Re: [xine-devel] Re: Playing movies across a cluster

[Siggi L. <si...@us...>]

Hi Andre,

On Wed, 27 Apr 2005, Andre Pang wrote:

[...]
> Wow, sounds very good.  Just a short question about what you're
> planning to do: does your synchronisation idea rely on any special APIs
> provided by your clustering software?  I ask because I've been wanting
> to do synchronised playback between just two machines (over the
> Internet), and it's one of those projects that I'll just never have the
> time to do.  It'd be very cool if your xine plugin doesn't require any
> special clustering stuff to work, so we could use it on normal Linux
> machines!

If you just want to playback 2 streams synchroneously on 2 Linux machines
in the same network, there's a much simpler way to achieve this:

Just synchronize the system clocks of both machines via NTP and xine's
standard Unix SCR will do the rest. (Well, if your machines have bad
hardware clocks, you may need to disable the use of Posix' monotonic clock
for optimal results, same thing for bad sound card clocks: you may want
to force resampling for synchronization in this case...)
The only thing you'll have to do is start playback on both machines
simultaneously. That can be done by writing a small front end that waits
for all machines to connect via TCP and then gives a "start" command via
those connections or even as simple as using something like cron or at to
start playback on all machines at a particular time. Both methods work
fine and sync differences have stayes well below the duration of a frame
during a 1h test...

Cheers,
	Siggi

-- 
WARNING: RAID-6 is currently highly experimental.  If you
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or re-appoint George W. Bush.                -- Linux 2.6.10