librespot:// source plays as noise

[arpena]

Describe the bug
Since Spotify disabled the use of username/password for librespot, I tried to configure a librespot:// source without username/password parameters to use zeroconf. It works on the Spotify part, but reproduce as noise on Snapcast.

Relevant part of snapserver.conf:

source = librespot:///usr/bin/librespot?name=Spotify&devicename=Snapcast&bitrate=320&wd_timeout=3600&params=--volume-ctrl%20fixed

Everything works fine If instead I configure a new fifo on Snapcast server, and run an external librespot using pipe backend.

Steps to Reproduce

1. create a librespot:// source without username/password parameters
2. play on the device using Spotify
3. Noise is reproduced on Snapcast clients

Environment details

• OS: Alpine Linux
• Snapcast version: 0.28.0-r2
• Installed from https://pkgs.alpinelinux.org/package/edge/community/armv7/snapcast-server.

Attach logfile if applicable

$ /usr/bin/snapserver --logfilter debug
2024-08-15 17-18-50.861 [Error] (Avahi) Failed to create client: Daemon not running
2024-08-15 17-18-50.863 [Error] (AsioStream) Error reading message: End of file, length: 0, ec: asio.misc:2
2024-08-15 17-19-11.909 [Warn] (librespot_core::apresolve) Ignoring blacklisted access point ap-gew4.spotify.com:80

Interestingly, the output from librespot is a lot more verbose when I run it outside of snapcast:

$ /usr/bin/snapserver --logfilter debug & librespot --backend pipe --device /tmp/snapspot --name Snapcast --bitrate 320 --volume-ctrl fixed
[2024-08-15T20:21:40Z INFO  librespot] librespot 0.4.2 UNKNOWN (Built on 2023-08-01, Build ID: 1690865570, Profile: release)
2024-08-15 17-21-40.748 [Error] (Avahi) Failed to create client: Daemon not running
2024-08-15 17-21-40.750 [Error] (AsioStream) Error reading message: End of file, length: 0, ec: asio.misc:2
2024-08-15 17-21-40.750 [Error] (AsioStream) Error reading message: End of file, length: 0, ec: asio.misc:2
[2024-08-15T20:21:56Z WARN  librespot_core::apresolve] Ignoring blacklisted access point ap-gue1.spotify.com:443
[2024-08-15T20:21:56Z INFO  librespot_core::session] Connecting to AP "ap-guc3.spotify.com:4070"
[2024-08-15T20:21:56Z INFO  librespot_core::session] Authenticated as "csalmeri" !
[2024-08-15T20:21:56Z INFO  librespot_playback::mixer::softmixer] Mixing with softvol and volume control: Fixed
[2024-08-15T20:21:56Z INFO  librespot_playback::convert] Converting with ditherer: tpdf
[2024-08-15T20:21:56Z INFO  librespot_playback::audio_backend::pipe] Using StdoutSink (pipe) with format: S16
[2024-08-15T20:21:56Z INFO  librespot_core::session] Country: "AR"
[2024-08-15T20:21:57Z INFO  librespot_playback::player] Loading <Habanera> with Spotify URI <spotify:track:6pUlLSkBmvHzDaPlzZsvtr>
[2024-08-15T20:22:00Z INFO  librespot_playback::player] <Habanera> (288385 ms) loaded
[2024-08-15T20:22:16Z INFO  librespot_playback::player] Loading <Other Jewels> with Spotify URI <spotify:track:43QCn1fqNpaVllvjNXx5eX>
[2024-08-15T20:22:17Z INFO  librespot_playback::player] <Other Jewels> (347377 ms) loaded
2024-08-15 17-22-33.562 [Error] (AsioStream) Error reading message: End of file, length: 2304, ec: asio.misc:2

So the issue seems that some INFO messages from librespot are consumed as sound data by snapserver, also something is changing the format of log messages for librespot

UPDATE 16/Aug/2024
Cannot reproduce this anymore. Will stick to the librespot:// source configuration to see if this happens again

[arpena]

Looking at the code it seems that the stream processor is consuming stderr from librespot to get track name and duration.

I made some tests and messages from librespot zeroconf negotiation are still being output to stderr, no stdout were the audio should be written. I couldn't find any extra message on stdout.

I remember that without zeroconf, messages from librespot username/password auth was written on snapserver logs. Sadly, I cannot reproduce that anymore. So somehow the stream processor is being confused by the delayed authentication that with zeroconf occurs only when the device is selected on the Spotify app.

[arpena]

Darn, I reverted back to the librespot:// source and cannot reproduce the noise. I'll stick to this configuration to test if I get the noise again.

[codesalatdev]

Can you reproduce the noise by skipping a few songs while playing from a librespot:// source?

[pookieman]

Hello I'm having the same problem, did someone repro and/or find a fix?

I tried skipping songs but it doesn't seem to help. This started happening when I switched to using libre-auth credentials.json file, when I used user name password it worked fine, but that doesn't work with spotify anymore

This is my configuration

source = spotify:///librespot?name=Home%20Assistant&devicename=Spotify&wd_timeout=7800&volume=100&normalize=false&autoplay=false&disable_audio_cache=true&params=--device-type%20avr&params=--volume-ctrl%20fixed&params=--format%20S32

I also tried this

source = spotify:///librespot?name=Home%20Assistant&devicename=Spotify&wd_timeout=7800&volume=100&normalize=false&autoplay=false&cache=/var/cache/librespot&cache-size-limit=2G

same :(

[pookieman]

This is probably nothing to do with it .. but I thought I'd see if I can figure out the version of librespot that is part of the snapserver container.. so I ran this

root@8505a85afae7:/# librespot [2024-09-23T02:13:35Z INFO librespot] librespot 0.4.2 6537c44 (Built on 2024-08-08, Build ID: d77PPi6H, Profile: release)

is this old? should it be newer?

[arpena]

Can you reproduce the noise by skipping a few songs while playing from a librespot:// source?

Nop. No way to reproduce it now. However I noticed that the songname scrapping logic is not keeping up with the song being played if I skip forward or backward on Spotify a little too fast.

[arpena]

@pookieman no clue about why it is happening to you. librespot, as far as I could test it, sends all messages to stderr, and snapcast never uses stderr as sound data.

Your version of librespot is ok. It wasn't updated in a while.

Did you try setting up librespot to use a fifo sound device? Also, please send your log output.