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Have you had a closer look at that synchronize state stuff? I can't see much in the article. > devices synchronize state using a LAN If that has anything to d

by szszrk 5y ago

Have you had a closer look at that synchronize state stuff? I can't see much in the article. > devices synchronize state using a LAN If that has anything to do with music latency, then it's not "nothing substantial". It's their core business and their flagship feature. What they do well, that others could not, is playing multiple speakers perfectly in sync. Either stereo, or multiple rooms, almost as many speakers as you want, connected via wired network, or wireless, or by their on mesh system. And each speaker is basically a separate computer. It's not connected by analogue cable. Anyone who were looking for Sonos alternatives with that functionality knows it's very hard to find and suddenly their prices become somewhat justified.

cosmotic 5y ago
Slim Devices' squeezebox had this feature before Sonos. I implemented it in high school using visual basic. The most non-trivial part is that if you try to synchronize an MP3 or other encoded stream instead of the decoded PCM stream, you end up seeking to mid-frame points which causes invisible adjustments to the seek point. In the end, it's as simple as 'seek to this point' and then check if the point is off by less than some threshold, don't do anything. I did a few other fancy things like not seeking until the 'heart beat' lined up a few times in a row (duration in heartbeat was same as difference in time since last heartbeat).
KingMachiavelli 5y ago
I admit I only briefly looked at each patent but even looking a second time, I can not find anything more specific basically the devices share clock information and calculate the difference between their clocks. How is this different than syncronizing transactions between database servers or how GPS works? I found a GPL license multi-room/device audio player that discussed this very lawsuit last year [1]. The developer raises the same point than anything like this will involve something resembling clock syncronization. Looking through the lawsuit itself, about 90% of it is just comparing the end result of Sonos' & Google's products in that both let you add/group speakers, adjust volume and playback of the group, etc. I cannot find any claim that Google's implementation is a copy of Sonos'. It seems to try to sugest that is the case by bringing up that prior to Google's devices, Google had worked with Sonos and had access to details of their implementation. [1] https://github.com/badaix/snapcast/issues/642 https://github.com/badaix/snapcast/issues/642

by szszrk 5y ago

cosmotic 5y ago

Slim Devices' squeezebox had this feature before Sonos. I implemented it in high school using visual basic. The most non-trivial part is that if you try to synchronize an MP3 or other encoded stream instead of the decoded PCM stream, you end up seeking to mid-frame points which causes invisible adjustments to the seek point. In the end, it's as simple as 'seek to this point' and then check if the point is off by less than some threshold, don't do anything. I did a few other fancy things like not seeking until the 'heart beat' lined up a few times in a row (duration in heartbeat was same as difference in time since last heartbeat).

KingMachiavelli 5y ago

I admit I only briefly looked at each patent but even looking a second time, I can not find anything more specific basically the devices share clock information and calculate the difference between their clocks. How is this different than syncronizing transactions between database servers or how GPS works? I found a GPL license multi-room/device audio player that discussed this very lawsuit last year [1]. The developer raises the same point than anything like this will involve something resembling clock syncronization. Looking through the lawsuit itself, about 90% of it is just comparing the end result of Sonos' & Google's products in that both let you add/group speakers, adjust volume and playback of the group, etc. I cannot find any claim that Google's implementation is a copy of Sonos'. It seems to try to sugest that is the case by bringing up that prior to Google's devices, Google had worked with Sonos and had access to details of their implementation. [1] https://github.com/badaix/snapcast/issues/642 https://github.com/badaix/snapcast/issues/642