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

linux: 4 channel output
by Atte André Jensen 25 Oct '07

25 Oct '07

Hi I'd like to have four outputs with linux chuck. However I only have one onboard (2 channels) and an usb soundcard (2 channels). So the question is: can I use these two soundcards as a four channels device in chuck? Actually I only need dac and something like dac2 (the second soundcard). The idea is to have chuck generate click and sendit on one card, and the other is the actual music, which goes to the PA... -- peace, love & harmony Atte http://atte.dk | http://myspace.com/attejensen http://anagrammer.dk | http://modlys.dk

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KBHit with miniAudicle
by Atte André Jensen 25 Oct '07

25 Oct '07

Hi I'm trying to use something like the following with miniAudicle, but it doesn't work :-( Works great with chuck. Am I doing anything wrong? Is there otherways to grap keyboard input that works with miniAudicle? Thanks in advance for any response! KBHit kb; int key; while(true){ kb => now; while(kb.more()){ kb.getchar() => key; <<<key>>>; } } -- peace, love & harmony Atte http://atte.dk | http://myspace.com/attejensen http://anagrammer.dk | http://modlys.dk

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demonstrating the sampling theorem in Chuck
by jakob kaiser 22 Oct '07

22 Oct '07

Hi, As a first step into the wonderful and time consuming world of DSP<=>Chuck I want to make audible the effect of disregarding the sampling theorem. So all I'm trying to do at the moment is creating a simple down-sampler without any proper filtering. As it is said in the sampling theorem this should not create any distortion as long as my new sampling rate is at least twice as high as the highest sine wave in my input signal. However, when I'm sampling down a sine wave of for example 440 Hz in Chuck, I get a lot of funny noises long before going down to a SR of 880 Hz. For example: SinOsc inputSignal; Step stepSeq; inputSignal => blackhole; stepSeq=> dac; 440 => inputSignal.freq; 0.5 => inputSignal.gain; //takin every nTh sample of the inputSignal 10 => int n; <<<"real sample rate: " + 1::second/1::samp>>>; <<<"new sample rate: " + 1::second/(1::samp*n)>>>; //duration of the output signal 1::second => dur durationOfTest; now + durationOfTest => time timeToFinish; //don't-care-about-Nyquist-downsampling while (now < timeToFinish) { inputSignal.last() => stepSeq.next; n::samp => now; } By using a common sample-rate like e.g. 44100 Hz in Chuck this should satisfy the sampling theorem. I guess the reason, why I doesn't get a nice 440-sine wave here is because I have to reconstruct the sine wave after the down sampling with the remaining samples, as the output cannot know that they are part of a proper sine wave. Is this right? If yes, could someone give me a hint how to realize something like this? Of not, what is the real problem? My target is a downsampler which for example would produce an undistorted sine wave of 440 Hz after downsampling to 880 Hz (i.e. a working demonstration of the sampling theorem) A second and a bit stupid question: As far as I understand it, it is not possible to downsample a signal with a given SR to any new SR, but only to a new SR which is = (Old SR)/N, whereas N is a simple positive number (of course after converting the new SR to integer). Did I get this right? OK, I would be very grateful if someone could give me a hint or two. I => bed, have a nice day! Jakob _________________________________________________________________ Invite your mail contacts to join your friends list with Windows Live Spaces. It's easy! http://spaces.live.com/spacesapi.aspx?wx_action=create&wx_url=/friends.aspx…

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chuck <<-->>OSC<<-->>Python?
by AlgoMantra 18 Oct '07

18 Oct '07

If anyone could give me some pointers here, I'll be grateful: I KNOW: Python (decent), Pygame (medium), ChucK (n00bie), OSC (null) ZERO KNOWLEDGE: OSC ( I have NO idea what it is, except that it may be useful for interfacing two platforms on the same computer. I know there is a Python wrapper available, but I have no idea how to use it) I WANT: chucK to speak/listen to a python script in realtime. WHAT: The GUI is a game/visualisation in Pygame. It responds visually to messages coming in from a Chuck audio set ( is one of them a "server" type thingie?) and sends back new messages which manipulate the sound. They way the 'game' is played visually modifies the music. To put the problem simply: ChucK <<-->>OSC<<-->>Python? => ?? ------- -.- 1/f ))) --. ------- ... http://www.algomantra.com

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stupid n00bie question: Part III
by AlgoMantra 17 Oct '07

17 Oct '07

1. What is the simplest way to detect the pitch of an audio signal (from the mic) in Chuck? 2. How much wood could a woodChucK ChucK if a woodchucK could chucK wood? ------- -.- 1/f ))) --. ------- ... http://www.algomantra.com

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stupid n00bie question: Part II
by AlgoMantra 17 Oct '07

17 Oct '07

Okay, I beg your pardon in advance again...... 1. Are the MAUI modules available only for miniAudicle, and not Audicle? That would mean that one can only do this on Mac. I'm a dodo using XP. 2. Can two ChucK shreds throw data at each other in the same VM, like two Python sockets? So I could read Microphone data in RMS off one shred and throw it towards a Python GUI using another shred which is using OSC? Can two shreds talk? I'll be grateful for your answers. ------- -.- 1/f ))) --. ------- ... http://www.algomantra.com

