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Shairport MQTT or UDP client

Torsten Beyer

December 17, 2020 07:29

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Hi all,

want to display what's currently playing on my magic mirror. Preferably via shairport's function to send metadata to a UDP listener. Alternatively to a MQTT broker (probably better functionality but would mean for me to install such a broker in the first place). 

Question 1: the shairport running on the standard hifiberry distribution, does it support MQTT and UDP metadata-forwarding?

Question 2: when I touch shairport's config file, what happens at the next software update? Will it be overwritten?

regards

Torsten

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24 comments

• 0
  
  HiFiBerry team December 17, 2020 07:51

  If you're using HiFiBerryOS, you should not try to retrieve metadata directly from a specific service. First of all it won't work with other services and second it might break with updates.

  The right way to deal with metadata on HiFiBerryOS is audiocontrol:
  https://github.com/hifiberry/audiocontrol2
  
  

  You can just create your own Metadata display class that does what you want (e.g. forward it to another system):

  https://github.com/hifiberry/audiocontrol2/tree/master/doc
  https://github.com/hifiberry/audiocontrol2/blob/master/doc/extensions.md

• 0
  
  Torsten Beyer December 17, 2020 07:54

  Thanks for the quick turnaround. Will look into Audiocontrol.

  cheers

  Torsten

• 0
  
  Torsten Beyer December 17, 2020 09:02

  Hi there,

   

  just ploughed through the audiocontrol git and stumbled accross the http poster plugin. Is this used for something? Or could I use that for my purposes?

  cheers

  Torsten

• 0
  
  HiFiBerry team December 17, 2020 09:13

  Yes, this is used already to send data to the front end. You would have to duplicate this if you want to use it for your own purpose, otherwise the UI won't work anymore. 

• 0
  
  Torsten Beyer December 17, 2020 10:11

  okidoki - understood...

  tnx

  Torsten

• 0
  
  Torsten Beyer December 17, 2020 12:32

  What's the best way to have audiocontrol re-read it's config? Restart? Reboot? Some signal?

  cheers

  -tb

• 0
  
  HiFiBerry team December 17, 2020 12:33

  restarting it is the only way

• 0
  
  Torsten Beyer December 17, 2020 12:38

  Additional question: how can I use "artUrl" in metadata? Is that a relative (to where) location of a cached cover png?

  cheers

  -tb

  Edited by Torsten Beyer December 17, 2020 12:39
• 0
  
  HiFiBerry team December 17, 2020 15:25

  Depends on the service. It can be absolute URLs. If these are relative, they are relative to the root directory of the API server.

• 0
  
  Torsten Beyer December 17, 2020 15:46

  ok - tnx. Have written some test code now. Fails on the hifiberry, though, with "ModuleNotFoundError: No module named 'ac2' " - where have you guys put the module? Couldn't find any reference to ac2 with python's help("modules") function either. Anything I am missing? I  was under the impression the ac2 module was somewhere on the hifiberry...

   

• 0
  
  HiFiBerry team December 17, 2020 16:37

  ac2 is the whole audiocontrol package. See the systemd config:
  
  

  # cat /lib/systemd/system/audiocontrol2.service
  [Unit]
  Description=Audiocontrol2
  Wants=dbus.service
  After=sound.target dbus.service
  
  [Service]
  Type=notify
  Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket
  Environment=PYTHONPATH=/data/ac2plugins:/etc/audiocontrol2
  WorkingDirectory=/opt/audiocontrol2
  ExecStartPre=/opt/hifiberry/bin/bootmsg "Starting AudioControl2"
  ExecStart=/usr/bin/python3 /opt/audiocontrol2/audiocontrol2.py ${AUDIOCONTROL2_ARGS}
  StandardOutput=journal
  Restart=always
  RestartSec=5
  TimeoutStopSec=10
  
  [Install]
  WantedBy=multi-user.target

• 0
  
  Torsten Beyer December 18, 2020 07:18

  Tnx guys. Test  code is working...now, when I put my module in the /data/ac2plugins directory will it survive hifiberry updates? Also the module specific configurations in /etc/audiocontrol2.conf?

