Since 1994, Scripps Networks has grown from the successful launch of Home & Garden Television (HGTV) to a multichannel network that includes Food Network, Do It Yourself network (DIY) and the most recent addition, Fine Living. Recently, Scripps and A.F. Associates completed phase three of the additions to the network facility in Knoxville, TN, to support the network launch of Fine Living.
With the expanding number of networks, and the need to size for the future, Scripps and A.F. Associates re-examined the entire playout process. The goal was to simplify the on-air playout system while ensuring absolute quality control of the final programs.
Scripps Networks was an early adopter of server-based playout systems, basing its first system on the BTS/Philips MediaPool. It was also one of the first facilities to incorporate mass data storage of its air library, all under automation control. With multiple networks involved, uptime is critical, so the network carefully examined its use of these systems.
After this careful re-examination, the network decided that a bit of technology retrenchment would actually improve operations. Ultimately, it decided to move from server-based on-air playout to creating compilation reels and using VTRs in library cart machines to deliver programs over dual signal paths. This design greatly simplifies master control’s operational requirement, providing the highest on-air reliability, and a seamless transition strategy for the deployment of the next-generation server system.
The first step was to construct a new broadcast operations center (BOC) that contains the following functional areas:
program playout/master control
The compile preparation and dubbing area initially handle the media (assets) and their eventual ingest into the video server system. The traffic system and playlist drive the instructions to the automation system. The staff ensures that all content scheduled on the playlist is in the main data archive or video server. A playlist for each of the four networks is set up on automation, which then compiles it to Digital Betacam and DVCAM tapes.
Scripps traffic system outputs an electronic log to the BOC staff. The staff uses this log to create the playlist they need to create the compilation reels. If content is not already on the server, the staff must dub it into the server. Traffic generates this list about 48 hours prior to air.
Assets arrive primarily in Digital Betacam format, but the dubbing department often encounters other formats. When this occurs, the department staff dubs that asset onto the house standard Digital Betacam format. Once the staff identifies the needed assets, they retrieve the tapes (from the library, for example) and dub them (if necessary) onto a Digital Betacam compilation tape. They check the quality and then move the tape into the digital archive.
The video file server system then batch ingests this compiled tape of commercials and programs. The staff archives the assets to the data archive, which consists of a StorageTek Powderhorn with 9940B data drives for near-line storage. Interstitial content remains solely on the video file server. The data archive system currently has five 9940B drives and 6000 data cassettes, each with a storage capacity of 200GB. This yields a total storage capacity of nearly 1 petabyte. The current video file server is a Thomson Grass Valley MediaPool using MJPEG compression. The network uses a 45Mb/s encoding rate which, when multiplied by the storage capacity of the data archive, yields a total storage capacity of 59,000 hours.
Based on current per-network storage requirements of approximately 14,000 hours, the four existing networks require 18,000 hours of archive storage. Eventually, Scripps plans to originate up to eight networks from this facility, so its total archive needs could grow to approximately 112,000. However, some of the new channels could repurpose existing assets and rely on some repeat programming schedules. This could cut total storage requirements for each channel by two-thirds.
The actual ingest requirements vary from day to day, depending on the availability of content. At a typical data transfer rate of 8MB/s, it can take five drives 4.25 hours per day to move the data from server to archive, not including the time required for tape mount and dismount, robot retrievals and other mechanical overhead.
Once the server has ingested the assets and archived the program segments, the BOC staff plays out the assets in proper sequence and records them in two-hour packages, complete with interstitials and graphics.
The compile signal-processing chain consists of a Pinnacle DekoCast CG processor, a Norpak TES-5 VI data inserter for closed-caption data, V-chip, and other ancillary data inputs, and an Evertz GPI data inserter for DTMF/GPI insertion. The system uses the Thomson Grass Valley Saturn master-control switchers as an alternate air path feeding Evertz 12x1 switchers, but the staff may use them in the compile processing chain if the playlist calls for additional processing. A Pinnacle DekoCast with DVE option provides squeezeback functions. Because this entire process is accomplished offline, a failure of any one element in the chain will not affect on-air signals. Once the BOC staff records the compiled reels, a QC station screens the tape and the tape is ready for air.
