Play it one more time

Digital signage is becoming one of the most exciting applications of AV technology. But away from the ubiquitous flat panel display, what’s behind it all that makes it tick ? InAVate finds out.

When large flat plasma screens were first introduced several years ago, their use was limited largely to displaying PC screens in high tech offices. This rapidly progressed to today’s all-encompassing applications, including electronic notice boards, entertainment, advertising and office presentation facilities; as well as the ubiquitous “flat screen TV” as known and loved by a large proportion of the population for domestic use.

Along the way, flat screens have picked up a host of features and facilities that drive them into new markets and sectors. The first screens had 15-pin VGA and composite video sockets and not much else. Nowadays most screens sport a full range of standard inputs to supplement the basic PC and video connections. Internal features are added as screens become targeted at individual applications; the most obvious is the integral Freeview receiver, turning the screen into a complete TV set

In the commercial world, forward-looking screen manufacturers have incorporated useful video processing that delivers additional functionality. NEC’s Plasmasync range has for some time included a video wall feature that turns an individual screen into a segment of a multi-screen display, requiring no external processing. These screens even include a video loop-through to enable simple connectivity between panels.

With the recent expansion of the digital signage industry, manufacturers are now adding features that turn simple display devices into complex, networkable intelligent devices, capable of receiving, managing and displaying digital content remotely. Samsung’s MagicNet enabled displays incorporate a network interface and configuration/scheduling software that enables photo, video, Powerpoint, Word and Acrobat files to be streamed across the network to each screen.

This type of display is ideally suited to small networks and general-purpose self-contained displays. For very specialised systems and until the time that all screens incorporate an inbuilt PC and network capability there will still be a requirement for standalone playback devices and sophisticated network capability for distribution of content, playlists and schedules. And of course, digital signage is not limited to plasma and LCD screens. More and more projectors, whiteboards, interactive kiosks and matrix LED panels are in use as general information displays in a variety of applications. Which has led to a market demand for equipment that forms the backbone of digital signage technology: the hardware that makes it all tick, storage and playback devices and distribution methods. All of different form and capability, but of similar concept: a central content preparation and control station communicating with multiple remote display devices over a local or wide-area network. The differences relate largely to the size of the installation: the number of active display screens and the number of geographic zones (clusters of screens with the same content) that are deployed. To a lesser extent the importance of the type of content to be displayed; whether it is video or message centric, which determines the ratio between live transmission and file store-and-display, which in turn affects the type and power required of the receiver-display device.

It is at the receiving end that a variety of technologies is found. In general, applications that replay ready-to-go image sequences and those with large amounts of stored video and audio will often utilise simple replay devices based on solid state memory and hardware decoding devices. These may be built on small-factor PC motherboards with Windows but in many cases will use Linux platforms for reliability and low cost, although the addition of new features is slow. In this type of cheap, small form-factor, high volume device the focus is on providing a small footprint with fast response. These form the simpler systems, in which specific video sequences are produced as MPEG video files, sent to the players and continuously played out at the point of display. It is possible to build a player with several hours of video playback very cheaply, using Compact Flash or memory sticks that will deliver DVD-quality images endlessly. Remote Media’s SolidMedia player is a typical example, offered at a price of around £130 per unit, they are cheap enough to deploy with any size screen for an effective advertising network and small enough (about the size of a small paperback) can be secreted in most locations on retail floors and other space-limited environments.

Cabletime, known for their IP based TV distribution system has recently launched a similar type of device: the Mediastar Evolution Digital Signage Player, playing MPEG files delivered to them over a network or locally using a standard USB memory stick. It will automatically look for new content and collect, replace and playout the new material. Comm-Tec manufactures the ProPlay range of solid state, remotely controllable video and file players for MPEG, JPEG, MP3 etc. These have the interesting ability to be controlled locally by attached barcode readers. So shoppers can request information on a specific product by scanning it, with a audio-visual file presented to them. Playbox, a new entrant to the digital signage industry has a history of developing broadcast automation systems and has extended that ability into the sign market, using IP and DVB video streaming, with an installation example in 60 airports and stations in Bulgaria.

