Core Audio in Mac OS X Tiger to improve audio handling

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Comments

  • Reply 21 of 27
    Quote:

    Originally posted by Kickaha

    I think the vagaries of network latency would eat it alive.



    And yet, MIDI is designed specifically to allow multiple instruments to be digitally connected and play in sync, isn't it?



    I know it's not applied to playing songs [top 40 hits]... but surely the technology and timecodes to get things synchronised would work for either?



    Though, I am no MIDI expert!!!!



    [edit: definition of 'songs']
  • Reply 22 of 27
    kickahakickaha Posts: 8,760member
    MIDI has tight synchronization across all devices by means of a clock signal.



    Networking is deliberately *A*synchronous. You can't make it work in lockstep.
  • Reply 23 of 27
    I hereby nominate this thread title for the Captain Obvious Award.



  • Reply 24 of 27
    Yeah I guess the title is obvious: "Core Audio in Mac OS X Tiger to improve audio handling". If it didn't improve audio why would they do it!? hehe



    Anyway, back to MIDI -



    I've done some reading around on various sites for the relationship of MIDI to Ethernet. MIDI currently IS used over ethernet, it uses time servers (including standard internet NTP), and the greatest network latencies of your connected devices are found and used to set a standard delay, hopefully quite short.



    It is hopefully short with MIDI because they want to work with instruments in REAL TIME. Of course, a delay when playing music on 2 separate computers doesn't matter even if it's a few seconds as long as they are playing in time with each other - it just means that when you skip to the next song, it will take that long to start playing.



    BUT, that said - MIDI is really using multiple networking technologies to synchronise the devices over ethernet. So yes it's obviously not using the old style midi that required quality 5 pin cables less than 50 feet. In fact, Apple could probably just say "we're synchronising our audio and video now" and put together the technologies without using MIDI at all.



    So who knows if Apple are planning on synchronising video, audio, etc in Tiger - maybe this rumour relates to that, maybe not - though I hope when they do work in this area they use an existing standard.



    Hope that's useful.



    Main source (plus the relevant links for timecodes!):

    http://www.fact-index.com/m/mu/music...interface.html

    http://www.grame.fr/MidiShare/fr/Reseaux/Reseaux.html
  • Reply 25 of 27
    vinney57vinney57 Posts: 1,162member
    Quote:

    Originally posted by GregAlexander

    >Meanwhile, a new clock API will allow developers to create and track

    >MIDI time formats. The API will reportedly support the use of the

    >MIDI Time Code (MTC) and MIDI Beat Clock protocols to synchronize

    >operations between MIDI-based controllers.





    This is another great little code nugget for developers. It means that MIDI sync becomes part of the core API's, which basically means that any app and several apps together can be time synchronised. Lots of possibilities here... a few off the top of my head: How about MS Word flipping pages in sync to Logic, Karaoke style; Keynote changing slides synced with an external sequencer: FCP playout synced to Garageband; Maya animation timed in response to Digital Performer. It should make it much easier to obtain MIDI sync over ethernet/WiFi. Of course the main benefit is to encourage new apps that we can't even imagine yet:



    Man I'm going to have to hit those Cocoa Programming books again. Tiger rocks!
  • Reply 26 of 27
    kickahakickaha Posts: 8,760member
    Quote:

    Originally posted by GregAlexander

    Yeah I guess the title is obvious: "Core Audio in Mac OS X Tiger to improve audio handling". If it didn't improve audio why would they do it!? hehe



    Anyway, back to MIDI -



    I've done some reading around on various sites for the relationship of MIDI to Ethernet. MIDI currently IS used over ethernet, it uses time servers (including standard internet NTP), and the greatest network latencies of your connected devices are found and used to set a standard delay, hopefully quite short.



    It is hopefully short with MIDI because they want to work with instruments in REAL TIME. Of course, a delay when playing music on 2 separate computers doesn't matter even if it's a few seconds as long as they are playing in time with each other - it just means that when you skip to the next song, it will take that long to start playing.



    BUT, that said - MIDI is really using multiple networking technologies to synchronise the devices over ethernet. So yes it's obviously not using the old style midi that required quality 5 pin cables less than 50 feet. In fact, Apple could probably just say "we're synchronising our audio and video now" and put together the technologies without using MIDI at all.



    So who knows if Apple are planning on synchronising video, audio, etc in Tiger - maybe this rumour relates to that, maybe not - though I hope when they do work in this area they use an existing standard.



    Hope that's useful.



    Main source (plus the relevant links for timecodes!):

    http://www.fact-index.com/m/mu/music...interface.html

    http://www.grame.fr/MidiShare/fr/Reseaux/Reseaux.html




    Good links... but they don't address the real problems I was thinking of.



    1) That's MIDI over Ethernet, not MIDI over a full-fledged network. What's the difference? Their network topology wasn't described in #2, but from that I assume that it was pretty flat, without routers, switches, and such. Heck, mLAN from Yamaha is MIDI over FireWire, and now we have FireWire networking too - saying that Ethernet has replaced the old serial MIDI wiring is still a long ways from MIDI over a full network. Now, they could have very implemented this on, say, a campus network, and just didn't state so clearly.



    2) WiFi (the original technology under discussion) makes Ethernet look positively deterministic. It is much, much worse, as just a physical layer.



    Edit: Ok, drilled through to the OpenSound Control page... very interesting stuff! *Almost* makes me think a MIDI *replacement* over the network is a solved problem.
  • Reply 27 of 27
    Quote:

    Originally posted by MoBird

    This feature ia already available. It is known as JackOSX.



    Check it out:

    http://www.jackosx.com/




    Jack does NOT support multiple interfaces in OS-X! Contacted the developers and said that it is a function of the OS and the app to gett multi interface support. Still waitingfor it in Tiger and Logic 7. One interface is all you can use with Logic 6 Pro and OS-X 10.3x.
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