Achieving gapless play regardless of renderer, and other requirements..

[Pastim]

I have spent many, many, hours trying to get an acceptable UPnP set-up working as an alternative to Squeezebox (Logitech Media Server). My main requirements are:

- a linux server that can handle flacs of varying quality up to 24/192, with support for non-standard tags for classical music
- gapless playback even on UPnP renderers that don't support it
- playback of the highest quality flacs on renderers that support that quality without any degradation, and on those that don't with some acceptable loss of quality
- a control point on linux and/or Android
- multi-room playing of the same tracks would be a bonus.

To cut a very long story short I finally achieved most this. If this is of interest, read on. If not, don't!

1. I use MinimServer as my server, running on my linux desktop. It provides the best library menu I have seen anywhere, by some margin, and is very flexible. The hierarchical menu structure, using the tags that I want to use, dynamically shows what is relevant at each level. This is exactly what I need. People reading further might wonder why I don't use foobar2000 as the server. The answer is that although the menu can be tailored somewhat, it is not a patch on MinimServer's.

2. I then use foobar2000 as the software that streams music to my UPnP Hi-Fi, in my case running under Wine on my linux desktop, with the foo_upnp plugin. The UPnP Server settings are:

Basic Settings - to achieve compatibility between different renderers (mine seem to have the same 'User-agent' string so cannot be differentiated by foobar2000 profiles):

- always use the default streaming profile
- add WAV and LPCM 44.1/16 compatibility stream

Streaming Profiles - Default profile (so always used for all devices)

Renderer Capabilities (probably unnecessary):
- samplerate range: 11025 to 192000
- Max bit depth: 24

Playback Stream Capture:
- codec: lpcm
- samplerate: 192000 (the best my best UPnP player will do)

This foobar2000 will then act as a renderer, playing what it is told to by my Control Point.

I have checked that if I turn off the 44.1/16 WAV/LPCM compatibility stream, files at 24/192 still play on by best renderer but don't play on others of lesser quality, proving that these settings work to a degree. However, it does seem that I only get 16 bit streams (i.e. 16/192) which is disappointing.

3. For the Control Point, either another instance of foobar2000 on my laptop acting as a control point, or BubbleUPnP on my smartphone, can be used as controllers of MinimServer, both with an option to play 'gapless'. (A Control Point with support for gapless playback is required - I tried KinskyDS but could not get it to work on linux). The Control Point is set to select foobar2000 on my desktop as the renderer. That in turn streams the music to my Hi-Fi device(s).

After all this, how does the sound get played on my Hi-Fi renderers?

A. Start MinimServer on my desktop (automatic at boot).
B. Start the foobar2000 server on my desktop, and the UPnP server within it (automatic on starting foobar2000).
C. Start a Control Point and set it to use MinimServer as the source, and the foobar2000 server as the renderer
D. On the Hi-Fi, select foobar2000 instance on my desktop as the server, playing the 'Playback Stream Capture' stream
E. Select music using the excellent MinimServer menu, and play on happily.

The music is now uninterrupted, with no gaps because foobar2000 can play flacs gapless, the Control Point is set to ask it to do so, and the players effectively only see 1 'track' so it doesn't matter if they aren't inherently gapless. Further, if it the device cannot cope with the data quality, it falls back to 44.1/16 (i.e. CD quality). It also transpires that I can play the same music in different rooms. The sync isn't adjustable, but seems reasonable.

At last. No gaps, a really usable music selection method, and decent sound. All that remains is to find those missing 8 bits for my best quality tracks