Audio service

[forslund]

In late November @penrods led a discussion about how an audio service in Mycroft could work. This is a simple implementation of what was discussed. This is a quick implementation of the system as I understood it and I think this can be used to continue the discussion. Ideas and suggestions on improvements are very welcome.

The PR adds support for commands like

"Hey Mycroft, play the news in the livingroom"

Backends

The current system includes support for the following "backends"

• Mpg123, very limited implementation
• VLC
• Mopidy

"backends" currently in the works:

• Chromecast
• Kodi

Backends are quite easy to add and an existing baseclass can be extended to add new ones.

AudioService

Skill creators will use an audio service interface to communicate with the audio service / playback control. the AudioService interface uses the standard message bus.

from mycroft.skills.audioservice import AudioService
[...]
  as = AudioService()
[...]
  as.play(file_or_uri) # handles both lists and single uris

See the npr_news skill for basic usage.

The AudioService currently only support play and track_info requests but this will probably be expanded for increased usefulness.

Playback control skill

Features:

• backend/location selection from utterance ("...in kitchen" etc.)
• lowering volume while Mycroft speaks
• playback control (Pausing/Resuming, skipping, Stopping)

The backend/location selection is currently done using basic string parsing and should probably be done using adapt instead.

This skill removes much of the basic functions that needs to be implemented for an audio playback skill and the skill creator can focus on the trickier parts.

Currently most of the audio logic is implemented in the playback control skill and should maybe be moved but this was a good starting point.

Configuration

A Configuration the audio services:

{
  "Audio": {
    "backends": {
      "local": {
        "type": "mpg123",
        "active": true
      },
      "kitchen": {
        "type": "mopidy",
        "url": "http://localhost:6680",
        "active": true
      },
      "livingroom": {
        "type": "mopidy",
        "url": "http://192.168.10.232:6680",
        "active": false
      },
      "vlc": {
        "type": "vlc",
        "active": true
      }
    },
    "default-backend": "local"
  }
}

If you try it I suggest you install vlc and pyvlc and use the vlc backend since mpg123 only has basic functionallity.

I've tested this mainly with the mopidy skill and the npr_news skill.

Todo

• more backends, Kodi and chromecast is a minimum
• possibly separate the backends from the playback control skill
• populate the AudioService interface with more functions so skill creators can do more interesting things with the audio (A music quiz-skill should be able to skip ahead in the playlist when a correct answer is provided)
• More configuration options
• Maybe some way to send credentials from a skill to the backend to access some music services
• Better utterance parsing when starting playback, along with more keywords (like half volume)

[forslund]

Major refactoring done after discussion with @ethanaward. The audio backends now runs separately from the skills. The loading of backends is now done using a method similar to how the skills work and should be easy to extend to include thirdparty backends.

[forslund]

Skills using the audio service interface
NPR news:
https://github.com/forslund/skill-npr-news/tree/audio-service
Ethan's demo skill:
https://github.com/forslund/demo_skill/tree/audio_service/
play all using vlc to enque all tracks and play using vlc for example

most important, the playback control skill:
https://github.com/forslund/playback_control_skill

The playback control skills implement the common commands for skills using the audio service. like skipping tracks, pausing and resuming. The idea is that the skill creator only needs to implement the finding of audio files and the command that starts playback. (The other commands are of course available to the skill creator if they wish to use them)

[coveralls]

Coverage decreased (-4.6%) to 30.071% when pulling c981119 on forslund:audio-service into 52af555 on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.6%) to 31.641% when pulling 104621e on forslund:audio-service into d68b1dd on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.6%) to 31.622% when pulling 306bbf5 on forslund:audio-service into 60867fc on MycroftAI:dev.

[forslund]

Finally rebased, phew

[augustnmonteiro]

please change to mycroft.audio.service.play like the others mycroft events

[coveralls]

Coverage decreased (-4.6%) to 31.622% when pulling 5df592e on forslund:audio-service into 60867fc on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.7%) to 33.946% when pulling aa884e5 on forslund:audio-service into a5592d8 on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.7%) to 33.787% when pulling 7834bf6 on forslund:audio-service into 5bb7d25 on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.6%) to 33.882% when pulling 4a68ab7 on forslund:audio-service into 5bb7d25 on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.6%) to 33.882% when pulling 2e75056 on forslund:audio-service into 5bb7d25 on MycroftAI:dev.

[coveralls]

Coverage decreased (-4.6%) to 33.882% when pulling 939c678 on forslund:audio-service into 5bb7d25 on MycroftAI:dev.

[coveralls]

Coverage increased (+0.5%) to 39.003% when pulling a49d1ea on forslund:audio-service into 8e17fe3 on MycroftAI:dev.

[coveralls]

Coverage increased (+0.5%) to 38.937% when pulling d7da37d on forslund:audio-service into fc3ede1 on MycroftAI:dev.

[augustnmonteiro]

Let's rebase and wait finish the new release to merge it

[coveralls]

Coverage increased (+0.003%) to 40.103% when pulling b7a1754 on forslund:audio-service into 0108a26 on MycroftAI:dev.

[penrods]

Let's get this merged after the next (July 6th) release.

[coveralls]

Coverage increased (+0.3%) to 39.849% when pulling cbbd72e on forslund:audio-service into 7bab1d1 on MycroftAI:dev.

[coveralls]

Coverage increased (+0.4%) to 39.83% when pulling a7d81ad on forslund:audio-service into 63d90ce on MycroftAI:dev.

[augustnmonteiro]

@forslund can we merge this one?

[forslund]

Fixed the conflict it should be good to merge now.

[coveralls]

Coverage increased (+0.06%) to 41.727% when pulling 0fa0ee5 on forslund:audio-service into a5d349a on MycroftAI:dev.

[coveralls]

Coverage increased (+0.2%) to 41.488% when pulling d272bd6 on forslund:audio-service into 2a59593 on MycroftAI:dev.

[coveralls]

Coverage increased (+0.04%) to 41.367% when pulling 9c49f97 on forslund:audio-service into edbd8ed on MycroftAI:dev.

[penrods]

So why isn't this merged yet! Reviewed by Augusto, merge away!

[coveralls]

Coverage increased (+0.06%) to 41.385% when pulling df18f42 on forslund:audio-service into edbd8ed on MycroftAI:dev.

[augustnmonteiro]

@penrods I reviewed before the last release and didn't merged to that release and forgot to merge after the release is done, Sorry @forslund