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View Full Version : SqueezeCenter gapless syncing seems much worse than SlimServer



rbl
2008-04-23, 12:25
I have just installed SqueezeCenter having used SlimServer for a couple of years now. Gapless play works perfectly on both versions with one SB3, but with 2 sync'd SB3's SqueezeCenter seems a lot worse. I get gaps between tracks of upto 10 seconds, although more normally a couple of seconds. I thought SC7 was meant to be "vastly improved" with regards to sync'ing?? My wireless network performance seems fine, running on a 2GHz PC with XP Pro so that side of things should be fine.

I read that the developers have no plans to improve this. Frankly this is bad news!!!! Guess I'll go back to SS6.5 but frankly it is very disappointing, and possibly time to look for another solution, unless someone knows how to improve things?

CatBus
2008-04-23, 13:37
SC7 sync *is* vastly improved over SlimServer. Long tracks stay in sync now, poor network conditions don't throw off sync anymore. Stuff that didn't work well at all now works perfectly--I think it's fair to call that a vast improvement.

That's not to say all sync bugs were fixed. For example, gapless sync was broken before SC7, and it continues to be broken after SC7. No significant change as far as I'm concerned. You've expressed that you don't mind the degree to which this feature is broken in SlimServer, but many people, including myself, consider SlimServer's gapless sync so badly broken that it's unusable. Half a second or five years, a gap is a gap. I can't see how SlimServer's behavior was even remotely tolerable, so SC7 is no worse.

I don't know where you've read that the developers have no plans to fix this but that is not true. There is already a bug filed on this topic and the developers involved have expressed an interest in fixing it. It is an extremely difficult problem to fix, however, and the fix is unlikely to be done anytime soon. I don't think, however, that there are any plans to revert from Broken Gapless Sync Method #2 back to Broken Gapless Sync Method #1, because it wouldn't actually fix anything and it would break the sync improvements that were actually delivered with SC7.

aubuti
2008-04-23, 13:46
I have just installed SqueezeCenter having used SlimServer for a couple of years now. Gapless play works perfectly on both versions with one SB3, but with 2 sync'd SB3's SqueezeCenter seems a lot worse.
Have you tried fiddling with the various settings for fine-tuning sync that are available in SC7? There's a lot there that wasn't in 6.x, and something might fix your issues. It still won't be gapless sync, because it's not designed for that (yet), but you should be able to improve it.

rbl
2008-04-23, 14:05
Have you tried fiddling with the various settings for fine-tuning sync that are available in SC7? There's a lot there that wasn't in 6.x, and something might fix your issues. It still won't be gapless sync, because it's not designed for that (yet), but you should be able to improve it.

Not really apart from setting server priority to -16 (High). I just noticed some settings under Settings->Players->Audio, but not sure how to set these. I am not so worried about the two players being perfectly in sync with each other since I cant here them both at the same time, but am worried about the gaps.

CatBus - thanks for the info. I guess I had hadn't appreciated the good work done as not so relevant to me, but I can't help but feel the gaps are worse, at least in my configuration.

aubuti
2008-04-23, 14:10
Not really apart from setting server priority to -16 (High). I just noticed some settings under Settings->Players->Audio, but not sure how to set these. I am not so worried about the two players being perfectly in sync with each other since I cant here them both at the same time, but am worried about the gaps.
I'm not in front of SC7 right now, but my recollection is that there is good guidance in the help for those settings (eg, if a track starts-stops-restarts then do this, or if the transitions between tracks are too long do that, etc.). Given what you're saying here, you might get some satisfaction by reducing how much the buffer has to fill up before it starts playing.

rbl
2008-04-23, 14:26
I'm not in front of SC7 right now, but my recollection is that there is good guidance in the help for those settings (eg, if a track starts-stops-restarts then do this, or if the transitions between tracks are too long do that, etc.). Given what you're saying here, you might get some satisfaction by reducing how much the buffer has to fill up before it starts playing.

Little information boxes come up if you drag your mouse over the "I", which helps somewhat, but nothing particularly conprehensive that I can see. Think I'll have to play around with it...

aubuti
2008-04-23, 14:51
You can also look at some of the discussion in the threads in the Beta and/or Developers forums. Look especially for posts by user "awy", who did most of the rewriting for sync. Probably more details than you want, but might give an appreciation of how much work went into sync on SC7, and how gapless sync is far from trivial.

GeeJay
2008-04-23, 17:09
I've had the same issue, rbl, since I switched to SC7. I also had a problem with one player starting 3-4 seconds after the other. Never had these problems with 6.x.

I switched back to the Classic skin, which seemed to help for awhile. Problems started again a week or so ago, so I switched all players to start as a group. Things seem to be working fine right now, so I think I'll try going back to the Default skin and see if the problem recurs.

rbl
2008-04-24, 06:28
I switched all players to start as a group. Things seem to be working fine right now, so I think I'll try going back to the Default skin and see if the problem recurs.

How do you switch all players to work as "a group"? Is this under SC7.0 or SS6.x

GeeJay
2008-04-24, 17:43
SC7. Go to the "Audio" settings for each player. Underneath "Synchronize Power", choose "Power Off/On With Group". Save the settings before going to the next player.

CatBus
2008-08-31, 20:48
FWIW most remaining gapless sync issues seem to be fixed right now with the brand new sync code in the 7.3 betas. Please try it out and report bugs.

ModelCitizen
2008-08-31, 21:06
The biggest change in 7.3 is the New Streaming. It was introduced into the Boom beta branch for a while and was very impressive. Logitech obviously take the synced streaming issue very seriously indeed and are about to cure what for me is probably the largest issue of the current architecture (and the only reason I'd ever consider buying a Sonos system).

I don't know why you get a 5 second gap though. Mine is just a tiny glitch....

MC

awy
2008-09-01, 02:01
I have no idea where a 5s gap could come from, unless some preferences have been explicitly set to achieve that.

In terms of what you can fiddle with in 7.2, the two most likely candidates are the syncBufferThreshold (per player) and syncStartDelay (server wide, under Networking in the WebUI, default 100ms). This latter is new and, in the case that perfect synchronized track start is not required, could be reduced to 1 (not 0, as 0 => default => 100ms). This would add to the chance of resync jump just after track start in which case, if you were happy with the old behaviour where sync can drift during a track, you could turn off maintainSync (per player).

There is no UI to change syncBufferThreshold, but the default is only 4kB and it has not changed since SC6. If you want to change it, then you need to use the CLI.