TRANSITIONING FACILITIES IN THE DTV AGE
May 1, 2007 12:00 PM, BY JOHN LUFF
Infrastructure
In addition to the cost issues, there is simply less infrastructure available for HD nonlinear news, and what is available is still new in the marketplace. The cost and training barriers are exacerbated by the need to integrate SD legacy and field footage into HD news programs. Even the national news providers that have announced plans to transition to HD acknowledge that field acquisition will remain 4:3 SD, while converting to 16:9 SD and HD over an extended period of time.
At the network level, the investment required to fully enable HD acquisition and production for news is a huge barrier, one without proven sources of new revenue to justify the investment. It's possible that HD news conversion will proceed for the same reasons that helicopters and other large-ticket purchases for news are made, which is of course competitive pressure.
HDV
Figure 2. Studio sets require the same aspect ratio as cameras. The photo on top shows an SD image, while the photo on the bottom shows an HD one. Courtesy HD Consulting.
One factor that helps significantly in ramping up the conversion of field acquisition to HD is the availability of HDV as an acquisition format. Although it was initially conceived as a format for consumers and prosumers, the incredible picture quality and availability of professional features on cameras costing less than $7500 make this an attractive option for newsgathering at all levels.
Network conversion strategies announced by more than one company include the use of HDV as a primary newsgathering system. Editing HDV in some systems has been available for more than a year. Now it is quite possible to integrate HDV into a professional workflow.
In most cases, a nonlinear workflow can accommodate the changes in aspect ratio and resolution in the editing system. This leaves a burden on the editor, but allows the freedom to compose a story using both SD and HD content on one timeline. Render times will suffer, of course, which might make external format conversion before editing more desirable.
Control rooms
The control room is in a state of conversion. For the last decade, it has been considerably more expensive and complex to design a production system for HD origination. As HD equipment has become less expensive, and more available in all product categories, the incentive to build less expensive SD control rooms has eroded.
Figure 3. An example of an SD image center cut from HD. Courtesy HD Consulting.
Now the premium for HD facilities is less than 20 percent, and compared with SD costs a few years ago, it is now about the same price. The complication of building a facility that integrates both formats is that many converters might be necessary to convert all media to a house format, for example 1080i, before feeds are recorded and sent to a control room. One factor that makes this a bit easier is that most HD VTRs have downconverted SD outputs for use as needed, and some format agile SD-capable machines have upconverted outputs as well.
That leaves the most likely choice an HD control room from which a center-cut SD program is derived. Several manufacturers have developed production switchers that integrate both SD and HD internally, lessening or removing the need to convert signals before feeding to the production switcher.
Some of these switchers can process both SD and HD simultaneously. This is a powerful workflow feature that removes the need to build a single format facility and leaves flexibility for the production to seamlessly adapt to content that arrives unexpectedly in the wrong format.
In sync
Studio, control room editing can integrate HD and SD. There is no free lunch, even, or perhaps especially, with audio. Digital production switchers, monitor wall multiviewer processors and flat-screen displays all have latency that is not present in audio. This requires considerable care when designing a control room to ensure that the production team sees and hears precisely the right signals, and that sync is carefully maintained before it leaves the control room. Lip sync is the biggest complaint from consumers, and if facilities don't treat it with caution, it will be difficult to address effectively later. BE
John Luff is a broadcast technology consultant.
| Want to use this article? Click here for options! |  |
