PREPARING AUDIO FOR POSTAudio editors and mixers in film and broadcast post have established simple processes for working with sound from Avid systems. This involves some basic (albeit irritating) conversions from Avid to Pro Tools via Avid’s Open Media Framework Interchange (OMFI) format. Once in the Pro Tools realm, we’re free to work with the tools of our trade.
As directors and editors migrate to digital video, and often to Apple’s Final Cut Pro systems, sound editors are left trying to figure out how to keep up. Unfortunately, Final Cut Pro doesn’t yet support OMFI, so here are a few tips to help your DV production audio make the conversion to Pro Tools:
FOLLOW THE LEADERAlways insert Academy (or homemade “fake-cademy”) leader at the head of every sequence. (If you can’t find it, just digitize from someone else’s reel.) This is usually a count from eight down to two in single seconds, with two seconds of black before the picture starts. Its primary purpose is to provide a visual reference for your two-pop, which should be on all your tracks. Used as each track’s universal sync reference, the two-pop is a one-frame, 1kHz sine wave beep tone placed exactly on the number “two” in the leader (two seconds before picture start).
HANDLES WITH CAREEditing using “handles” (the little pieces of audio before the beginning of an edited region and after its end) is the single most important step for retaining truly usable location sound in the move from Final Cut Pro to Pro Tools. When you cut two clips together, the audio at the edit point is butted up, one clip to the other. In order to create a dissolve (crossfade), your edit system uses these hidden handles, which it knows are in the source file. No handles = no crossfades = a “pop” at nearly every edit point.
To create handles, you must use extra audio tracks so you can “checkerboard” your audio. Checkerboarding consists of putting every odd audio edit on tracks 1/2 and every even edit on tracks 3/4, for example. This way, their starts and ends can be extended without overlapping. Next, lock the video track(s) and extend the beginning of each audio region 2 to 3 seconds earlier and the end 2 to 3 seconds later. You can use the audio level breakpoints to prevent the new handles from playing. Just remember to remove the audio level changes before mixing down or the homemade handles will be lost.
QUICKTIME: THE OMFI STAND-IN?Use the Export command to create 48kHz .AIFF QuickTime mixdowns of every stereo pair in each sequence, regardless of whether the material is dual mono or true stereo. Also, remember to remove all volume automation so you’ll get your handles back. These are the final files that will go into Pro Tools. To reconstruct the exact audio you had in Final Cut Pro, the sound editor simply imports a sequence’s stereo .AIFF files, lines up their two-pops and sets the Pro Tools sessions to sync to the dubs.
JUST LAY OFF”Edit to Tape” digital cuts of your program (or program reels). Each individual sequence should usually occupy its own tape and must have the Academy leader mentioned above. Put your rough audio tracks on these digital cuts for reference sake. On a DV project, most audio-post houses will dub to another format, as DV – especially miniDV – is not very robust for projects where timecode and constant shuttling are the norm.
Whew! This process may seem complex, but it lets you keep all your location audio in the digital domain from initial digitizing to the final mix. This is only the beginning, and Final Cut Pro will continue to expand its place in feature and broadcast use. As soon as Apple includes direct OMFI (or some other Pro Tools) support, Final Cut Pro will function in the studio as seamlessly as the Avid.