LMS Qobuz Plugin - random samplerates

[soundcheck]

Hi.

I did some Qobuz related tests recently.

ENV:
I am running the most recent LMS-git based server.
On a wired GBIT network and 100MBit DSL!

I figured out that, even with a highest data quality setting (96+) I am not always able
to get access to their highest quality tracks. It's more a random thing. Nothing I can
rely on. That's pretty annoying considering my stable network conditions.

A Roon user over at Audio Asylum claimed, if e.g. he goes for Hires 192kHz, he gets it.

On LMS this seems to be random.

I was told by Qobuz support that they limit access in certain cases, such as
high server loads or poor connections.
I am pretty sure that's not what I am looking at. My network is stable and
it happens all the time. That gets me back to LMS as a potential source for
that random behaviour.

Now. Why I show up here in the forum?
Because of the "Roon" user comment I've been referring to, claiming he gets what he wants.
I know that's vague. Anyhow.

Are you - by chance - aware of the or a similar subject?
Have you guys been looking into it?

Does Roon use a different API or different Qobuz interface?
Or a different algorithm to access Hires?

The interesting thing is that the Qobuz app on my iPhone also streams
different rates than LMS! More randomness to me.

Let's hope all this is no too complex.

If anybody has an idea - shoot.

Thx.

[mherger]

You ask many questions... and for some of them we can't give you an answer. Does Roon use a different API? How should I tell? Do they have high server load? You doubt it. But how would you know?

What I can say is that I'm requesting the highest quality possible, according to the latest documentation I have available (May '22). But I'm no longer granted access to their dev sites. Which means my documentation might be outdated.

And the maximum quality available also depends on the player in use. And whether it's in a sync group or not.

[soundcheck]

OK. I conclude.

1. You're not aware of the issue
2. The plugin might be outdated, due to lack of most current API info
3. No further developments can be expected on the plugin
4. Based on the May22 status it would be expected that the best quality will be supplied,if

• the network speed is sufficient
• the Qobuz server is not dragging down the rates
• the player allows it ( e.g. my squeezelite - with 384k DAC attached)
• no sync groups are active
• and the setting shows 96+

That means. The issue I experience is here to stay.

Perhaps I can find some more Roon related info.

Anyhow. Thx for the feedback.

[mherger]

2. The plugin might be outdated, due to lack of most current API info
3. No further developments can be expected on the plugin

I wouldn't say so. Time will tell. Sometimes there's a kind soul inside or outside a service who shares some knowledge with me :-).

• the player allows it ( e.g. my squeezelite - with 384k DAC attached)
• no sync groups are active
• and the setting shows 96+

What I'm not sure about is whether your experience is consistent or not. I thought it was "random": sometimes you'd get hi-res, sometimes you wouldn't.

I'm not too familiar with squeezelite. But is there a way to make sure it tells LMS about its capabilities? If so, did you configure it correctly?

[soundcheck]

I sneaked around a bit in the Roon universe.
They were talking about similar stuff some time (1-2 years) back.
They btw also noticed differences between the Qobuz App and
the Roon implementation.

Two things hit me over there.

1.
Qobuz seemed to differentiate between download and stream
sample-rates. Don't know if that's still the case. And I don't actually
know what's meant with "download". Is it a track that you can
purchase and download and/or is it a track that gets fulltrack
bulk-loaded into a buffer, like the App is doing it.
There used to be different rates for stream or download according to
Roon.

Fact is. If I tag a 192khz favorite on the Qobuz app it doesn't mean
I get that 192kHz track also on LMS.

Would the full file-(RAM)-buffering bulkloading of a track be an option for LMS?
On squeezelite I can bulkload and buffer a track by setting the stream buffer to
huge sizes e.g. 150MB+. Depending on RAM size you can increase that heavily.


2.

Another point that was discussed is that the Qobuz server
seems to analyze and dynamically respond to the streaming
speed capabilities it sees in the first couple of seconds.
If there's a delay or slowdown it restarts and dials the samplerate down.

At this point, depending how fast and steady LMS/squeezelite responds,
I could imagine some impact from that side. A little hickup might force
the Qobuz server to dial down.
A big full-file buffer might avoid that I guess.



3.

squeezelite capability reporting - I need to look it up or talk to Ralphy.
I do have 192kHz working - randomly. Therefore that should be OK.

Are you suggesting that LMS does handover samplerate infos or restrictions
towards Qobuz?

