Logging of UPnP stream.view

[simonbun]

Hi @epoupon

I was curious how Symfonium was able to present the track waveform (Plex generates it on the back end for PlexAmp), so I looked in the logs and sure enough it appears to be downloading each track:

[2025-Jun-17 10:02:26.706] 1 - [info] "wthttp: 192.168.1.10   GET /rest/stream.view?id=tr-75&apiKey=999&v=1.13.0&c=Symfonium&f=json HTTP/1.1 206 32500433"
[2025-Jun-17 10:02:31.894] 1 - [info] "wthttp: 192.168.1.11   GET /rest/stream.view?id=tr-75&apiKey=999&v=1.13.0&c=Symfonium&f=json HTTP/1.1 206 32500433"

The first call is from Symfonium and the second from my player (UPnP streamer).

Setting the progress bar to basic (as I really don't want to download each track to the phone just so it can display the waveform) I was expecting to see just the stream.view from the UPnP streamer, but instead all I see is:

[2025-Jun-17 10:04:10.045] 1 - [info] "wthttp: 192.168.1.10   GET /rest/getSong.view?id=tr-64&apiKey=999&v=1.13.0&c=Symfonium&f=json HTTP/1.1 200 886"

I have no idea why getSong.view is only called when not displaying the waveform (unless it's hoping to get it), but that's something I can ask Tolriq, but is there a reason I'm not seeing the stream.view from the UPnP endpoint?

Symfonium isn't proxying the track as the CurrentURI of the UPnP streamer is stream.view from LMS (and I don't see a stream.view from Symfonium).

I tried with logging set to Debug, and whilst I could see stream.view being fulfilled there was no mention of the initial call or where the data was being sent.

[epoupon]

Hello!

This is a question for @Tolriq indeed.

When the waveform feature was added, it showed that the same song was downloaded multiple times (one time from the player and one time from symfonium itself to analyze and generate the waveform, possibly in parallel with the player). This also makes ffmpeg to be spawned several times in parallel if transcoding is active. For the last point, @srett was working on a solution.
AFAIR, the waveform is extracted only if you are in wifi.

That being said, extracting waveforms is not free, and this is something LMS will eventually do itself in the future to restore its similarity based engine. I guess we could somewhat extend the OS API to provide the computed waveform...

[Tolriq]

I have some very specific needs to also support smart fades. But for other clients why not, I'll just probably not use it.

But wave forms for similarity is not really enough, it requires more the AI models specialized for that like Essentia (@itm if you plan to work on that tell, I support Sonic analysis from Plex already)

[simonbun]

Ahah no pb :) If it is not logged, then it just not happens. Maybe it uses another endpoint like download?

Wouldn't the download endpoint be logged?

I've just repeated the test with Sonos and the only calls in the log are from Symfonium (getSong.view and stream.view), yet Sonos reports the source as /rest/stream.view.

If you have a UPnP renderer (Sonos ideally as it's less clear what WiiM is doing) it would be great just to confirm my findings, even if that's where it ends.

[epoupon]

I have some very specific needs to also support smart fades. But for other clients why not, I'll just probably not use it.

But wave forms for similarity is not really enough, it requires more the AI models specialized for that like Essentia (@itm if you plan to work on that tell, I support Sonic analysis from Plex already)

Noted!
Sure waveforms are not enough (actually this was just to tell that lms will scan the file to do audio analysis to extract low level features, waveforms could be part of this costly process). Any pointer on what Plex exposes is welcome :)

[simonbun]

I have some very specific needs to also support smart fades. But for other clients why not, I'll just probably not use it.

You wouldn't use the computed waveform if supplied by LMS? I assume I must have set the Progress bar style to Waveform at some point (as it would be a strange default), but downloading the whole track (if that's what you do) just to display the waveform is, not very efficient.

[Tolriq]

That's not exactly what's done, and the more efficient solution currently is magic getting of the data ;) But as you hopefully know, magic is not real ....
And then with a basic wave form try to do the smart fades that Symfonium do, and see figure out that actually magic does exist ;)