From kde-multimedia Fri Sep 10 12:52:35 2004 From: Lennart Poettering Date: Fri, 10 Sep 2004 12:52:35 +0000 To: kde-multimedia Subject: Re: Vote for a MM system (Was: Re: summary of the aKademy meetings) Message-Id: <20040910125235.GA9623 () seth2 ! intheinter ! net> X-MARC-Message: https://marc.info/?l=kde-multimedia&m=109482078908627 On Thu, 09.09.04 16:05, Allan Sandfeld Jensen (kde@carewolf.com) wrote: > I am sorry if I missed something. I only took a quick glance at polypaudio to > see if you fixed all of the deficiencies of esd, and synchronizations wasn't > advertised on the front-page, but I will have a closer look now. > > Actually I would expect networked audio over a high latency network to work > fine, as long as the buffersize matched the fluctuations in bandwidth. For > instance if you use 200ms of buffer on the recieving side, and advertise that > to the client-streamer. Everything could be synchronized fine, as long as no > more than 200ms of audio is ever in transit at any time. If that happend you > would need to increase buffersize and resynchronize. That part isn't a problem. The issue is synchronization, meaning: when will the sample I write to the sound server now be played? It is impossible to solve this problem precisely. See: you're playing a movie on machine A using a sound card on machine B. To synchronize video and audio the movie player needs to know when to show the right video frame for the a certain sound sample. So it queries machine B: "what is your current latency?". This request takes some time to travel to machine B, let's say 10ms. Machine B replies with "50ms". That reply takes some time to travel back to machine A. let's say 5ms. The real latency is 50ms+10ms. but machine A can only estimate that the real latency is something like 50ms+7.5ms. (7.5ms is half the roundtrip time.) Lennart -- name { Lennart Poettering } loc { Hamburg - Germany } mail { mzft (at) 0pointer (dot) de } gpg { 1A015CC4 } www { http://0pointer.de/lennart/ } icq# { 11060553 } _______________________________________________ kde-multimedia mailing list kde-multimedia@kde.org https://mail.kde.org/mailman/listinfo/kde-multimedia