View source for D-VHS

{{short description|Magnetic tape-based format meant for the distribution of digital HD movies}}
{{Multiple issues|
{{More citations needed|date=June 2013}}
{{original research|date=April 2016}}
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{{Infobox media
| name = D-VHS
| logo = D-VHS (logo).svg{{!}}class=skin-invert
| image = 
| caption = 
| type = [[Magnetic cassette tape]]
| encoding = [[NTSC]], [[PAL]], [[SECAM]], [[ADAT]]
| capacity = 50&nbsp;GB
| read = [[Helical scan]]
| write = [[Helical scan]]
| standard = 
| owner = [[Hitachi]], [[JVC]], [[Panasonic Corporation|Matsushita]], [[Philips]]
| use = [[Home movie]]s, [[Television production]]
| extended from = [[S-VHS]]
| extended to = 
| released = {{Start date and age|1997|12}}
}}

'''D-VHS''' (short for '''Digital VHS''') is a digital video recording format developed by [[JVC]] in collaboration with [[Hitachi]], [[Panasonic Corporation|Matsushita]], and [[Philips]]. Introduced in December 1997,<ref>{{Cite web|url=http://www.jvc-victor.co.jp/english/products/vcr/D-VHS-e.html/|title=All Specifications of D-VHS Digital Recording Format Finalized |publisher=JVC|date=July 3, 1998|archive-url=https://web.archive.org/web/20050109091257/http://www.jvc-victor.co.jp/english/products/vcr/D-VHS-e.html|archive-date=2005-01-09}}</ref><ref>{{Cite magazine|url=https://books.google.com/books?id=Uu5UrE70BQsC&dq=d+vhs&pg=PA52|title=A Fix for Satellite TV Recording |magazine=Popular Science|date=September 23, 1997|via=Google Books}}</ref> it was designed to record digital video, including [[high-definition television|high-definition]] content, using the same higher-grade tapes as [[S-VHS]] (Super VHS), which could accommodate the increased data rates required by the format.

Unlike analog-based VHS and S-VHS, D-VHS records video digitally using [[MPEG-2]] compression and stores it in an [[MPEG transport stream]], a format also used in DVDs and digital television broadcasts. The format was standardized by the [[International Electrotechnical Commission]] as IEC 60774-5.<ref>{{cite web |title=IEC 60774-5:2004 Helical-scan video tape cassette system using 12.65 mm (0.5 in) magnetic tape on type VHS – Part 5: D-VHS |url=https://webstore.iec.ch/preview/info_iec60774-5%7Bed1.0%7Den.pdf |publisher=[[International Electrotechnical Commission]] |date=7 April 2004}}</ref>

JVC also developed '''D-Theater''', a proprietary variant of D-VHS used for prerecorded high-definition movies. D-Theater tapes featured studio-released content in 720p or 1080i resolution, offering a home viewing experience similar to early [[Blu-ray]] and [[HD DVD]] formats. However, the system required compatible D-VHS players and included copy protection, which limited its adoption.

== Design ==

{{Update section|date=December 2024|reason=Section has become out of date more than a decade ago. The proposed uses of D-VHS did not materialize}}

As a final effort for VHS, the D-VHS system had significant advantages as a highly versatile domestic recorder (the other tape-based formats are [[DV (video format)|DV]] and [[Digital8]], which never gained any traction except as [[camcorder]] media), but given the wholesale move to [[DVD]] and then [[hard disk drive]] (HDD) recording, the format failed to make any headway into the video market.

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 are no longer 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 in the US. Cable, satellite companies, TiVo, and PCs equipped with cable card tuners all offered high-definition [[digital video recorder]]s, but archival has proven to be an obstacle, as proprietary boxes have restrictions on moving encrypted content. Outside of D-VHS, only HD capture devices that use an analog conversion process, such as the Hauppauge HD PVR, have enabled removal of encrypted content off many of the above proprietary boxes. This uses an analog conversion process, producing slightly degraded but still high definition grade recordings. D-VHS, on the other hand, does not need to take advantage of this so-called "analog hole", since D-VHS makes possible a pure bit-for-bit recording with no conversion necessary. This is made possible by compliance with [[Copy Control Information|CCI]] flag values carried by the digital streams, wherein only D-VHS is allowed to digitally move recordings of content originally flagged as Copy Once from a DVR device and onto a D-VHS tape. This programming that complies with the CCI flags then marks such material on the tape such that no second generation copies can be made from the tape itself, though additional copies can still be made directly from the original DVR unit to additional tapes.