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a general note to chuck3rz
by AlgoMantra 17 Oct '07

17 Oct '07

Dear Chuck3rz, Over the short period that I have been learning ChucK, I have been very appreciative of the support from this list, especially the open and sharing attitude of Kassen the Benevolent. I believe I will continue needing your help, but in the meantime I would be even happier if I could reciprocate these huge favors. Knowledge shared is knowledge gained, huh? I have been coding only for a short while (7 months) but I have a fairly broad range of interests - algorithms, generative startegies, AI, and mythology to name a few. I am constantly expanding my skills, though. While learning ChucK, I am keeping a private diary that might serve as a handy tutorial for future users. However, technically speaking, I can only say that I am well acquainted with the programming of Nokia S60 smartphones using Python. Just to give you an indication of the power these tiny instruments wield, the Nokia 5500 Sport has an accelerometer embedded, which can be hacked to be used as a musical interface, in a similar way I see you treating the Wiimote. The other hackable sensory organs include the cameras (two in the N70, back and front), GPS (N95), audio channels, SMS, cell tower IDs, Bluetooth, GPRS internet, and dialing programs. It is fairly simple ( I have the code) to convert your N70 into a Bluetooth remote for DJing, live composition etc. It is not too difficult to use the 5500 as a motion detecting joystick for live performance. The possibilities are many: Phone Motion>Bluetooth>ChucK + GUI In fact, I have motion detection happening on the phone via the camera(s), but the CPU is far too slow for any real application. You can play Pong with a couple of chopsticks, though. The platform is slowly opening up with deeper access to Symbian. So in case any of you find yourselves interested in the interface model outlined above, I'll gladly share what I know. FYI. cheers, ------- -.- 1/f ))) --. ------- ... http://www.algomantra.com

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classes / bpm?
by Josh Lawrence 16 Oct '07

16 Oct '07

I have two questions for the ChucK group - 1) regarding the midisender.ck file located at: http://www.rattus.net/~packrat/audio/ChucK/files/midisender.ck how do I use this in ChucK? I'm assuming that I need to drop it somewhere so it can be called by ChucK. I use ChucK on both Windows and Linux. 2) I need to be able to figure out how to handle time-based stuff using bpm. for example, if I have a song that is 80 bpm, how do I send quarter notes at that tempo? I've done some research on the 'net, and it seems that figuring this out is harder than I think it should be. considering I'm a math idiot, can someone give me some simple(r) way to do this? -- Josh Lawrence http://www.hardbop200.com

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SndBuf: setting loop
by Atte André Jensen 13 Oct '07

13 Oct '07

Hi I looked in the manual but couldn't find the answer: Is is possible to set the loop start/end with SndBuf from within chuck? It's not mentioned at http://chuck.cs.princeton.edu/doc/program/ugen_full.html#sndbuf. Alternatively: is there another mechanism to play samples that allows setting the loop start/end? -- peace, love & harmony Atte http://atte.dk | http://myspace.com/attejensen http://anagrammer.dk | http://modlys.dk

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analog to digital conversion simulation
by eduard 13 Oct '07

13 Oct '07

Hi list, I'm trying to simulate how adc conversion works using chuck. However, I'm not succeeding as I'm getting too many artifacts in the output sound. Don't know whether i'm getting this wrong from a conceptual point of view or I'm using/setting chuck's UGens wrongly. The patch I use is: <<<"usage:", "sample_and_hold.ck:output_gain:sr" >>>; adc => OnePole lpf => blackhole; Impulse pulse => lpf => Gain g => dac; .8 => g.gain; if( me.args() ) Std.atof( me.arg(0) ) => g.gain; 1::second/1::samp => float chuck_sr => float new_sr; if( me.args() > 1 ) Std.atof( me.arg(1) ) => new_sr; chuck_sr/new_sr => float next_samp; 1. - new_sr/chuck_sr => lpf.pole; <<<lpf.pole()>>>; <<< next_samp>>>; while(true) { now => time T; next_samp::samp +=> T; lpf.last() => pulse.next; while( now < T ) { 1::samp => now; } } Then the user should be able to give a certain SR and experience how the input sound would sound when sampled at SR. I'd like to be able to set lpf cutoff frequency at SR/2 and what I thougt of is something like: 1. - new_sr/chuck_sr => lpf.pole; thus, if user_sr= 44100, then pole=0 and cutoff freq=chuck_sr/2 (should be 22050 if running at 44.1). if user_sr=22050, then pole=0.5 and cutoff freq=chuck_sr/4 (should be 11025 if running at 44.1) etc... Am I doing this right? On the other hand, a Onepole filter will not suffice to get rid off all frequencies above the cutoff. Is there a way of having a kind of brickwall filter in chuck? Thanks, eduard

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