We've looked at a digital signage overview, graphics capability, and hardware maintenance and security ideas and trends. Now, we shift gears and take a look at the content presentation software side.


In simple architectural form, digital signage systems are a display powered by a media player (a dedicated computer with multimedia capability) attached to a network. They are often called on to just display information today, but these systems are increasingly becoming more interactive with a touchscreen for user input. The implementation usually includes an application which manages content on a schedule, running over a standard operating system which performs the network, display, and storage management with support for the multimedia content presentation.


Content presentation

There are three aspects related to content - creation, delivery, and presentation. Creation depends on desktop applications and toolsets, delivery involves the network, storage, and scheduling information, and once ready the content can be presented accordingly by the system. We'll look at what a digital signage system typically needs to support for content presentation, namely the display and management functions.


A flexible signage system is capable of accepting content in a wide variety of formats. Legacy formats include Microsoft PowerPoint, and jpeg formats. Modern signage systems are dealing with much more dynamic formats, such as Adobe Flash 10.1, Microsoft Silverlight, and a range of full motion formats including .avi, .mp4, .wmv, and others. After all, to be engaging to consumers, full motion multimedia formats are now the expectation based on the desktop and mobile experience.


The presentation manager software on each digital signage system should provide several common functions:


  • Network distribution of content files: As we said in part 3 of this series, digital signage systems are "edge" devices in enterprise apps. They are connected over a network to a content server. The server manages where content goes - it might go to all signs in a network, to only some, or to just one.
  • Web-based scheduling management: not only are content files distributed, but they have to be slotted into a playlist including many other pieces of content. Each player has to maintain its content storage, playlist, and player software. (This is another reason content usually isn't streamed in real-time - it's often played over and over again during its usage life. It might be streamed on the first usage, but then captured locally for replay on its schedule.) Also needed are functions to remove outdated content files, and update schedules or replace content files with newer versions.
  • Recovery and synchronization: a really important function. Let's say the player has a problem and requires maintenance, and the remedy is installation of a new computer. The tech has no way of knowing how to reload the current content set - that information is stored on the server and is completely time and location dependent. The player software needs to go out, and pull in the required current content based on its location in the physical setting of the signage network.
  • Emergency mode: many signage systems are capable of displaying urgent or emergency information which preempts regularly scheduled content.


This diagram from Intel® Embedded Alliance Premier member Advantech shows a simplified version of a signage application, and highlights that a single signage display may actually be composed of several content "zones" with video, images, and text sourced in a cohesive view. The content may also be directed to different types of players: an LCD panel, a projector, or even a mobile device.




The larger the signage application network, the more complex and important these functions become. Modern digital signage management software provides many more sophisticated functions, and there are hundreds of solutions on the market from a wide range of VARs. Embedded solutions can benefit from some enterprise-style technology, such as Intel Active Management Technology appearing in several processor families, to improve the manageability of these large distributed systems.


Operating systems

Digital signage content management applications are of course based on an operating system, running on the signage system's computer.


One choice is from Microsoft, an Intel Embedded Alliance Associate member. Microsoft Windows Embedded is an easy choice for a digital signage system, because it contains several pieces of needed infrastructure.  Windows Embedded in its various forms obviously supports the required networking, whether it be wired Ethernet, Wi-Fi, or WiMAX. It supports the necessary playback formats, including legacy formats like Microsoft PowerPoint and new advanced formats such as Silverlight and Adobe Flash 10. Interactivity, power management, and rich traffic management are some of the additional attributes that are essential for a digital signage media player. Windows Embedded is well suited to offer these capabilities. There is also the possible need to deploy content on both fixed devices running Windows Embedded, and mobile devices running Windows CE Embedded or Windows Mobile. Intel works closely with Microsoft, building on applications from the enterprise side for embedded applications as well.


With the portability of Adobe Flash, Linux is also a possible choice especially at the entry level, from providers like Intel® Embedded Alliance Affiliate member LynuxWorks and Associate members MontaVista and Wind River. Linux offers similar networking benefits, and with more and more open source applications there are a range of solutions emerging. Intel's experience with projects like Moblin is driving some of this new development.


The next choice

Digital signage is no different than any other application development and deployment choice. The system architecture, development methods, installation requirements, licensing, performance, and many other factors need to be considered to arrive at the right choice.


As we wrap up this series, we've touched on many ideas in developing hardware and software for these systems. To finish up our discussion, we'd like your thoughts: What is the right operating system for today's digital signage systems? What features do you look for in a content management system for a digital signage player? What are you looking for in terms of networking, storage, or display capability at the player to help with performance or quality? Ideas welcome.



Don Dingee
OpenSystems Media®, by special arrangement with Intel® Embedded Alliance