Audio commentary (DVD)

On disc-based video formats, an audio commentary is an additional audio track consisting of a lecture or comments by one or more speakers, that plays in real time with video. Commentaries can be serious or entertaining in nature, and can add information which otherwise would not be disclosed to audience members.

The DVD medium allows multiple audio tracks for each video program. DVD players usually allow these to be selected by the viewer from the main menu of the DVD or using the remote. These tracks will contain dialogue and sound of the movie, often with alternative tracks featuring different language dialogue, or various types of audio encoding (such as Dolby Digital, DTS or PCM). Among them may be at least one commentary track.

There are several different types of commentary. The two main types simply define the length of the commentary rather than the type of content. They are:

Typically a commentary track will include feature-length commentary from the film's director, cast members, or occasionally writers and producers. Occasionally actors will perform commentary in-character. (In recording sessions with multiple speakers, a designated moderator may encourage the discussion flow.) Some DVDs include outsider commentary performed by film critics, historians, scholars or fans. In more elaborate productions, multiple speakers from various recording sessions may be edited together for a single audio program.

Some DVDs feature commentaries with on-screen video enhancements, such as telestrator prompts, (allowing the director or commentator to "draw" on the screen, pointing out specific details), or the Ghostbusters "video commentary", where one of the subtitle tracks is used to add silhouettes of the speakers in a manner where they seem to be in a theater commenting on the movie as it was screened for them in the style of Mystery Science Theater 3000. Less common are actual video commentaries, showing the speakers as they are recording the commentary, requiring separate video tracks.

The value of audio commentaries as a marketing tool was revealed during the heyday of laserdisc, the laser-based video format produced before the introduction of DVDs. The Criterion Collection company, for example, produced high-quality "deluxe" editions of classic films on laserdisc, using the best available prints and re-edited versions. These were often very expensive compared to today's DVDs and included bonus material such as trailers, deleted scenes, production stills, behind-the-scenes information, and audio commentaries from the directors, producers, cast, cinematographers, editors, and production designers. They were marketed to movie professionals, fans and scholars who were seen as an elite niche of consumers who could afford to pay more for definitive, quality editions. The audio commentaries on laserdiscs were typically encoded on secondary analog tracks which had become redundant, as modern laserdiscs had stereo audio encoded digitally alongside. This is why certain older videodisc players, which pre-date the digital audio standard, are only able to play back analog tracks with audio commentary.

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