Table of Contents
Rivendell includes full support for the origination and transmission of program associated data (PAD) in realtime, including a Python module (PyPAD) that can be used to create scripts for interfacing Rivendell's PAD feed to most any arbitrary external system.
All Rivendell PAD updates are emitted as
JSON documents of
type padUpdate via TCP port 34289. A typical update
looks like:
{
"padUpdate": {
"dateTime": "2019-03-28T15:09:01-04:00",
"hostName": "elastigirl",
"shortHostName": "elastigirl",
"machine": 1,
"onairFlag": false,
"mode": "Automatic",
"service": {
"name": "Production",
"description": "Production Log"
"programCode": ""
},
"log": {
"name": "Example"
},
"now": {
"startDateTime": "2019-03-28T15:09:01-04:00",
"lineNumber": 0,
"lineId": 0,
"cartNumber": 10477,
"cartType": "Audio",
"cutNumber": 1,
"length": 225500,
"year": null,
"groupName": "MUSIC",
"title": "Allentown",
"artist": "Billy Joel",
"publisher": "",
"composer": "",
"album": "The Complete Hits Collection 1973-1997",
"label": "",
"client": "",
"agency": "",
"conductor": "",
"userDefined": "",
"songId": "",
"outcue": "",
"description": "Cut 001",
"isrc": "",
"isci": "",
"externalEventId": "",
"externalData": "",
"externalAnncType": ""
},
"next": {
"startDateTime": "2019-03-28T15:12:46-04:00",
"lineNumber": 1,
"lineId": 1,
"cartNumber": 10153,
"cartType": "Audio",
"cutNumber": 1,
"length": 168700,
"year": null,
"groupName": "MUSIC",
"title": "Me & You & A Dog Named Boo",
"artist": "Lobo",
"publisher": "",
"composer": "",
"album": "'70s Radio Hits",
"label": "",
"client": "",
"agency": "",
"conductor": "",
"userDefined": "",
"songId": "",
"outcue": "",
"description": "Cut 001",
"isrc": "",
"isci": "",
"externalEventId": "",
"externalData": "",
"externalAnncType": ""
}
}
}
Rivendell ships with a Python 3 module called "pypad" that
automates away most of the work involved in reading, parsing and
processing the raw JSON data feed described above. A copiously
commented example script can be found in the Rivendell source
tree at apis/pypad/tests/now_and_next.py.
Rivendell can be configured to start one or more PyPAD scripts automatically whenever the "rivendell" systemd service is (re)started. In order to support this, a PyPAD script must meet the following requirements:
Accept exactly three command-line arguments as follows:
script
host-name
port-num
config
The config value should be
passed to the pypad.Receiver.setConfigFile() method,
and host-name and
port-num values should be
passed to the
pypad.Receiver().start() method.
See any of the production PyPAD scripts in the Rivendell
sources in apis/pypad/scripts/ for
an example.
If the script is configurable via a configuration file,
provide a sample copy of the configuration file, using
wherever possible sane
default values along with comments documenting
what the various parameters do. The file should have the
the same base name as that of the script, but have an
.exemplar extension.
For example, if the script is called
myscript.py,
the sample configuration file would be called
myscript.exemplar.
Install a copy of the script, along with a copy of the
sample configuration file (if needed) in the Rivendell
PyPAD script directory
/usr/lib/rivendell/pypad/.
All PyPAD scripts started in this manner will be run under the
user/group specified by the PypadOwner=
and PypadGroup= directives in the
[Identity] section of the
rd.conf(5) configuration
file.
See Section 12.5.14, “Managing PyPAD Instances” for instructions on enabling a script that has been prepared in this manner.