Savvy broadcasters and content distributors are finding creative new ways to leverage the capabilities of the now-ubiquitous media server to solve specific challenges beyond record, store and playout. Media servers are now standard equipment for television broadcasters. As the cost per channel of broadcast-quality servers has come down and file-based workflows have become essential to efficient, high-quality production, these station workhorses are being used in innovative ways beyond their original scope as VTR replacements.
Budget limitations and new content repurposing opportunities are spurring many of these new uses. Declining advertising revenue due to online media competition, as well as the cost of HD conversion, is adding to the pressure on station engineers to be resourceful in designing storage and archive workflows.
To ride the wave of viewer migration to Web 2.0 entertainment sites, stations are adding streaming capability for Web broadcast of traditional over-the-air programming. Other new media outlets — such as digital signage networks, and Web-based news and content aggregators — give broadcasters even more options for extending their potential audience.
This article will take a closer look at original ways broadcasters use video servers for file transfer, storage, content distribution, virtual sets, distribution of programming to digital signage outlets and content management.
Improving file transfer and storage efficiency
As the volume, complexity and size of digital assets increase, file transfer and management workflows are being redesigned to save time and reduce cost; and video servers are proving to be valuable tools for improving efficiencies. Program file storage in the digital age has evolved into a four-tier system, based on immediacy of access. The four tiers are:
- online, with files stored in onboard server hard drives for immediate access and playout;
- nearline, with files stored on network-attached hard drives that can be transferred to online access and inserted into the online workflow;
- offline, with files stored on external drives, optical, or tape media, but housed in the building; and
- archive, with files stored off-site.
Each storage tier requires different management workflows. For example, because data tape can degrade, archived storage may need to be refreshed at regular intervals. For nearline storage to support playlist building, a fast-access drive array must be used to make a direct connection to the server, as opposed to slower media.
Because HD content file size can be more than six times larger than equivalent SD files, workflows and infrastructure designed for SD content storage and transfer is costly and time-consuming. Serial attached SCSI (SAS) offers higher transfer rates (3Gb/s) for moving HD files in nearline storage to online servers. However, this is a point-to-point protocol with dedicated, not networked, connectivity.
The traditional solution for distributing content to multiple stations is satellite data delivery in a point-to-multipoint solution, pushed from a central location. But new options are emerging. One U.S. public broadcasting station group recently installed a system that enables remotely located stations to share access to the servers and archives. This allows affiliates to select and download only the specific content they require, rather than ingesting and storing large quantities of unneeded content.
Some broadcasters are discovering that storing and transferring files on portable hard drives offers many advantages over network and satellite file transfers, including instant access, quick regeneration and lower distribution cost. Moving data can be as simple as using a Web browser to drag and drop files. At a cost of around €85 each, hard drives also deliver fast and economical backup compared with standard tape backup systems.
Portable hard drive storage is an effective solution for stations that continually ingest live local, network and satellite feeds. Modular network-attached storage systems can pack petabytes (1000TB) of hard drive capacity into a rack-mounted unit. Interfaces to automation and station management software are readily available.
Efficiently moving massive amounts of data to multiple locations is time-consuming. Many storage product companies have devised clever ways of increasing efficiency, but the pipe to move data can be costly. Consider the new 1.5TB hard drives. A single drive holds more than 1000 22-minute episodes of SD content (at 8Mb/s data rate) and more than 180 episodes of HD (50Mb/s) content. To move all of the data on this disk on a point-to-point dedicated GigE network with reasonable efficiency would take five-and-a-half hours. If the only pipe available was a DS3 (45Mb/s), the transfer would take approximately three days, and using a T1 line (1.4Mb/s) would take about three months! Sending hard drives via overnight express is faster and far more economical.
Doing more with less
Remote control and management capabilities enable more efficient server operation, making storage and file transfer possible from numerous locations virtually anywhere.
For example, a chief engineer managing three Illinois stations in the United States runs commercial breaks for all three stations with a personal computer, using the remote workstation feature on servers. A satellite service provider in Bahrain discovered that if it rented rack space for servers that can be remotely controlled, broadcasters could enjoy the benefit of server-based workflow without having to build their own physical plant.
In other cases, broadcasters installed backup servers at their transmitter towers so that, in the event of a microwave failure, content can be transferred via FTP to the server and remotely controlled until regular transmission resumes. With remote capabilities, a TV station in Beijing, for example, could record content, edit it and send it to a remote server in Mongolia for playback.
Video walls and virtual sets
Some broadcasters are employing servers for video walls, such as a line of monitors behind newscasters on a set, or for graphics playback and virtual sets. In place of a dedicated virtual set, servers can enable the creation of backgrounds for virtual sets via the use of blue or green screens. A multichannel server can provide a different background for compositing with each camera feed, creating the appearance of a camera moving around in space.
A three-camera news broadcast can be shot with a virtual background and a three-channel server. The background is shot from the same angles that will be used in the live production, either with a single camera for static backgrounds, or with multiple cameras to capture moving backgrounds where continuity between different angles is desired. The talent on the set is then shot from the same angles during live production. The production switcher controls compositing the feeds from the various channels with the proper camera.
Backgrounds do not have to be live video. They can be created in graphics applications, and different backgrounds can be running at once, for example a different news and weather set. One major European news broadcaster recently replaced tape with a bank of video servers running looped scenes. Because the server allows FTP file input directly from Final Cut Pro, the station achieved a sophisticated graphic set with a dependable, flexible and easy to manage system.
Digital signage networks
By using a multichannel video server to loop content, digital signage programmers can achieve a seamless, professionally produced viewer experience without using automation equipment. All that's required is an infrastructure to distribute the signal.
A large UK retail center is currently providing RSS news programming via overhead plasma monitors in food courts and central gathering spots. System operators use the video server's capability to ingest RSS news feeds and advertising content via Internet FTP, and program the playlist using built-in software. Adverts from mall stores and event bulletin boards are tracked by as-run logs generated by the server. Server-based aggregation and distribution delivers a huge boost in efficiency compared with a tape, which would require a minimum of two VTRs as well as an automation system to provide a continuous feed, with nowhere near the same level of variety.
By taking advantage of the remote media transfer and remote control possibilities afforded by video servers, a broadcaster can offer advertising services to area shopping malls and grow additional ad markets.
Time delay
Time delay features on some video servers can be valuable in managing content workflow. For example, stations in the Middle East that ingest programming delivered via satellite employ this feature in their standard program workflows to review and remove material deemed undesirable for their audiences. The standard features in a mid-priced three-channel video server support this easily. Channel 1 is dedicated to recording, channel 2 to simultaneously view and edit, and channel 3 to broadcast the delayed and edited content.
Time delay functions also economically increase a channel's viewership. Dedicated time delays have become popular in Europe to broadcast plus-one, plus-three and plus-five channels. By delivering programming to multiple cable channels with a time delay of one, three or five hours, broadcasters can deliver each program to multiple, new audiences.
Brad Cox is principal systems analyst and John Hancock is senior design engineer for 360 Systems.
