MIDI over IP and Rendezvous protocols

Alex Reynolds · Post by **Alex Reynolds** » Sat Nov 16, 2002 5:44 pm

iMIDI provides MIDI over IP and Rendezvous protocols for OS X:

http://www.versiontracker.com/moreinfo. ... 014&db=mac

Haven't tried it yet with my wireless setup. I'll test it and send a report.

Would be useful for MIDI clock stuff...

-Alex

Geraldo · Post by **Geraldo** » Sat Nov 16, 2002 9:36 pm

Is it Rendevous dependant? Sounds interesting, maybe it could be used like VST System Link? Please report back if you get it working.

Alex Reynolds · Post by **Alex Reynolds** » Sat Nov 16, 2002 10:41 pm

Actually, it just works over Rendevous, not TCP/IP.

So far it doesn't seem to work for syncing a MIDI clock. iMIDI crashes as soon as I reset the clock.

But the two iMIDI objects see each other and present MIDI ports to Live.

This looks promising...

-Alex

Alex Reynolds · Post by **Alex Reynolds** » Sat Nov 16, 2002 10:44 pm

Here's some information on Rendezvous for the curious:

-- http://developer.apple.com/macosx/rendezvous/

-Alex

Guest · Post by **Guest** » Sun Nov 17, 2002 2:47 am

This is a very cool concept. Just turn up a gig/ friends place, open up your airport enabled machines and bingo, midi and midiclock over the air. play the virtual synths on your friends machine!.

I wonder how far this could be pushed?

could audio be sent over airport with reasonable latency?

that would make vst system link rather limited in comparison.

very cool.

-songCarver

Alex Reynolds · Post by **Alex Reynolds** » Sun Nov 17, 2002 3:06 am

I was going to start writing this exact application using TCP/IP sockets instead of Rendezvous.

In hindsight this protocol seems better suited for "plug and play" audio sharing within a small network, the kind that would be in a studio or enclosed performance space.

I'm going to turn my attention to a free Cocoa RAM disk utility, instead...

-Alex

Guest · Post by **Guest** » Sun Nov 17, 2002 3:38 am

This is more than "plug and play"!

This is "just turn up."

I really think this is some of the stuff that will make my dream of laptop musicians a reality, where you can just turn up and play, jam, compose and rehearse with other computer musicians very easily, just like in a traditional band or ensemble.

Hey Alex I look forward to your ramdisk utility, much needed.

cherios

Geraldo · Post by **Geraldo** » Mon Nov 18, 2002 6:22 pm

Ok, we all agree it is a lovely idea. Now does anyone have it working yet?

Alex Reynolds · Post by **Alex Reynolds** » Mon Nov 18, 2002 8:46 pm

If you run it and it crashes, send bug reports and crash logs to the developer:

BTW - is Live getting the correct tempo for you? I and others have had a hard time getting live to detect the right tempo - it seems to be 3/4 of the transmitted tempo.

To help me figure out what's going on I'd appreciate the iMIDI crash log from the G4 - it's ~/Library/Logs/CrashReporter/iMIDI.crash.log

Thanks,
Robert.

His email address is [email protected]

-Alex

tjwett · Post by **tjwett** » Mon Nov 18, 2002 10:42 pm

kewl.

rasda · Post by **rasda** » Wed Nov 20, 2002 5:12 pm

hey people,

i just tried this little iMidi yesterday and it works great.
in our studio setup we have a g4 350 tower and two g3pismo400 laptops. i set it up like follows.

on the big tower i had logic 5.3 under os9 with an amt8 > from there it goes to an mt4 in the first laptop running live > from the first laptop it goes over iMidi to the second laptop running live too.

i synced the first laptop with midi clock over the conventional midi-interfaces to the g4tower and then put a midiclock signal out over iMidi from the first to the second laptop.

It works great. When i now push start on the master computer and the two laptops are in slave mode all three machines are in perfect sync.

Then we had a great intuive jam-session with very good results.

The great thing is that if you have a multichannel audiocard and a analog mixing console with busses like we do you can record the session or parts of it on the fly and you are even able to tweek your sounds on your analogue equipment. And all in perfect sync.
THAT'S A REAL BAND-FEELING.

cheers rasda

Alex Reynolds · Post by **Alex Reynolds** » Sun Nov 24, 2002 5:23 am

iMIDI and Rendezvous do not seem to like it when the built-in OS X Firewall is enabled.

I finally got iMIDIs to talk to talk to one another after disabling the firewall on each of the stations running it.

Live's clock is still f*&^ed up though. I sure hope that will be fixed in v2.

-Alex

criteriaz · Post by **criteriaz** » Sun Nov 24, 2002 8:30 am

how do you guys compesate latency in this case?
And i'm not talking anoly about audio latenc, but midi clog PROBLEMS. I HAVE A LAPTOP DUO with a friend of mine, and we are having a hard time syncing up both computers, using just the "sound manager' or core audio option......
is it better having just an EXTERNAL CLOCK, like a smtpe to a motu , and then feed both computers...

any ideas?

thanx!

Guest · Post by **Guest** » Sun Nov 24, 2002 12:21 pm

can this work over airport?

What is the simplest way to make this work?? ie, what cables are required?

how good is the midi latency??

CRITERIAZ:

Live 1.5 does not sync properly to incoming midi clock on a lot of mac machines. Mine does not work (667 tibook)
FYI am told it is fixed in 2.0

-SongCarver

sevo · Post by **sevo** » Sun Nov 24, 2002 3:24 pm

In theory, latency is not much of an issue over a dedicated direct Ethernet/IP connection (and Rendezvous is just another IP sub protocol suite) - on a 100bT link, the RTT for small UDP packets is far below a millisecond (i.e. considerably faster than serial MIDI) even when we assume some low level traffic from the stacks.

But once LANs or WANs get into the equation, things get more difficult, as Ethernet over whatever medium doesn't have any solid realtime support (like bandwidth reservation at guaranteed rount-trip time) - other machines will easily get in the way of your timing. One layer down on the network this will be the crippling factor for Airport even if you have only two machines on your own WLAN - you may still be sharing the airspace bandwidth with other networks...

Sevo

MIDI over IP and Rendezvous protocols

MIDI over IP and Rendezvous protocols

it works

watch out!

latency