Re: [LAU] Synchronizing 2 computer with MIDI

2008/12/6 <torbenh@email-addr-hidden>

> On Wed, Dec 03, 2008 at 02:02:53PM +0100, Mysth-R wrote:
> > Hi,
> >
> > Sorry for my late answer
> > 2008/11/30 <torbenh@email-addr-hidden>
> >
> > > On Wed, Nov 26, 2008 at 10:29:15AM +0100, Mysth-R wrote:
> > > > Hi,
> > > >
> > > > Yesterday I tried with a friend of mine to synchronize our computers
> with
> > > a
> > > > simple midi cable.
> > > > We just want to make music together, and synchronize, the transport
> AND
> > > the
> > > > tempo with a Master and a Slave.
> > > >
> > > > After hours and hours of tests, we just made the transport sync
> works.
> > > But
> > > > we couldn't sync the tempo.
> > > >
> > > > Someone told me on the #LAD IRC, about netjack, but it seems to be to
> > > "loud"
> > > > for what we want to do.
> > >
> > > can you explain loud ?
> >
> > Sorry for my bad english. I meant loud in the sense of to complicated,
> > difficult. Because it is so simple with a midi cable. You wire it, and
> press
> > play. and everything is ok.
>
> aparently its not so simple, because you would have not written the
> initial mail.
> I personally would not find it simple, because my computer does not
> have a midi port. But i cant think of a reasonable computer which
> does not have a network card.
>
>
> > > > In fact, most of the softs can sync themself each other with JACK
> > > transport,
> > > > but can't send Midi Time Code to the midi out.
> > >
> > > so why not use netjack ?
> > > grab current jack release and go.
> >
> > I understood that the slave computer using netjack backend can't use
> audio,
> > or through alsa_out and alsa_in.
> > I own a firewire sound card, so I think this is not possible for me... is
> it
> > ?
>
> do you have to be the slave computer ?
> i suspected, if you want to sync 2 computers, you would be in the same
> room. So it does not look like its necesary to use 2 soundcards.
>
>
> > > it now works over wireless. use celt codec to
> > > reduce bitrate. should give you 4channels in both directions easiely.
> > > and i guess you only want 8 channels in one direction.
> >
> > Does it offers good performances ? latencies speaking ?
> > I can't really imagine how it works. and how to implement this solution.
>
> wait for jack-0.116.1 to be released,
> install on both machines.
> connect machines to ethernet.
>
> [option 1]
> on hostA: run jackd -R -d net
> on hostB: run jack_netsource -h hostA -P 6 -C 6 -l1
>
> hostB is the one with soundcard running normal jackd.
> start seq24 on hostB and hostA.
>
> press play on hostB.
>
> [option 2]
> on hostA: run jackd -R -n synced_server -d net
> on hostA: run jackd -R -d alsa
> on hostB: run jack_netsource -h hostA -P 0 -C 0 -l1
> (you might also use -l0)
>
> on hostA: export JACK_DEFAULT_SERVER="synced_server"; seq24
> on hostA: run softsynths on default server.
> seq24 only speaks alsa sequencer anyways, not necesary to run inside
> same jackd.
>
> press play on hostB.
>
>
>
>
> well... wireless can still dropout sometimes.
>
> But ethernet is rocksolid.
> (At least if you use jack-svn, expect jack-0.116.1 tomorrow)
>
> i did not yet check how many channels you can do with 100Mbit,
> but 10 in both directions worked ok with netjack-0.12.
> I am talking about a roundtrip latency of 1 period, thats 5.8ms
> for 256 samples. And 2.9ms for 128.
>
> the transport synchronisation is latency compensated.
>
> Yes we are playing in the same room. Sorry for my poor knoledges, but, it
means that all, audio and midi event pass trough the ethernet cable ?
If I understand I use my computer normally, but I do not use my sound card,
I use the network. And my friend will receive all the midi and sounds, and
route them through his sound card ?
5.8 and 2.9ms are very exiting !
Is there any complete documentations on the net ?
What are your jack settings ?
I imagine there are some network settings too ?
Thank you for your answer.
cheers,
Mysth-R

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Received on Sat Dec 6 12:15:02 2008