Digital8
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Digital8 (or D8) is a digital videotape format invented by Sony in the late 1990s.
Quite simply, Digital8 is the combination of the venerable Video8 tape-transport with the DV codec. Digital8 recorders use conventional analog Video Hi8 videocassettes, but store audio and video information in digital-form (using the DV-codec.) The higher datarate of digital-recording requires a doubling in tape-speed (compared to analog Video8 recording.) A 120 minute Hi8 (NTSC) tape will store 60 minutes of Digital8 video (SP.)
As Digital8 uses the same audio/video compression scheme as miniDV, the Digital8 format offers excellent audio and video (A/V) quality, far better than mainstream VHS or Video8. While older analog Hi8 video was used by electronic news organizations and current affairs TV programs, Digital8 remains strictly a consumer format. This is likely a reflection of Digital's design goals; to serve as a low-cost upgrade-path (from analog Video8), by leveraging the existing manufacturing infrastructure of 8mm video equipment. Little or no equipment has been produced for the professional market, although there are no technical barriers opposing its development.
The Digital8 format, although physically incompatible, is completely interchangeable with the DVC (Digital Video Cassette, eg. MiniDV) on a data level. No conversion is taking place when copying footage from Digital8 to DVC or vice versa, the bits stay unchanged.
As of 2005, Digital8 product lines are limited to entry-level consumer gear. In terms of delivered camera performance, higher-priced miniDV camcorders outperform Digital8. Sony, Digital8's sole backer, is still the only company to produce Digital8 equipment.
Some Digital8 camcorders offer limited backward compatibility with Hi8 and Video8 analog-recordings. These units can play (but not record) the analog recordings, simultaneously transcoding them into the DV format. This allows analog Video8/Hi8 recordings to be transferred to home computer using the camcorder's Firewire interface.