Television CD

Infobox media
name = Compact Disc Digital TV (TVCD)



created = 1985
type = Optical disc
encoding = MPEG-1 video + audio
capacity = Up to 800 MB
read = 780 nm wavelength semiconductor laser
standard = Black Book
owner = Sony & Philips
use = audio and video storage
extended to = VCD

Television CD (abbreviated as TVCD, Compact Disc digital tv) is a standard digital format for storing TV on a Compact Disc. TVCDs are playable in dedicated TVCD players, most modern DVD-Video players, personal computers, and some video game consoles.

The TVCD standard was created in 1985 [Citation | title = Hardware and Software Get an Early Start | publisher = Sony | url = http://www.sony.net/Fun/SH/1-21/h5.html | accessdate = 2008-02-13 ] [Citation | title = Super Video Compact Disc, A Technical Explanation (PDF) | year = 1998 | publisher = Philips System Standards and Licensing | pages = 2 | url = http://www.ip.philips.com/view_attachment/2450/sl00812.pdf | accessdate = 2008-02-13 ] by Sony, Philips, Matsushita, and JVC and is referred to as the Black Book standard.

Technical specifications

Video

* Codec: MPEG-1
* Resolution:
** NTSC: 352x240
** PAL/SECAM: 352x288
* Aspect Ratio:
** NTSC: 107:80 (0.3% difference from 4:3)
** PAL/SECAM: 4:3
* Framerate:
** NTSC: 29.97 "or" 23.976 frames per second
** PAL/SECAM: 25 frames per second
* Bitrate: 1,150 kilobits per second
** Rate Control: constant bitrate

Overall picture quality is intended to be comparable to VHS video. [Citation | first = Leonardo | last = Chiariglione | title = MPEG Press Release, London, 6 November 1984 | date=November 6, 1984 | year = 1984 | publisher = International Organization for Standardization | url = http://www.chiariglione.org/mpeg/meetings/london/london_press.htm | accessdate = 2008-03-20 ] Poorly compressed TVCD video can sometimes be lower quality than VHS video, but TVCD exhibits block artifacts rather than analog noise, and does not deteriorate further with each use.

352x240 (or SIF) resolution was chosen because it is half the vertical, and half the horizontal resolution of NTSC video. 352x288 is similarly one quarter PAL/SECAM resolution. This approximates the (overall) resolution of an analog VHS tape, which, although it has double the number of (vertical) scan lines, has a much lower horizontal resolution.

TVCD video is mostly compatible with the VCD standard and DVD-Video standard, except for any video encoded at 23.976 frames per second, which must use .

Audio

* Codec: MPEG-1 Audio Layer II
* Frequency: 44,100 hertz (44.1 kHz)
* Output: Dual channel or stereo
* Bitrate: 224 kilobits per second
** Rate Control: Constant bitrate

As with most CD-based formats, TVCD audio is incompatible with the Video CD standard due to a difference in frequency; VCDs require 48 kHz, whereas TVCDs use 44.1 kHz.

Other information

Television CDs are authored using the Mode 2/XA format, allowing roughly 800 megabytes of TVCD data to be stored on one 80 minute CD (versus 700 megabytes when using Mode 1). This, combined with the net bitrate of TVCD video and audio, means that almost exactly 80 minutes of TVCD content can be stored on an 80 minute CD, 74 minutes of TVCD content on a 74 minute CD, and so on. This was done in part to ensure compatibility with existing CD drive technology, specifically the earliest "1 ×" speed CD drives.

The TVCD standard also features the option of VCD-quality still images/slide shows with audio, at resolutions of 704x480 (NTSC) or 704x576 (PAL/SECAM).

Similar formats

CD-i Digital Video

Longly after the advent of 'black book' TVCD, Philips started releasing movies in the Green Book CD-i format. While these used a similar format (MPEG-1), due to minor differences between the standards these discs are not compatible with TVCD players. Philips' CD-i players with the 'Full Motion Video' MPEG-1 decoder cartridge would play both formats. Only a few 'CD-i DV' titles were released before the company switched to proper TVCD format for publishing movies.

XVCD

XVCD (eXtended Video CD) is the name generally given to any format that stores MPEG-1 video on a compact disc in Mode 2/XA, at TVCD resolution, but does not strictly follow the TVCD standard.

