4 ms·
> Why distribute the music that way Because distributing music over multicast works very well, and it's rather simple in nature: You get audio frames as UDP pa
by anyfoo 4y ago
> Why distribute the music that way
Because distributing music over multicast works very well, and it's rather simple in nature: You get audio frames as UDP packets, you play them. Because it's multicast, they reach where they should.
> why not just attach it to a radio directly
Because you lose control of what's being played, and there are probably not many "elevator music" radio stations.
> or some RPi that will pull the stream
Because then every location that plays the music has to pull an individual stream, quickly saturating the bandwidth for no reason, instead of just subscribing to the multicast stream.
I also would not say "some RPi" is less engineering, and less maintenance, than the current solution that likely uses an off the shelf multicast audio system.
> or just have it prerecorded
Because you lose control of what's being played without a significant replacement step, when you could just play a multicast stream instead.
> Despite its simplicity, seems to be overengineered.
I'm honestly not convinced I read a less "overengineered" solution so far...
- hot_gril 4y ago> I'm honestly not convinced I read a less "overengineered" solution so far... Prerecorded music on an MP3 player sounds like the one simpler solution, though it wouldn't put the elevators in sync with each other or let you control it remotely.
- anyfoo 4y agoYes, but if you want to do even as much as not play the music in the middle of the night, now your MP3 player needs a clock. That clock may drift, or it may drop out completely when the power goes out, unless you synchronize that clock over the network. But if you have network on your MP3 player, you may as well let it subscribe to the multicast stream instead of reading the stream from internal storage. If you do not have network, and you want to change the schedule of when your music plays, have fun to send out some maintenance crew to every single one of those devices. And don't forget any...
- hot_gril 4y agoYeah, this is if you just want your playlist on loop 24/7, which seems reasonable in many scenarios.
- burntwater 4y agoIn the U.S. at least, most jurisdictions will require the music to be shut off in an emergency -- namely, if the fire alarm goes off. Audio sources commonly are required to have a relay/GPIO input that triggers the shutoff, a network command is not good enough (network switches typically not being life safety rated). In this hotel scenario, you have one audio source that can be located in a location that can be conveniently tied into the fire alarm relay panel. Stop the audio there and you've stopped it everywhere.
- hot_gril 4y agoThat makes sense, never mind the MP3 player solution then.
- ibz 4y ago>> why not just attach it to a radio directly > Because you lose control of what's being played, and there are probably not many "elevator music" radio stations. Radio is still by far the simplest and most fail-safe solution. But not playing an existing radio station. Rather buying a radio transmitter, like the ones used in churches - strong enough to emit FM throughout the hotel, and yet not requiring a radio license. Then the speakers would just be plain speakers with a FM receiver attached - no more wifi/wired infrastructure involved, routers, ability of the speakers to connect to the wifi, ...
- anyfoo 4y agoI think this might have been a popular solution once, but my guess is that it came with its own set of problems. Hotels often being pretty big (bigger than most churches, which also tend to be relatively open structures), usage of the license free bands from other devices, audible interference (which you don't care about in ham radio or portables as long as you can still understand what's being said, but for music in a hotel even low interference is bad as soon as it's audible)... though admittedly, I have no experience with radio transmitters for that particular use case.