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Video CD

From Wikipedia, the free encyclopedia
(Redirected fromVideo cd)
"VCD" redirects here. For other uses, seeVCD (disambiguation).
This article is about the all-digital Video CD format. For the earlier analog/digital hybrid, seeCD Video.
See also:Videodisc
Compact Disc Digital Video (VCD)

Media typeOptical disc
EncodingMPEG-1 video + audio
CapacityUp to 800MB/80 minutes of Video
Readmechanism780 nm wavelength semiconductor laser
StandardIEC 62107
DevelopedbyPhilips,Sony,Panasonic,JVC
Usageaudio and video storage
ExtendedfromCD Video / Video Single Disc
ExtendedtoSVCD
Released1993
Optical discs
General
Optical media types
Standards
See also

Video CD(abbreviated asVCD,and also known asCompact Disc Digital Video) is ahome videoformat and the first format for distributing films on standard 120 mm (4.7 in)optical discs.The format was widely adopted inSoutheast Asia,South Asia,East Asia,Central AsiaandWest Asia,superseding theVHSandBetamaxsystems in the regions untilDVD-Videofinally became affordable in the first decade of the 21st century.

The format is a standarddigital dataformat for storingvideoon acompact disc.VCDs are playable in dedicated VCD players and widely playable in mostDVD players,personal computersand somevideo game consoles.However, they are less playable in mostBlu-ray Discplayers,vehicle audiowith DVD/Blu-ray support and video game consoles such as the SonyPlayStationandXboxdue to lack ofbackward compatibilityfor the olderMPEG-1format, inability to read MPEG-1 in.datfiles alongside MPEG-1 in standard MPEG-1, AVI, and Matroska files, or inability to readCD-ROM XAdiscs. SomeLaserdisc playersthat were released in the late 90s support VCD as well as the Sony PS1 model SCPH-5903 marketed in Southeast Asia.

The Video CD standard was created in 1993[1][2] bySony,Philips,MatsushitaandJVC;it is referred to as theWhite Bookstandard. The MPEG-1 format was also released that same year.

Brief history

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LaserDiscwas first available on the market, inAtlanta, Georgia,on December 15, 1978.[3]This 30 cm (12 in) disc could hold an hour of analog audio and video (digital audio was added a few years later) on each side. The LaserDisc provided picture quality nearly double that ofVHS tapeand analog audio quality far superior to cheap mono VHS recorders (although the difference to the more expensive VHS HiFi stereo recorders was minuscule).

Philips later teamed up withSonyto develop a new type of disc, thecompact discor CD. Introduced in 1982 inJapan(1983 in theU.S.andEurope), the CD is about 120 mm (4.7 in) in diameter, and is single-sided. The format was initially designed to store digitized sound and proved to be a success in the music industry.

A few years later, Philips decided to give CDs the ability to produce video, utilizing the same technology as its LaserDisc counterpart. This led to the creation ofCD Video(CD-V) in 1987. However, the disc's small size significantly impeded the ability to store analog video; thus only 5 minutes of picture information could fit on the disc's surface (despite the fact that the audio was digital). Therefore, CD-V distribution was limited to featuringmusic videos,and it was soon discontinued by 1991.

By the early 1990s engineers were able to digitize and compress video signals, greatly improving storage efficiency. Because this new format could hold 74/80 minutes of audio and video on a 650/700MB disc, releasing movies on compact discs finally became a reality. Extra capacity was obtained by sacrificing theerror correction(it was believed that minor errors in the datastream would go unnoticed by the viewer). This format was named Video CD or VCD.

