DV(redirected from DV tape)
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DV(1) (Digital Video) A generic term for capturing and/or editing video in the digital domain.
(2) (Digital Video) A digital videotape format introduced in 1995 for camcorders. Over the years, DV has been widely used in both consumer and professional applications, and the small MiniDV cartridge was very popular in handheld units. Tapeless DV camcorders have also come on the market using optical discs, hard disks and flash memory cards for storage (see image below).
DVCAM and DVCPRO
Soon after DV debuted, Sony and Panasonic introduced their own professional variants geared to make editing easier (see DVCAM and DVCPRO). However, the tape width and encoding format are the same, and the cartridges are mostly interchangeable. In pro models, quality camera lenses and electronics make a difference.
Mini DVD Camcorders
Some camcorders have been built that record onto small "mini DVD" discs. However, DVD and DV are not the same video format, and a mini DVD is a disc, while MiniDV is a DV cassette size (see DVD).
DV Is Standard Resolution (SD)
DV records 720 horizontal pixels and 480 interlaced lines of standard resolution in countries with 60Hz electric current and 576 lines for 50Hz. High-definition versions of DV with 720 and 1080 lines are the official HDV standard and Panasonic's DVCPRO HD (see HDV and DVCPRO).
Compression and Specifications
Depending on the motion content of the scenes, DV provides about a 5:1 compression. It uses the same DCT algorithm as MPEG for compression, but it is easier to edit because each frame is compressed independently without relying on the prior frame (intraframe compression).
Based on the IEC 61834 standard, DV tape moves at a constant rate of 18.8mm per second, providing a data rate of 25 Mbps. The SMPTE 314 standard supports 25 Mbps and provides 50 Mbps for studio use. See Micro DV and SD formats.
|DV uses 1/4" (6.35mm) metal evaporated (ME) tape, and the large cassette holds 4.5-hours of DV and three hours of DVCAM. MiniDV cassettes hold one hour of DV. DVCPRO metal particle (MP) tapes also come in a mid-size cassette, with varying recording time depending on DVCPRO format (see DVCPRO).|
|DV camcorders range from handhelds (top) to prosumer models (middle) to professional units (bottom).|
|In 2004, this Focus Enhancements module let professional JVC DV camcorders record directly onto a hard disk, thus eliminating the tape-to-computer disk conversion step. DTE stands for "direct-to-edit."|