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Build a Multi-Output MP3 Server?
z80 asks: "I'm rebuilding my house and I am thinking about fitting speakers in every room of the house and pulling some massive amount of cables in the walls. I also want to control and send the output to each set of speakers from the same source, and was thinking that a PC, with 4-6 soundcards, would do the trick, and there are of course a couple of questions I have. What kind of hardware would be required to be able to stream up to six different MP3's through six soundcards at the same time ? Can it even be done? What kind of software can be used to do it? Which OS? How can it be remotely controlled? With respect to the last question, I'm thinking about mounting a couple of flat displays around the house connected to old PC's that run some sort of connection (VNC maybe) to the mp3 server." This is a topic Ask Slashdot tackled three years ago. Now, with applications like Ardour showing off the power of Open Source frameworks like JACK, it seems like building such a machine might not be as hard as it once was. For those of you who have managed to build something like this, what did you do and what hurdles did you have to navigate before things were working? How would you set up a machine to run independent audio to 4 or more rooms?
You could use ATI Remote Wonders (or, perhaps, a similar kind of X10 remote).
These are RF remotes and 16 of them can be configured to use different channels. They use USB dongle for reception - same dongle can serve multiple remotes if needed (just don't transmit simultaneously).
Linux driver can be found at GATOS website
While the idea of using several soundcards and OSS is quite sound, this is a problem which has already been solved by professional audio installers several times over, with equipment custom-tailored for this exact purpose. IMHO, you should get a professional consultation from a home theatre/automation business. The difficulty is not the soundcards or even the software, it's integrating functional control panels (with displays) into each room that will prove to be the most difficult. While you certainly *can* do this with off-the-shelf parts, the pros will always do this sort of thing better.
Good luck!
Playing the files on a local machine off a networked drive would probably give you better sound than snaking analog audio cable across the entire length of your house, too.
Information wants to be anthropomorphized.
There are several options for what you're looking to do these days. My brother is doing a similar thing, but he's using 802.11b for control (through Girder) and PocketPCs for remotes!
Ah yes, if there's one thing the nice folks on the AV Science Forum don't understand well, it's budget constraints. How many people can afford to go out and buy Pocket PCs to replace their remote controls?
-- If you try to fail and succeed, which have you done? - Uli's moose
Well, if you're going to go Linux, ALSA supports multiple sound cards pretty nicely, just tell XMMS (or whatever media player it will be) to use the different /dev/ devices (use devfsd). My first though was an implementation in Windows, Winamp also offers you the choice which soundcard you want to use, although one has to wonder about the IRQ hell of 6 of them in the same computer!
VNC wouldn't be such a good idea, because AFAIK it grabs the pointer so you'll probably end up with a situation where 2 or more people in different rooms wrestle for control of the pointer. A thin X display that connects to the server would work ok, although that would mean 6 computers in 6 different rooms, and when you already have that, it'd probably be wiser to have a "1 MP3-fileserver and 6 clients that draw MP3s across the ethernet" setup. Or you can just use SSH (or even telnet) to connect to the server and let them use mp3blaster, a text-based interface. Yeah, ugly, you can put it to the bottom of your list. But if the 6 clients need 6 "real" computers, it'll be so much waste - with SSH you can connect from a Palm Pilot, but then you'll need 802.11b for significant distances, and you can only get that from high end Palms..
But oh, depending on how long the VGA cable must be, you can always have 2 computers, each with 1xAGP, 2xPCI graphic cards and 3xPCI sound cards, and one of them as an NFS server for the other.. or even use the on-board sound. That should be easier to set-up, IMO.
Anyway, have a lot of fun, IMO you should document the process with lots of pics and put it up on a server, you can then wear the proud tag of "I've been slashdotted".
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One six minute Ogg file at 256 kB/sec takes up about 10MB of space, which translates to 10 hours of music per gigabyte. At about $1/gig, a 100 GB hard drive will cost around $100, and will hold 1000 hours of music, without having to rotate anything. Figure an average of 4 minutes a file, and you're looking at 15,000 songs, compared to 19 on a CD. A 50-pack of CDs costs $17, for 34 cents, and you'll need about 789 70-minute CDs, for a total cost of $268.26.
Since the CD option costs more per-song and is more inconvenient (since you have to change the CDs every 70 minutes), I'd judge it inferior.
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I have a home audio system which is customised to my own needs. I started off at http://en.tldp.org/HOWTO/MP3-Box-HOWTO.html and built diskless systems such as this for all the rooms in my house, and can use all independently of each other.
They all run off a standard computer which I turned into a server when it became out of date (500mhz K6-2, 384MB).
It's very cheap to build the diskless systems and the only extra expense you'll have is the CAT5 cabling over the house (if you're like me though, your house is already CAT5 capable).
Tim
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