Userful Industry Insight: Decoding Modern Video Wall Technologies
Half of digital signage is capturing people’s attention and the other half is powerful visual communication. With the proliferation of digital displays, means wow people isn’t as easy as it used to be. Organizations involved in digital signage and public display technology are constantly looking for ways to regain that “Wow!” factor. One of these approaches—and the focus of this article—is Video Walls. They capture attention and provide a big canvas to communicate and promote brands in a unique way. Not surprisingly video walls are one of the fastest sub-sectors of the world of digital displays.
Video wall technology is often misunderstood, and perhaps sometimes even feared. In this article, I want to help shed some light into some of the most common approaches to implementing video walls. There are basically 4 core technologies on the market today driving video walls:
1. Traditional Video-card based video wall controller:
This is the oldest of the technologies. A dedicated computer—basically a specialized PC equipped with extra video cards—is physically attached to the displays, each video output driving one display. These video wall controllers typically come with software and capture cards to connect multiple inputs, configure presets, control outputs and manage the overall configuration. Traditional video wall controllers are proprietary hardware solutions with a fixed number of inputs and outputs purpose built for video walls. Typically video wall controllers scale captured input sources, but some video wall solutions allow you to render content directly on the controllers. These are often very expensive but offer very high total resolution via the large number of installed graphics card.
- Vendors include: Barco, Christie Digital.
2. Tile-matrix scaler:
Many of the commercial zero-bezel video-wall displays come with a built in daisy chain solution that allows the displays to scale a single input source across an entire grid video wall. Tile matrix solutions work best video walls which don’t require high resolution or advanced features like rotations, multiple simultaneous content streams, preset zones. Obviously the tile matrix approach you still need a player to generate the HDMI or DisplayPort source.
- Vendors include: Samsung, LG.
3. Media-players playing back pre-split content:
Some companies have taken multiple signage player devices and time-synched them together to create a video walls playback system. Here the content must be pre-split and only the relevant portion of the video uploaded to each of the corresponding individual players—one per display. The players constantly talk to each other or to a server during over the network during playback to maintain synchronization. The key disadvantage of this is the inflexibility and cost of having to prepare the content in advance and the high subscription fees.
- Vendors include: Brightsign.
4. Network-based (AV-over-IP) video wall controller:
This technology marries the power and flexibility of a traditional video wall controller, with the cost, scalability and flexibility advantages inherent AV-over IP. A central PC renders, captures and splits the content then sends it out over a standard Ethernet network to the displays. This offers all the resolution, multi-source and flexibility advantages of a traditional video wall controller. All the content management, splitting and delivery is done in real time, and capture cards and network streaming source offer a wide range of inputs (like HDMI and SDI). But unlike the traditional controller it has built-in distribution and almost unlimited scalability (in terms of number of outputs) and artistic flexibility.
- Vendors include: Userful.
Each technology has its benefits and downsides, for example, traditional video card based controllers have the ability to output very high resolutions, and spread as well as divide and subdivide the display as you want. Unfortunately, these systems are the most expensive and rely on proprietary hardware, and must be sized in advance for a specific configuration limiting opportunities for system expansion.
Tile-matrix scalers provide a low-cost—usually included with high-end commercial displays— solution that is simple to set up. However future upgrades—for example moving from 4k source content to 6k source content—would require the entire solution to be upgraded.
Pre-splitting the content then delivering via media players is a great trick if your video wall content changes very infrequently. However this can often lock you into a specific content management system at very high subscription costs, lock you out of real-time content (like social media feeds, weather, news, live TV). The key downside is pre-splitting content is time consuming (which can be a deterrent keeping content fresh) also the approach rules out interactive content or real-time feeds such as social media posts, weather, live TV/video.
Network based video wall is comparable in cost to tile-matrix or pre-splitting but offers all the traditional controller. Finally, with network-based video walls, the only restrictions on the scalability of the solution are the power of the PC and the capacity of the network, which can be virtually unlimited. Also, these solutions have the flexibility to display and arrange multiple simultaneous real-time content sources, as well as support for multiple video walls running off a single PC. Network transport enables advanced features like high-availability as well as built-in cable extension enabling the PC to be securely locked away. The key disadvantage is since distribution is over an IP network at gigabit speeds, you need to install at least Cat5e cabling. Additionally most solutions recommend operation at 30fps to conserve bandwidth (whereas some high end installations require 60fps).and support for multiple simultaneous content, non traditional, artistic ‘mosaic-style’ video walls.
In conclusion, with any other technology market out there, companies should focus their attention on implementing solutions that are more powerful and flexible, without breaking the bank. Obviously picking the right core technology is just part of the decision. Features like easy setup and configuration; and flexibility to support your full range of customer use cases with a single product can be a huge time-saver for system integrators. Another key consideration is how future proof the solution is, and what type of upgrades or expansion would necessitate a complete replacement of the system. In 2016 expect to see more activity in the AV-over-IP space due to the enormous advantages this offers for video walls and digital signage in general.