Echo Dot Youtube Skill

This skill is intented for personal use only (in development mode), is highly recommended to not push it on amazon marketplace.

Information

I wrote and tested this code on a Raspberry Pi 2 b+ model. It should also work an Raspberry Pi 3 on any other vps online but is not tested. All the needed steps to make it work are described in INSTALL.md file at the root of this repository.

Note: In my setup, I used a domain name and CloudFlare free account because my home IP address is dynamic. If you don’t have a domain name, you can register a free .tk one. CloudFlare is used beause it offers an API to updated the online records and also provides free SSL certificates for domains (SSL is required for amazon integrations).

Prerequisite

• Raspberry Pi 2 with latest raspbian installed (or any linux server)
• A domain name (free .tk domain can work - not tested -)
• A free CloudFlare account
• Maybe some general linux knowledge?

Known Issues

• Next and Previous are not fully functional
• There are some issues with some videos that don’t play and I don’t know why, Yet
• Only video can be played, this is indended and it will not be fixed (no playlist support)
• Others?

Currently Implemented

Play {search_query}
Search for {search_query}
Play me {search_query}
Listen to {search_query}
Listen {search_query}

How it works

This skill, search youtube for the {search_query} on youtube and plays the first video found.

Thanks to

• Python pafy - used to get the audio stream from youtube video
• Youtube-dl - used with pafy to get youtube information
• Flask - used to serve this application
• Flask-Ask - used for mapping alexa requests
• uWsgi & nginx - both used to host the flask application
• avconv - used to provide an audio stream that alexa can use

How it does the job

When Alexa hears the invocation name, it will search for an api tied to that ‘invocation’ and will find the one defined by us in the developer accound. After that, it will call the api with the {search_query} as a parameter and the Intent as method. Flask-Ask handles that call and returns a response that Alexa can handle. This code is located in alexa/intents/selection.py:

@ask.intent("PersonalPiePlayYoutube")
    def play_youtube(search_query):
    [...]

Inside that method, an api to youtube is called and the first video (id and title) is returned along with 9 other ‘related’ videos. Then, Alexa start playing that stream. The stream itself is virtual and defined into alexa/controller.py:

@app.route("/stream/<video_id>.mp3")
def stream(video_id):
    video = Stream(video_id)
    return Response(response=video.get(), status=200, mimetype='audio/mpeg',
                    headers={'Access-Control-Allow-Origin': '*', 'Content-Type': 'audio/mpeg',
                             'Content-Disposition': 'inline', 'Content-Transfer-Encoding': 'binary',
                             'Content-Length': video.length})

When this url is accessed, the best audio stream from that youtube video is selected using pafy and passed to avconv to be streamed as a .mp3 stream. Avconv takes the audio file stream and provide another stream, but this time, one that Alexa can ‘play’ (an mp3 one).

Local test

You can run a local version with Docker. If you have Docker installed, just run docker-compose up in the root of this repo. In order to use this local endpoint with Alexa you will need the help of ngrok. You must use ngrok to expose the local port 5000:

ngrok http 5000

After the service starts, it will provide you with the external url that you can set on amazon developer site (Note: use the https one, alexa can only use https for requests).