[linux-audio-dev] OSC, mDNS and LASH: a good combo?

My impression is that more and more applications are moving to OSC for inter-process communication. Question 1: Are most audio/midi applications converging on OSC? Are there any moving away from it? Or are there other strong contenters in this area? AFAIK all linux audio/midi applications use an arbitrary UDP port number, and rely on manual configuration of this for the server and all clients. With OSC popularity increasing this will pose a growing problem for end users who have to configure the ports, and for developers of client programs that want to interact with multiple servers. The answer to this issue is service discovery, which was recently discussed on the OSC_dev list [1]. That thread leads to a product called howl [2], which is an open implementation of mDNS/redezvous/ zeroconf (take your pick). It provides 3 daemons (of which 2 should be run) and some libraries. Using this implementation all applications would (ideally) register or discover services using the howl libraries. Apart from this, the programs would communicate via OSC. To me this seems like a lot of overhead for a relatively small gain. OTOH it seems like a very flexible and future-proof solution. An alternate way I've been considering is an OSC-based service discovery daemon. It would accept OSC messages to register and discover services. The advantage of this is that it only uses 1 small daemon, but more importantly that applications do not need to use any additional libraries besides the OSC one (<insert liblo plug here> :). So far I can see 6 input messages for such a daemon, with 4 response messages. The disadvantage is that the daemon would still need an arbitrary port number, and all applications would need to know it (at least for a while). For intra-host discover the daemon could still interact with howl or something like it if that is needed. But if this approach is successfull we could request one dedicated port from IANA. Question 2: Are there other better alternatives? Question 3: Which alternative is better or do you prefer? (mDNS/OSC-daemon) The only thing I haven't mentioned yet is LASH. Well, in my opinion it is the prime example of an application that needs to interact with all other linux audio/midi appications. As such, I think it could gain most from a service discovery scheme. And there has been talk about using OSC for it [3]. Comments/suggestions/questions? Blast away! Phasers on stun please! And Steve: appologies for stepping on your turf. Best regards, -- Martin [1] http://www.create.ucsb.edu/pipermail/osc_dev/2004-December/000841.html [2] http://www.porchdogsoft.com/products/howl/ [3] http://music.columbia.edu/pipermail/linux-audio-dev/2004-August/009288.html [4] http://www.cnmat.berkeley.edu/OpenSoundControl/ --------------------------------------------------------------------------- 30 years from now GNU/Linux will be as redundant a term as UNIX/MERT is today. - Martin Habets ---------------------------------------------------------------------------