Re: [Haskell-cafe] Re: Livecoding music in Haskell
On Sat, 11 Nov 2006, Rohan Drape wrote: When I run this, then SuperCollider emits the error FAILURE ew Command not found Do you use some new feature? No, however you may need to run darcs update, there was an error in the OSC bundle encoder that I located writing that example: Wed Nov 8 21:29:28 EST 2006 Rohan Drape [EMAIL PROTECTED] * Fix error in OSC bundle encoder hence the sly reference to current repository in the post! Indeed, that was the problem. Thanks! Now the scheduling is really accurate. I'll use that in future. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Livecoding music in Haskell
On Wed, 8 Nov 2006, Rohan Drape wrote: import Sound.SC3 import Control.Concurrent (forkIO) ping f a = out 0 (sinOsc AR f 0 * e) where c = EnvNum (-4.0) e = envGen KR 1 a 0 1 removeSynth (envPerc 0.1 0.6 1 [c,c]) latency = 0.01 bundle t m = OscB (t + latency) m pinger = do now - utc at (fromIntegral (ceiling now)) f where f t = do fd - sc send' fd (bundle t [s_new ping (-1) AddToTail 1]) putStrLn Sending ping return 1.0 main = do fd - sc putStrLn Sending Ping Instrument sync' fd (d_recv' ping (ping 440 0.1)) putStrLn Resetting scsynth reset fd putStrLn Starting schedule thread forkIO pinger putStrLn Delaying main thread pause 30 putStrLn End of delay, exiting When I run this, then SuperCollider emits the error FAILURE ew Command not found Do you use some new feature? (I could even not tell you my SuperCollider version, 'scsynth --version', 'scsynth -v' and the like, don't tell me. :-( ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Livecoding music in Haskell
When I run this, then SuperCollider emits the error FAILURE ew Command not found Do you use some new feature? No, however you may need to run darcs update, there was an error in the OSC bundle encoder that I located writing that example: Wed Nov 8 21:29:28 EST 2006 Rohan Drape [EMAIL PROTECTED] * Fix error in OSC bundle encoder hence the sly reference to current repository in the post! Regards, Rohan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Livecoding music in Haskell
On Tue Nov 7 16:32:11 EST 2006, alex wrote: The way I see it there are two big issues - the first is drift and the second is latency. As hinted at when Alex's work was discussed last November: OSC messages can be timestamped, and SuperCollider has a sample accurate scheduling queue, so language timing jitter can easily be worked around. http://www.haskell.org/pipermail/haskell-cafe/2005-November/012483.html Currently Sound.SC3 has a procedure 'at' that can be used for scheduling. This procedure doesn't really belong in Sound.SC3, and ought probably be taken out. Still, with the current darcs repository the following makes a ping every second, on the second, sample accurately, for half a minute. If you run the binary twice the pings will be twice the amplitude, no phase errors - fingers crossed. import Sound.SC3 import Control.Concurrent (forkIO) ping f a = out 0 (sinOsc AR f 0 * e) where c = EnvNum (-4.0) e = envGen KR 1 a 0 1 removeSynth (envPerc 0.1 0.6 1 [c,c]) latency = 0.01 bundle t m = OscB (t + latency) m pinger = do now - utc at (fromIntegral (ceiling now)) f where f t = do fd - sc send' fd (bundle t [s_new ping (-1) AddToTail 1]) putStrLn Sending ping return 1.0 main = do fd - sc putStrLn Sending Ping Instrument sync' fd (d_recv' ping (ping 440 0.1)) putStrLn Resetting scsynth reset fd putStrLn Starting schedule thread forkIO pinger putStrLn Delaying main thread pause 30 putStrLn End of delay, exiting The above assumes that scsynth is running on the local host at the standard port, 57110, and that the GHC runtime scheduler jitter plus localhost network latency for this task is below 0.01 seconds, which is true on my otherwise idle X31 at 600MHz - this is not at all bad, I am impressed in any case - setting latency to zero gives reports from scsynth of: late 0.008414722 late 0.006882722 late 0.005348722 late 0.003815721 late 0.002282721 late 0.000748721 Tacked on below, for interested readers, are some notes on a related scheme scheduler, the notes were written in response to a related query about scheme scsynth some time ago. The relation to the haskell above is pretty straightforward, the haskell 'at' discards the notion of a mutable schedule - with cheap concurrency such a thing is of arguable use - and the haskell 'at' ought to allow the event generator to return Nothing to stop scheduling. Regards, Rohan ++ Simple sample accurate scheduling