We captured a very large Wireshak of the comms last week and did analysis of where time was going.
Summary so far:
the stream is delivered in 10second fragments
we aim to have 3 hls fragments loaded (so 30secs of audio buffered). Most the time we achieve this. That is a lot of audio buffered.
during the problem time if not streaming from the USA (eg. Europe) there is a huge amount of traffic congestion which results in that its impossible to read 10secs of audio in less than 10seconds. The round time of the link (typically 140ms but can jitter to 300ms+) that can make it unfeasible for it to be all transferred and ack’d in time. We also replicated the issue on PC version of VLC.
at 320k rates it is feasible when playing from Europe to transfer the data in time.
We’re now exploring options on what we can do to improve matters. We’ve also been discussing the above with the team at Groove Salad.
So, better understanding of what is going on, but scratching head on what we can do about it.
The Beat, Montreal - typically we pick AAC over mp3 even though the rate is lower as AAC works so much better at lower rates. However, in the case of this station i think they re-encode the aac from the mp3 so double trouble. Adjusted to use mp3 stream.
Steve,
I read your answer that you added a second WDR3 stream in MP3 quality. However, I don’t see a second WDR3 station in the radio directory. The current stream still gives hick ups. They seem to coincide with the underruns. Perhaps the attached print screen from my diagnostics will help.
Steve, I just want to pause and take a moment to thank you personally and Naim for the awesome work you are doing.
I understand that this may have been the plan with rolling Naim own’s webradios service but your involvement, speed of resolution and feedback is just stunning.
BIG THANK AND KUDDOS.
I can’t say I’m having any issues with Groove Salad, has been fine for me using the HD stream…(BTW, thanks for highlighting the station, didn’t know it previously but quite enjoying it…Good to switch to from RP at times…!) – Reminds me of hanging out in bars with the same chilled vibe in my London days…!
I’m listening in Australia however, so obviously a completely different time zone – I’ll have to try late evening at some point and see if I experience the same drop outs as you report in the European afternoon….
Noticing I’m now getting artwork showing on Groove Salad…Is this a recent change or I just never noticed until today…? It’s not every track…
One thing I have noticed occasionally this morning is a slight sync issue with the track info and the actual music playing – the current playing track info changes quite a bit before the actual track changes, something like 10-15 secs at times…
I’m used to it being the other way round, say with Radio Paradise, the track will change and then the info will change 3-4 secs afterwards…
Don’t know if this is a buffering issue or a SomaFM issue…?
Edit: Apologies @fritsveer , hadn’t seen your earlier post re artwork…Seems it’s been happening all the while. Strange it’s one of the few stations that does show it….
In the case of Groove Salad there are 2 streams that are broadcast with very different buffering delays from their servers.
Groove Salad MP3 - approx 8secs behind live ‘FM’ broadcast
Groove Salad FLAC - approx 30secs behind live broadcast
XPeri who independently supply the live meta are synchronised to the FM broadcast, so we have an issue to be in sync.
In our system we can adjust this sync, so we’ll aim to find a sensible middle ground. We currently had it set to 5secs, so add on 3-4secs of identification and delivery time is about right for mp3. I’ve added on another 10secs to hopefully find a sensible compromise.
Interesting to read how it works and yes a bit of a tricky one to solve…As you say, with the different buffers and then all the other variables, latency etc, it’s something of a compromise it seems…
I’ve tried to follow the last 45mins or so of play and it does seem a bit better timing wise (one or two track changes were spot on!), but it does seem to vary…I don’t know if it’s something that needs to settle after backend changes are made…?
One thing I have noticed a couple of times, particularly when the info goes to the generic station credit, i.e when there’s a station broadcast/appeal, that it has ‘stuck’ on that when the next music track comes on…only way I found to unfreeze that and show the current playing track info was to flick out of the App and back in again, though it wasn’t 100%…Not sure if that would be an App issue or XPeri…?
hi @Stevesky
new to this thread so it may have been asked before
is it possible to look at genres across a geographical area?
eg classical stations across europe
or world/traditional across middle-east
many thanks for the great iradio service and for your involvement here on the forum
