When it Comes to Compression, Smaller is Definitely Better

Working in TV means looking at all the angles to simplify a hectic workflow. When your parent company mandates that all your programming be archived to film, your SD deliverables become HD and the angles multiply. How best to manage a high-definition workflow that’s flexible enough for creative work but efficient enough for working with large files?
"Simplifying is almost always going to save you time and effort," says Tony Tedford, post-production supervisor/editor at Cartoon Network Studios. And in this business, simpler means smaller. So Tedford has adopted Avid’s DNxHD codec, designed to cram high-quality editorial files into manageable bandwidth, as a critical element of a new, totally tapeless animation pipeline.
Until recently, overseas animators delivered assets to Cartoon Network using QuickTime’s animation codec, which is tweaked specifically to handle 2D animation content. The files were huge, meaning Tedford and crew treated SD and HD as two separate processes. (The show was re-assembled in high resolution at an outside facility.) Starting this year, with The Life and Times of Juniper Lee, edited by Roger Hinze, the animators are being asked to deliver files using DNxHD.
"Before Avid DNxHD, when overseas would send us an entire set of take-one files- that’s anywhere from 170 to 300 scenes- it would be, in the [QuickTime] animation codec, anywhere from 200 to 500 GB," Tedford explains. "With the Avid codec, the same number of scenes is about 30 to 40 GB, max." Even better, the whole process is tapeless until Cartoon Network creates a final D5 deliverable, which Warner transfers to film.
Here’s how it works. Every scene of every cartoon is sent to Cartoon Network as a separate QuickTime file, encoded at 1920×1080 in 8-bit 24fps Avid DNxHD files at 175 Mbps. Files are sent electronically via the DigiDelivery option in Pro Tools (essentially a sleek FTP service), on DVD-R, or on a hard disk drive, depending on where they are in the production process. "If we’re in a hurry on a shot, we have them sent DigiDelivery. But if it’s a lot of files, we’ll have them sent on an external hard drive or DVD-R. And our audio post workflow has been almost entirely taken off of tape and gone to digital files, and those are most often sent via DigiDelivery as well."
The files are edited and mastered in real time at SD resolution, and then the Avid project is changed to an HD project, re-linked to the HD versions of the files, and then mastered to D5. The D5 tape is sent out to be recorded to film to meet the archive requirements of Warner Bros. technical operations. "It’s nicer importing and editing [smaller files], and it saves our outside people having to reassemble our entire show to high-resolution in order to record film," Tedford says.
Four Cartoon Network shows are now using the same workflow- in addition to Juniper Lee, My Gym Partner’s a Monkey, Ben 10, and the third season of Camp Lazlo have all gone DNxHD. Eventually, Tedford says, all of Cartoon Network’s series will be converted.
DNxHD actually represents a reduction in resolution from the previous workflow in terms of the film-out, but tests showed that film prints from D5 looked great, and the smaller file sizes made post-production much more manageable.
Is higher resolution in the foreseeable future? "Not for what we do, unless it’s mandated by Warner Bros.," Tedford says. "As long as they like what we send them on film, and also now on HD tape, they’re happy. And we’re happy, too- as long as we keep the kids laughing."