"Copy Protected" logo on a VCD package produced inHong Kong

VCD enjoyed a brief period of success, with a few major feature films being released in the format (usually as a 2 disc set). However the introduction of theCD-Rdisc and associated recorders stopped the release of feature films in their tracks because the VCD format had no means of preventing unauthorized (and perfect) copies from being made.[citation needed]However, as of 2013VCDs are still being released in several countries in Asia, but now with copy-protection.[citation needed]

The development of more sophisticated, higher capacity optical disc formats yielded theDVDformat, released only a few years later with a copy protection mechanism.DVD playersuse lasers that are of shorter wavelength than those used on CDs, allowing the recorded pits to be smaller, so that more information can be stored. The DVD was so successful that it eventually pushed VHS out of the video market once suitable recorders became widely available. Nevertheless, VCDs made considerable inroads into developing nations, where they are still in use today due to their cheaper manufacturing and retail costs.[citation needed]

Technical specifications

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Structure

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Video CDs comply with theCD-i Bridgeformat, and areauthoredusing tracks inCD-ROM XAmode. The first track of a VCD is in CD-ROM XA Mode 2 Form 1, and stores metadata and menu information inside anISO 9660filesystem.This track may also contain other non-essential files, and is shown by operating systems when loading the disc. This track can be absent from a VCD, which would still work but would not allow it to be properly displayed in computers.[4]

The rest of the tracks are usually in CD-ROM XA Mode 2 Form 2 and contain video and audiomultiplexedin anMPEG program stream(MPEG-PS) container, butCD audiotracks are also allowed.[4]Using Mode 2 Form 2 allows roughly 800 megabytes of VCD data to be stored on one 80 minute CD (versus 700 megabytes when usingCD-ROMMode 1). This is achieved by sacrificing the error correction redundancy present in Mode 1. It was considered that small errors in the video and audio stream pass largely unnoticed. This, combined with the net bitrate of VCD video and audio, means that almost exactly 80 minutes of VCD content can be stored on an 80-minute CD, 74 minutes of VCD 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 "1x" speed CD drives.

Video

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VCD resolution compared to other formats

Video specifications[5]

Although many DVD video players support playback of VCDs, VCD video is only compatible with theDVD-Videostandard if encoded at 29.97 frames per second or 25 frames per second.

The 352×240 and 352×288 (orSIF) resolutions, when compared to theCCIR 601specifications (defining the appropriate parameters for digital encoding of NTSC and PAL/SECAM TV signals), are reduced by half in all aspects: height, width, frame-rate, and chrominance.

Audio

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Audio specifications[5]

As with most CD-based formats, VCD audio is incompatible with theDVD-Videostandard due to a difference in sampling frequency; DVDs require 48 kHz, whereas VCDs use 44.1 kHz.

Advantages of compression

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By compressing both the video and audio streams, a VCD is able to hold 74 minutes of picture and sound information, the same duration as a standard 74 minute audio CD. The MPEG-1 compression used records mostly the differences between successive video frames, rather than write out each frame individually. Similarly, the audio frequency range is limited to those sounds most clearly heard by the human ear.

Other features

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PlayBack Control (PBC) added in VCD 2.0 requires a special 'Return' button

The VCD standard also features the option of DVD-quality still images/slide shows with audio, at resolutions of 704×480 (480i,analog NTSC compatible) or 704×576 (576i,analog PAL/SECAM compatible). Version 2.0 also adds the playback control (PBC), featuring a simple menu like DVD-Video.

Similar formats

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CD-i Digital Video

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Shortly before the advent of White Book VCD, Philips started releasing movies in theGreen BookCD-iformat, calling the subformat CD-i Digital Video (CD-i DV). While these used a similar format (MPEG-1), due to minor differences between the standards these discs are not compatible with VCD players. Philips' CD-i players with the Full Motion Video MPEG-1 decoder cartridge would play both formats. Approximately 30 CD-i DV titles were released before the company switched to the current VCD format for publishing movies in 1994.

XVCD

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XVCD(eXtended Video CD) is the name generally given to any format that stores MPEG-1 video on a compact disc in CD-ROM XA Mode 2 Form 2, but does not strictly follow the VCD standard in terms of the encoding of the video or audio.

A normal VCD 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. Some XVCDs use lower bitrates in order to fit longer videos onto the disc, while others use higher bitrates to improve quality. MPEG-2 may be used instead of MPEG-1.

To further reduce the data rate without significantly reducing quality, the size of theGOPcan be increased, a different MPEG-1quantization matrixcan be used, the maximum data rate can be exceeded, and the bit rate of the MP2 audio can be reduced or even be swapped out completely for MP3 audio. These changes can be advantageous for those who want to either maximize video quality, or use fewer discs.

