Author Topic: Multiple external soundcards for multi-room audio?  (Read 2485 times)

trentend

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Multiple external soundcards for multi-room audio?
« on: March 05, 2009, 08:27:57 pm »
I have a Toshiba Multimedia Center Audio/USB hub and remote control.  The SB0500 and RM1500 remote appear to be slight variations on the Creative SB Live24! External.  It's supported through a recent patch to ALSA (sometime in late January) in latest kernals.  I seems to work in Intrepid, but not in Hardy.

A couple of questions.

Would this be too problematic to get it working under LinuxMCE?

How many of these external soundcards could I reasonably run under LinuxMCE bearing in mind the need to connect them through the USB controller?

I have one of these, but they are currently stupidly cheap (10 UKP), and would like to get more to use them for multi-room audio.

Thanks in advance for any help or advice that you can offer.

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #1 on: March 06, 2009, 02:26:05 pm »
Okay, I've taken the plunge and bought *some*. I'll let you all know how I get on, though it may be some time.

colinjones

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Re: Multiple external soundcards for multi-room audio?
« Reply #2 on: March 06, 2009, 02:54:15 pm »
You cannot have multiple audio or video outs in LMCE irrespective of what the kernel or hardware supports. You are not just using the KDE desktop to play video/sound so what it supports isn't relevent. What is relevent is what the LMCE media control system can do, and currently multiple Entertainment Areas (The logical units that a Media Director controls) cannot be controlled by a single Media Director providing more than a single internal source of media. Only alternative sources of media can be "directed" by a single MD to more than one EA, eg the media director is the first source (AV for instance) and you also use the same MD to control and "direct" media from a second source (like a BluRay player or STB) directly to the display/playback device.

This isn't to say that it couldn't be done or that it hasn't been discussed or requested, however LMCE's architecture is extremely complex and this would require a lot of work to add to it. It has nothing to do with whether the hardware or OS is capable of it, it is all about whether LMCE can control it.

posde

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Re: Multiple external soundcards for multi-room audio?
« Reply #3 on: March 06, 2009, 03:16:35 pm »
A lot of people coming to lmce think about multi room audio like it was done in the old days. A single machine, a single receiver, and lots of audio wiring through out the house.

This is possible with lmce, but usually not the best practice.

Instead, people put dedicated boxes in the rooms, where they want their media. Whether these boxes are SqueezeBoxes for audio only, or small PCs (like the Asus EEE boxes or Asus EEE tops), is a matter of the kind of media you'd like to have.

If you do want to go the route with multiple sound cards in your system, you can do that with some work. You have to setup multiple softsqueeze instances, and will be limited to audio transport over it.

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #4 on: March 06, 2009, 03:17:52 pm »
You cannot have multiple audio or video outs in LMCE irrespective of what the kernel or hardware supports. You are not just using the KDE desktop to play video/sound so what it supports isn't relevent. What is relevent is what the LMCE media control system can do, and currently multiple Entertainment Areas (The logical units that a Media Director controls) cannot be controlled by a single Media Director providing more than a single internal source of media. Only alternative sources of media can be "directed" by a single MD to more than one EA, eg the media director is the first source (AV for instance) and you also use the same MD to control and "direct" media from a second source (like a BluRay player or STB) directly to the display/playback device.

This isn't to say that it couldn't be done or that it hasn't been discussed or requested, however LMCE's architecture is extremely complex and this would require a lot of work to add to it. It has nothing to do with whether the hardware or OS is capable of it, it is all about whether LMCE can control it.

Clearly my knowledge is sketchy and incomplete.  My understanding was that multiple soundcards could be used to run multiple instances of softsqueeze.  So it was my intention to attempt to install multiple (in this case) external soundcards, and connect these to the "system" as softsqueeze players.

Are you saying that I'm labouring under a substantial misapprehension?

*****Edit*****

Squeezeslave, not softsqueeze.
« Last Edit: March 06, 2009, 03:27:12 pm by trentend »

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #5 on: March 06, 2009, 03:23:56 pm »
....If you do want to go the route with multiple sound cards in your system, you can do that with some work. You have to setup multiple softsqueeze instances, and will be limited to audio transport over it.

That's what I had in mind.  In my case I have ceiling speakers wired into various rooms in my house. These are all wired back to the central wiring cabinet (that also contains a rack where my core will be located, along with the media directors for the lounge and dining room). I intend to use these speakers for ambient music, and (hopefully/possibly) announcements (like alarm conditions, the doorbell, etc.).  Independent of these speakers certain rooms will have media directors, and there will be portable media directors.

One of the things that I hope to be able to achieve with this is multi-room sound, without having to boot up a media director in every room (which I would consider to be impractical in some rooms, like bathrooms. I have three bathrooms....).

posde

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Re: Multiple external soundcards for multi-room audio?
« Reply #6 on: March 06, 2009, 03:26:43 pm »
I would still not use softsqueeze, but invest 120EUR per room, and buy Squeezebox Receiver.

