S-VHS, the common initialism for Super VHS, is an
analog video
cassette format introduced by
JVC
JVC (short for Japan Victor Company) is a Japanese brand owned by JVCKenwood. Founded in 1927 as the Victor Talking Machine Company of Japan and later as , the company was best known for introducing Japan's first televisions and for developin ...
in 1987 as an improved version of the
VHS
VHS (Video Home System) is a discontinued standard for consumer-level analog video recording on tape cassettes, introduced in 1976 by JVC. It was the dominant home video format throughout the tape media period of the 1980s and 1990s.
Ma ...
(Video Home System) format. S-VHS improved image quality by increasing the bandwidth of the
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, is emitted from, or is reflected from a particular area, and falls wit ...
(brightness) signal, allowing for a
horizontal resolution
Dots per inch (DPI, or dpiThe acronym appears in sources as either "DPI" or lowercase "dpi". See "Print Resolution Understanding 4-bit depth – Xerox" (PDF). Xerox.com. September 2012.) is a measure of spatial printing, video or image scanner ...
of approximately 400 lines, compared to the 240 lines typical of VHS. The format used the same physical cassette shell as VHS but required higher-grade magnetic tape and compatible recording and playback equipment.
S-VHS decks are
backward-compatible
In telecommunications and computing, backward compatibility (or backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with inp ...
with standard VHS tapes, allowing them to play and record in VHS format. However, S-VHS tapes generally cannot be played in VHS-only machines, due to differences in the signal encoding.
Despite its technical advantages, S-VHS struggled to gain widespread consumer adoption due to the higher cost of equipment and tapes, along with the limited availability of pre-recorded content. The format found moderate success in professional, educational, and industrial applications, including video production, surveillance camera recording, and television broadcasting, where its higher resolution and compatibility with VHS tapes made it a practical transitional format.
Technical information
Like VHS, the S-VHS format uses a ''color under A''
modulation
Signal modulation is the process of varying one or more properties of a periodic waveform in electronics and telecommunication for the purpose of transmitting information.
The process encodes information in form of the modulation or message ...
scheme.
S-VHS improves
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, is emitted from, or is reflected from a particular area, and falls wit ...
(luma) resolution by increasing luminance
bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
.
[ Increased bandwidth is possible because of the increased luminance carrier from 3.4 ]megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base ...
(MHz) to 5.4 MHz.[ The luminance modulator ''bandwidth'' also is increased: in contrast to standard VHS's frequencies of 3.8 MHz (synch tip) to 4.8 MHz (peak white), S-VHS uses 5.4 MHz synch tip and 7.0 MHz peak white. Increased luminance bandwidth produces a 60% improvement in luminance picture detail—a ]horizontal resolution
Dots per inch (DPI, or dpiThe acronym appears in sources as either "DPI" or lowercase "dpi". See "Print Resolution Understanding 4-bit depth – Xerox" (PDF). Xerox.com. September 2012.) is a measure of spatial printing, video or image scanner ...
of 420 vertical lines per picture height, versus VHS's 240 lines. The often quoted horizontal resolution of "over 400" means S-VHS captures greater picture detail than even NTSC
NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170.
In 1953, a second ...
[ analog cable and broadcast TV, which is limited to about 330 television lines (TVL). In practice, when ]time-shifting
In broadcasting, time shifting is the recording of programming to a storage medium to be viewed or listened to after the live broadcasting. Typically, this refers to TV programming but it can also refer to radio shows via podcasts.
In recent yea ...
TV program
A television show, TV program (), or simply a TV show, is the general reference to any content produced for viewing on a television set that is broadcast via over-the-air, satellite, and cable, or distributed digitally on streaming platf ...
s on S-VHS equipment, the improvement over VHS is noticeable. Yet, the trained eye can easily spot the difference between live television
Live television is a television production broadcast in real-time, as events happen, in the present. In a secondary meaning, it may refer to streaming television where all viewers watch the same stream simultaneously, rather than watching vide ...
and an S-VHS recording of it. This is because S-VHS does not improve other key aspects of the video signal, particularly the chrominance
Chrominance (''chroma'' or ''C'' for short) is the signal used in video systems to convey the color information of the picture (see YUV color model), separately from the accompanying Luma (video), luma signal (or Y' for short). Chrominance is usu ...
(chroma) signal. In VHS, the chroma carrier is both severely bandlimited
Bandlimiting is the process of reducing a signal’s energy outside a specific frequency range, keeping only the desired part of the signal’s spectrum. This technique is crucial in signal processing and communications to ensure signals stay cl ...
and noisy, a limitation that S-VHS does not address. Lack of color resolution was a deficiency shared by S-VHS's contemporaries, such as Hi8
The 8mm video format refers informally to three related videocassette formats. These are the original Video8 format (analog video and analog audio but with provision for digital audio), its improved variant Hi8, as well as a more recent digit ...
and ED-Beta – all of which were limited to 0.4 megahertz or 30 TVL resolution.
