February 2009 - chuck-users - lists.cs.princeton.edu

dur frame?
by Kassen 17 Feb '09

17 Feb '09

Fellow ChucKists, suppose we have a stream of data coming in over HID (or MIDI or whatever). Suppose we wish to have something done based on the data that came in over the last frame and we want to make sure this gets done before the next frame starts and hence before any new data could come in. This would be useful to create smooth transitions based on HID data at the expense of lagging one frame. How would we go about this? I don't think we can without introducing "magic numbers" based on our settings. I'd like to propose the introduction of a duration named "frame" of a length of a "n::samp" where n is the size of a single frame in samples. Yours, Kas.

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Timing with ChucK
by rkramer 17 Feb '09

17 Feb '09

Being a relative non-programmer, I'm not quite sure if this is even possible... My goal is a quick and dirty program that will measure the time between two large audio events (in the input sound buffer, live recording.) Essentially what I want to do is use ChucK for practical demonstrations of simple physics... IE demonstrating average velocity of a falling object (that generates a sufficiently loud event when it is released and when it hits the floor.) Any tips where to start on this project? Ryan

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ChubbY (ChucK in Ruby)?
by Robert Poor 13 Feb '09

13 Feb '09

Has anyone considered of implementing all the wonderful functionality of ChucK in Ruby? I'm not trying to start a fight or ruffle feathers -- it's an honest question. I love ChucK for all of its functionality -- it has a full house of great unit generators and signal processing objects coupled with an easy-to-use thread / scheduling mechanism. But for all that, I find ChucK the language lacking. For example, when I really push on defining classes, I can't do all the things I'm used to. Might not a marriage of ChucK's rich functionality with Ruby's rich language be nearly ideal? At the very least, we'd get Mr. Bowkett to -- in Yoda's words -- TFSU. - Rob

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Re: [chuck-users] determining the type of an Object in code
by mike clemow 12 Feb '09

12 Feb '09

Hello, fellow Chuckers! I keep finding myself returning to this issue of trying to determine the class of an object instance at runtime. We talked about it here: https://lists.cs.princeton.edu/pipermail/chuck-users/2008-September/003242.… I recently pulled from CVS and started fooling around and discovered a remarkably simple hack. There's a method in Object, toString(), which returns a string containing the class of the object as well as the reference ID. Like this (supposing a class called "Test"): "Test:11ceff0" There's also a stub in chuck_lang.cpp for a method getType(), which isn't implemented (yet). So, I copied the implementation of toString(), minus the printing of the reference ID, and placed it where the implementation of getType() should be. Now all objects (not UGens yet, although that would be sweet) respond to getType(). Example: class Test { 5 => int i; fun void sayHi() { <<< "hi" >>>; } } Test test; test @=> Object o; // Object still knows it's a Test! <<< o.toString() >>>; <<< o.getType() >>>; // Object can't sayHi() //o.sayHi(); // but this is now possible if( o.getType() == "Test" ) { (o $ Test).sayHi(); } The above code will print this: "Test:11cf160" : (string) "Test" : (string) "hi" : (string) This makes me very happy and opens up many doors, although I have no idea what getType() was originally intended to do--I assume a similar purpose. I'm sure that this will work as a mod to the current release as well, although I made my changes in the CVS version (I'm excited for FileIO). This ought to make implementing things like ArrayList a lot easier. ;-) I consider this a feature request (for this or something like it). I think this would be super helpful for UGens and primitives also. Primitives, however, don't support the dot notation... Oh well. I'll take what I can get. -Mike -- http://michaelclemow.com http://semiotech.org

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cheap parallel ChucKing
by Graham Percival 10 Feb '09

10 Feb '09

Hi all, We're using ChucK as a cheap synthesizer for a bunch of new electronic instruments. To make best use of the dual-core CPU, we're launching ChucK in two separate threads: $ chuck first-server.ck & $ chuck second-server.ck This works great (it almost maxes out both cores on a mac mini), although the second instance of chuck complains that it can't bind to port 8888. Are there any potential pitfalls to this method? I know that we can't (easily[1]) get any communication between these two chuck instances, but in this case we don't need it -- each instrument's synthesis is completely independant of the other one. In CS terms, this problem is "embarrasingly parallel". :) [1] we could add code to our OSC servers to send messages back and forth via loopback, which isn't precisely "hard", but it's not as easy as everything else we do in ChucK -- this language is awesome. :) Cheers, - Graham Percival

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Fresh bug
by Kassen 10 Feb '09

10 Feb '09

Get it while it's hot! int count; 3 %=> count++; //or 3 %=> ++count; Whether such constructions should be used at all is of course debatable and we do have this; ++count%3 => count; ....which does work but the above examples shouldn't lead to VM-collapses, which they do. Yours, Kas.