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #7 on: March 06, 2009, 03:34:16 pm »
I would still not use softsqueeze, but invest 120EUR per room, and buy Squeezebox Receiver.

Can I ask the criteria on which you base that decision, and why you would choose that?  For multi-room cost is very much a factor. The soundcard option works out at about 10 UKP + amplifier (approx 20 UKP, depending on solution). The squeezebox (boom) is circa 180 UKP each.  Multiply that by approximately ten, and it's the difference between 300 UKP (just about viable) and 1800 UKP.  At the top end it's not a solution that I would consider, rather I would have one (or two) player(s) and link all the speakers to it.  That wouldn't allow me to have different sound in different rooms, but it would at least allow me to have background sound for parties and announcements.
« Last Edit: March 06, 2009, 03:36:44 pm by trentend »

posde

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Re: Multiple external soundcards for multi-room audio?
« Reply #8 on: March 06, 2009, 03:40:02 pm »
The receiver has the advantage of working without a problem if configured correct. Softsqueeze is a kludge. And I do not like kludges.

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #9 on: March 06, 2009, 03:51:47 pm »
The receiver has the advantage of working without a problem if configured correct. Softsqueeze is a kludge. And I do not like kludges.

I understand that.  Is it technically possible, and does it work, though?  I ask because that's the impression that I had gained through looking at the forum and the wiki, and now I'm concerned that I'm trying to do something that is known not to work.

posde

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Re: Multiple external soundcards for multi-room audio?
« Reply #10 on: March 06, 2009, 03:56:48 pm »
People got it to work, softsqueeze is what you are looking for.

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #11 on: March 06, 2009, 04:06:36 pm »
People got it to work, softsqueeze is what you are looking for.

Thanks. I'll report back with how I get on.

colinjones

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Re: Multiple external soundcards for multi-room audio?
« Reply #12 on: March 06, 2009, 08:15:15 pm »
trentend

just be aware that squeezeboxes (soft or otherwise) are not true Media Directors even just for sound. the implementation of slimserver-streamer that controls the slimserver/squeezecenter on the LMCE machine is far from complete so there are numerous things that you cannot do on it that you can with a proper media director.... for instance, you cannot send internet radio streams, moving media around the house does not continue where it left off it restarts at the beginning of the track you were playing, and most importantly you cannot move track forwards or backwards in a playlist from the squeezebox buttons - this is because the squeezebox is not really playing a playlist it is playing only the current track, the media plugin in LMCE keeps track of the play list and sends the next track, the "streamer" plugin does not relay track forward/backward button commands back to LMCE....

clearly having LMCE handle multiple sound cards (and video cards), with separate pipes and EAs would be far a more elegant and comprehensive true MD solution compared with softsqueeze if we were going to cater for the option of MDs serving multiple areas but as I say this is going to require a lot of effort to get working. The MD/room that possy mentions is by far the preference, but going with squeezeboxes or even softsqueezes is an alternative as long as you are aware of the limitations.

trentend

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Re: Multiple external soundcards for multi-room audio?
« Reply #13 on: March 06, 2009, 10:42:12 pm »
Thank you for that.

My choice is relatively simple.  Either I have a small number of sound sources, driving many speakers, or I accept the limitations of softsqueeze. I'm okay with the later.

What is important for me is that I can synchronise media playback.  Is that achievable?  An inability to stream radio might become an issue for me, but I'll work with what I have and see where I get to.

colinjones

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Re: Multiple external soundcards for multi-room audio?
« Reply #14 on: March 07, 2009, 01:06:40 am »
hmmm no, I don't believe that the LMCE control of SqueezeCenter allows for splitting of streams so that they remain synchronised... sync is quiet difficult at the best of times, but if LMCE doesn't have full control over the output devices (which it really doesn't, SqueezeCenter controls them albeit on a LMCE machine) its going to be impossible unless SqueezeCenter itself supports synchronised playback, exposes that functionality to the TCP control port, and the slimserver-streamer plugin for LMCE supports that functionality (which it doesn't currently)... lots of ifs followed by a no.. sorry!

Even with MDs it is difficult to get perfect sync - the only realistic way around this is the xine-server/client model I proposed recently, which would allow for at least broadcasting possibly even multicasting, either of which would immediately solve the sync issues with MDs. However, that is something outside my capabilities to implement and is not high on the list of priorities for the devs, currently.

Streaming Internet radio, as I say, is currently not supported by the slimserver-streaming plugin, however there is nothing stopping you configuring the individual Squeezeboxes/softsqueezes with presets for the Radio stations you want. They are perfectly capable of playing Internet Radio without LMCE's intervention. However, again, sync will be a problem, primarily because you cannot guarantee what buffering is involved. These protocols simply are not real-time. Again, the only way to ensure this is to have LMCE pulldown and buffer the stream itself, then use a realtime broadcast or multicast to get them to the end points.