To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.

From Wikipedia, the free encyclopedia

D-2 (video)
Sony D-2 VCR
Media typeMagnetic Tape
Encodingdigital composite video
Read mechanismHelical scan
Write mechanismHelical scan
Standardinterlaced (NTSC, PAL)
Developed byAmpex/Sony
UsageVideo production

D-2 is a professional digital videocassette format created by Ampex and introduced on 1988[1] at the NAB Show as a composite video alternative to the component video D-1 format. It garnered Ampex a technical Emmy in 1989.[1] Like D-1, D-2 stores uncompressed digital video on a tape cassette; however, it stores a composite video signal, rather than component video as with D-1. While component video is superior for advanced editing, especially when chroma key effects are used, composite video is more compatible with most existing analog facilities.


Ampex created the first D-2 video machine, the ACR-225 commercial spot player[2] working with Sony, who had done some early research into composite digital video,[3] as a cost-effective solution for TV broadcasters with large investments in composite analog infrastructure such as video routers and switchers, since it could be inserted into existing analog broadcast facilities without extensive redesign or modifications. This was because D-2 machines accepted standard analog video and audio inputs and outputs. D-2 machines are capable of interfacing through either serial digital video or analog video connections. Four PCM audio channels are available for editing (an improvement over the then-popular Type C analog machines with two audio channels) as well as an analog cue channel and timecode, also with digital or analog connections.


Like D-1, D-2 uses 19 mm (¾ inch) tape loaded into three different sized videocassettes to support commercial spot playback as well as long-form programming such as movies. Although D-2 videocassette housings are nearly identical to their D-1 counterparts, they are not interchangeable due to D-2's metal particle tape formula, needed for its higher recording density.[2]

Ampex D-2 tape transports are extremely fast. A high speed search at 60 times playback speed with a recognizable color picture allowed three hours of videotape to be searched through in approximately three minutes.

The D-2 offered read before write or preread functionality, which allowed simultaneous playback and recording on the same transport.[4] For example, a title could be superimposed over existing video already on the same video tape by playing the tape through a video switcher, adding the title, and recording the new composite image back onto the same location of the tape. This eliminated the need for an additional recorder and saved considerable time in video editing. Steven Fuiten was the first PreRead Editor to composite video using a full D2 digital system.[citation needed]


During its early stages, finished episodes of South Park were hastily recorded to D-2 to be sent to Comedy Central for airing in just a few days' time.[5] D-2 replaced Type C videotape for the mastering of LaserDiscs in the late 1980s.

D-2 was in widespread use for some ten years, as the computer-based video server (with fewer moving parts and correspondingly greater reliability) became available not long after its release. By 2003, only a handful of broadcasters continued to use the D-2 format, and even then only to access materials recorded on the format.[citation needed]

Panasonic introduced D-3 in 1991; it is very similar to D-2 it uses a smaller cassette case.

Format Description

  • General:
    • Format name: D2 digital
    • SMPTE type: D2
    • Format type: digital composite
    • Scanning system: multi head segmented helical
    • Year introduced: 1989
    • Developer: Ampex/Sony
  • Physical Data:[6]
    • Tape width: 19 mm
    • Tape speed(s): 5.19 ips
    • Tape thickness: .55 mils
    • Playing time(s): 32, 94, 208 minutes (Small, Medium, Large cassette sizes)
    • Headwheel diameter: 2.95"
    • Speed: 5400 rpm
    • Head-to-tape writing speed: 1078 in/sec.
    • Sampling rate: 4fsc (14.31818 MHz for NTSC)
    • No. of bits: 8
    • Data rate: 60.1 MB/sec
  • Audio:
    • No. of digital channels: 4
    • Sampling rate: 48 kHz
    • No. of bits: 20


Sony DVR-28
Sony DVR-28
  • Ampex
    • VPR-200, VPR-250, VPR-300
    • ACR-225 Commercial Spot Player (robotic tape system)
  • Sony
    • DVR-10, DVR-18, DVR-20, DVR-28
    • DCR-10, DCR-18, DCR-20, DCR-28 (sold by BTS)
    • DVC 80, DVC 1000s LMS (Library Management System)


  1. ^ a b "Ampex History". Ampex. Archived from the original on 14 September 2013. Retrieved 14 September 2013.
  2. ^ a b Watkinson, John (1990). The Art of Digital Video. Focal Press. ISBN 0-240-51287-1.
  3. ^ Watkinson, John (1990). The D-2 Digital Video Recorder. Focal Press. p. 5. ISBN 0-240-51302-9.
  4. ^ "Ampex history: 1988". Ampex. Archived from the original on 3 September 2013. Retrieved 18 September 2013.
  5. ^ "The Making of South Park". South Park Scriptorium. Retrieved 15 September 2013.
  6. ^ (multiple authors). "Videotape Formats". LionLamb. Retrieved 19 September 2013.

See also

External links

This page was last edited on 12 September 2020, at 14:44
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.