greenscreen-control 0.0.2

Python module, server and utility to control greenscreen.

A simple module, command line utility and tcp server to headlessly control a GreenScreen installation and a set of Chromecasts. Controls the assignment of GreenScreen channels to Chromecasts using the GreenScreen API, and then can start/stop casting to a particular Chromecast.

Requires a working GreenScreen installation.

AppID

In these instructions, $APPID is the value of your “Application ID” from the Google Cast Developer Console. This will have been setup as part of the GreenScreen installation.

Using the command line utility

Set the CCTV channel on the Kitchen Chromecast:

$ greenscreen_control -c CCTV set-channel Kitchen

Start casting a given AppID on a Chromecast:

$ greenscreen_control -a $APPID cast Kitchen

Stop casting on the Kitchen Chromecast:

$ greenscreen_control stop-cast Kitchen

Available arguments:

usage: greenscreen_control_cli.py [-h] [-g GREENSCREEN_SERVER] [-a APPID]
                                  [-c CHANNEL] [-l {ERROR,WARNING,INFO,DEBUG}]
                                  [-r TRIES] [-t TIMEOUT] [-w RETRY_WAIT]
                                  {set-channel,cast,stop-cast} chromecast

positional arguments:
  {set-channel,cast,stop-cast}
                        Command
  chromecast            Chromecast name

optional arguments:
  -h, --help            show this help message and exit
  -g GREENSCREEN_SERVER, --greenscreen_server GREENSCREEN_SERVER
                        GreenScreen server:port
  -a APPID, --appid APPID
                        Chromecast Greenscreen App ID
  -c CHANNEL, --channel CHANNEL
                        GreenScreen channel to set
  -l {ERROR,WARNING,INFO,DEBUG}, --loglevel {ERROR,WARNING,INFO,DEBUG}
                        Logging level
  -r TRIES, --tries TRIES
                        Chromecast connection tries. Default is infinite.
  -t TIMEOUT, --timeout TIMEOUT
                        Chromecast socket timeout seconds. Default is 30.
  -w RETRY_WAIT, --retry_wait RETRY_WAIT
                        Seconds to wait between Chromecast retries. Default is
                        5.

Starting the server

Start a simple TCP server (default port 4995) to control greenscreen and Chromecast casting.

$ greenscreen_control_server -l INFO -a $APPID

Available arguments:

usage: greenscreen_control_server.py [-h] [-g GREENSCREEN_SERVER] [-a APPID]
                                     [-c CHANNEL]
                                     [-l {ERROR,WARNING,INFO,DEBUG}]
                                     [-r TRIES] [-t TIMEOUT] [-w RETRY_WAIT]
                                     [-p PORT]

optional arguments:
  -h, --help            show this help message and exit
  -g GREENSCREEN_SERVER, --greenscreen_server GREENSCREEN_SERVER
                        GreenScreen server:port
  -a APPID, --appid APPID
                        Chromecast Greenscreen App ID
  -c CHANNEL, --channel CHANNEL
                        GreenScreen channel to set
  -l {ERROR,WARNING,INFO,DEBUG}, --loglevel {ERROR,WARNING,INFO,DEBUG}
                        Logging level
  -r TRIES, --tries TRIES
                        Chromecast connection tries. Default is infinite.
  -t TIMEOUT, --timeout TIMEOUT
                        Chromecast socket timeout seconds. Default is 30.
  -w RETRY_WAIT, --retry_wait RETRY_WAIT
                        Seconds to wait between Chromecast retries. Default is
                        5.
  -p PORT, --port PORT  TCP server port number

Server Protocol

The TCP server uses a simple line-based protocol, easily controlled from scripts, cron or home automation.

Assign the “CCTV” channel to the “Kitchen” chromecast, and start casting it:

chromecast=Kitchen,channel=CCTV,cast=1

Assign the “CCTV” channel to the “Kitchen” chromecast, don’t cast it (either prepares for future casting, or assumes already casted):

chromecast=Kitchen,channel=CCTV

Cast the currently assigned channel (whatever that is):

chromecast=Kitchen,cast=1

Stop casting:

chromecast=Kitchen,cast=0

Starting the server by default

Use the included greenscreen_control.service to start the server as a systemd unit.