Program playout and master control
The program playout system consists of two Sony Flexicart systems, each with four Digital Betacam DVW-510 VTRs and 12 L-format Betacam cassette bins controlled by Flexicart automation software. HGTV and DIY use one Flexicart, Food Network and Fine Living use the other. Scripps uses separate DVCAM tape machines for mirrored playback and can switch to them if it encounters a problem on one of the Flexicart VTRs (see Figure 1).
The Flexicarts feed DAs for monitoring and then feed a pair of Evertz 12x2 clean switch routers (one primary, one secondary). Their outputs pass through DAs for monitoring and then on to the coax tie lines to the transmission-control room. This signal chain is replicated for each of the network streams.
The master-control switchers are connected in parallel to the Flexicarts so that production can send a live event to air. These outputs connect to routers that feed the transmission-control room. There, the signals are processed and uplinked to the satellites for national distribution.
To keep things simple, A.F.A. designed virtual monitor walls for easy viewing and control. Avitech Video multi-window display processor systems, each of which can support up to four audio 42” Sony PFM-42B1 plasma display panels, create a virtual monitor wall. Each processor group has eight SDI inputs, each with AES digital audio (four channels per video input). The Avitech processors can overlay audio metering as part of the virtual monitor wall. Signals monitored include program video and audio, and satellite return video and audio.
There are three primary subsystems in the transmission area: signal processing, signal monitoring and uplink control. The transmission-control and monitoring systems receive broadcast-to-air signals from the BOC and pass them on to the satellite uplink system. Additional processing is required for audio compression, live ancillary data insertion and video processing (such as color legalization).
The center receives dual-path signals from the BOC through tie lines and uses reclocking digital DAs on each path. The “A” and “B” paths for each network feed an Evertz 4x1 switcher whose output is processed prior to uplinking. The 4x1 switcher is actually configured for 2x1 operation and can be controlled from two locations: a hardware-control button located in the BOC network-control room, or locally in the transmission-equipment center.
The air path passes through a series of signal processors prior to the 2x1 switcher. A Videotek DPA-100 performs color legalization. An Orban Optimod compresses the AES audio. After this processing, a General Instruments VideoCipher encoder scrambles the Home & Garden signals for conditional access. A Motorola DigiCipher II encoder scrambles the Food Network, DIY and Fine Living feeds. Commercial-break cue tones (either through sub-audible DTMF tones or GPI contact closures) are input to the encoders. The DTMF tones go through a Wegener system to the VideoCipher, while cue tones flow to the DigiCipher Event Trigger System (ETS).
The encryption system output connects to a Miteq modulator, whose output connects to the uplink shelter through a fiber-optic connection. This L-band signal also goes to an IRD for confidence monitoring of the DigiCipher encoded signal.
The systems were successfully completed in late 2002. Through creative design, both new and older technologies have been effectively melded into an efficient and high-quality play-to-air system. The new system lets machines do the mundane tasks and allows operators to concentrate on duties that require human intervention. This new system allows Scripps to plan for future networks, knowing that the facility is already in place to support them. While the success of such a project can be measured in many ways, the first must be how it met the initial operational goals. Scripps has found that, even with an increase in the number of on-air channels, the staff is fully able to maintain the fast-paced schedule and high-quality programming for which the network is well known.
Mike Donovan is vice president of engineering at Scripps Network. Tom Michales is senior project manager at A.F. Associates.
|Mark Hale, executive VP, production and operations|
|Mike Donovan, VP, engineering|
|John Ajamie, VP, operations|
|Jerry Nantz, chief engineer|
|Tim Harty, director of network engineering|
|Tom Michales, senior project manager|
|Mark Bressack, VP, sales|
|Scott Buchholz and Brian Luscombe, senior project engineers – BOC|
|Harry Thompson, senior project engineer - transmission|
|Tony Kilkenny, project leader and site supervisor|
|Odetics TCS-90 cart system|
|StorageTek Powderhorn data archive with 9940B data drives|
|Thomson Grass Valley MediaPool video file server|
|Pinnacle DekoCast CG processor|
|Norpak TES-5 VI inserter|
|Evertz GPI data inserter|
|Digital Betacam DVW-510 VTRs|
|Evertz 12x2 clean switch routers|
|Thomson Grass Valley Saturn master-control switchers|
|Avitech Video multi-window display processors|
|Sony 42-inch PFM-42B1 plasma display panels|
|Videotek DPA-100 color processor|
|Orban Optimod audio compressor|
|General Instruments VideoCipher|
|Motorola DigiCipher II encoder|
|DigiCipher Event Trigger System|