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

variables and memory
by Bozelos Dimitris 20 Apr '09

20 Apr '09

Hi all, as i've read in the documentation or maybe in some email in this list, ChucK lacks garbage collector. If my understanding is correct this means that it does not automatically free the memory that any variable needs after getting out of its scope. So this probably mean that if I run a loop that declares a variables like for( int i = 0; i < 100; i++; ) { int var1; float var2[10]; // do things } and have this code called many times inside an infinite loop and do other stuff in other shreds, after a while it's inevitable to run into problems. Is this correct? Is there anything like c++'s delete to free memory? Dimitris ___________________________________________________________ Χρησιμοποιείτε Yahoo!; Βαρεθήκατε τα ενοχλητικά μηνύματα (spam); Το Yahoo! Mail διαθέτει την καλύτερη δυνατή προστασία κατά των ενοχλητικών μηνυμάτων http://login.yahoo.com/config/mail?.intl=gr

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segmentation fault / OSC
by Bozelos Dimitris 04 Apr '09

04 Apr '09

Hi again guys, I've run into some more problems in my brief acquaintance with ChucK (although it's definitely fun!). For some reason I constantly get a "segmentation fault" fatal error sometimes just after some seconds I run my shreds. What does this mean? I do something that might be silly, I send/receive parameters between shreds using OscEvents, can this cause the problem? Is there another way of communicating (exchanging control signals in this case) between processes? Once or twice I had an "OSC packet ...: buffer (or stack) overflow" error. Is there a buffer or a limit on the messages you send / receive? Can I somehow declare global variables? I checked the documentation and I didn't find anything. If the problem is because of excessive use of OSC I could maybe read/write global variables. Cheers, Dimitri ___________________________________________________________ Χρησιμοποιείτε Yahoo!; Βαρεθήκατε τα ενοχλητικά μηνύματα (spam); Το Yahoo! Mail διαθέτει την καλύτερη δυνατή προστασία κατά των ενοχλητικών μηνυμάτων http://login.yahoo.com/config/mail?.intl=gr

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assigning Gen7 coefs
by Gregory Brown 30 Mar '09

30 Mar '09

Hello all, I am trying to use Gen7 for the first time and I am running into trouble assigning the coefficients. The file shown in Example 2 works fine, but Example 1 generates no sound and the lookup gives only NaN. The difference between the two examples is in how I create the coefs array, although I don't see how this affects the outcome. Can someone help me understand what the difference is and why one might work while the other does not? Thanks, - Greg //+_+_+_+_+_+_+_+_+_+_+_+_+_++_++_+++_+_+ // Example 1 //+_+_+_+_+_+_+_+_+_+_+_+_+_++_++_+++_+_+ // setup Phasor driver => Gen7 g7 => dac; 220 => driver.freq; // declare array for coefs 5 => float num_values; float coefs[ ((num_values$int)*2) - 1]; // insert random values into every even index for ( 0 => int i; i < num_values ; i++ ) { Std.rand2f(0,1) => coefs[i*2]; } // insert time values into every odd index for ( 1 => int i; i < num_values ; i++ ) { 1 / num_values => coefs[(i*2)-1]; } // print it out for ( 0 => int i; i < coefs.cap() ; i++ ) { <<< "coefs[",i,"]: ", coefs[i] >>>; } // assign the table coefs => g7.coefs; // do a lookup <<< g7.lookup(.5) >>>; // loop while (true) { 100::ms => now; } // +_+_+_+_+_+_+_+_+_+_+_+_+_++_++_+++_+_+ // Example 2 //+_+_+_+_+_+_+_+_+_+_+_+_+_++_++_+++_+_+ // setup Phasor driver => Gen7 g7 => dac; 220 => driver.freq; // declare array for coefs 5 => float num_values; float coefs[ ((num_values$int)*2) - 1]; // directly assign floats to array [0.709912 , 0.200000 , 0.496574 , 0.200000 , 0.911184 , 0.200000 , 0.270048 , 0.200000 , 0.701863] @=> coefs; // print it out for ( 0 => int i; i < coefs.cap() ; i++ ) { <<< "coefs[",i,"]: ", coefs[i] >>>; } // assign the table coefs => g7.coefs; // do a lookup <<< g7.lookup(.5) >>>; // loop while (true) { 100::ms => now; }

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ChucK Internet Radio Broadcast
by Les Hall 28 Mar '09

28 Mar '09

Yesterday (Friday March 27, 2009) we enjoyed the first ChucK internet streaming broadcast on electro-music.com. Kassen was there in the chatroom and he had a fun exchange with my friend Carroll who was here in my studio for the broadcast. I think they were talking about her fingernails for some reason. Whatever. All had a blast! There was a tiny bit of dead air, but for the most part things went well. I played some of kijjaz's stuff and some of mine as well. We improvised and I coined the phrase "Jack Noise!", referring to the sound that my puter makes when I unplug or replug the jack to switch from ChucK to mic or revverse. All in all things went well and I invite you to next week's show on Friday at 23:00 to 00:00 GMT. Be there or be square! Les (Inventor)