In audio recording
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording t ...
, S-VHS retains VHS's conventional linear (baseband
In telecommunications and signal processing, baseband is the range of frequencies occupied by a signal that has not been modulated to higher frequencies. Baseband signals typically originate from transducers, converting some other variable into ...
) and high fidelity
High fidelity (hi-fi or, rarely, HiFi) is the high-quality reproduction of sound. It is popular with audiophiles and home audio enthusiasts. Ideally, high-fidelity equipment has inaudible noise and distortion, and a flat (neutral, uncolored) ...
(Hi-Fi) – Audio Frequency Modulation
Audio Frequency Modulation (AFM) is an audio recording standard used by Betamax and VHS Hi-Fi stereo, 8mm and Hi8 video systems. AFM is mono on 8mm systems and stereo
Stereophonic sound, commonly shortened to stereo, is a method of sound ...
(AFM) soundtracks. Some professional S-VHS decks, and high end domestic S-VHS VCRs such as the Victor HR-Z1 can additionally record a pulse-code modulation
Pulse-code modulation (PCM) is a method used to digitally represent analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitud ...
(PCM) digital audio
Digital audio is a representation of sound recorded in, or converted into, digital signal (signal processing), digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical sampling (signal processing), ...
track (stereo 48 kHz), onto S-VHS tape along with normal video and Hi-Fi stereo and mono analog audio.
This is performed by using a high carrier frequency of 3 MHz for the digital audio with O-QDPSK (Offset Quadrature Differential Phase Shift Keying) modulation and PCM encoding which is then recorded onto the same helical tracks as the video. This frequency is above those used for VHS Hi-Fi (1.7 MHz for the left channel, 1.8 MHz for the right channel) but below the luminance signal frequency for regular VHS of 3.4 MHz. The digital audio stream has a bit rate of 2.6 Mbps. O-QDPSK is based on QDPSK (Quadrature Differential Phase Shift Keying), also known as DQPSK (Differential Quadrature Phase Shift Keying), and is very similar to it, except O-QDPSK signals are free from zero crossing
A zero-crossing is a point where the sign of a mathematical function changes (e.g. from positive to negative), represented by an intercept of the axis (zero value) in the graph of the function. It is a commonly used term in electronics, mathema ...
; the signals never cross the 0 voltage point. Instead they are above and below the 0 voltage point. This type of digital audio requires a bandwidth of 500 KHz. It is also possible for this audio channel to have a carrier frequency of 2 MHz.
The bandwidth of S-VHS allows PAL
Phase Alternating Line (PAL) is a color encoding system for analog television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
recordings to contain Teletext
Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the to ...
data along with the normal video signal, which then can be displayed as an overlay of the conventional TV picture (though not on standard VHS machines). A suitably Teletext-equipped receiver/decoder (TV, PC card, etc.) displays the recorded Teletext data information as if the video were a television transmission being received at that moment.
Hardware
S-VHS video cassette recorder
A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other AV sources and can play back the recording after rewinding. The use of a VCR to ...
s (VCRs) and cassette tapes are nearly identical in appearance and operation, and backward compatible
In telecommunications and computing, backward compatibility (or backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with inpu ...
with VHS. VHS VCRs cannot play back S-VHS recordings at all but can record onto an S-VHS tape in the basic VHS format. Newer VHS VCRs, depending upon their specification, offered a feature called ''S-VHS quasi-playback'' or ''Super Quasi-Play Back'', abbreviated to SQPB. SQPB lets basic VHS players view (but not record) S-VHS recordings, though reduced to the lesser VHS quality. This feature is useful for viewing S-VHS camcorder
A camcorder is a self-contained portable electronic device with video and recording as its primary function. It is typically equipped with an articulating screen mounted on the left side, a belt to facilitate holding on the right side, hot-sw ...
recordings that use either the full-size S-VHS cassette or the smaller S-VHS-C
VHS-C is a compact version of the VHS videocassette format, introduced by Victor Company of Japan (JVC) in 1982, and used primarily in consumer-grade analog recording camcorders. VHS-C uses the same magnetic tape as full-size VHS cassettes and c ...
cassette.
Later model S-VHS VCRs offered a recording option called S-VHS ET, which allowed SVHS VCRs to record on VHS tape. S-VHS ET is a further modification of the VHS standards that permitted near S-VHS quality recordings on more common and less expensive basic VHS tapes. S-VHS ET recordings can be viewed on most SQPB-equipped VHS VCRs and S-VHS VCRs.