from runtimes with moderate scheduling jitter is straightforward using SuperCollider. One simple model is: (at Q TIME (lambda (t f) (EVENT t) (f DELTA))) at = the scheduler interface Q = a schedule value TIME= a UTC timestamp t = the scheduled UTC time (ie. TIME or subsequent delta), regardless of when the procedure actually runs f = a rescheduling function that in effect does (at Q (+ t DELTA) *SELF*) EVENT = the action, usually constructs an osc bundle and sends it to scsynth DELTA = the delta time to reschedule to, to not re-schedule just don't call f The EVENT sends a bundle to scsynth and adds latency as required so that the scheduled bundle arrives ahead of the timestamp, the actual sample-accurate scheduling is handled by a queue at scsynth. The example below will schedule a ping at each whole second, and the scheduling will be sample accurate so long as the scheme runtime jitter is less than 0.1 seconds minus the network latency to get a UDP packet to the scsynth address. Here (utc) gets the current time, (- s p) sends an OSC packet p to the server s, (/s_new ...) makes a /s_new OSC message, (bundle t m) makes an OSC packet converting the UTC timestamp to NTP. (define s (open-udp* 127.0.0.1 57110)) (define Q (make-schedule*)) (define L 0.1) (define (ship t m) (- s (bundle (+ t L) m))) (at Q (ceiling (utc)) (lambda (t f) (ship t (/s_new ping -1 1 1)) (f 1.0))) Obviously to schedule just one ping in five seconds time: (at Q (+ (utc) 5) (lambda (t _) (ship t (/s_new ping -1 1 1 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Livecoding music in Haskell
On Tue Nov 7 16:32:11 EST 2006, alex wrote:
Latency I deal with by calculating everything a second or so ahead of
time, and timestamping my OSC packets with times in the future. Then on
the other side I have some scheduling stuff to trigger sounds at the
right moment, for example in SuperCollider's sclang:
A second seems excessive? Working directly with ghc - scsynth
latencies of ~ 0.075 do not seem to be and issue with even relatively
heavy scheduling loads.
response = {
arg time, responder, message;
if (message[1] == 'on',
{
SystemClock.sched(time - Date.getDate.rawSeconds,
{Synth(noisebox,
[\lgain,message[2] / 100,
\rgain,message[3] / 100,
\ts, message[4] / 100,
\browndel, message[5] / 100,
\filter, message[6],
\envtype, message[7]
]
); nil;
};
);
});
};
o = OSCresponder(nil, '/noise', response);
o.add;
Even sclang, remarkable as it is, will need to be sending time-stamped
bundles for reliable sample-accurate timing? Even to avoid
perceptible jitter under high load?
Regards,
Rohan
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Re: [Haskell-cafe] Re: Livecoding music in Haskell
On Wed, 2006-11-08 at 22:35 +1100, Rohan Drape wrote: A second seems excessive? Working directly with ghc - scsynth latencies of ~ 0.075 do not seem to be and issue with even relatively heavy scheduling loads. Yes you're right, although with my current timescales of livecoding, an extra second of latency doesn't make much difference. I'm not dealing with individual notes, but longer term structures. Even sclang, remarkable as it is, will need to be sending time-stamped bundles for reliable sample-accurate timing? Even to avoid perceptible jitter under high load? Ah, good point - so I am falsely conflating sclang with scsynth? I am (still) a beginner sclang programmer as well as a beginner haskell programmer. In any case I intend to move to your hsc library soon, so thanks for the scheduling details in your other mail. Thanks also to those pointing me at Haskore on #haskell, so far it looks a lot like my existing representation of music, only much better. alex ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Livecoding music in Haskell
I meant to add that of course once you have sample-accurate timing, the next job is to mess things up again with some model of expression in performance (unless you're making german techno). For example I intend to apply some of these rules within Haskore as part of my project: http://www.speech.kth.se/music/performance/performance_rules.html The alternative to this is to stick with a flawed system and decide that it's expressive :) Relatedly, one thing I dislike about supercollider (or at least the way I'm using it right now) is that its failure mode is to crash rather than produce inaccurate output. To me part of the enjoyment of an instrument is what happens when you go beyond its normal limits. alex ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
