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Dedicated audio server

The server plays a key role in the 3A concept. It has a number of functions:

  • First of all, it stores all your music files.
  • Next, it has an audio server loaded, Slimserver, for streaming music to dedicated hardware (Squeezebox) or software (SoftSqueeze).
  • It also takes care of automatically transcoding your lossless files (flac) into lossless (mp3/ogg).

One of the key aspects in the 3A concept, is that we want the music to be always and everywhere available. As a consequence, it is inevitable to have some kind of server, i.e. a computer that never have to be switched off. In short, this can be the definition of a server; it doesn't have to be a huge computer in climate controlled rooms, the only thing is that it is always powered on!

Thinking about the server requirements for a bit more, we can think of the following:

  • It has to be small because nobody wants an extra 'monster' in the living room
  • It has to have a very low power consumption because it's always switched on
  • It has to have a very large storage capacity, one CD stored as flac takes about 300 MB disk space, so 1000 CD's occupies about 300 GB
  • It has to be very silent, it's not possible enjoying music next to a starting plane so to say.

The server concept

So this is what we come up with:

Barebone. This means that the computer's case is as small as possible. It doesn't mean it's limited in capabilities; still it's a complete PC within a very small case.

VIA chipset. VIA is the producer of X86 compatible processor and chipset's. In short, it means that any software running on Intel or AMD processors, will also run on VIA. Typical benefits of this chipset are ultra low power consumption (can drop to 20 Watt), ultra low form factor (motherboard "Mini-ITX" is only 17x17 cm), low sound levels (because the low power consumption only requires small fans or even passive cooling). A disadvantage is that the processor is not the fastest possible. Typically, a 1 Ghz VIA processor, now the fastest in the range, is comparable with Intel or AMD processor running equally fast.

Linux. Best-of-breed server operating system. It's stable, powerful, free, versatile and safe. Every benefit of Linux fit's within the 3A concept.

Virtually unlimited storage capacity. Because a barebone is a normal computer, so typically all features from the PC architecture and Linux are available. With this, you can choose for a single disk of 300 GB, large enough for storing about 1000 CD's. A 300 GB disk is nowadays very cost effective, but if you're willing to invest, you can buy larger disks, up to 1 TB for storing about 3000 CD's. You can also choose for extra safety in the form of mirroring or RAID5 (striping), all with standard soft-raid capabilities of Linux.

Integrated backup. Because you want your investment in ripping and tagging to be safeguarded, backing up your server is integrated in the server concept. Again, typical benefits from the Linux environment with modules like rsync, rsnapshot and rbackup are taking automatically care of backing up your valuable music files onto a separate external hard disk.

Automatic transcoding

The server stores all lossless audio files which have been created by a PC client which is doing the ripping, encoding and tagging task. Once a new lossless file is placed on the server or on existing one is changed, think of re-tagging, this is monitored by the server. The server transcodes this lossless file automatically to a lossy file at choice (mp3 or ogg) in the quality level at choice (bit rate). This transcoding is a complete background process, no interaction is needed.

The tree of lossless music files is exactly synchronised to one or two trees of lossy files. Removing an entry from the lossless tree, also removes the entry from the lossy tree(s). Removing or deleting an entry from the lossy tree, results in re-transcoding that entry. When tags are changed in the lossless tree, these changes are also resynchronised to the corresponding lossy files. The is done without re-transcoding, making the process far more efficient.

Re-transcoding to a different quality level of lossy files is simple done by setting the quality level in the configuration of the transcoder and removing the whole tree of lossy files. Because all the files are deleted, files will be automatically be transcoded with the appropriate quality level.

Additional benefits

Within the 3A concept, we are always talking about a dedicated audio server. This is not entirely true. Once the server is in place, you can extend it with anything you like:

  • general storing purposes like digital photo's, documents, etc.; for this, everything is already in place, so you don't have to do anything extra for that
  • other server tasks like a web or a database server

Once again, it shows that the 3A concept is not limiting your possibilities, it extends them...

Epia Center [epiacenter.com]

Advanced Audio Architecture