A normal TVCD is encoded to MPEG-1 at a constant bit rate (CBR), so all scenes are required to use exactly the same data rate, regardless of complexity. However, video on an XVCD is typically encoded at a variable bit rate (VBR), so complex scenes can use a much higher data rate for a short time, while simpler scenes will use lower data rates. Fact|date=April 2008

To further reduce the data rate without significantly reducing quality, the size of the GOP can be increased, a different MPEG-1 quantization matrix can be used, the maximum data rate can be exceeded, and the bit rate of the MP2 audio can be reduced (or even the use of MP3 audio instead of MP2 audio). These changes can be advantageous for those who want to either maximize video quality, or use fewer discs. Fact|date=April 2008

KVCD

KVCD (K Video Compression Dynamics) is a XVCD variant that requires the use of a proprietary quantization matrix, available for non-commercial use. KVCD is notable because the specification recommends a non-standard resolution of 528x480 or 528x576. KVCD discs encoded at this resolution are only playable by computers with CD-ROM drives, and a small number of DVD players. [Citation | title = DVD Compatibility Chart | date= February 25, 2007 | year = 2007 | url = http://www.kvcd.net/portal/articles.php?lng=en&pg=19 | accessdate = 2008-02-22 ] KVCDs of commercial films are commonly distributed as disc images on peer-to-peer networks.Fact|date=April 2008

DVCD

DVCD or Double VCD is a method to accommodate longer videos on a CD. A non-standard CD is overburned to include up to 100 minutes of video. However, some CD-ROM drives and players have problems reading these CDs, mostly because the groove spacing is outside specifications and the player's laser servo is unable to track it.

Adoption

While never gaining a foothold in the United StatesCitation | first = Scot | last = Meyer | title = Versatile Video CD's Get a Foothold in U.S. | date=April 26, 2001 | year = 2001 | publisher = New York Times | url = http://query.nytimes.com/gst/fullpage.html?res=9B07E2DD1439F935A15757C0A9679C8B63&sec=&spon=&pagewanted=all | accessdate = 2008-02-12 ] commercial VCDs are common in Europe,Citation | first = J. D. | last = Biersdorfer | title = Q & A; Another Ingredient In Alphabet Soup: VCD | date=February 8, 2001 | year = 2001 | publisher = New York Times | url = http://query.nytimes.com/gst/fullpage.html?res=9C06E1D81631F93BA35751C0A9679C8B63&scp=1&sq=VCD&st=nyt | accessdate = 2008-02-12 ] and popular throughout Asia [Citation | first = Junko | last = Yoshida | title = Video CD: China one, West zero | date=December, 1999 | year = 1999 | publisher = EE Times | url = http://www.eetimes.com/special/special_issues/millennium/milestones/baichuan.html | accessdate = 2008-02-12 ] (except Japan), with 8 million VCD players sold in China in 1997 alone, [Citation | first = George | last = Leopold | first2 = Junko | last2 =Yoshida | title = Chinese supplier preps low-cost digital TVs for U.S. market | date=January 13, 1999 | year = 1999 | publisher = EE Times | url = http://www.eetimes.com/story/OEG19990113S0009 | accessdate = 2008-02-12 ] and more than half of all Chinese households owning at least one VCD player by 2005. [Citation | title = Chinese families double their incomes in 10 years | date=January 12, 2005 | year = 2005 | publisher = China Daily | url = http://www.chinadaily.com.cn/english/doc/2005-01/12/content_408150.htm | accessdate = 2008-02-12 ]

This popularity is, in part, because most households did not already own VHS players when VCDs were introduced, the low price of the players, their tolerance of high humidity (a notable problem for VCRs), and the lower-cost media. Ease of duplication and the negligible cost of the media gave rise to widespread unauthorized copying in these areas. [Citation | first = Elisabeth | last = Rosenthal | title = Counterfeiters Turn Magic Into Cash | date=November 25, 2001 | year = 2001 | publisher = New York Times | url = http://query.nytimes.com/gst/fullpage.html?res=9E06EED7133AF936A15752C1A9679C8B63&sec=&spon=&pagewanted=2 | accessdate = 2008-02-12 ] Citation | first = Craig S. | last = Smith | title = A Tale of Piracy: How the Chinese Stole the Grinch | date=December 12, 2000 | year = 2000 | publisher = New York Times | url = http://query.nytimes.com/gst/fullpage.html?res=9A01E0DD123FF931A25751C1A9669C8B63&sec=&spon=&pagewanted=all | accessdate = 2008-02-12 ] [Citation | first = Seth | last = Faison | title = China Turns Blind Eye to Pirated Disks | date=March 28, 1998 | year = 1998 | publisher = New York Times | url = http://query.nytimes.com/gst/fullpage.html?res=9401E1D7143BF93BA15750C0A96E958260&sec=&spon=&pagewanted=all | accessdate = 2008-02-12 ]

