Video servers
Sep 1, 2008 12:00 PM, By Todd Roth
Video servers are evolving into media platforms that improve workflow efficiency.
The introduction of information technology (IT) into the traditional broadcast facility allowed television's associated workflows to become more integrated — and thus, more efficient. With this IT-fueled growth in networkability and processing power, the video server emerged as the preeminent component within the broadcast television facility.
We are now on the cusp of the latest evolutionary leap — a platform that combines the file-based workflow functionality of the video server with the ability to host previously discrete media applications in a single, compact chassis. Along with reducing the hardware cost and complexity of the broadcast facility, this platform provides the infrastructure to add new media applications, processes and services with the ease of installing software-enabled functionality. Integrated applications also reduce the costs of installation, operation and maintenance.
The rise of server-centric workflows
Until the introduction of the video server, most broadcast facilities built their workflows around the capabilities of their routers. In VTR/router-based infrastructures, a large router managed the flow of content throughout the facility, and components were discrete and connected via baseband. Moving content from one part of the facility to another often meant that tapes had to be physically copied, or dubbed. In a fully implemented video server model, in which a storage area network (SAN) becomes the facility nucleus, all users gain simultaneous access to the same material, so the whole concept of dubbing tape evaporates.
The ability to share media over a SAN reduced baseband routing requirements and enabled new server-centric workflow models. Furthermore, network access to media as files allowed the efficient implementation of new services with minimal incremental staffing requirements. The “IT-ization” of the broadcast facility was now fully under way.
As technology advanced and products evolved, external applications and processes that were once discrete were incorporated into the core server and master control platforms. Simpler applications and processes, such as play-to-air sequencers and proc amps, were the first candidates for integration. This assimilation was usually accomplished by adding special-purpose hardware and software to the platforms. With fewer independent components, routing requirements were greatly reduced. Generally, every function built into the server reduced the load on a routing switcher by three ports.
Just as production processes became more streamlined, the storage infrastructure improved in bandwidth and capacity. New capabilities emerged, such as SAN-based editing, which offered specialized environments such as television newsrooms the ability to get stories to air faster than ever before.
CPU-based processing capabilities of the platforms continued to increase, and more complex components became integrated as software features. Enhanced processing capability added multiviewer monitoring to routers, and allowed the integration of master control applications. It also brought the ability to integrate up/down format conversion and aspect ratio conversion to servers.
Benefiting most from Moore's Law are CPU and storage-based components, and the video server is no exception. Dual-core processors multiplied software-processing capabilities exponentially. The newfound processing power allowed codecs to move from hardware ASICS on add-in cards to CPU-hosted real-time processes. Compression format flexibility was now possible, and new compression standards, such as XDCAM and DV100, could be retrofitted as software upgrades.
What's more, as multi-core CPUs and graphics processors (GPUs) are added, the server platform becomes powerful enough to host many more applications in the broadcast chain, and a new platform is born. (See Figure 1 on page 28.) The addition of previously discrete processes such as channel branding delivers the ability to dramatically improve workflow. These user applications essentially become thin “clients,” and the need for routing is eroded further.
The evolution of the video server into this new platform not only revolutionizes the approach to facility design, but also streamlines operations. Smaller facilities can be built around one or two (for redundancy) platforms with internal storage, while larger facilities can take advantage of the SAN architecture.
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