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Newbie - chuck segfaults...
by Mark Knecht 09 Feb '09

09 Feb '09

I've been trying to get started with Chuck today but am having problems. My platform is Gentoo 64-bit. I've tried compiling chuck with both Alsa and Jack support and am having some trouble with each. I have two cound cards in the system. The first is onboard and I normally use for system sounds, browsers, etc. The second is the HDSP which I normally use with Jack: mark@lightning ~/Desktop $ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: CK804 [NVidia CK804], device 0: Intel ICH [NVidia CK804] Subdevices: 0/1 Subdevice #0: subdevice #0 card 0: CK804 [NVidia CK804], device 2: Intel ICH - IEC958 [NVidia CK804 - IEC958] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: DSP [Hammerfall DSP], device 0: RME Hammerfall HDSP 9652 [RME Hammerfall HDSP 9652] Subdevices: 0/1 Subdevice #0: subdevice #0 mark@lightning ~/Desktop $ I can play audio through the first card using aplay, as I do here: aplay /home/mark/Desktop/My\ Data/Music/Painting\ After\ Hours/AFTERHOURS\ EDM\ pahPROMO\ 01.wav Using Alsa chuck seems to be unhappy with my first sound card. Same results using 44.1K or 48K: mark@lightning ~/Desktop $ chuck.alsa --srate44100 ChuckExample1.ck [chuck]: (via rtaudio): no devices found for given stream parameters: ... RtApiAlsa: pcm device (hw:CK804,0) won't open: Device or resource busy. ... RtApiAlsa: pcm device (hw:CK804,1) won't open: No such file or directory. ... RtApiAlsa: error setting sample rate (44100) on device (hw:CK804,2): Invalid argument. ... RtApiAlsa: pcm capture open (hw:DSP,0) error: Device or resource busy. [chuck]: cannot initialize audio device (try using --silent/-s) mark@lightning ~/Desktop $ I don't see how the device is busy in the sense that I have no problem playing audio through it with aplay. When I try to use chuck with the second card I see the segfault. Jack is running at 44.1K: mark@lightning ~/Desktop $ chuck.jack --srate44100 ChuckExample1.ck Segmentation fault mark@lightning ~/Desktop $ chuck.jack --srate44100 ChuckExample1.ck --verbose [chuck]:(2:SYSTEM): setting log level to: 5 (INFORM)... [chuck]:(2:SYSTEM): initializing virtual machine... [chuck]:(2:SYSTEM): | behavior: HALT [chuck]:(2:SYSTEM): | locking down special objects... [chuck]:(2:SYSTEM): | allocating shreduler... [chuck]:(2:SYSTEM): | allocating messaging buffers... [chuck]:(2:SYSTEM): | real-time audio: YES [chuck]:(2:SYSTEM): | mode: CALLBACK [chuck]:(2:SYSTEM): | sample rate: 44100 [chuck]:(2:SYSTEM): | buffer size: 512 [chuck]:(2:SYSTEM): | num buffers: 8 [chuck]:(2:SYSTEM): | devices adc: 0 dac: 0 (default 0) [chuck]:(2:SYSTEM): | channels in: 2 out: 2 [chuck]:(2:SYSTEM): initializing compiler... [chuck]:(3:SEVERE): | initializing type checker... [chuck]:(3:SEVERE): | | adding base classes... [chuck]:(3:SEVERE): | | | class 'object' [chuck]:(3:SEVERE): | | | class 'array' [chuck]:(3:SEVERE): | | | class 'string' [chuck]:(3:SEVERE): | | | class 'ugen' [chuck]:(3:SEVERE): | | | class 'uanablob' [chuck]:(3:SEVERE): | | | class 'uana' [chuck]:(3:SEVERE): | | | class 'shred' [chuck]:(3:SEVERE): | | | class 'event' [chuck]:(3:SEVERE): | | | class 'io' [chuck]:(3:SEVERE): | | | class 'class' [chuck]:(3:SEVERE): | initializing emitter... [chuck]:(3:SEVERE): | loading built-in modules... [chuck]:(3:SEVERE): | | module osc... [chuck]:(3:SEVERE): | | module xxx... [chuck]:(3:SEVERE): | | module filter... [chuck]:(3:SEVERE): | | module STK... [chuck]:(3:SEVERE): | | module xform... [chuck]:(3:SEVERE): | | module extract... [chuck]:(3:SEVERE): | | class 'machine'... [chuck]:(3:SEVERE): | | class 'std'... [chuck]:(5:INFORM): | | initializing KBHitManager... [chuck]:(5:INFORM): | | starting kb loop... [chuck]:(3:SEVERE): | | class 'math'... [chuck]:(3:SEVERE): | | class 'opsc'... [chuck]:(2:SYSTEM): type dependency resolution: MANUAL [chuck]:(2:SYSTEM): initializing synthesis engine... [chuck]:(3:SEVERE): | initializing 'dac'... [chuck]:(3:SEVERE): | initializing 'adc'... [chuck]:(3:SEVERE): | initializing 'blackhole'... [chuck]:(2:SYSTEM): | initializing 'real-time' audio... [chuck]:(5:INFORM): | | initializing callback... [chuck]:(3:SEVERE): | | new buffer size: 512 -> 256 [chuck]:(3:SEVERE): | allocating buffers for 256 x 2 samples... [chuck]:(3:SEVERE): starting compilation... [chuck]:(2:SYSTEM): starting listener on port: 8888... [chuck]:(2:SYSTEM): running virtual machine... [chuck]:(3:SEVERE): | initializing audio buffers... [chuck]:(3:SEVERE): | virtual machine running... Segmentation fault mark@lightning ~/Desktop $ I hope this is just me making some small mistake. Thanks in advance. Cheers, Mark

