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Re: [sc-users] Clock sync: New quark ddwOSCSyncClocks (testers wanted)



Well, I guess as I'm at the ICLC in Madrid next week, there might well be SC people there who would give it a try…

On Sun, 13 Jan 2019 at 10:02, <mail@xxxxxxxxxxxxxxxxx> wrote:

I'd like to test this out on some raspberry pi's. I'll let you know of my results, thanks for the code :)

On 13/01/2019 08.56, jamshark70@xxxxxxxxx wrote:
Splitting off from my thread about clock sync, I'd like to throw a new
quark out there for testing.

I haven't added it to the master quark list yet, but if you have git,
you can get it this way:

Quarks.install("https://github.com/jamshark70/ddwOSCSyncClocks.git")

Otherwise visit https://github.com/jamshark70/ddwOSCSyncClocks .

Basic usage is simple:

// On the master machine (substitute your tempo):
TempoClock.default = DDWMasterClock(myTempo);

// On the slave machines:
TempoClock.default = DDWSlaveClock.new;

Wait a couple of seconds, and the slave clock should jump to the
master’s beat count. Then you can use both clocks as normal
TempoClocks (except, the slaves can’t change tempo or meter – they
have to follow the master clock).

My testing so far:

- Two sclang instances running on the same machine. The slave clock
has a feature to simulate random delays in message delivery, going up
beyond 100 ms. I'm running one of those tests now, and sync is
surprisingly clean considering the fluctuations in the time data
(which I'm also watching via debug posts) -- within a dozen ms or so.
So, the principle seems to be sound.

- Two computers (one Windows, one Linux) on a WLAN with the exciting
"feature" of considerable jitter in message delivery and frequent
dropped UDP packets. Sync was pretty close, but the master machine was
audibly slightly early. I'm not sure if this is because dropped
packets caused the slave to overestimate some timing values, or if
it's maybe just different latency in the audio driver.

I don't have access to my school's resources now (Spring Festival
semester break), but in a month and a half or so, I should be able to
turn this loose on half a dozen computers in the media lab. I *think*
the network might be less jittery...?

Anyway, if anyone is doing group work with SC and has a network
environment to try this on a larger scale, it would help me to know
how it behaves outside of my apartment.

Thanks!
hjh

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--

Best Regards,
Mads Kjeldgaard



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