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Hi-Def Jam
Family of Formats Don't Always Get Along
review by Ray Zone
High Definition Postproduction:
Editing and Delivering HD Video
by Steven E. Browne
Focal Press
230 pps, paperbound, $34.95
ISBN-13: 978-0-240-80839-0
ISBN-10: 0-240-80839-8
High Definition is not a format but a family,” writes Steven Browne. “And they don’t all get along.” Browne should know. He is a senior editor with over 25 years of experience. Browne’s previous book from Focal Press, Video Editing: A Postproduction Primer, is now in its fourth edition and it’s likely this new book on HD posting will go into many editions as well, given the speed at which the technology is evolving.
With this tome, Browne hoped “to clear up many of the misunderstandings that have evolved around high-definition technologies, and to clarify how this family of formats integrates with each other and our familiar NTSC, standard definition video.” So quickly is HD progressing that a week before Browne delivered the manuscript a new recording format was announced. Two weeks after he delivered it, three new HDV cameras appeared.
By clearing up some of the misinformation about HD and giving the reader a basic understanding of high definition, Browne has produced a useful guide for survival in the potentially confusing world of HD post-production. Charts and tables clearly enumerate the differences in HD formats and issues. “Some formats can only be digitized or edited on specific editing systems,” notes Browne. “Shooting at an incompatible or different frame rate and/or frame size from the final delivery format can potentially cause costly delays and expensive problems during the post-production process.”
Three elements are usually shown in an HD notation: frame size, recording method and image rate. For example, a 1080 frame size shot progressive segmented at 29.97 would be notated as follows: 1080psf29.97. However, a 1080 interlaced at 29.97 is usually notated as 1080i59.94. If you’re confused, Browne will clear the matter up. A progressive segmented frame (PsF) recording is a method that stores a progressive image as two separate fields, with odd and even lines. The two fields of a PsF frame are the same image that is combined. Interlaced fields contain two distinct and separate images that are not combined but displayed alternately, with half the resolution. When the PsF image is reconstructed and displayed, it is viewed as a single progressive frame.
Of the 12 high-definition broadcast formats––six of which were created to integrate with the NTSC broadcast frame rate––only one is “universal” and able to be converted to other high definition frame rates and sizes. If content is shot and edited in 1080p23.98 and output in the same format, the edited master can be converted to almost any other format, including PAL and standard definition NTSC. Particular networks, however, may require that a program be shot and delivered in a specific frame rate and size. When there is a lot of fast action, a rate of 23.98 frames per second may not be optimum, and some clients prefer camera footage shot in some other HD format. “The best solution to any production question is to obtain the company’s delivery requirements before shooting begins,” notes Browne.
Considerable confusion also results from wrong labels. Someone may call a format 1080i29.97 and somebody else may call it 1080i59.94. They are both the same. Yet another individual may call it 1080 60i. “Rounding frame rates to the nearest whole number can cause problems because six of the HD broadcast formats are whole numbers,” observes Browne. Manufactur-ers also contribute to the confusion. “Many manufacturers do not use the fractional frame rates for fear of confusing the consumer,” the author writes.
Each chapter of this book concludes with a summary reviewing chapter contents. Solid advice to editors and producers is also offered. All material of a specific program should be produced at the same frame rate, according to Browne. “To stay organized and shoot every location at the same frame rate is one of the best ways to avoid post-production problems,” he advises. “Some nonlinear editors will not allow mixing of certain frame rates and many will not mix progressive and interlaced formats. ”
Mixing editing systems for HD can also be a problem––doing an offline edit on one brand of system and an online edit on another. In many large post facilities, multiple editors and editing systems can also become an issue. “To be safe, it is best to keep things simple,” suggests Browne. “Conform on the same brand and type of editing system that the creative editing was done on, and, if possible, do not mix frame rates in a project.”
Browne shoots from the hip. “Many high definition problems stem from people being afraid of telling the truth,” he claims. “Sales and marketing people like to talk about and sell 30-, 60- and 24-frame production cameras when they are really talking about cameras that shoot at 29.97, 59.94 and 23.98 frames per second.” Many editing systems do not have the ability to convert a 29.97 sequence to a 23.98.
Despite the numerous provisos and cautionary tales, Browne is emphatic in his belief in HD. “High definiiton has arrived,” he declares. “With its various frame rates and frame sizes, there is certainly an understandable amount of confusion. Yet in a short amount of time, all of this will pass and we will enter a time of high definition calm.”
Ray Zone can be contacted at r3dzone@earthlink.net.