AVX is a library designed to allow control of A/V devices such as video switchers and PTZ cameras.

It's designed to allow control of devices locally or over a network via Pyro4 RPC. A "Controller" process acts as an interface to the devices, and controlling them is as straightforward as calling a method on the Controller object.

Rich client applications can be built with Qt or your windowing toolkit of choice, using Python and Pyro4 for communications.

You will need a Python (2.7 is what I've used) with python-serial, PySide, and Pyro4.

The easiest method of installing is to either grab a pre-built egg or build one from source yourself (python setup.py bdist_egg) and install using easy_install. AVX requires:

• Python 2.7
• python-serial
• PySide
• Pyro4
• setuptools

In theory, easy_install should take care of the dependencies for you.

Mapping of physical hardware devices through serial ports to virtual devices is done in the config.json file. A typical definition of a single-device system may look like:

{
  "devices" : [
    {
      "deviceID" : "Main",
      "class" : "avx.devices.KramerVP88.KramerVP88",
      "options" : {
        "serialDevice" : "/dev/usb-ports/1-1.3.3:1.0",
        "machineNumber" : 1
      }
    }
  ]
}

Elements under "options" are passed directly as named parameters to the constructor of the class. Most, but not all, current devices require a serialDevice option.

Be sure to map devices based on their USB device path - /dev/ttyUSBx'es might get swapped round after a reboot, which would be sad. Everything GUI-side refers to the deviceID string you assign to each device, so balance these between descriptive and concise.

You will need a Pyro4 nameserver running somewhere on your network. The runNameserver.sh script will take care of this for you, or use the contrib/pyro-nsd init script for Debian (maybe others?)

The runController.py script will start a Controller instance and register it with the Pyro4 nameserver, making it available to all machines on your network. By default it will load a config.json configuration file, or whatever you specify with -c on the commandline. Installing via pip/easy_install will generate an avx-controller script which is run in the same way.

The controller machine can also use the contrib/avx-controller init script to run the controller as a daemon.

There's a basic HTTP interface built in. To enable it, ensure you have the following in your config file ('options' should be a sibling of 'devices'):

  "options" : {
    "http" : true
  }

In addition, each device must have an httpAccessible option set to true for it to be accessible via the HTTP interface.

By default the HTTP server will listen on port 8080 (currently hardcoded).

The URL scheme to call methods is:

http://server:8080/deviceID/method/option,option...

For example,

http://server:8080/Main/sendInputToOutput/2,1

will tell the video switcher with ID "Main" to send input 2 to output 1.

The controller will respond with an appropriate HTTP response code:

• 200 - OK (followed by whatever data is returned by that method)
• 400 - no such method
• 403 - not permitted to call methods on that device over HTTP
• 404 - no such device

Currently the devices best supported include:

• Kramer video switchers supporting Protocol 2000 over serial
  • e.g. VP-88
• Kramer 602 (non-Protocol 2000)
• Inline 3080 video switcher
• Kramer VP70x scan converters
• Coriogen Eclipse scan converter
• Sony VISCA PTZ cameras
• ETC Unison lighting controller
• Several models of USB relay cards
• Philips amBx ambient lighting system

In many cases support is partial but straightforward to improve - patches welcome!