D-VHS
Encyclopedia
D-VHS is a digital recording
Digital recording
In digital recording, digital audio and digital video is directly recorded to a storage device as a stream of discrete numbers, representing the changes in air pressure for audio and chroma and luminance values for video through time, thus making an abstract template for the original sound or...

 format developed by JVC
JVC
, usually referred to as JVC, is a Japanese international consumer and professional electronics corporation based in Yokohama, Japan which was founded in 1927...

, in collaboration with Hitachi
Hitachi, Ltd.
is a Japanese multinational conglomerate headquartered in Marunouchi 1-chome, Chiyoda, Tokyo, Japan. The company is the parent of the Hitachi Group as part of the larger DKB Group companies...

, Matsushita, and Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

. The "D" in D-VHS originally stood for Data VHS, but with the expansion of the format from standard definition to high definition capability, JVC renamed it Digital VHS and uses that designation on its website. It uses the same physical cassette format and recording mechanism as S-VHS
S-VHS
S-VHS is an improved version of the VHS standard for consumer-level analog recording videocassettes. It was introduced by JVC in Japan in April 1987 with the HR-S7000 VCR and certain overseas markets soon afterwards...

 (but needs higher quality and more expensive tapes), and is capable of recording and displaying both standard definition and high definition
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...

 content. The content data format is in MPEG transport stream, the same data format used for most digital television
Digital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...

 applications. The format was introduced in 1998.

As a final effort for VHS, the D-VHS system is seen by its fans as a highly versatile domestic recorder (the other tape-based formats are DV
DV
DV is a format for the digital recording and playing back of digital video. The DV codec was launched in 1995 with joint efforts of leading producers of video camcorders....

 and Digital8
Digital8
Digital8 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...

, which never gained any traction except as camcorder
Camcorder
A camcorder is an electronic device that combines a video camera and a video recorder into one unit. Equipment manufacturers do not seem to have strict guidelines for the term usage...

 media), but given the wholesale move to DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

 and then hard disk drive (HDD) recording, the format has failed to make any headway into the video market.

There has been no small-format version of D-VHS equivalent to VHS-C
VHS-C
VHS-C is the compact VHS videocassette format introduced in 1982 and used primarily for consumer-grade compact analog recording camcorders. The format is based on the same video tape as is used in VHS, and can be played back in a standard VHS VCR with an adapter...

; JVC, the originator of the format, chose to use MiniDV for its digital camcorder lines, and since 2005 has also expanded into tapeless camcorder
Tapeless Camcorder
A tapeless camcorder is a camcorder that does not use video tape for the digital recording of video productions as 20th century ones did. Tapeless camcorders record video as digital computer files onto random access data storage devices such as optical discs, hard disk drives and solid-state flash...

 designs based on hard drive storage (the Everio line). JVC does market the Digital-S
Digital-S
D-9 or Digital S as it was originally known, is a professional digital video videocassette format created by JVC in 1995. It is a direct competitor to Digital Betacam. Its name was changed to D-9 in 1999 by the SMPTE...

 format for professional use; while the tapes and technology used are superficially similar to D-VHS tapes, the underlying data format is based on the DV
DV
DV is a format for the digital recording and playing back of digital video. The DV codec was launched in 1995 with joint efforts of leading producers of video camcorders....

 codec and the media formulation is drastically different.

Tape Length and Speeds

D-VHS VCRs come with multiple speeds. "HS" is "High Speed", "STD" is "Standard" and "LS" is "Low Speed"; where LS3 and LS5 represent 3 and 5 times the standard length of tape. High-definition
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...

 content such as 1920x1080 or 1280x720 is typically stored at 28.2 Mbit/s (HS speed). Standard-definition
Standard-definition television
Sorete-definition television is a television system that uses a resolution that is not considered to be either enhanced-definition television or high-definition television . The term is usually used in reference to digital television, in particular when broadcasting at the same resolution as...

 content such as 720x480 can be stored at bit rate
Bitrate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....

s from 14.1 Mbit/s down to 2.8 Mbit/s (STD, LS3, LS5 speeds).

The quality of STD speed is actually superior to the average DVD, since this speed has a much higher bitrate (approximately 14 versus 5 Mbit/s average) and suffers few compression artifacts. The LS3 speed is roughly equal to an amateur DVD with some visible artifacts in high-action scenes (4.7 Mbit/s), and LS5 appears similar to a medium-quality video download (2.8 Mbit/s). JVC's 40000 VCR was the only unit to support LS5 recording.