Monthly rental fees to cable, [[TiVo]], and satellite were also less with D-VHS.{{Clarify| reason=What are "rental fees to cable", and how are they "less"?| date=April 2012}}

The only PAL D-VHS model sold in Europe was the JVC HM-DR10000, also sold as the Philips VR-20D, and was standard definition only. This model was not 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]]es for digital broadcasts. The deck was able to record D-VHS signals onto [[S-VHS]] tapes, which made it a cost-effective source of high quality domestic recordings (the US version also allows use of cheaper S-VHS media). Pictures were noticeably superior to S-VHS and were essentially [[Transparency (data compression)|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 color model|RGB]] input via the [[SCART]] connector. [[NTSC]] versions had [[component video]] outputs.

== Tape length and speeds ==
[[file:VHS tape identification.jpg|thumb|Differences between [[Video home system|VHS]], [[S-VHS]] and D-VHS cassettes]]
[[file:Thomson dvh 8090.jpg|thumb|D-VHS recorder Thomson DVH-8090]]

D-VHS VCRs can record at 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, respectively. [[high-definition television|High-definition]] content such as 1920x1080 or 1280x720 is typically stored at 28.2&nbsp;Mbit/s (HS speed). [[standard-definition television|Standard-definition]] content such as 720x576 (720x480) can be stored at [[Bitrate|bit rate]]s from 14.1&nbsp;Mbit/s down to 2.8&nbsp;Mbit/s (STD, LS3, LS5 speeds).<ref>{{Cite web |title=JVC Pro Technical Description |url=http://pro.jvc.com/prof/attributes/tech_desc.jsp?model_id=MDL101392&feature_id=02 |access-date=2022-09-02 |website=pro.jvc.com}}</ref>

The quality of STD speed is superior to the average DVD, since this speed has a much higher bitrate (approximately 14 versus 5&nbsp;Mbit/s average) and suffers few compression artifacts. LS2 speed has a bitrate of 7&nbsp;Mbit/s. The LS3 speed is roughly equal to an amateur DVD with some visible artifacts in high-action scenes (4.7 Mbit/s),<ref name="auto">{{Cite web|url=https://ascii.jp/elem/000/000/324/324201/|title=究極のD-VHSまるごと大全 (1/3)|website=ASCII.jp}}</ref> and LS5 appears similar to a medium-quality video download (2.8 Mbit/s).<ref>{{Cite web|url=http://pro.jvc.com/prof/attributes/tech_desc.jsp?model_id=MDL101392&feature_id=02|title=JVC Pro Technical Description|website=pro.jvc.com}}</ref> JVC's HM-DH40000U and SR-VD400U were the only units 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. There is also an additional speed called LS7.

{| class="wikitable"
|+ Common D-VHS tape lengths
|-
! rowspan="2" | Label
! rowspan="2" | Data storage
! rowspan="2" | Length
! colspan="4" | Recording time
|-
! HS or VHS-SP !! STD or VHS-LP !! LS3 !! LS5
|-
| DF-240 || 25 GB
| 248&nbsp;m (813&nbsp;ft) || 120 min (2 h)|| 240 min (4 h)|| 720 min (12 h) || 1,200 min (20 h)
|-
| DF-300<ref name="auto"/> || 31.7 GB
| 314.5&nbsp;m (1,048&nbsp;ft) || 150 min (2:30 h)|| 300 min (5 h)|| 900 min (15 h) || 1,500 min (25 h)
|-
| DF-420 || 44 GB
| 433&nbsp;m (1,420&nbsp;ft) || 210 min (3:30 h)|| 420 min (7 h) || 1,260 min (21 h) || 2,100 min (35 h)
|-
| DF-480<ref name="auto"/> || 50 GB
| 500&nbsp;m (1,640&nbsp;ft) || 240 min (4 h)|| 480 min (8 h) || 1,440 min (24 h) || 2,400 min (40 h)
|}

== Pre-recorded tapes ==
[[file:D-Theater.svg|thumb|D-Theater logo]]