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How can a non-programmer start to make use of Chuck?
by Mark Knecht 08 Feb '09

08 Feb '09

Hi all, I've been thinking for a while that I'd like to try out a tool like Chuck. I'm on an AMD64 Gentoo platform it seems that Chuck is my best bet. I've started scanning the chuck-users list to get familiar with what sort of discussions happen here - and they are interesting - but as I am more of musician than a programmer I'm wondering how I might attempt to get to know Chuck better? To start exploring I've built Chuck-1.2.1.2 from portage and am building miniaudicle now. Neither has yet made a sound. I *think* (but am not sure) that I'd like my first exploration to be in the area of using Chuck to create rythmic patterns of sort of a break-beat nature using noise generators and filters as the sound source. This is not something I'm set up to do with any of my other tools in Linux or Windows so if I was successful it would add another tool to my tool box. I'm wondering whether more experienced folks: 1) Think this is a reasonable goal? and 2) Might have suggestions about how I'd get started? Thanks in advance for any comments and ideas. Cheers, Mark

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emulating UGen connections in own classes
by Atte André Jensen 07 Feb '09

07 Feb '09

Hi We can do: SndBuf s => dac; Is it possible to write my own class, MySndBuf and make the following possible, and if so, how?: MySndBuf s => dac; I know I've asked this before (and it wasn't possible, IIRC), so basically I'm wondering if things have changed with the latest release? -- Atte http://atte.dk http://modlys.dk

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sample player class
by Atte André Jensen 07 Feb '09

07 Feb '09

Hi I've written a sampler class that simplifies various things, that I found I have to re-invent over and over again: * Polyphony, with dynamic voice allocation (stealing of oldest note) * Optional envelope * Automatic handling of stereo samples * Supports multi-samples (zones) I tried to make it easy to use and flexible enough to work with simple one-shot drums and polyphonic, multi-sampled, enveloped samples (strings, piano, etc). I'm gonna add build-in midi support + support for more code like length based triggering. Have anyone done something similar? Any interest in me posting it on http://wiki.cs.princeton.edu/index.php/Chuck/Lib when it's more thoroughly tested? -- Atte http://atte.dk http://modlys.dk

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