On Sunday 15 August 2004 12:21 pm, you wrote: > Quoting John Check <[EMAIL PROTECTED]>: > > Google Nelson Posse Lago. He stopped posting to this list about 02.. I > > was wondering if he got hit by a bus or something, but apparently not. > > I'm alive > And the world shines for me today... (ELO) > > Sorry, I haven't been able to keep up with the list, much to my regret... > But don't worry, I'll be back! > > Anyway, lowlat audio over ethernet works and the ethernet delays are > negligible in practice, they are on the order of a few hundred > microsseconds *with retransmits* in practice and most of the time they > won't even happen. Please take a quick look at > http://gsd.ime.usp.br/~lago/masters/artigo-webmidia.pdf . It is small > and most of the text may be skipped (but please note the "sliding windows" > stuff). > > As for resampling and resyncing multiple cards, that's more complicated... > > Quoting Benno Senoner <[EMAIL PROTECTED]>: > > I don't think raw ethernet will buy us anything over using UDP. These > > few usecs less simply won't matter. > > Definitely right. AND udp is simpler to use and allows for packets > up to 64K; the resulting ethernet fragmentation, apparently, doesn't > have a significant impact on performance either. This all tested with > relatively low-end hardware. > > > (but with ethernet you would have the disadvantage that you loose > > routability) > > I didn't try, but I guess this system only works well (with lowlat) > in a LAN. > > > About the packet loss ratio: besides from broken equipement (avoid hubs > > completely, use only switched networks), the packet loss ration in a LAN > > is pratically zero. > > Again, that's right. If the net is dedicated, there should be virtually > no ethernet packet loss; but even if there is, the hardware retransmits > fast enough (IIRC, on the order of nanoseconds) for that to be transparent. > > There are four important TODO things with my code: > > - remove the CORBA stuff; it is a legacy from a past where I intended > corba to have a much more important role, but right now it only gives > us the ability to discover the nodes available, which would be much > easier with multicast/broadcast. > > - clear up the C++ code so that it compiles with g++ 3.x. >
BTW this is nearly done. I have the code in CVS, but I'm in over my head. The remaining problem would likely take somebody who's current about 15 minutes to clear up. > - create a simple gui for the manager (should be eeeeasy). > > - improve error handling (calling exit() at any error is not the best > way to go ;-) > > See ya, > Nelson > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program.