[coyrls]

To step back a little, not all Qobuz tracks are available at 192Khz, are you sure you are using tracks that are available at 192Khz? Is is possible that Roon is upsampling to 192Khz? My experience is that the Qobuz plugin plays tracks available at 192Khz at 192Khz in all cases.

[mherger]

Download vs. Streaming: you can buy files from Qobuz. Those are the downloads. They're files you'd store on your computer, and they'd be played in whatever quality they are. Streaming Qobuz decides what quality you get.

And no, Qobuz streaming as implemented in LMS will NOT adjust bitrate and whatever. It's getting the song in the exact quality that's advertised in the headers, and that quality will not change within a song.

[SamY]

It works fine for me. Here are some screen shots. The first one shows the Qobuz plugin settings page, where the "Preferred format" must be set to "FLAC Hi-Res 24 bits />96 kHz". The second and third show the track info while playing in the Material Skin client. The fourth shows what the Denon DAC sees at its HDMI input, which is connected to the output of my RPi running Squeezelite. My experience is that of coyrls . If the source track is 24/192, I consistently get 24/192. That being said, I normally limit playback to 24/96 in the plugin settings as I can't really hear much (any) improvement at 24/192.

[soundcheck]

Look folks.

To wrap it up from my side.

1. I am aware that not all tracks are available in all formats. My and other people findings are referring to all HiresFormats.
2. Even Qobuz admits that formats can be changed and also the catalogue can change. (which adds already a certain randomness to the whole thing )
3. There used to be a mixup with downloaded/streamed formats - mixing up samplerates. That might have changed.
4. Dynamic rate adjustment on network quality is a pretty standard thing and not up for discussion - it just adds more randomness.
5. If you mark a 96kHz track as favorite, next time you play it, it can be 44.1 without noticing - that's what I call randomness. You simply can't trust the service level!
6. Since the LMS plugin is not build on the latest Qobuz API version, we all face a certain uncertainty.
7. And yep. All that doesn't happen all the time on all HiRes tracks for all users. Most people wouldn't even noticel! More randomness.
8. I think "streambuffering/full-trackbuffering" would be worth to look at on the LMS-QobuzPlugin side.
Qobuz is doing it on the iOS App from the very beginning. There might be DRM restrictions involved that prevent it. I don't know.
Something like that can heavily improve the streaming quality and also lowers the continuous load (turning it into a short peak-load) on the streamer.

To sum it up.

There's a lot to chew on. You could say - Who Cares !?!? Who cares about HiRes !?!?

The point is - you pay an expensive subscription fee and end up with random service level.

My intent would be to limit this randomness as much as possible.
Since LMS has some areas of concern around this subject, I opened this thread.
If there's nothing to enhance on LMS. Fair enough.


Have a good one.

[coyrls]

Dynamic rate adjustment on network quality is a pretty standard thing and not up for discussion - it just adds more randomness.

As mherger explained, there is no dynamic adjustment on network quality. If your network is not up to it, you will experience drop outs and jumps. Where would the resampling to adjust the rate take place anyway? Qobuz doesn't do it, LMS doesn't do it, you can configure Squeezelite to do it but it's not dynamic and by the time the data gets to Squeezlite, its at the player and there is no more network to traverse.

[ohan]

100Mbit DSL is pretty slow. And 100Mbit is probably the optimal speed published by your ISP, so your speed may be even slower. I doubt any latency in Squeezelite unless your installation has an issue. I have 1GIG cable (which usually is more like 850 Mbit) As a test, I used play.qobuz.com from a chrome browser and explored around 20 24/192 tracks from the "HI-RES" featured playlists. Chrome played all 20 tracks at 24/192. Squeezelite played all 20 tracks at 24/192. I've never had a track saved as a favorite 24/96 track play at 16.44. I think it is your DSL connection or your hardware. Additionally, you may want to check the Squeezelite logs for the location of the Akamai server that is routing your stream for Qobuz. Sometimes, mine is within 20 miles and other times 2000 miles away.

I'm using logitechmediaserver_8.3.1~1674060640_amd64.deb on Debian Bullseye (dedicated server) and squeezelite on an RPI-3B with DietPi OS.

[coyrls]

Audio data is not that demanding, a 192/24 bit file requires less than 10Mbps per second bandwidth and so a 100Mb DSL should be more than adequate.

[brannou]

I confirm this since my DSL has a slow throughput (<10mbps) and Qobuz works fine (24/96) with LMS installed on a Raspberry Pi 3B. Issues comes with other media flows at the same time...