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first video from live ChucK gig w/ modlys
by Atte André Jensen 27 Mar '09

27 Mar '09

Hi A couple of weeks ago I announced a gig with my electronic project, modlys. One of the audience recorded a couple of tracks on his mobile, and the first one is here: http://modlys.dk/video/fodspor_vcd.mp4 Only audio software running is chuck under linux. -- Atte http://atte.dk http://modlys.dk

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EChucK Forum and Progress Update
by Les Hall 25 Mar '09

25 Mar '09

Hello ChucKists! I'd like to announce that we just created an EChucK forum right next to the ChucK forum on www.electro-music.com. I was really surprised and happy with this especially since the project is still in its infancy. Some updates: I bought a netbook running XP (love it!), which now enables me to run the microchip MPLAB IDE so I can now write code for the EChucK dsPIC chips. After extensive learning curve of a few days I was able to write a simple little program that generates a square wave. I still don't have chips or a programmer, but that will happen in time. I also finally figured out how to cut up the EChucK circuit boards that I've had for months now into the little bitty boards that are the basis of EChucK. I used a Dremel tool with a diamond cutting wheel in a rickety drill press stand and thus created a very crude sort of horizontal PCB table saw. It worked pretty well, though some of the cuts were a little too close. I cut one board up for experimentation and left the other three intact. Also on the www.justinguitar.com forum, the other day I was mentioning EChucK and the possibility of doing guitar synth stuff with it. It turns out that one of the moderators there is looking for that "Matt Belamy of Muse" guitar sound and wants me to make us both a little mini guitar pedal. We decided to code up a test file in ChucK first, which I did with AGC followed by soft distortion to get something like the sound that he wanted. So it looks like after the square wave program, the first real application of EChucK will be to implement a ChucK program for guitar synth. That's about it for now. Please feel free to stop by the EChucK forum or view the EChucK web page at www.freedomodds.com/music/echuck/ . Les (Inventor)

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two patches
by Atte André Jensen 23 Mar '09

23 Mar '09

Hi I'm not sure posting patches here is the right thing to do, maybe I should put them elsewhere? At least I'm hoping this could be fixed in this years release! The first allows 2 byte midi messages, for instance allowing program change to be send from chuck. The second allows --channels>2 (also --in and --out) with jack + makes chuck *not* connect its jack ports. Without this --channels3 (or greater) doesn't work for me. Both are simply disabling some checks or code that IMHO are too strict. The first have been running flawlessly for over a year. The second seems to work just fine with some quick testing. Of course any feedback/discussion from users regarding the behavior would be interesting. -- Atte http://atte.dk http://modlys.dk

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stereo buffer?
by Matt Diamond 20 Mar '09

20 Mar '09

Thanks for the responses to my previous question... my little glitch sequencer project is coming along quite well now. Just a quick question: Is it true that LiSa has absolutely no way to connect individual voice inputs/outputs as part of the signal chain? I wanted to use LiSa as a stereo buffer, and I assumed that the multiple voices would make it easy to assign the left channel to voice 1 and the right to voice 2, but if I can't connect them to separate adc/dac channels, then I guess it's impossible. Should I just create my own stereo buffer class that contains two separate LiSa objects? - Matt

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Congrats to Ge
by Mark Knecht 19 Mar '09

19 Mar '09

for getting his picture in the Mercury News Tech section today playing a wind instrument created with the iPhone. (At least I think it's our own Ge Wang!) :-) Looks like fun. Maybe I'll have to get an iPhone. I'm curious as to whether the demo used ChucK? Check out pictures 15 & 16: http://www.mercurynewsphoto.com/2009/03/iphone/ Cheers, Mark

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record audio directly into sndbuf?
by Matt Diamond 18 Mar '09

18 Mar '09

My apologies if this question is silly, I'm a bit of a programming amateur... I'd like to create a patch wherein I could record a few seconds of audio from the adc (mic input), then play random segments of that audio back. Seems simple enough, but I'm having trouble mastering the art of recording sound in ChucK. Ideally, I'd like to use sndbuf to store the audio in a temporary buffer, though I'm wondering if my only option is to use WvOut to write the audio to an actual file. I'm not even doing very well using WvOut to record... I'd like the recording to be triggered by a button toggle (or even just triggered by a normal button with a set recording duration). I think I'm fairly comfortable with the MAUI button object, but I'm not sure how to implement triggered recording. I've seen examples that merely set up an adc => WvOut w => blackhole configuration, then tell the program to just do this for 5 seconds and then close the file, but I'd like something where I could have the shred running, and then activate a recording process when the button is pushed. I've tried implementing this with a while (button.state()) loop inside of an infinite time loop, but it usually ends up crashing. I also thought I saw something about a w.record operation in the ChucK wiki, but I didn't see anything about this function in the documentation. Anyway, sorry that this is so unfocused... I'm just not sure how to even start approaching the problem. Bottom line: can I use sndbuf to record live audio, and if not, how can I use WvOut to do this? Thanks, Matt Diamond

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