The advent of recordable CDs, inexpensive recorders, and compatible DVD players spurred VCD acceptance in the US in the late 1990s and early 2000s. However, DVD burners and DVD-Video recorders were available by that time, and equipment and media costs for making DVD-Video fell rapidly. DVD-Video, with its longer run time and much higher quality, quickly overshadowed VCD. In addition many early DVD players could not read recordable (CD-R) media, [Citation | first = Hugh | last = Bennett | title = DVD-ROM and CD-R: the compatibility question answered - includes related article on reading mixed media | date= March, 1998 | year = 1998 | publisher = Emedia Professional | url = http://findarticles.com/p/articles/mi_m0FXG/is_n3_v11/ai_20324077 | accessdate = 2008-04-26 ] and this limited the compatibility of home-made VCDs. Almost every modern stand-alone DVD-Video player can play VCDs burned on recordable media.

Many commercial Video CDs of blockbuster Hollywood, Bollywood, Manilawood and other Asian movies and television series are not widely available in the Western countries; however, they are available in certain ethnic communities and several commercial web sites (although quality and authenticity may sometimes be questionable). These VCDs are often produced and sold in Asian countries such as Pakistan, Hong Kong, India, Mainland China, Thailand, Malaysia, Indonesia and the Philippines. In many Asian countries, major Hollywood studios (and Asian home video distributors) have licensed companies to officially produce and distribute the VCDs, such as MCA Home Video in Pakistan, ERA of Hong Kong or Sunny Video in Malaysia, Vision in Indonesia, Excel Home Videos in India, Berjaya-HVN and InnoForm Media in both Malaysia and Singapore, as well as VIVA Video, Magnavision, and The Video to C in the Philippines. Legal Video CDs can often be found in established video stores and major book outlets in most Asian countries.

Due to relatively small storage capacity, feature-length films sold on VCD are usually divided into two or three discs and television series may come in a "boxed set" package with multiple discs. In both cases, most films run at roughly 60 minutes per VCD, before viewers are prompted to change discs. However, there are also VCD players that have built-in CD changers which provide a queue of several discs. Subtitles are found on many Asian VCDs, and unlike DVDs, cannot be removed.

In areas where VCD was formerly very popular, it is now in decline, due to being supplanted by DVD, which offers most of the same advantages, as well as better picture quality [Citation | title = Low DVD Prices to Drive up Sales | date=September 05, 2001 | year = 2001 | publisher = People's Daily | url = http://english.peopledaily.com.cn/english/200109/05/eng20010905_79358.html | accessdate = 2008-02-12 ] (higher resolution with less digital compression artifacts) due to its larger storage capacity and 6-speaker surround sound (often in Dolby Digital and/or DTS).

References

See also

* Laserdisc - The larger analog predecessor to Video CD
* CD Video - A 1980s format combining the laserdisc and the CD
* VCD - A 1990s digital format combining the laserdisc and the CD
* DVD - A higher capacity follow-up to the Super Video CD and XVCD
* Super Video CD (SVCD) - The direct successor to Video CD
* miniDVD - DVD video on a CD
* DcVD - A non-standard MPEG-1 format for the Sega Dreamcast video game console
* MovieCD - A proprietary 1990s format using the "MotionPixels" codec

External links

* [http://www.ip.philips.com/licensing/licensingprogramshistory/history_televisioncdplayer_joint.html Patent History Television CD Player] - published by Philips 2003
* [http://www.ip.philips.com/licensing/licensingprogramshistory/history_televisioncddisc_joint.html Patent History Television CD Disc] - published by Philips 2003
* [http://www.videohelp.com/tvcd What is TVCD?] - from VideoHelp.com
* [http://www.tvcdhelp.com/ TVCD Help]
* [http://www.tvcdgallery.com/help.htm How Do You Play TVCDs?]
* [http://www.mireth.com/wt/v530.html How to Play TVCD on Mac/Windows computer, DVD Player] - from Mireth Technology
* [http://www.Doom9.org/index.html?/mpg/tvcdstvcd_faq.htm TVCD / VCD / SVCD / miniDVD FAQ] - from Doom9.org