The Move to Digital

The move to digital video and audio has had a major impact on the entire production and postproduction process.

  • Suddenly, your desktop or laptop computer can be turned into a videotape-editing console. (Complete, 90-minute productions -- even feature-length films -- are now being edited on PCs and laptop computers.)
  • New three-chip camcorders can equal the quality of video cameras that previously cost many times more.
  • The terms off line and on line editing may soon be obsolete distinctions.

Although digital signal processing has changed many areas of audio and video, we'll talk about just one area here: digital video recording. Since the digital signal is recorded in terms of clearly defined "off'' and "on'' (or "0'' and "1'') pulses just the way computer information is, there is no generational loss in making digital copies.

A fifth generation recording from the best analog VTR shows signs of deterioration. A fifth, or even the 50th generation of digital video is not significantly different from the original. This advantage is extremely important in postproduction, where video may have to go through multiple generations of digital effects.

Next, the signal-to-noise ratio of digital video remains consistent through repeated stages of amplification and signal processing. (The signal-to-noise ratio is the degree to which video or audio information stands out from background interference, or noise. The higher the signal-to-noise ratio, the clearer and stronger the signal will be.)

Because sophisticated error correction equipment is normally a part of digital equipment, playbacks are immune to most video problems. These include dropouts, velocity errors, impact errors, and general color errors.

Next, digital video can be processed by computer equipment without going through analog-to-digital conversion.

And finally, digital videotapes have a much better "shelf life'' than analog tapes, which means they are better suited for storage and archival use.