[tcdiem]

0. This is because of aggressive AE behaviour - it exclusively locks the audio device, even when xbmc itself is not playing audio, when it should release it (at least when media isn't playing and GUI sounds are off) - Disable exclusive mode. I am presuming this is your issue, that's what happens with Frodo on Windows, I haven't tried with Linux yet myself. Nothing mych I can do about it, I have raised the issue several times with teh AE people but no response yet. I presume that before release they will tidy this up and as release gets closer I will certainly push hard for this as this will cause a LOT of issues without outside-of-xbmc behaviour.

I kinda understand that AE is using exclusive lock, since this is the same from few years back (and multiple platforms, not linux only) to do audio passthrough ... I was trying to see if there's a way to play into AE but apparently that isn't possible, not in a overnight hack

3. I haven't done much with the Pi myself - Paul Webster in this thread seems bit of an expert. But my guess is OE Pi does not include the required alsa stuff. It works moderately ok with Raspbmc, but alsa on the Pi is thoroughy alpha quality so far.

4. Sync - Are you actually measuring this somehow? I've not heard anything that feels like 200 ms of difference...but if you're mixing different platforms with distinctly different architectures, then I am not that surprised. There are controls in both squeezeslave and LMS you can explore to improve things. But yeah, as I said, it's basically fine for room to room sync, but in room sync you'd really want identical systems and even then with software players it's basically impossible for it to be perfect....because there are buffers involved.

Not sure if you are aware that in http://code.google.com/p/squeezeslave/downloads/list there's also the armhf binaries available (not only armel). Most currently builds of OpenELEC, raspbian and so on uses the hardfloat opposed to armel. Since I've trashed already my openelec SD card to install raspbian, I cannot test it on openelec. At least on raspbian squeezeslave works flawlessly (well .. apart from some random lockups ).

Regarding sync, no bulletproof way of measuring it, if a music is about 120-140 bpm, its one beat per 0.5s. If the audio is out of sync for approximately half a beat, I've guessed its close to 0.2s. Now that I've got squeezeslave to work on raspberry pi, I will try to use and and comment later on my experience. If it works nicely, I will try to setup some build environment for xbmc and its libraries for the rpi, which might take a bit long to build.