• 0
  
  HiFiBerry team December 18, 2020 07:21

  Yes, /data is untouched during updated and updates to configuration files are usually incremental.
  In rare cases that might not be possible. Therefore, you should always have a backup (which is a good idea anyway).

• 0
  
  Torsten Beyer December 18, 2020 07:23

  Yeah, I do :-) It's all safe and sound on TimeMachine :-)

  Is there a safe way to install additional python module? Still thinking about MQTT as a means for distribution of song played. Using that would mean (at least it would make life much easier) to install a mqtt python module on hifiberry.

• 0
  
  HiFiBerry team December 18, 2020 07:25

  You would also have to install this into /data. Note that this might break during upgrades as Python version might change during upgrades. 

• 0
  
  Torsten Beyer December 18, 2020 07:28

  Hmm, ok. Not ideal but certainly doable. Tnx

• 0
  
  Torsten Beyer December 18, 2020 07:57

  Confused by the way plugins are being configured in audiocontrol2. I have created a plugin called "MagicMirrorPush" (roughly based on your lametric  plugin). Put it in /data/ac2plugins and added this to /etc/audiocontrol2.conf

  [plugins]
  plugin_dir=/data/ac2plugins
  metadata=MagicMirrorPush

  For the lametric example you have added this line
  [metadata:ac2.plugins.metadata.lametric.LaMetricPush]

  Would I add this?
  [metadata:ac2.plugins.metadata.magicmirror.MagicMirrorPush]

• 0
  
  Tron January 09, 2021 12:48

  Hello Torsten and Hifiberry Team. I am also interested in this. 

  I am envisioning making a decorative little table box using an ESP8266, a battery and a dot matrix text display. It's just an idea for now but.. I think it has promise. 

  It will be driven by MQTT, with messages providing track metadata. Possible expansion of functionality could be duplex mqtt in order to do next/prev/play/pause and vol. HTTP won't be a great solution.

  I am thinking to make it in oak with chunky old buttons that really click, maybe from an old tape recorder or something like that. 

  The ESP8266 has some direct IO, uses low power, has wifi. It's a 3.3v system, so it can be powered by 5V usb via stepdown or perhaps two AA batteries in series will work. 

   

  First off, the Hifiberry would need to support pushing data via MQTT and preferably also hosting a local MQTT broker. There must be more people than me who have had the idea though! I see that there is a commercial product which is supported as a remote screen, I don't know how that works but if I were to take a guess I would say it's a duplicate HTTP system like mentioned above.

• 0
  
  HiFiBerry team January 11, 2021 11:47

  You could install an MQTT broker in a docker container. This is definitely not something we would add to the default HiFiBerryOS installation.

• 0
  
  Tron January 11, 2021 12:58

  Okay, fair enough, leave the broker out of it, but an MQTT client and some kind of API would be fantastic. 

• 0
  
  HiFiBerry team January 11, 2021 13:02

  Feel free to contribute. This isn't something we will implement by ourselves but we might integrate contributed code.

• 0
  
  Torsten Beyer January 11, 2021 13:22

  @Tron: just go ahead and write a little notification plugin that pushes song info to MQTT. Use the code for the LAMetric plugin as a starting point. Not being familiar w/ MQTT I assume there are python packages out there that make sending messages to a broker easy enough to implement.

• 0
  
  Tron January 11, 2021 13:27

  Thank you for your feedback Torsten Beyer. I am not experienced with development in Python, but I have done similar things in C and C#. MQTT is lovely once you're comfortable with it, it cuts out all the fat of a HTTP message and replaces it with a message and a topic. You have then have as many subscribers as you want for that information. So you don't need to duplicate anything if you want to say, send your info to a home automation system, a screen and a mobile app. Since it's truly ultra light, small battery powered devices can use it, and it's very fast. It's probably not great for complex input. 

  I am very much into this projects philosophies, and I will consider making this, but I hope this thread gets some more feedback and that others also want to use it. 

• 0
  
  Torsten Beyer January 11, 2021 13:29

  Well, my python rest server plus the notification interface to Audiocontrol2 total 137 lines of python (including about 15 lines of comments). So: not that crazy and fairly light weight.