KVCD

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KVCD(K Video Compression Dynamics) is an XVCD variant that requires the use of aproprietaryquantization matrix,created by Karl Wagner and made available for non-commercial use. In addition to standard VCD resolutions, KVCD allows for non-standard resolutions like 528×480/576, though hardware support for KVCDs authored with these resolutions is limited.[6]

DVCD

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DVCDor Double VCD is a method to accommodate longer videos on a CD. A non-standard CD isoverburnedto 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.

DVI

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DVI(Digital Video Interactive) is a compression technique that stored 72 minutes of video on aCD-ROM.In 1998,Intelacquired the technology fromRCA's Sarnoff Research Labs. DVI never caught on.[7]

SVCD

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Super Video CDis a format intended to be the successor of VCD, offering better quality of image and sound. The format usesMPEG-2video at 480x480 or 480x576 and supports multiple bitrate and channel options for encoding audio.

Adoption

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In North America

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Video CDs were unable to gain acceptance as a mainstream format inNorth America,chiefly because the established VHS format was less expensive, offered comparable video quality, and could be recorded over.[8]The advent ofrecordable CDs,inexpensive recorders, and compatible DVD players spurred VCD acceptance in the US in the late 1990s and early 2000s.[9]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 areas that could afford it. In addition many early DVD players could not read recordable (CD-R) media,[10]and this limited the compatibility of home-made VCDs.

In Asia

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The VCD format was very popular throughoutAsia[11] (exceptJapanandSouth Korea) in the late 1990s through the 2000s, with 8 million VCD players sold in China in 1997 alone,[12] and more than half of all Chinese households owning at least one VCD player by 2005.[13]However, popularity has declined over the years, as the number ofHong Kongfactories that produced VCDs dropped from 98 in 1999 to 26 in 2012.[14]

This popularity was due, in part, to most households not already owningVCRswhen VCDs were introduced, the low price of the players, their tolerance of high humidity (a notable problem for VCRs), easy storage and maintenance, and the lower-cost media.[9]Western sources have cited unauthorized content as a principal incentive for VCD player ownership.[15][16][17]

VCDs are often produced and sold in Asian countries and regions, such asChina(includingHong Kong),Taiwan,Singapore,Malaysia,Thailand,Cambodia,Laos,Brunei,Myanmar,Indonesia,Philippines,Vietnam,Bangladesh,India,Turkey,PakistanandAfghanistan.[18]In many Asian countries, major Hollywood studios (and Asian home video distributors) have licensed companies to officially produce and distribute the VCDs, such as Intercontinental Video Ltd. of Hong Kong, Sunny Video in Malaysia, Vision Interprima Pictures in Indonesia, CVD International and Pacific Marketing and Entertainment Group in Thailand, Excel Home Entertainment in India, Berjaya-HVN and InnoForm Media in both Malaysia and Singapore, Scorpio East Entertainment in Singapore, as well asViva Video,Magnavision Home Video, and C-Interactive Digital Entertainment in the Philippines. Legal Video CDs can often be found in established video stores and major book outlets in most Asian countries. They are typically packaged in jewel cases like commercial CDs, though higher-profile films may be released inkeep cases,differentiated by the VCD logo.

In Asia, the use of VCDs as carriers forkaraokemusic is very common. One channel would feature a mono track with music and singing, another channel a pure instrumental version for karaoke singing. Prior to this, karaoke music was carried onLaserDiscs.[citation needed]

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VCD's growth had slowed in areas that can affordDVD-Video,which offered most of the same advantages, as well as better picture quality[19] (higher resolution with fewer digital compression artifacts) due to its larger storage capacity. However, VCD had simultaneously seen significant growth in emerging economies likeIndia,Indonesia,South America,andAfricaas a low-cost alternative to DVD. As of 2004, the worldwide popularity of VCD was increasing.[20][21]

