May 2006 - chuck-users - lists.cs.princeton.edu

user study!!!
by Ge Wang 21 Jun '06

21 Jun '06

Dear all, We would like to conduct a N-part user study (where N >= 1) on using ChucK. To start, we are interested in learning about how everyone is using ChucK, the ways (if any) ChucK has effected the way you write/think about audio programming, and/or your thoughts on ChucK. A dissertation is being written (mine), and we want to include evaluations/feedback from the primary ChucK community (this list). Also, we hope to construct a page to showcase works being done using ChucK. So fire away! Thank you all very much!!! (slightly) more detail here: http://wiki.cs.princeton.edu/index.php/ChucK/UserStudy Best, chuck team

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What about "delayp"
by Jim Hinds 08 Jun '06

08 Jun '06

I'm looking at the documentation for the unit generator 'delayp' Too cryptic for me. The source code isn't very helpful either. And the delayp.ck example prog seems to have gone missing. Can anyone enlighten me about the adjustable write window and what that is supposed to do? Jim Hinds jahbini(a)jahbini.org http://www.celarien.com/ http://www.jahbini.info/

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More buffer record and samplelooping
by Hans Leeuw 31 May '06

31 May '06

Hi list, I tried a few things with the array solution mentioned. It works but it takes a lot of the processor. I got about 10 sporks going (plain playing), but I'd like to use some of the flexibility of 'sndbuf' So I'd like to try writing to disk and using a sndbuf as well. But with the following lines of code it does not work. The sound is not properly written to disk. //sucking samples; adc => WvOut w => blackhole; // this is the output file name "/Users/hansleeuw/miniaudiclefolder/examples/data/trumpet.wav" => w.wavFilename; 1 => w.record; //start recording 2::second => now; //a soundfile of 2 seconds 0 => w.record; //stop recording w.closeFile; //to do it properly (also tried without) // Now loading the soundfile in and here the program crashes // (miniaudicle and terminal) sndbuf buf => dac; "/Users/hansleeuw/miniaudiclefolder/examples/data/trumpet.wav" => buf.read; while( true ) 1::second => now; In terminal I get the messages: ugen_xxx.cpp:1986: failed assertion `d->fd == NULL' Abort trap What can be the problem? It seems the soundfile is not written properly. Quicktime gives "incorrect duration" (-1024). I don't have a problem loading 'proper' soundfiles with sndbuf. Thanks for your time. Best, Hans.

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ChucKML Download
by DANIEL MAGNUSZEWSKI 22 May '06

22 May '06

ChucKML ( http://wiki.cs.princeton.edu/index.php/ChucKML ) appears to be very interesting, and useful for what I want to do. I don't know if I'm missing or overlooking anything, but I can't find where to download this. Can someone point me in the right direction? Thanks. -Dan

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Joypad abuse.
by Kassen 22 May '06

22 May '06

Hi list. In testing my new joypad I quickly cooked this up. It's kinda cheap but like many cheap things it's good fun so I thought somebody else might have fun with it too. I'm asuming everybody has amen or simmilar break lying around somewhere. With a little practice somewhat convincing jungle can be made, this takes considderably less time then it took years ago cutting&pasting in a wave editor.... It's just a quick toy, if anybody needs comments somewhere I'd be happy to help. By the way; I'm using one of these "thrustmaster" youpads now that are styled after teh PS2 ones. With this the "stutter" and "reverse" buttons end up conveniently under your index fingers. If you are using some flight-sim joystick none of thismay make sense and you may need to edit a little. For what it's worth, Kas. ------------------------- sndbuf buf => PitShift ps => dac; "data/amnbreak.wav" => buf.read; 1 => buf.loop; 1 => ps.mix; buf.samples() => int A; (A / 32) => int beat; beat::samp => dur click; int pos2; int pos1; 1 => int dir; int stut; click / 4 => dur frtclick; 4 => int rate; fun void joyreader() { // make HidIn and HidMsg HidIn hi; HidMsg msg; // open joystick 0, exit on fail if( !hi.openJoystick( 0 ) ) me.exit(); // infinite event loop while( true ) { // wait on HidIn as event hi => now; // messages received while( hi.recv( msg ) ) { <<< msg.type, msg.which, msg.idata, msg.fdata >>>; if (msg.type == 0 && msg.which == 1 ) (-msg.fdata + 1) * dir => buf.rate; if (msg.type == 0 && msg.which == 0 ) ((16 * msg.fdata) + 16) $ int => rate; if (msg.type == 0 && msg.which == 2 ) 1 - msg.fdata => ps.shift; if (msg.type == 0 && msg.which == 3 ) (A * msg.fdata * msg.fdata) $ int => pos2; if (msg.type == 1 && msg.which == 0 ) 0 => pos1; if (msg.type == 1 && msg.which == 1 ) (A / 4) => pos1; if (msg.type == 1 && msg.which == 2 ) 2 * (A / 4) => pos1; if (msg.type == 1 && msg.which == 3 ) 3 * (A / 4) => pos1; if (msg.type == 1 && msg.which == 4 ) { -1 => dir; if ( (buf.rate() * dir) < 0) (-1 * buf.rate() ) => buf.rate; } if (msg.type == 2 && msg.which == 4 ) { 1 => dir; if ( (buf.rate() * dir) < 0) (-1 * buf.rate() ) => buf.rate; } if (msg.type == 1 && msg.which == 6 ) 1 => stut; if (msg.type == 2 && msg.which == 6 ) 0 => stut; } } } spork ~ joyreader(); 0 => int step; fun void sync() { click - (now % click) => now; while(true) { if(!stut) { step * beat => pos1; pos1 => buf.pos; } 1 +=> step; (step % 32) => step; click => now; } } spork ~ sync(); click - (now % click) => now; while (true) { if (stut)(pos1 + pos2) % A => buf.pos; if (rate==0) 1 => rate; rate * frtclick => now; }