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 not bearing the D-Theater logo. They provide content in both [[720p]] and [[1080i]] as well as at least one [[Dolby Digital]] audio track.{{citation needed|date=October 2018}} Supported films studios include [[20th Century Fox]], [[Artisan Entertainment]], [[DreamWorks Pictures|DreamWorks]], and [[Universal Pictures]].{{citation needed|date=February 2021}} D-Theater does have region code restrictions. There are 3 known regions; 1 for the US, 2 for Japan, and 3 for South Korea.{{citation needed|date=October 2018}} There has never been a D-Theater video release in region 2 or 3.{{Citation needed|date=July 2013}} Region code hacks for Japanese decks have been performed to support playback of US titles.{{citation needed|reason=where is this information coming from?|date=January 2018}} The last film available was 20th Century Fox's ''[[I, Robot (film)|I, Robot]]''.<ref>{{Cite web|url=https://www.redsharknews.com/studio-broadcast/item/5494-this-is-how-your-hd-film-collection-might-have-been|title=D-VHS: This is how your HD film collection might have been|first=Adrian|last=Pennington|website=www.redsharknews.com}}</ref> 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 (film)|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'' was never shipped to retailers.

Most tapes have built-in [[copy protection]] mechanism ([[Digital Transmission Content Protection|DTCP]], also known as "5c") (copy never) that disables copying via [[IEEE 1394|FireWire]]. [[AXS TV|HDNet]] productions and [[2929 Entertainment]] 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 owner [[Mark Cuban]] encouraging the viewer to make copies of the program in order to help distribute them.

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

== Compatibility ==

There are technical issues with compatibility between recordings from Mitsubishi and JVC D-VHS decks.<ref>{{Cite web|url=https://www.lifewire.com/when-vhs-went-high-definition-1847994|title=A Look Back at The D-VHS Video Format|date=April 26, 2021| publisher = Lifewife|archive-url=https://web.archive.org/web/20210426220851/https://www.lifewire.com/when-vhs-went-high-definition-1847994|archive-date=2021-04-26}}</ref> PAL and NTSC recordings are also incompatible.{{citation needed|date=August 2021}}

== Adoption ==
Very few models were available to the world market and sales of this format have been weak; correspondingly, prices remained high for both VCRs and media, contributing to low demand. In 2000, Sony arranged with [[JVC]] to manufacture D-VHS VCRs under the Sony label, marking one of the first collaborations between the two former rivals.<ref>{{Cite web |title=Panasonic Launches World's First HD-Compatible Digital VCR in US Market |url=https://www.digitalbroadcasting.com/doc/panasonic-launches-worlds-first-hd-compatible-0001 |date=July 8, 1999 |language=en}}</ref> The lack of consumer knowledge of D-VHS's advantages and capabilities as well as input limitations led to its eventual demise. The introduction in 2006 of Blu-ray and HD-DVD rendered the format abandoned.<ref>{{Cite web |last=Pennington |first=Adrian |title=D-VHS: This is how your HD film collection might have been |url=https://www.redsharknews.com/studio-broadcast/item/5494-this-is-how-your-hd-film-collection-might-have-been |access-date=2022-09-02 |website=www.redsharknews.com |language=en}}</ref>

== Similar formats ==

There has been no small-format version of D-VHS equivalent to [[VHS-C]]; JVC, the originator of the format, chose to use [[MiniDV]] for its digital camcorder lines, and since 2005 has also expanded into [[tapeless camcorder]] designs based on [[hard drive]] storage (the Everio line). JVC does market the [[Digital-S]] 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 (video format)|DV]] codec and the media formulation is drastically different. Sony's [[MicroMV]] format uses the same codec as D-VHS. Therefore, D-VHS capture software can also be used to transfer MicroMV tapes.

== See also ==

* {{annotated link|Blu-ray}}
* {{annotated link|ED Beta}}
* {{annotated link|HD-DVD}}
* {{annotated link|HDV}}
* {{annotated link|MicroMV}}
* {{annotated link|Sony HDVS}}
* {{annotated link|W-VHS}}

== References ==

{{reflist}}

== External links ==

* [https://web.archive.org/web/20070226190356/http://archive2.avsforum.com/avs-vb/showthread.php?t=313242 Audio Video Science Forum D-VHS list]
* [http://www.lddb.com/list.php?format=dvhs&list=all LaserDisc Database D-VHS Catalog]
* [https://www.youtube.com/watch?v=fT4lDU-QLUY Demonstration video ''New York City in 1993 in HD - DTheater DVHS Demo Tape'']

{{Hitachi}}
{{Homevid}}
{{High-definition}}
{{High definition media}}

[[Category:Video storage]]
[[Category:VHS]]
[[Category:High-definition television]]
[[Category:Audiovisual introductions in 1998]]
[[Category:Japanese inventions]]
[[Category:Videocassette formats]]