Compared with VHS

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Overall picture quality is intended to be comparable toVHSvideo.[22] PoorlycompressedVCD video can sometimes be of lower quality than VHS video, for example exhibiting VCD block artifacts[23](rather than the analog noise seen in VHS sources), but does not deteriorate further with each use. Producing video CDs involves stripping out high- and low-frequency sounds from the video, resulting in lower audio quality than VHS.[23]While both formats need fast-forwarding to find certain scenes, rewinding to the beginning upon reaching the end is not required in VCD. The resolution is just half below that of common VHS resolution.[citation needed]

Video CDs did not come withclosed captioning(on-screen text to aid viewers with hearing problems). When watching a film that exceeds 74 minutes (nearly 1¼ hours), the maximum video capacity of one disc, a viewer had to change the disc upon reaching halfway (unless the discs were played on a VCD changer that could hold multiple discs and play them automatically in succession), whereas a single VHS tape could hold 3.5 hours of continuous video.

Compared with DVD

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Films released on VCD can come on as many as 3 discs, depending on the length of the film; cases of VCDs are shaped like those of audio CDs

When playing aDVD,the viewer is taken to a main menu which gives them options (watch the feature film, view "deleted scenes", play some special applications, etc.). VCDs are usually straightforward; playing them often goes directly to the video with extras (mostly trailers and commercials) taking place before or after it, like on a VHS cassette.

Subtitles are found on many Asian VCDs but cannot be removed, unlike on DVDs. The subtitles are embedded on the video during the encoding process ( "hardsubbed"). It is not uncommon to find a VCD with subtitles for two languages.

Though the VCD technology can support it, most films carried on VCDs do not contain chapters, requiring the viewer to fast-forward to resume the program after playback has been stopped. This is mostly because VCD technology is able to start playback at a chapter point but there is nothing to signal to the player that the chapter has changed during a program. This can be confusing for the user as the player will indicate that it is still playing chapter 1 when it has played through to chapter 2 or later. Pressing the Next button would cause playback from the beginning of chapter 2. However, preview material is sometimes stored in a separate chapter, followed by a single chapter for the film.

VCDs are often bilingual. Because they feature stereo audio, disc players have an option to play only the left or right audio channel. On some films, they feature English on the left audio channel and Cantonese on the right; more commonly Hong Kong VCDs will feature Mandarin on one channel and Cantonese on the other. This is similar to selecting a language track on a DVD, except it is limited to 2 languages, due to there being only two audio channels (left and right). The audio track effectively becomes monaural.

VCD's most noticeable disadvantage compared to DVD is image quality, due both to the more aggressive compression necessary to fit video into such a small capacity as well as to the compression method used. Additionally, VCD movie surround sound capability is limited to Dolby Surround matrixed within the stereo tracks, while DVDs are capable of six channels of discrete surround sound viaDolby DigitalAC-3.

Hardware and software support

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Early devices supporting Video CD playback include thePhilips CD-isystems and theAmiga CD-32(albeit via an optional decoder card).[8]Disc playback is also available both natively and as an option on some CD- and DVD-based video game consoles, including theoriginal PlayStation(only on the SCPH-5903 model).

Early software supporting Video CD playback includeXingMPEG.Early PC hardware supporting Video CD playback include proprietaryVCD decoder card.Later, because the introduction ofPentium IIprocessor which supportsMMXextension, and latergraphics cardshad included video decoding function, the use ofVCD decoder carddeclined.

VLCis afree, open-sourcemedia player softwarewhich supports VCD onWindows,MacOS,LinuxandBSD.[24]

Windows Media Playerprior to version 9 does not support playing VCD directly.Windows Vistaadded native support of VCD along withDVD-Videoand can launch the preferred application upon insertion. The disc format is also supported natively byMedia Player Classic,VLC Media PlayerandMPlayer.[4]

QuickTime Playeralso does not support playing VCD directly, though it can play the.DAT files (stored under \MPEGAV for video and audio data) reliably,[25]andpluginswere available.

Direct access playback support is available withinWindows XP MCE,Windows Vistaand newer (includingWindows 10),classic Mac OS,BSD,macOS,andLinuxamong others, either directly or with updates and compatible software.

