[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [sc-dev] osc bundle timestamps



The lang doesn't know the time on the server. If the server is on a separate machine, clock sync issues can be pretty critical, because the assumption is that absolute time is the same on both. (Try setting the time on the server to 1s later than the the client - you'll get tons of late messages, until you set the latency to about 1s - then it works perfectly).

This seems like somewhat of an outstanding problem for SC when working with multiple machines... the easiest empirical solution is to make sure the time on the server machine is => the time on the lang machine - then, generate a huge stream of events (simulate high osc message load) and lower the latency until you start to get late messages. Obviously, that's going to be the lowest possible latency, regardless of differences in clock time. This doesn't solve keeping clocks synced over time, or syncing between more than two machines.

- Scott


On Dec 14, 2009, at 12:34 PM, Jonatan Liljedahl wrote:

> Hi, I'm new on the lists and new to supercollider as well, and I have a question regarding timestamping of OSC bundles.
> 
> Is the timestamp in absolute time, according to the OSC spec? If so, how does the sclang know the current time in the server? For example, s.makeBundle(0.5,...) makes a timestamp 0.5 seconds from "now", but how does sclang know when "now" is for the server?
> 
> I'm interested to understand how this works both for a local server running on the same machine (where one solution might be to use the same clock-mechanism in the machine) and a remote server on another machine.
> 
> The reason I'm asking this is because I want to create my own SC client that talks to the server directly (an algorithmic graphical score editor), and I need accurate timing.
> 
> /Jonatan
> http://kymatica.com
> 
> _______________________________________________
> sc-dev mailing list
> 
> info (subscription, etc.): http://www.beast.bham.ac.uk/research/sc_mailing_lists.shtml
> archive: https://listarc.bham.ac.uk/marchives/sc-dev/
> search: https://listarc.bham.ac.uk/lists/sc-dev/search/
> 


_______________________________________________
sc-dev mailing list

info (subscription, etc.): http://www.beast.bham.ac.uk/research/sc_mailing_lists.shtml
archive: https://listarc.bham.ac.uk/marchives/sc-dev/
search: https://listarc.bham.ac.uk/lists/sc-dev/search/