As a result of all these different speeds, the tape labels are a bit confusing for the consumer. D-VHS was originally a standard definition format that recorded at the STD speed. When High Definition recording and HS speed was later introduced, it required twice the amount of tape. For this reason, a DF-240 will record 240 minutes of standard definition, and 240/2 = 120 minutes of high definition. When reviewing the table, note that the digital speeds HS and STD are equivalent to the older analog speeds SP and LP.
Common D-VHS Tape Lengths
Tape Label Data storage Tape Length Rec. Time
HS or VHS-SP STD or VHS-LP LS3 LS5
DF-240 25 GB 248 m (813 ft) 120 min (2 h) 240 min (4 h) 720 min (12h) 1200 min (20 h)
DF-300 31.7 GB 314.464 m (1,048 ft) 150 min (2:30 h) 300 min (5 h) 900 min (15 h) 1500 min (25 h)
DF-420 44 GB 433 m (1,420 ft) 210 min (3:30 h) 420 min (7 h) 1,260 min (21 h) 2100 min (35 h)
DF-480 50 GB 500 m (1,640 ft) 240 min (4 h) 480 min (8 h) 1,440 min (24 h) 2400 min (40 h)

Issues/Advantages

There are technical issues with compatibility between recordings from Mitsubishi and JVC D-VHS decks. PAL and NTSC recordings are also incompatible. Very few models are available to the world market and sales of this format have been weak; correspondingly, prices have remained high for both VCRs and media, contributing to low demand. Also hurting demand, say D-VHS advocates, is poor marketing, resulting in low consumer knowledge of D-VHS's advantages and capabilities. Another primary roadblock to expansion, is the D-VHS's input limitations. The FireWire input is the only way to record high definition content to tape from an owner's TV, but very few TVs have FireWire connections (no current models), and cable boxes with FireWire have to be specially requested from cable companies. Satellite FireWire-equipped boxes are rare or nonexistent.

Existing tape media is bulky and more expensive than hard drives. Although cable companies are gradually switching to the H.264 codec, this should not be an issue for D-VHS units since they can act purely as data stores (like a hard drive but using tape instead), and thereby pass the previously-recorded H.264 data directly to the Set-top Box or TV (via i.Link/FireWire). Another alternative is a lengthy transfer to a computer for viewing. Finally, since machines will soon no longer be manufactured, maintenance of current recorders may prove difficult.

D-VHS's primary advantage is that it is still the best way to archive encrypted high definition material from cable programming. Cable, satellite companies, TiVo, and PCs equipped with cable card tuners all offer high-definition digital video recorder
Digital video recorder
A digital video recorder , sometimes referred to by the merchandising term personal video recorder , is a consumer electronics device or application software that records video in a digital format to a disk drive, USB flash drive, SD memory card or other local or networked mass storage device...

s, but archival has proven to be an obstacle because proprietary boxes have restrictions on moving encrypted content, though HD capture devices from Hauppauge (HD PVR) and Elgato (EyeTV HD) have enabled removal of encrypted content off many of the above proprietary boxes. The HD DVR's analog conversion is slightly degraded but still high definition grade, and much better than standard definition. D-VHS does not need to take advantage of the so called "analog hole" that allows encrypted content to be recorded since D-VHS is a pure bit-for-bit recording with no conversion necessary, and therefore higher quality. Monthly rental fees to cable, TiVo, and satellite are less with D-VHS.

The JVC D-VHS deck released in the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, was not a bitstream
Bitstream
A bitstream or bit stream is a time series of bits.A bytestream is a series of bytes, typically of 8 bits each, and can be regarded as a special case of a bitstream....

 recorder, although it did have a FireWire input. Instead it is best thought of as a digital recorder for traditional analog inputs such as domestic analog TV and digibox
Digibox
The Digibox is a device marketed by British Sky Broadcasting in the UK and Republic of Ireland to enable home users to receive digital satellite television broadcasts from the Astra satellites at 28.2° east. An internet service is also available through the device, similar in some ways to the...

es for digital broadcasts. The deck was able to record D-VHS signals onto S-VHS
S-VHS
S-VHS is an improved version of the VHS standard for consumer-level analog recording videocassettes. It was introduced by JVC in Japan in April 1987 with the HR-S7000 VCR and certain overseas markets soon afterwards...

 tapes, which made it a cost-effective source of high quality domestic recordings (USA version also allows use of cheaper S-VHS media). Pictures were noticeably superior to S-VHS and were essentially transparent
Transparency (data compression)
In data compression or psychoacoustics, transparency is the ideal result of lossy data compression. If a lossy compressed result is perceptually indistinguishable from the uncompressed input, then the compression can be declared to be transparent...

 when compared to an off-air source. Using the LS3 mode, approximately 17.25 hours of digital video could be stored on a S-VHS E-240. The deck's biggest shortcomings were the lack of a DV output and, perhaps more crucially, the lack of RGB
RGB color model
The RGB color model is an additive color model in which red, green, and blue light is added together in various ways to reproduce a broad array of colors...

 input via the SCART
SCART
SCART is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together...

 connector. NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...

 versions had component
Component video
Component video is a video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video information that is transmitted or stored as three separate signals...

 outputs.

