- chuck-users - lists.cs.princeton.edu

constructing UGens by composition
by Graham Coleman 03 Oct '06

03 Oct '06

Object Orientaters, In languages like Java or ChucK, there are two OO ways to reuse code (besides copy-paste): by Inheritance: in this method, the class being defined is an elaborated version of the parent class (uses the extends command), like the way Orange is a special version of a Fruit by Composition: in this method, the class being defined is pieced together with instances of other classes, perhaps the way a Car class might be assembled with four instances of Wheel Now, if we wish to make a special version of a UGen by inheritance alone, we can already do this. By extending the UGen class you wish to use, you should be able to add or overwrite methods or variables. But what about composition? What if we wish to chain together several already useful into some compound effects object (for brevity's sake, perhaps)? public class StdFx extends UGen { //preconstructor PoleZero pz => NRev nrev => pan2 p; //dc filter - some STK synths need this pz.blockZero( 0.99 ); //no rev by default nrev.mix( 0.0 ); //random pan p.pan( std.rand2f( 0.1, 0.9 )); //omitted: controls for pan, rev, gain ... } This does the trick, basically. However, ChucK has no way of knowing that, to connect an object to StdFx, you connect its input to the PoleZero and the output from the pan2 into the output of this UGen. We must create a method to facilitate this: public void inOut( UGen in, UGen out ) { in => pz; p => out; } Which sort of breaks the flow in the calling program; sndbuf inst; StdFx stdfx; stdfx.inOut( inst, dac ); instead of just: snfbuf inst => StdFx stdfx => dac; So, to get the behavior we are going for in the language, it seems like the most direct way would be to specify an in and out reference for the correct UGens like so: public class StdFx extends UGen { //preconstructor PoleZero pz => NRev nrev => pan2 p; pz @=> this.in; p @=> this.out; //other stuff ... } So, will this kind of behavior be possible within the language as currently designed? I don't know. Most likely this behavior would stem from the implementation of Chuck_UGen::add( Chuck_UGen * src ) which is eventually executed by the VM on finding a => that resolves to a link operation. Offhand, we come up with two alternatives for producing this kind of behavior: 1. route link operations of a composite UGen in Chuck_UGen::add 2. some sample copying arrangement that would seem similar to linking So, what's the plan for supporting this? Graham

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how to set bufsize in miniaudicle
by vb 29 Sep '06

29 Sep '06

hello chuckers, just started looking into chuck and miniaudicle and already had a lot of fun playing with it. thanks a lot for making this available! i'm wondering how to set the bufsize when using miniaudicle (v. 0.1.3.6). using chuck in the terminal, i can do something like: chuck --bufsize512 myFile.ck how would i do this in miniaudicle? thanks, volker.

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heads up for 1.2.0.7
by Ge Wang 28 Sep '06

28 Sep '06

Greetings fellow ChucKists, Here is a (not so) quick summary/warning about upcoming changes in chuck-1.2.0.7, to be released probably next week. what it don't got: - garbage collection is still on a holding pattern and will not be in 1.2.0.7 - the long-overdue string operations, unfortunately, insist on waiting for garbage collection, and also will not in 1.2.0.7 - file i/o api's have been implemented (thanks to Martin Robinson), will be included soon but not in 1.2.0.7 Sorry about that. Now that we've apologized about what's not in the release, it's time to apologize about what is. Due to recent discussions on this list, two sets of changes and additions have been made. We want to preview them here to get feedback before setting them in concrete. API deprecations. Our discussion more or less determined that it's best to unify the naming scheming now before things get further out of hand, particularly for UGen names and such. So the current solution deprecates the object names in question and provides more consistent naming. By default, when a deprecated name, such as 'sinosc', is encountered, a warning will be issued, such as 'line(1): deprecated: 'sinosc' --> use: 'SinOsc''. The behavior should be otherwise unchanged. In other words the program should still work as before. We've also added a --deprecate flag that allows you to stop, warn, or ignore upon encountering a deprecated item. The default is 'warn'. Here are the objects deprecated so far, and their replacements: - (api) deprecated --> new classes -------------------------- sinosc --> SinOsc triosc --> TriOsc sqrosc --> SqrOsc sawosc --> SawOsc pulseosc --> PulseOsc phasor --> Phasor osc --> Osc noise --> Noise cnoise --> CNoise impulse --> Impulse step --> Step halfrect --> HalfRect fullrect --> FullRect gain --> Gain zerox --> ZeroX delayp --> DelayP sndbuf --> SndBuf pan2 --> Pan2 mix2 --> Mix2 onepole --> OnePole onezero --> OneZero polezero --> PoleZero twopole --> TwoPole twozero --> TwoZero biquad --> BiQuad std --> Std math --> Math machine --> Machine A few more UGen's. From another discussion on list, also by popular demand, it seems convenient to have out-of-the-box filters, in addition to general 1st and 2nd order filters (OnePole/Zero, BiQuad, etc.). We've examined and plundered from Csound, SC, and PD source code, and chuckified a few UGen's. We are going to do this in installments, adding various UGens every release. In 1.2.0.7, They include: LPF : lowpass filter (2nd order butterworth) (also with cutoff resonance control) HPF : highpass filter (2nd order butterworth) (also with cutoff resonance control) BPF : bandpass filter (2nd order butterworth) BRF : bandreject filter (2nd order butterworth) ResonZ : resonant filter (BiQuad with equal-gain zeros) FilterBasic : base class to above filters Of course, all of these can be designed and implemented using existing filters, but these provide direct access to cutoff and Q out-of-the-box and behave in a familiar um Butterworthy way. (More are on the way) We'd appreciate your feedback on these. For example: 1. api changes are in general, not reasons for group celebration. what can be done to further smooth the transition? 2. new naming optimal? 3. anything else Thanks! Best, chuck team

