On 8/17/07, Ross Levis <ross@stationplaylist.com> wrote:> Is it at all possible to synchronize listeners so they hear the audio at the > exact same time? It doesn't matter if the source and listener is a few > seconds different.Not with icecast, no. If I wanted to do this, I'd write something using gstreamer, and the network clocking code it provides. Mike
Is it at all possible to synchronize listeners so they hear the audio at the exact same time? It doesn't matter if the source and listener is a few seconds different. Someone I know wants to send Ogg Vorbis encoded audio across a wireless LAN using Icecast to 2 LPFM transmitters on the same frequency, and they really need to be closely synchronized to prevent echo in an overlap coverage area. He could be willing to pay money towards custom development, if it is in fact possible. Thanks, Ross.
Ross Levis wrote:> Is it at all possible to synchronize listeners so they hear the audio at the > exact same time? It doesn't matter if the source and listener is a few > seconds different.I was thinking about this one. It occurs to me that ogg bitstreams contain timing data (similar to timecode). You could develop a player that used this ogg-based timecode in conjunction with accurate PC clocks to develop some kind of sync protocol (matching ogg timestamps to time-of-day). I guess you would have to have a master/slave setup where one system was authoritative and others would sync to it. I guess you could also have mechanisms where the master was declared unsound if say it lost the stream, and another master would be "elected" or something. The parallels I see here are the ways that MIDI sequencers and audio devices can sync with SMPTE et al. It's used in video too I think. Of course, you would have to have accurate time, but NTP is capable of very good time-keeping. YOu'd also have to be able to ensure the same latancy for the actual playing of the audio... but that's more complex than I'm qualified to speculate on. Geoff.