W-VHS
Encyclopedia
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
.
W-VHS was named so because "W" means double to the Japanese.
The recording medium of W-VHS is a ½-inch metallic magnetic tape
stored in a cartridge the same size as VHS
. The tape can be used to store 1035i or 480i analog signals (but not 480p, 720p or 1080i). The video signal is recorded using a method called "time compression integration" which "records separated component video
, Luminance
and Color
signals offset by time in alternating parts of the video track". Because video signals are recorded in component form instead of the s-video
(Y/C) color under method used by S-VHS
, standard definition image quality for W-VHS is typically much higher, due to the lack of noise caused by a chroma sub-carrier. Audio is stored in the VHS Hi-Fi or S-VHS Digital Audio
formats.
W-VHS VCRs were one of the only devices consumers could use to record a Standard or High Definition video signal via an analog Y/Pb/Pr component interface. Very few devices with this capability exist, possibly due to content copyright restrictions. W-VHS has also been used for medical imaging, professional previewing, and broadcasting.
Currently, it is very difficult to find either W-VHS VCRs or tapes. Since W-VHS tapes are harder to find many people have been using the similar Digital-S
(D-9) tape. While D-9 are still not that easy to find, they are more available than W-VHS tapes in certain regions. JVC Professional even recommends the use of them for W-VHS. The running time between W-VHS and Digital-S is not the same. A Digital-S tape with a length of 64 min is approx 105 min when used with W-VHS.
Analog recording
Analog recording is a technique used for the recording of analog signals which among many possibilities include audio frequency, analog audio and analog video information for later playback.Analog recording methods store signals as a continual wave in or on the media...
videocassette format created 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...
. The format was originally introduced in 1994 for use with Japan's Hi-Vision, an early analog high-definition television system named MUSE
Multiple sub-nyquist sampling Encoding system
MUSE , was a dot-interlaced digital video compression system that used analog modulation for transmission to deliver 1125-line high definition video signals to the home. Japan had the earliest working HDTV system, which was named Hi-Vision with design efforts going back to 1979...
.
W-VHS was named so because "W" means double to the Japanese.
The recording medium of W-VHS is a ½-inch metallic magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
stored in a cartridge the same size as VHS
VHS
The Video Home System is a consumer-level analog recording videocassette standard developed by Victor Company of Japan ....
. The tape can be used to store 1035i or 480i analog signals (but not 480p, 720p or 1080i). The video signal is recorded using a method called "time compression integration" which "records separated component video
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...
, Luminance
Luminance
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square...
and Color
Chrominance
Chrominance is the signal used in video systems to convey the color information of the picture, separately from the accompanying luma signal . Chrominance is usually represented as two color-difference components: U = B' − Y' and V = R' − Y'...
signals offset by time in alternating parts of the video track". Because video signals are recorded in component form instead of the s-video
S-Video
Separate Video, more commonly known as S-Video and Y/C, is often referred to by JVC as both an S-VHS connector and as Super Video. It is an analog video transmission scheme, in which video information is encoded on two channels: luma and chroma...
(Y/C) color under method used by 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...
, standard definition image quality for W-VHS is typically much higher, due to the lack of noise caused by a chroma sub-carrier. Audio is stored in the VHS Hi-Fi or S-VHS Digital Audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
formats.
W-VHS VCRs were one of the only devices consumers could use to record a Standard or High Definition video signal via an analog Y/Pb/Pr component interface. Very few devices with this capability exist, possibly due to content copyright restrictions. W-VHS has also been used for medical imaging, professional previewing, and broadcasting.
Currently, it is very difficult to find either W-VHS VCRs or tapes. Since W-VHS tapes are harder to find many people have been using the similar 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...
(D-9) tape. While D-9 are still not that easy to find, they are more available than W-VHS tapes in certain regions. JVC Professional even recommends the use of them for W-VHS. The running time between W-VHS and Digital-S is not the same. A Digital-S tape with a length of 64 min is approx 105 min when used with W-VHS.