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Sound for Video

Contributed By Fred Ginsburg

Sound for video
The more recent advent of computerized non-linear editing has changed and simplified the (tape based) process of video editing. Camera original is loaded into the editor. Audio is loaded in and then synced up by means of clapstick or production timecode. Audio can then be edited with picture (sort of single system) or creatively manipulated (double system-ish). Some systems allow the creation of multiple tracks, so that sweetening can be combined with picture editing.

The next step, after production, consists of the first picture edit. In video, this is referred to as an "off-line" edit, because it is done using a small format dupe of the original videotape, and a small format viewing/editing system. In video, along with picture & audio, it is possible to record what is known as SMPTE time code. Time code is an electronic frame by frame "edge number" that identifies every single frame on the videotape in terms of Hours, Minutes, Seconds, Frames. By means of this time code, it is possible to conform the original videotape to an edit made on a smaller format copy of the original.

On some shows, the producers will first do what has been nicknamed an "off off-line" first edit. The original videotape is duped onto consumer VHS format tape along with a time code "window dub" (SMPTE time code is keyed onto the picture portion, like credits). The producer can view the tapes on any player system noting down the approximate start and stop time codes of any take or scene. This information is passed along to the editor. Otherwise, the "off-line" edit consists of preparing a rough cut using a professional ¾-inch video editing system. Some ¾-inch systems provide for straight cuts only in the rough cut stage (dissolves and other effects are merely noted on the time code log, known as the "Edit Decision List", that will be later used to conform the original). Other, more sophisticated edit systems allow for creating visual effects on the off-line version itself, along with storing the time code instructions.

Since the video editor only has a total of two audio tracks to work with (one of which contains the production sound, and the other may contain time code on some systems), there isn’t much that can be done in the way of fancy sound editing at this time.

After the on-line version is complete, video editors begin work on the soundtrack. The process of sound editing and mixdown is known as "sweetening".

The first step in sweetening is to transfer the edited version of the production track onto a multi-track audio recorder. Matching time code recorded onto the last track of the multi-track tape is used to maintain exact frame sync between the audio and the videotape. This entire phase is called "laydown".

A computerized controller/synchronizer allows the multi-track to be played in exact sync with the videotape, and also allows other audiotape players to roll in at designated time code points.

The editor splits his production track into separate elements by re-recording portions onto remaining open tracks of the multi-track. Sound effects, narration, and music are transferred over from the other audio sources onto the multi- track with frame accuracy.

If needed, ADR and Foley can also be recorded using special controllers that synchronize video with multi-track audio by means of time code.

After all of the individual tracks have been built, checkerboard fashion, onto the multi-track—the editor then begins the task of final mixdown. Usually, there are still enough unused tracks remaining on the multi-track to allow the mixer to record onto the same tape. Otherwise, the tracks will be mixed down in sync onto another audio recorder. Depending on the budget of the show and the number of tracks involved, the mixer may create a DM & E. Otherwise, the tracks will simply be mixed down to a single monaural or 2-track stereo.

The final process is to transfer the mixed soundtrack back onto the finished videotape from whence it came. This is called the "layback".

Syncing Sound
sound syncing; topics covered include 60 Hz sync pulse, crystal sync, audio time code, Nagra IV-STC, HHB and Fostex DAT and Aaton Master Clocks.
dialogue definitions are discussed: lip sync, wild sync, production dialogue, ADR and looping. Sound track building is also addressed.
Sound Expendables
Dr. Fred Ginsburg, CAS, offers some practical advice on budgeting tape usage, stock allocation, battery usage and sundry items for a film or video production.
Production Mixing
Dr. Fred Ginsburg, CAS sketches an overview of production mixing; mixing panels, dB levels, VU meters, headphone monitoring, signal recording and recording priorities.
music as a sound track element is discussed, differences between extraneous and practical music, canned and original score, needle drop and blanket rights.