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A friendly note on joypad axes.
by Kassen 28 Sep '06

28 Sep '06

Hi list! Spencer and me figured out that with the new version of the HID object some axes changed name compared to the old version. At least number 3 is now called 5 and so there's probably (hopefully?) at least one more change. This will affect existing code so I thought it'd be nice to have it out in the open instead of leaving it to cause undocumented confusion. Not sure where stuff like that officially goes? Kas.

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irc://irc.freenode.net/#ChucK
by Tasmo 27 Sep '06

27 Sep '06

finally welcome to irc://irc.freenode.net/#ChucK tasmo

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list searching
by Tasmo 26 Sep '06

26 Sep '06

Is there any possebility to search the users list archive like through an online interface? Sometimes I wish to view entries only discuss a specific topic.

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Re: [chuck-users] How can I filter silence?
by Jim Hinds 25 Sep '06

25 Sep '06

Kas, Graham! Ya gotta love the way you think out of the box. Break the rules to make better ones! Thanks for the comments, code and inspiration. Jim ---"I dream of cheese, It's toasted, mostly" Ben Gunn, Treasure Island. On Sep 24, 2006, at 8:55 09PM, Graham Coleman <gc(a)gehennom.net> wrote: > > From: Graham Coleman <gc(a)gehennom.net> > Date: September 24, 2006 9:50:44 AM HST > To: ChucK Users Mailing List <chuck-users(a)lists.cs.princeton.edu> > Cc: jahbin(a)romatictrances.com > Subject: Re: [chuck-users] How can I filter silence? > Reply-To: ChucK Users Mailing List <chuck- > users(a)lists.cs.princeton.edu> > > > I came up with some cheesy code to implement the idea. > It speeds up the tape when it hits silence. You'll need to > tune the time constants and the threshold for best results: > > sndbuf buf => dac; > buf.read("speak/wave.wav"); > buf.pos( 0 ); > > 0.05 => float tresh; > 0.01 => float rt; //release const > 0.4 => float at; //attack const > float xd; > > while(true) { > > math.fabs( buf.last() )-xd => float a; //amp diff > if ( a < 0 ) 0=>a; //non-negative > xd*(1-rt)+at*a => xd; //the attack/release exponential filter > > if ( xd<tresh ) { > buf.pos( buf.pos()+6 ); //skip ahead > } > > 1::samp=>now; > } > > To compute the time constants, use this formula: > //AT = 1 - e ^ (-2.2T/t<AT) > > or this if t is in samples: > > time const = 1.0 - exp( -2.2 / t ); > > best, > > Graham > > On Sun, 24 Sep 2006, Graham Coleman wrote: > >> I'm not sure if there's anything in chuck that will currently do >> this, >> but I think you could write something like a noise gate, that >> tracks the >> amplitude of samples coming from a SndBuf and skips ahead until >> the level >> rises above a threshold. >> >> Not sure how well this would run in real time. >> >> Better, would be something that preprocesses the file with in/out >> points >> so the skips are quick. >> >> Graham >> >> On Sun, 24 Sep 2006, Jim Hinds wrote: >> >>> I want to scan some audio for dropped out sections. It's long and >>> talky with 'significant' pauses between question and answers. These >>> sections are filled with background noise, and often several seconds >>> long. I'd like to shorten these empty sections (there are a lot of >>> them). >>> >>> I'd like to keep the files more or less intact (not sliced up into a >>> zillion intermediate files) >>> >>> Is there a unit in chuck that will be able to delete samples as they >>> pass through? >>> >>> Jim >>> _______________________________________________ >>> chuck-users mailing list >>> chuck-users(a)lists.cs.princeton.edu >>> https://lists.cs.princeton.edu/mailman/listinfo/chuck-users >>> >> _______________________________________________ >> chuck-users mailing list >> chuck-users(a)lists.cs.princeton.edu >> https://lists.cs.princeton.edu/mailman/listinfo/chuck-users >> > > > > > From: Kassen <signal.automatique(a)gmail.com> > Date: September 24, 2006 10:23:58 AM HST > To: "ChucK Users Mailing List" <chuck-users(a)lists.cs.princeton.edu> > Subject: Re: [chuck-users] How can I filter silence? > Reply-To: ChucK Users Mailing