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multi channel and EMU under XP?
by Kassen 19 May '06

19 May '06

Hi, list. Has anybody gotten the multi-channel stuff to work with one of the EMU cards that use Patchmix under XP? I dug through a stack of online posts and it seems that in the past these cards had issues with multi channel DX but right now Winamp is set to "primary sound driver" and does a perfect job of playing a six channel wave file while ChucK --probe doesn't get beyond 2 channels on any of the devices it sees. I use a1616m but I think the drivers are basically the same for all of them. Any pointers would be very welcome. Kas.

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newbie confusion
by plutek 11 May '06

11 May '06

obviously i'm a complete newbie here.... could someone please explain to me why the inner loop in this code is not terminated by the outer loop, after ten seconds: now + 10::second => time later; while( now < later ) { while( 1::second => now ) { <<< now, "inner loop" >>>; } } i suppose i'm victim to some horribly wrong assumption about How Things Work, which brings up my other question: is there some material somewhere (more than just the tutorials) which would take me deeper into a general understanding of the mechanics of coding in ChucK? the language reference is excellent, but doesn't help one to learn how to put all the details together into coherent code. i do have a decent understanding of the principles of synthesis, so it's really questions of logic flow, semantics, and style that concern me. i don't know if material related to other languages will be applicable, due to the strongly-timed nature of ChucK. any advice? (other than enrolling in princeton) :-) many thanks in advance! .pltk.

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On Division, Arithmetic and expressions
by Jim Hinds 10 May '06

10 May '06

Kassen has run into a "feature" of chuck that needs some explanation. The apparent strange behavior of division of integers is common among most computer languages that support integers. The basic common feature is that we want integer computations to result in integers. If it starts with all integer variables and constants, we want to finish with integers (when possible.) You learned about integer division well before you learned about fractions or decimals, and WAY before you learned binary. You remember that the answer to 2 / 3 was: "it doesn't go even once" -- that's zero. The result is well defined and consistent. Integer division goes hand-in-hand with the remainder operation (mod, % or whatever in other languages). In most cases, you don't notice the subtle nature of integer computations. 5 + 3 = 8 is much the same as 5.0 + 3.0 = 8.0 if the answer is float or int, you just don't care. It is, however, important when you do division. It is ALSO important when you are working with "big" numbers (or very negative numbers). When this happens, well formed integer arithmetic will overflow in a predictable way (and we want it that way). For example, since 32767 (2 raised to the 15th power minus 1) is the largest positive number in 16 bit twos-complement arithmetic, we DO WANT our integer computation to result this way: 32767 + 1 = -32768. And not as 32768.0. Yes, this is bizarre, and probably not what you are expecting. But it is very common for computer languages, and those of us with little music and much computer (that's guys like me), it is like breathing: we are so aware of it, that we don't even mention it. OK, so how do you GUARANTEE that there is no funny stuff happening (like truncation or overflow)? Simple. You FORCE at least one side of the operation to be in floating point. The operation is then carried out in floating point and the result is in floating point. Example: 2/3 == 0 (integer divides integer results in exact integer), BUT 2.0 / 3 == .66666667 (integer divides float results in non-exact float) or 2/3.0 == .666666667 (float divides integer results in non-exact float) or float(a) / 3 should result in a float, not an integer. This is mostly the way it is. (you can tell I'm a programmer, since I almost always put that caveat word "mostly" in my explanations: there always seems to be an exception. I hope this helps to understand integer computations in chuck, and other languages. > Kassen sez: > > Hi list, > > Deviding a int by a int results in a int returned like here; > ------ > <<<(2 / 3)>>>; > > //or even like this; > > 2 / 3 => float a; > <<<a>>>; > ------ > > Is that realy the intended behaviour? > In that last case I personally find what happens a bit silly. > > If this realy is the way it should be I think it would be nice to add > a line about this to the manual because I only found out what was > happening exactly after several rounds of testing. Perhaps this is > typical behaviour for some languages but I wasn't used to it. > > Yours, > Kas. > > Jim Hinds http://www.jahbini.org/

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devide issue?
by Kassen 10 May '06

10 May '06

Hi list, Deviding a int by a int results in a int returned like here; ------ <<<(2 / 3)>>>; //or even like this; 2 / 3 => float a; <<<a>>>; ------ Is that realy the intended behaviour? In that last case I personally find what happens a bit silly. If this realy is the way it should be I think it would be nice to add a line about this to the manual because I only found out what was happening exactly after several rounds of testing. Perhaps this is typical behaviour for some languages but I wasn't used to it. Yours, Kas.

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zipper noise
by plutek 05 May '06

05 May '06

greetings! first off..... i am thoroughly enjoying ChucK; thanks a lot! my question is whether anybody has an elegant way of attacking the problem of zipper noise when using external MIDI controllers which send only integer values. it's great that ChucK uses float MIDI values, but we need a way of smoothing incoming controller data -- perhaps something like pd's "line" operator. i'll have to give some thought to how it could be built from scratch, using native primitive operators, but an optimized higher-level function to take care of this would certainly be useful. thanks again! .pltk.

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