D-Theater

In 2002, prerecorded D-VHS cassettes were sold under the brand name D-Theater in the US. While D-Theater is a D-VHS tape, it is incompatible with D-VHS decks without the D-Theater logo. They provide content in both 720p
720p
720p is the shorthand name for 1280x720, a category of High-definition television video modes having a resolution of 1080 or 720p and a progressive scan...

 and 1080i
1080i
1080i is the shorthand name for a high-definition television mode. The i means interlaced video; 1080i differs from 1080p, in which the p stands for progressive scan. The term 1080i assumes a widescreen aspect ratio of 16:9, implying a frame size of 1920×1080 pixels...

 as well as at least one Dolby Digital
Dolby Digital
Dolby Digital is the name for audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994. Except for Dolby TrueHD, the audio compression is lossy. The first use of Dolby Digital was to provide digital sound in cinemas from 35mm film prints...

 audio track. Supported films studios include 20th Century Fox
20th Century Fox
Twentieth Century Fox Film Corporation — also known as 20th Century Fox, or simply 20th or Fox — is one of the six major American film studios...

, Artisan Entertainment
Artisan Entertainment
Artisan Entertainment Inc. was a privately held independent American movie studio until it was purchased by a Canadian studio, Lionsgate, in 2003. At the time of its acquisition, Artisan had a library of thousands of films developed through acquisition, original production, and production and...

, DreamWorks
DreamWorks
DreamWorks Pictures, also known as DreamWorks, LLC, DreamWorks SKG, DreamWorks II Distribution Co., LLC, DreamWorks Studios or DW Studios, LLC, is an American film studio which develops, produces, and distributes films, video games and television programming...

, and Universal Pictures
Universal Pictures
-1920:* White Youth* The Flaming Disc* Am I Dreaming?* The Dragon's Net* The Adorable Savage* Putting It Over* The Line Runners-1921:* The Fire Eater* A Battle of Wits* Dream Girl* The Millionaire...

. D-Theater provides much better audio and video quality than previous formats (VHS and DVD), but has since been displaced by the newer Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...

 format. D-Theater does have region code restrictions. There are 2 known regions; 1 for the USA, 2 for Japan. There has never been a D-Theater video release in region 2. Region code hacks for Japanese decks have been performed to support playback of US titles. The last film available was 20th Century Fox's I, Robot
I, Robot (film)
I, Robot is a 2004 science-fiction action film directed by Alex Proyas. The screenplay was written by Jeff Vintar, Akiva Goldsman and Hillary Seitz, and is very loosely based on Isaac Asimov's short-story collection of the same name. Will Smith stars in the lead role of the film as Detective Del...

. This title was a surprise to many as there were no prior announcements nor any indication that the title was available. It was originally available only on JVC's D-VHS store in late 2004 and no other distributor had it (not even Fox itself). A couple of weeks later they started trickling out to more distributors after much delay and confusion about its existence. Alien vs. Predator was announced to retailers as also being released on the same day as I, Robot, but Fox later announced that Alien vs. Predator in fact was never shipped to any retail outlet; the copies that were produced have never seen the light of day, and the cause of this has never been explained by Fox.

Most tapes have built-in copy protection
Copy protection
Copy protection, also known as content protection, copy obstruction, copy prevention and copy restriction, refer to techniques used for preventing the reproduction of software, films, music, and other media, usually for copyright reasons.- Terminology :Media corporations have always used the term...

 mechanism (DTCP
Digital Transmission Content Protection
Digital Transmission Content Protection, or DTCP, is a digital rights management technology that aims to restrict "digital home" technologies including DVD players and televisions by encrypting interconnections between devices...