To get the most benefit from S-VHS, a direct video connection to the monitor or TV is required, ideally via an S-Video
S-Video (also known as separate video, Y/C, and erroneously Super-Video) is an analog video signal format that carries standard-definition video, typically at 525 lines or 625 lines. It encodes video luma and chrominance on two separate chann ...
connector and/or S-Video enabled SCART
SCART (also known as or , especially in France, 21-pin EuroSCART in marketing by Sharp Corporation, Sharp in Asia, Euroconector in Spain, EuroAV or EXT, or EIA Multiport in the United States, as an EIA interface) is a French-originated standard ...
.
Media
In order to take advantage of the enhanced capabilities of the S-VHS system, i.e., for the best recordings and playback, an S-VHS VCR requires S-VHS video tape
Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocasset ...
cassettes.[ These have a different oxide media formulation for higher magnetic coercivity. S-VHS video cassettes are sensed and identified by the video cassette recorder via a specific internal profile within a hole in the underside of the S-VHS video cassette body.
Videophiles were the first to theorize that since the only distinguishing feature of an S-VHS tape is a small 3 mm hole on the underside of the video cassette, it should be possible to use more common and inexpensive VHS tapes by duplicating that hole. However, S-VHS cassettes contain a higher grade and ]coercivity
Coercivity, also called the magnetic coercivity, coercive field or coercive force, is a measure of the ability of a ferromagnetic material to withstand an external magnetic field without becoming Magnetization, demagnetized. Coercivity is usual ...
of tape stock to effectively record the higher video bandwidth offered by S-VHS.
S-VHS tapes can be used with VHS VCRs, but an S-VHS recording will not play back properly on a VHS VCR without SQPB (sound is usually reproduced correctly, but the picture quality will be poor).
S-VHS ET
JVC introduced an ''S-VHS ET'' (Super-VHS Expansion Technology) system on its S-VHS consumer decks, allowing the use of normal VHS tapes for S-VHS recording, by slightly modifying the S-VHS recording specs, while still retaining compatibility, so that S-VHS ET tapes could be played with non-ET S-VHS VCRs. In S-VHS ET mode, the recording circuit is altered with:
# Change of the W/D clip level (reducing the white clip level from 210% in SVHS to 190% in SVHS ET)
# Change of the main emphasis characteristics (changing the frequency responses)
# Change of the recording level ( Y and C) and recording current
Use for digital audio
In 1991, Alesis
Alesis is an American company that designs and markets electronic musical instruments, audio processors, mixers, amplifiers, audio interfaces, recording equipment, drum machines, professional audio, and electronic percussion products. Based ...
introduced ADAT
Alesis Digital Audio Tape, commonly referred to as ADAT, is a magnetic tape format used for the Sound recording and reproduction, recording of eight digital audio tracks onto the same S-VHS tape used by consumer VCRs, and the basis of a serie ...
, an eight-track digital audio recording system that used S-VHS cassettes. An ADAT machine recorded eight tracks of uncompressed audio material in 16-bit (later 20-bit) resolution. The recording time was one-third of the cassette's nominal playing time, e.g., a 120-minute S-VHS cassette held 40 minutes of eight-track audio.
Studer
Studer is a designer and manufacturer of professional audio equipment for recording studios and broadcasters. The company was founded in Zürich, Switzerland, in 1948 by Willi Studer. It initially became known in the 1950s for its professi ...
produced the V-Eight (manufactured and sold by Alesis as the M20) and the V-Twenty-Four digital multitrack recorders. These used S-VHS cassettes for 8-track and 24-track digital audio recording, at a significantly lower cost than their DASH reel-to-reel digital recorders. The videotape transports were made for Studer by Matsushita.
See also
*D-VHS
D-VHS (short for Digital VHS) is a digital video recording format developed by JVC in collaboration with Hitachi, Matsushita, and Philips. Introduced in December 1997, it was designed to record digital video, including high-definition content ...
*W-VHS
W-VHS (Wide-VHS) is an HDTV-capable analog recording videocassette format created by JVC. The format was originally introduced on January 8, 1993 for use with Japan's Hi-Vision (aka MUSE), an early analog high-definition television system. ...
*Video 2000
Video 2000 (also known as V2000, with the tape standard Video Compact Cassette, or VCC) is a consumer videocassette system and analogue recording standard developed by Philips and Grundig to compete with JVC's VHS and Sony's Betamax video t ...
References
External links
Formats
— High-TechProductions.com
{{DEFAULTSORT:S-Vhs
Products introduced in 1987
Videotape
VHS
Japanese inventions
Videocassette formats
Composite video formats