It is, however, a case of ‘swings and roundabouts’: production costs for full video sequences are high and take days, if not weeks to plan and produce. To gain more digital signage functionality requires a greater level of intelligence at the player end, so that individual sequences, messaging and imagery are built within the player itself and delivered as dynamic messaging, with the advantage of instant change and impact.

An example of this is the Vario range, built by Blue Chip Technologies and used by Sedao as playout units for the Image Flyer Digital Signage suite. Whilst Image Flyer and other digital signage packages can, and often do operate on minimal specification machines; as low as 1GHz Celeron in some cases, more power is often more economic and allows better video performance. The Vario digital signage engine is highly configurable with processing options starting at 2.4GHz. As Barry Husbands, MD of Blue Chip Technology explains: “We design and manufacture the Vario specifically for the digital signage market. Our ruggedised hardware offers 24/7 reliability, platform stability and an efficient thermal profile in a footprint compact enough to mount on the display rear. The recently launched Vario Elite further is the next step in the evolution of the range, with HDTV support, PCI Express, Gigabit LAN and dual core processing options whilst retaining a competitive pricing point for a cost sensitive marketplace. The range includes a video capture facility that allows users to input TV feeds and include them within windows on the screen using the facilities of the Image Flyer digital signage package“.

Inspired Signage, which can also run on Blue Chip Vario PCs, uses the latest hardware in order to future-proof the installation. Damon Crowhurst, Sales Director: "With the recent availability of very high resolution screens, the content source must be capable of rendering at HD resolutions and beyond. We recommend 1080P at 60fps. Our multi-screen video walls require us to drive the content from multiple synchronized PCs, each rendering the appropriate section, avoiding the need for expensive video wall processors. One of our planned installations will be over 128 Megapixels per frame!" Another buoyant aspect is the use of digital signage in city and financial locations where data security is paramount. Damon: "We are regularly asked to secure the players for corporate companies. As more remotely-controlled digital signs appear in public they will become targets for hackers: imagine the 'fun' they could have at places like Piccadilly Circus - so security will become a greater issue in general."

These types of player are obviously more expensive than the video playback units, and because they are ruggedised have a slight premium over desktop PCs at around £600-700 in single units, but they do have the advantage of running dynamic digital signage screens which are inherently simpler, and therefore cheaper to program and create attractive images. Which means they are usually employed in small networks and self-contained systems; perhaps within a single site with a control PC feeding five to ten players around a retail floor.

The relatively low-cost and high performance aspects of PCs, coupled with the falling price of LCD screens means that digital signage technology is reaching into interactive kiosk and point-of-sale applications in a massive way. And spreading widely too, encompassing traditional information points in stores, tourist information offices and hotels, as well as finding use in museums and art galleries. Art Systems supplies a wide range of wall mounted touch panels, point-of-sale and museum kiosks and through-glass interactive screens. When combined with interactive digital signage software, the resulting package is a complete, easy-to-use solution that enables interactive information to be produced and displayed very effectively.

An alternative approach to distributed information systems that is beginning to become recognised as viable, is a hybrid system that combines multiple source devices with a multi-format video distribution system. An example is a new installation at a central London theatre that integrates four Vario Lite-Image Flyer devices with a DVD player and two camera feeds and an Endeleo managed hub; all located in the central computer room. The hub acts as a comprehensive media switch and distribution amplifier enabling 16 dedicated large screen LCD displays over four floors to be connected to the central system through small receiver units over the building’s Cat5 cable network. With browser control, operators can dynamically combine the screens into zones at will and distribute any source to any zone. The system is used to switch between booking information and forthcoming events, live stage feeds and DVD playback of trailers and adverts – all of which are appropriate to a cultural and media centre of this type

The Endeleo hub also includes remote device control which is put to good use in switching the screens to standby at preset times every day to save screen life and prevent potential burn-in. Whilst this is possible with local PC control at the displays, it requires additional connections and control which are not readily available within the pieces of equipment at the moment.

All in all, technology advances to the benefit of digital signage systems, allowing greater scope and flexibility and larger systems to be constructed, as summarised by Dave Oades, MD of Sedao: “Over the past twelve months or so we expected to see customers reducing the overall system cost as hardware price/performance increased. Instead they are installing higher specification systems in anticipation of better things to come”

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