[chuck-users] other ways to live-code with time

Kassen signal.automatique at gmail.com
Wed Apr 29 13:30:05 EDT 2009


That seems quite similar in approach to this;

I'd like to invite you to have a look at that and perhaps join the
mailinglist on it. If these two could be made inter-operable it could
be used to sync ChucK to a range of other open source music and
graphics systems.


2009/4/29 Mark Cerqueira <mcerquei at princeton.edu>:
> I've spent this semester doing some independent work with Perry and Dan on
> how to get good network synchronization for PLOrk so that we don't need a
> conductor and can focus on doing other things. I implemented a Time-Tagged
> OSC protocol similar to the stuff Adrian Freed does. Essentially the
> protocol first synchronizes everyone's clock via a protocol that is based on
> the Network Time Protocol (NTP). On the PLOrk network, one machine runs as a
> NTP Server and all others run as NTP Clients - NTP Clients calculate the
> offset of their VM time to the server VM time, as well as keeping track of
> the round-trip time of packets sent to synchronize to account for that in
> the offset.
> Once the clocks are synchronized, packets sent over the network include the
> current time (which should be synchronized pretty closely if the above
> protocol works) and a time-to-execute offset. When someone receives the
> packet they add the current time plus the time-to-execute offset and
> schedule the packet to be opened only at that time. The NTP-like
> synchronization protocol I described above also keeps track of all RTTs and
> broadcasts to everyone what a good time-to-execute field is (i.e. make sure
> we give enough time for the packet to travel over the network). If all works
> well, everyone should open the packet at the same time.
> Not sure how successful this implementation will be...I'm testing it
> tomorrow during PLOrk rehearsal! If anyone's interested in seeing the
> code/my write-up I can pass around a copy once I *crosses fingers* complete
> it and hand it in on Monday.
> Best,
> Mark
> Tom Lieber wrote:
>> On Wed, Apr 29, 2009 at 12:28 PM, Kassen <signal.automatique at gmail.com>
>> wrote:
>> Yeah, a wireless network. And for whatever reason (AirPort updates, OS
>> X updates, variation in laptop hardware), timing issues got worse from
>> the previous year. Actually, I don't know how this was solved in the
>> end, because I think things had improved by the end (or maybe we
>> stopped relying on the network so much and I didn't notice)...
>> On Wed, Apr 29, 2009 at 12:27 PM, Daniel Trueman <dtrueman at princeton.edu>
>> wrote:
>>> On Apr 29, 2009, at 11:36 AM, Tom Lieber wrote:
>>>> A lot
>>>> of rehearsal time in PLOrk this past semester was dedicated to
>>>> synchronizing the performers because we lacked good network
>>>> synchronization.
>>> i've come to view this as a feature, not a bug... ;--}
>> I chose my words carefully! There's no way I can view getting
>> everybody to practice being in sync as a bad thing, but having the
>> option of good network synchronization means we can make pieces where
>> players can give their full attention to something else, like making
>> patterns in beepsh.
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