Video wall systems are built to show lots of information, whether it is data feeds in control room video wall or pictures and movies for digital signage. In most cases, high resolution video wall systems show multiple content items at once, and most have a user interface that lets users design layouts and place objects where they want them. But what about responding to external events, or changing content programmatically? That calls for an API (Application Program Interface), a mechanism that lets a program access features of the video wall system and customize them.

Usage Scenarios

Why is external control important? It depends on the usage scenario for the video wall. If the video wall is digital signage, the contents can be automatically changed based on sensor inputs that detect who is looking at the wall. Such sensor systems can detect/guess gender and age of viewers, so the signage contents can be changed to present material appropriate to the audience.

Such sensor systems can detect/guess gender and age of viewers, so the signage contents can be changed to present material appropriate to the audience.

In a control room, systems monitoring factory equipment or network health can bring particular data feeds to the foreground of the video wall if problems are detected. A security operations center could have software monitoring social media feeds and pop up a map on the video wall if it detects threatening comments. A surveillance system could show a video feed if it detects an intruder.

The API also allows integration with third party room controllers, like AMX and Crestron systems, that can provide a simple one-button approach to configuring the LED video wall content, room lighting, speaker volumes, etc. Many video wall customers want such integration, so some sort of API or external control mechanism is essential.

Options

There are several ways to implement programmable control for video wall systems. One way is to integrate a scripting language, like Lua or Python. Other industries have taken this approach: several popular multiplayer online games incorporate Lua to allow customization of the user experience. If a video wall system incorporated such a scripting language, developers could write programs that call the video wall system’s API to show and manipulate content. This allows tight integration, but the video wall system must provide mechanisms required for the script programs to communicate with external systems, all of which must be maintained and secured. It also requires that the customers’ programmers learn the specific scripting language chosen by the video wall company. We chose not to take this approach at Hiperwall.

Hiperwall’s Network-based Approach

The approach we chose is to define a network API called HiperServices loosely based on a Web Services model. In this case, a client program (which can be written in nearly any programming language) sends an HTTP request to the video wall system to ask it for information or to command it to perform a task (show or manipulate an object, for example). These requests can get information about the video wall system itself (walls and their sizes), available content items, as well as content already on the wall. They can also command the wall (using a simple XML statement) to show a specified content item at a certain place with certain properties, including transparency, layering, color filters, and more. In our API, client programs specify an identifier for each object they show on the video wall. This can be thought of as a variable name in a programming language, so that identifier can be used in the future to manipulate that object or close it. XML-based commands can be used to move an object on the video wall or change other properties, making it stand out by turning it red, for example. These “change” commands can be chained and queued with a time parameter, thus animating an object in any way the client program desires. For example, wiggle the object to get attention, make it transparent and show what is behind it, and even more.

This very powerful network-based approach allows programmers to use programming languages they prefer, yet provides a flexible set of tools that can make the video wall and its content do amazing things. One of the earliest examples of the use of the XML-based API is HiperPong, a simple version of the video game Pong written to use the Hiperwall video wall. It is a small Java program that queries the wall size and available contents, then lets the user choose which content items will be used for the paddles and the ball. It then allows the user to control the paddles on each side of the video wall to play pong. Because it can use any object as the ball, for example, it can show a live video stream flying back and forth across the video wall rotating as the paddles hit it. The video below shows HiperPong in action.



The HiperPong program uses very simple physics to determine where the ball should be going, then it uses the HiperServices XML-based API to command the ball to move to the right location over the next 20th of a second, then when that 20th of a second has nearly expired, it does it again. This built-in animation capability allows the ball, paddles, and even the score numbers to move reasonably smoothly on the video wall without having to control the movement each frame (60 times per second). 

External control of a video wall system is a powerful feature that allows the video wall and its content to be controlled via client software and third party video wall controllers. It allows the content and layout to react to external events from social media feed monitoring, surveillance systems, or other control systems. Hiperwall’s tool kit, HiperServices, allows a video wall designer to create a dynamic video wall solution that meets the requirements of each unique usage scenario. It also adds animation capabilities that provide freedom and control to empower design creativity.

 

Maximizing a Video Wall Experience

What do you most need to know about making an informed decision when designing a video wall?  All too often, system designers, contractors or integrators do not always design a video wall aligned with the customer’s realistic goals, budget, and environmental limitations. Obviously, you’re looking for a solution that delivers a strong return-on-investment for both the current need and ability to expand in the future.  Here are some considerations to help maximize your video wall design:

1)  Determine how your video wall will be used today and in the future.  Knowing the requirements for the video wall will drive the selection of the right video wall software and hardware. 

2)  Content is critical to your video wall system.  Which of these will be showing on your video wall?  Still images, low-res/high-res videos, 4K content, HTML5 applications, and 3D graphics?  Once you know what kind of content you’ll display, then consider how it will be delivered to the video wall.
   
3)  Know your environment and limitations.  Before specifying a video wall system, be aware of the environment of where the video wall will be placed.  Physical dimensions, room space, layout and ambiance will determine the appropriate size for your video wall.  

4)  Consider alternatives for future-proofing your technology without blowing the budget.  You need flexibility in your design to ensure your video wall will grow with your future requirements. 
 
5)  Select the right technology. A well-designed video wall and the correct technology working together in your operations center enable the best results.  There are so many ways to specify and implement a video wall that it can be hard to cover every approach. However, all video walls require an array of high quality, commercial or professional grade monitor screens configured to create a larger screen – video wall.  

• The traditional proprietary hardware suppliers use video wall controllers that are designed around their own technology with multiple built-in video outputs.  There are expansion limitations with this technology and you are committed to a single vendor for the life of your video wall.  Also, it is expensive.
• Next generation video wall systems are based on new distributed visualization software that is transforming the industry by eliminating the need for specialized servers, matrix switches, tangled cables and time-consuming training in favor of a solution that is easy to install, easy to use and easy on the budget. Hiperwall, for example, has eliminated these barriers by developing a software-based video wall platform that is completely hardware agnostic and budget friendly allowing users to deploy systems with nothing more than commonly available PCs, monitors and network equipment.  

The usage for a video wall can go anywhere from a corporate lobby “wow factor” to managing nuclear power plants, major transportation facilities, data centers, metropolitan police departments, television production, digital signage, and more.  The demands put upon these video walls will dictate design specifications and the right technology to meet your expectations today and tomorrow.  While video wall technology has been available for decades, your due diligence may help you discover a revolutionary solution that combines powerful capabilities with ease-of-use functionality, and future-proof expansion at a cost that’s easy on the budget.