Digital8
| Media type | Magnetic Tape |
|---|---|
| Encoding | NTSC, PAL |
| Read mechanism | Helical scan |
| Write mechanism | Helical scan |
| Standard | Interlaced video |
| Developed by | Sony |
| Usage | Home movies |
Digital8 (or D8) is a consumer digital recording videocassette for camcorders based on the 8 mm video format developed by Sony, and introduced in 1999.
The Digital8 format is a combination of the older Hi8 tape transport with the DV codec. Digital8 equipment uses the same videocassettes as analog recording Hi8 equipment, but differs in that the signal is not analog audio/analog video, but is encoded digitally (using the industry-standard DV codec.) Since Digital8 uses the DV codec, it has identical digital audio and digital video specifications.
To facilitate digital recording on existing Hi8 videocassettes the helical scan video head drum spins 2.5× faster. For both NTSC and PAL Digital8 equipment, a standard-length 120-minute NTSC/90-minute PAL Hi8 magnetic tape cassette will store 60 minutes of Digital8 video (Standard Play) or 90 minutes (Long Play). LP is model specific, such as the TRV-30, TRV-40, and others. Digital8 recordings can be made on standard-grade Video8 cassettes, but this practice is discouraged in the Sony user manuals. Hi8 metal-particle cassettes are the recommended type for Digital8 recording, and most tapes currently sold are marked for both Hi8 and Digital8 usage.
Contrary to popular perception, the Digital8 format is not technically inferior to miniDV—both are identical at the bitstream level. From a user standpoint, Digital8 is DV (or rather, equivalent to and compatible with consumer miniDV.) At an application level (for example, in a 1394/Firewire link), a Digital8 camcorder appears and behaves exactly like a Mini DV camcorder.
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