, also known as "5c") (copy never) that disables copying via FireWire. HDNet
HDNet
HDNet is a men's interest television channel in the United States, broadcasting exclusively in high-definition format and available via cable and satellite television...

 productions and 2929 Entertainment
2929 Entertainment
2929 Entertainment is a media company with holdings in film and television production, film distribution, theatrical exhibition, home entertainment, television, and syndication. Billionaires Todd Wagner and Mark Cuban founded and currently own the privately held company...

 via Magnolia Entertainment did provide some of their original content on D-VHS but without copy protection. Many of the tapes have an introduction by the owner Mark Cuban
Mark Cuban
Mark Cuban is an American business magnate and investor. He is the owner of the National Basketball Association's Dallas Mavericks, Landmark Theatres, and Magnolia Pictures, and the chairman of the HDTV cable network HDNet....

 encouraging the viewer to make copies of the program in order to help distribute them.

DTS

Additional tracks may be included on D-Theater in other sound formats such as DTS. However, only the newest D-VHS players like JVC HM-DH40000, HM-DH5U, HM-DT100U, and Marantz MV-8300 include alternate audio track capabilities.

DTS D-Theater D-VHS tapes. * means DTS was not mentioned on the package.

Rare D-Theater tapes

When Lions Gate bought Artisan, a number of titles that were supposed to be released were cancelled. Some of them were Dirty Dancing
Dirty Dancing
Dirty Dancing is a 1987 American romantic film. Written by Eleanor Bergstein and directed by Emile Ardolino, the film features Patrick Swayze and Jennifer Grey in the lead roles, as well as Cynthia Rhodes and Jerry Orbach...

, Basic Instinct
Basic Instinct
Basic Instinct is a 1992 erotic thriller directed by Paul Verhoeven and written by Joe Eszterhas, and starring Michael Douglas and Sharon Stone....

, and Total Recall
Total Recall
Total Recall is a 1990 American science fiction action film. The film stars Arnold Schwarzenegger, Rachel Ticotin, Sharon Stone, Michael Ironside, Ronny Cox & Mel Johnson, Jr.. It is based on the Philip K. Dick story “We Can Remember It for You Wholesale”...

. 20th Century Fox, while experimenting with DTS, did test tapes of Phone Booth
Phone Booth (film)
Phone Booth is a 2002 American suspense-thriller film about a man who is held hostage in a telephone booth by a sniper. It stars Colin Farrell, Kiefer Sutherland, Forest Whitaker, Katie Holmes, and Radha Mitchell. The film was directed by Joel Schumacher, with music composed by Harry Gregson-Williams...

with DTS. There are also a number of Universal Studio test tapes without DTS tracks, but the released versions contain DTS without that fact being mentioned on the packaging. These DTS tracks were probably late additions. All of these examples of preproduction/review/test tapes have been in the hands of various D-Theater collectors.

See also

  • DVR
    Digital video recorder
    A digital video recorder , sometimes referred to by the merchandising term personal video recorder , is a consumer electronics device or application software that records video in a digital format to a disk drive, USB flash drive, SD memory card or other local or networked mass storage device...

  • VHS
    VHS
    The Video Home System is a consumer-level analog recording videocassette standard developed by Victor Company of Japan ....

  • S-VHS
    S-VHS
    S-VHS is an improved version of the VHS standard for consumer-level analog recording videocassettes. It was introduced by JVC in Japan in April 1987 with the HR-S7000 VCR and certain overseas markets soon afterwards...

  • W-VHS
    W-VHS
    W-VHS is a HDTV analog recording videocassette format created by JVC. The format was originally introduced in 1994 for use with Japan's Hi-Vision, an early analog high-definition television system named MUSE....

    , an analog high-definition recording format
  • MicroMV
    MicroMV
    MicroMV was a proprietary videotape format introduced in 2001 by Sony. This cassette is physically smaller than a Digital8 or DV cassette. In fact, MicroMV is the smallest videotape format — 70% smaller than MiniDV or about the size of two US quarter coins. Each cassette can hold up to 60 minutes...

     and HDV
    HDV
    HDV is a format for recording of high-definition video on DV cassette tape. The format was originally developed by JVC and supported by Sony, Canon and Sharp...

    , digital tape formats using MPEG-2
  • Digital-S
    Digital-S
    D-9 or Digital S as it was originally known, is a professional digital video videocassette format created by JVC in 1995. It is a direct competitor to Digital Betacam. Its name was changed to D-9 in 1999 by the SMPTE...

  • Blu-ray Disc
    Blu-ray Disc
    Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...

  • HD DVD
    HD DVD
    HD DVD is a discontinued high-density optical disc format for storing data and high-definition video.Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format...

  • TiVo
    TiVo
    TiVo is a digital video recorder developed and marketed by TiVo, Inc. and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose features include "Season Pass" schedules which record every new episode of a series, and "WishList"...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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