Intelligent Roadway Information System

Video Monitors

A video monitor is a dedicated screen which can display camera streams in real time. IRIS can quickly switch the stream and title text displayed on a video monitor, using supported protocols.


MonStream is a full-screen video streaming application which runs on low-cost Linux computers. IRIS has a MonStream protocol driver, which can be used for video monitor control.

A computer running MonStream can be configured to stream a grid of four or more video feeds onto a single large monitor. The only configuration required on the MonStream computer is to grant access to the /var/lib/monstream/ directory for the UID of the monstream process.

A controller must be configured to represent each MonStream computer. It will need to be on a comm link using the MonStream protocol, with a timeout of 2000 ms. The comm link URI should be of the form: [ip address]:7001. Each video monitor to be displayed should be associated with an IO pin of the controller. For example, a quad-screen monitor would have monitors associated with pins 1 thru 4.


Select View ➔ Video ➔ Video Monitor menu item

Each row of the table represents one video monitor.

Field Description
Name Video monitor name
Notes Location or usage text
Group name Privilege group, for access control
Monitor num Number for selecting and switching
Restricted Flag restricting monitor to published cameras only
Monitor style Style of title bar, etc

The monitor num is used to identify monitors when selecting cameras with a switching system.

API Resources 🕵️
  • iris/api/video_monitor (primary)
  • iris/api/video_monitor/{name}
Access Primary Secondary
👁️ View name
👉 Operate camera
💡 Manage notes restricted, monitor_style
🔧 Configure mon_num, controller pin


Select View ➔ Video ➔ Monitor Styles menu item

Field Description
Monitor Style Monitor style name
Force aspect Flag to preserve video aspect ratio
Accent Hexadecimal RGB color of title bar
Font Size Size of title bar font (points)
Title Bar Flag to enable title bar
Auto Expand Flag to use full screen when only one monitor is active


There are several methods available for switching video monitors. Using any of these methods, when a camera is assigned to a monitor num, all monitors and flow streams with that number will be switched.

Camera Tab

On the upper-right of the Camera tab, there is a monitor num selector. The number chosen here will be switched any time a camera is selected, either from the map or a list.

The selector tool can also be used to change the monitor num or camera.


Certain camera keyboards can be used for video monitor switching.

MonStream Control

With a USB joystick and keypad, a MonStream computer can be used for switching.

Play Lists

Select View ➔ Video ➔ Play Lists menu item

Play lists can be created to cycle through related cameras. Each user can have a personal play list, but system play lists are available to all users. Selecting a play list on a monitor will cause the play list to automatically switch. The interval is specified by the camera_sequence_dwell_sec system attribute.


A catalog is a collection of play lists. Both play lists and catalogs can be assigned sequence numbers, so they can be used in the same way.