color but rather generates something akin to a random Gray code. https://en.wikipedia.org/wiki/Gray_code
void BrownNoise_next(BrownNoise *unit, int inNumSamples) { float *out = ZOUT(0); RGET f loat z = unit->mLevel; LOOP1(inNumSamples, z += frand8(s1, s2, s3); // random sample between -0.125 and +0.124999
if (z > 1.f) z = 2.f - z; else if (z < -1.f) z = -2.f - z; ZXP(out) = z; ); unit->mLevel = z; RPUT }
void BrownNoise_Ctor(BrownNoise* unit) { SETCALC(BrownNoise_next); unit->mLevel = unit->mParent->mRGen->frand2(); ZOUT0(0) = unit->mLevel; }
On Sat, Nov 14, 2015 at 4:53 PM, Dan Wilcox danomatika@gmail.com wrote:
There is also s_pinknoise in rjlib which uses rpole filters. Not sure how accurate it is, but then again, I’ve never really needed that much accuracy for what I do :)
Dan Wilcox @danomatika https://twitter.com/danomatika danomatika.com robotcowboy.com
On Nov 14, 2015, at 2:38 PM, pd-list-request@lists.iem.at wrote:
*From: *Alexandre Torres Porres porres@gmail.com *Date: *November 14, 2015 at 2:09:54 PM MST *To: *Matt Barber brbrofsvl@gmail.com *Cc: *"pd-list@lists.iem.at" pd-list@lists.iem.at *Subject: **Re: [PD] brown/grey noise in pd*
was looking for a substitute/parallel object to BrownNoise in Sc, which is described just as "Generates noise whose spectrum falls off in power by 6 dB per octave."
Another one would be GreyNoise, described as "Generates noise which results from flipping random bits in a word. This type of noise has a high RMS level relative to its peak to peak level. The spectrum is emphasized towards lower frequencies."
thanks
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
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