Bob Miller wrote:
>As most of you are aware (and are really tired of hearing about), I'm
>building this mp3 jukebox. Currently, it's running on a server and
>streaming out over Icecast to the PC on my desk. That works, mostly,
>but the ultimate goal is to be able to feed the same audio stream into
>two stereos: the little one in my office, and the big one downstairs
>in the game room that drives eight pairs of speakers throughout the
>house (but not my office. )-: ). Obviously, I want both stereos to be
>in sync.
>
>Last night, I ran an Icecast client on a second machine to see whether
>Icecast clients are in sync. It was awful. The two PCs were about a
>second out of sync.
>
>I can move the jukebox to be next to one stereo or the other, no
>problem. But what's the best way to distribute the signal, preferably
>in digital form, from one room to another in such a way that the audio
>source stay synchronized? I'm thinking that I may need to distribute
>the actual PCM data, otherwise I'll be at the mercy of clock drift in
>the individual D/A's. Or else I need some fairly clever net protocol
>and resampling code.
>
>Mr. O. sent me a link last night to the SliMP3, which might or might
>not be part of the solution. Thanks, Mr. O.
>
> http://www.slimdevices.com/
>
In regards to the out of sync problem, are you sure the buffers on
whatever clients you were running were the same? Were you using the
same software on both machines. One second seems really bad.
If this doesn't fix your problem you could try the following: It
seems like if you were able to multicast or broadcast the MP3 data
across one subnet, and had identical client setups, you'd be able to get
these pretty close to in sync. The clients would be receiving the exact
same ethernet frames, so you'd only have the problems of hardware
differences in terms of latency of the network card and sound card. I
don't know what these values would be, I'm guessing pretty small. Even
small latencies will cause the sound to be different though, maybe like
running through some effects processor. The delay for Dolby surround is
around 22 milliseconds. You could put together your own Icecast client
that would then rebroadcast the packets, or perhaps Icecast already has
this ability?
Of course, the easier solution is to wire up some speakers in your
office and call it a day :).
Kahli
Kahli