List <chuck- > users(a)lists.cs.princeton.edu> > > > > > On 9/24/06, Graham Coleman <gc(a)gehennom.net> wrote: > I'm not sure if there's anything in chuck that will currently do this, > but I think you could write something like a noise gate, that > tracks the > amplitude of samples coming from a SndBuf and skips ahead until the > level > rises above a threshold. > > Not sure how well this would run in real time. > > Better, would be something that preprocesses the file with in/out > points > so the skips are quick. > > > But.... It doesn't look like it needs to be realtime. > > I'd think about playing the file once and storing the sample > locations where the volume drops below a treshold (as well as the > ones where it comes back) in a array, then playing it a second time > and skipping those sections while writing the results to a new > file. in "silent" mode this should be doable faster then realtime. > > You could also make a array of the length of the file (in samples) > and only write buf.last() => array[sample++] as long as it's over > the treshold. Once the buffer reaches it's end you'd playback the > array again and record that, taking care to stop after the highest > value that "sample" got to in the first pass. This would be CPU > intesive but it's quite clean as a method, I think. > > It all stands or falls with the quality of the envelope follower. > > I've been thinking about doing something similar to the first > option and pre-scanning wavefiles for positive zero-crossings and > storing those in a array. This would take extra time when loading a > file but from then on you could do very clean loops, for example to > loop just a few cycles. I wonder how samplers that have a "snap to > zero crossings" setting do this. It might still be quite tricky > because not all samplers that do this do it all that well.... > > Hope that's of some use. > Kas. >

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##ChucK @ freenode
by Tasmo 25 Sep '06

25 Sep '06

Even though the mailinglist is a good place for the ChucK coders comunity I thought about a live conversation. So I want to announce the unofficial ##Chuck channel at the freenode network: irc://irc.freenode.net/##ChucK You're very welcome to join and chat! The double ## means at freenode this is not a primary group channel (yet). http://freenode.net/policy.shtml#topicalchannels Tasmo

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How can I filter silence?
by Jim Hinds 24 Sep '06

24 Sep '06

I want to scan some audio for dropped out sections. It's long and talky with 'significant' pauses between question and answers. These sections are filled with background noise, and often several seconds long. I'd like to shorten these empty sections (there are a lot of them). I'd like to keep the files more or less intact (not sliced up into a zillion intermediate files) Is there a unit in chuck that will be able to delete samples as they pass through? Jim

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global UGen effects processing
by Graham Coleman 24 Sep '06

24 Sep '06

Chuck architects, In some cases, you may wish to filter sounds originating in several shreds. For example, dynamics processing, or just to provide a dramatic effect. I attempted to do this using a global HPF defined as a static variable, but it doesn't quite work the way it seems it should. I also figured out how to make it work as expected. The class in superfilt.ck: public class SuperFilt { static HPF @ highPass; } new HPF @=> SuperFilt.highPass; //instantiate SuperFilt.highPass => dac; //connect to dac The test class, superfilt-test.ck: StifKarp inst => SuperFilt.highPass; //connect to filter SuperFilt.highPass.gain( 0.4 ); SuperFilt.highPass.freq( 1000 ); while ( true ) { std.mtof(std.rand2(10,70))=>inst.freq; //random note inst.noteOn( 0.5 ); 200::ms => now; } As I was writing this post, I figured out how to fix it. Connect the filter to the dac in the instrument shred: StifKarp inst => SuperFilt.highPass => dac; //connect to filter & dac And things seem to work fine. But wierd. Maybe the ticking or copying is per-shred? best, Graham

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