MostDVDplayers are compatible with VCDs, and VCD-only players are available throughout Asia, and online through many shopping sites. Some olderBlu-rayandHD-DVDplayers also retained support, as doCBHDplayers as well. However, most Blu-ray players, mostvehicle audiowith DVD/Blu-ray support,Xboxfamily, and the SonyPlayStation(2/3/4/5) cannot play VCDs; this is because while they have backwards playback compatibility with the DVD standard, these player can not read VCD data because the player software does not have support for MPEG-1 video and audio, the player software lacks ability to read MPEG-1 stream in DAT files alongside MPEG-1 stream in standard MPEG,AVI,and Matroska files, or the player lacks ability to readCD-ROM XAdiscs.

See also

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References

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  1. ^Hardware and Software Get an Early Start,Sony,archived fromthe originalon June 25, 2010,retrieved2008-02-13
  2. ^Super Video Compact Disc, A Technical Explanation (PDF)(PDF),PhilipsSystem Standards and Licensing, 1998, p. 2, archived fromthe original(PDF)on 2008-05-28,retrieved2008-02-13
  3. ^"1979: The VideoDisc Is Here!",History of Media Technology,CED magic,retrieved8 April2011
  4. ^abc3.6. VCD playback,MPlayer,retrieved2018-04-03
  5. ^ab"MPEG1 Specifications",icdia.co.uk
  6. ^DVD Compatibility Chart,February 25, 2007,retrieved2008-02-22
  7. ^"Definition of: DVI",PC Magazine
  8. ^ab"Beginning of the End for Video CD?",Next Generation(3),Imagine Media:27–28, March 1995
  9. ^abMeyer, Scot (April 26, 2001)."Versatile Video CD's Get a Foothold in U.S."New York Times.Retrieved2008-02-12.
  10. ^Bennett, Hugh (March 1998)."DVD-ROM and CD-R: the compatibility question answered - includes related article on reading mixed media".Emedia Professional. Archived fromthe originalon 2012-07-12.
  11. ^Yoshida, Junko (December 1999)."Video CD: China one, West zero".EE Times.Archivedfrom the original on 2005-04-09.Retrieved2008-02-12.
  12. ^Leopold, George; Yoshida, Junko (January 13, 1999)."Chinese supplier preps low-cost digital TVs for U.S. market".EE Times.Archived fromthe originalon March 29, 2004.Retrieved2008-02-12.
  13. ^"Chinese families double their incomes in 10 years".China Daily.January 12, 2005.Retrieved2008-02-12.
  14. ^Amy Nip and Phila Siu (15 November 2012)."Customs criticised for pursuit of outdated CD and VCD piracy".South China Morning Post.
  15. ^Rosenthal, Elisabeth (November 25, 2001)."Counterfeiters Turn Magic into Cash".New York Times.Archived fromthe originalon January 23, 2009.Retrieved2008-02-12.
  16. ^Smith, Craig S. (December 12, 2000)."A Tale of Piracy: How the Chinese Stole the Grinch".New York Times.Archived fromthe originalon January 30, 2009.
  17. ^Faison, Seth (March 28, 1998)."China Turns Blind Eye to Pirated Disks".New York Times.Archived fromthe originalon January 23, 2009.
  18. ^"Taliban Rule Ends in Kabul (2001)".YouTube.
  19. ^"Low DVD Prices to Drive up Sales".People's Daily.September 5, 2001.Retrieved2008-02-12.
  20. ^"ESS Technology, Inc. 2003 Annual Report"(PDF).ESS Technology.2004. p. 3. Archived fromthe original(PDF)on 2006-03-14.
  21. ^"ESS product to vie with VCD players".People's Daily.August 10, 2004.Retrieved2008-04-01.
  22. ^Chiariglione, Leonardo (November 6, 1992),MPEG Press Release, London, 6 November 1992,International Organization for Standardization,archived fromthe originalon November 8, 2007,retrieved2008-03-20
  23. ^ab"Correction",Next Generation(4),Imagine Media:108, April 1995
  24. ^"Video CD - VideoLAN Wiki".wiki.videolan.org.Retrieved2020-08-23.
  25. ^"Mac OS X 10.3: Playing Video Compact Disc (VCD) media",apple
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