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S-VHS
Super VHS, commonly abbreviated as S-VHS, is an analog video cassette format introduced by JVC in 1987 as a more developed version of the VHS (Video Home System) format. S-VHS improved image quality by increasing the bandwidth of the luminance (brightness) signal, allowing for a resolution of approximately 400 horizontal 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 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.
Like VHS, the S-VHS format uses a color under A modulation scheme. S-VHS improves luminance (luma) resolution by increasing luminance bandwidth. Increased bandwidth is possible because of the increased luminance carrier from 3.4 megahertz (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 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 analog cable and broadcast TV, which is limited to about 330 television lines (TVL). In practice, when time-shifting TV programs on S-VHS equipment, the improvement over VHS is noticeable. Yet, the trained eye can easily spot the difference between live television 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 (chroma) signal. In VHS, the chroma carrier is both severely bandlimited 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 and ED-Beta – all of which were limited to 0.4 megahertz or 30 TVL resolution.
In audio recording, S-VHS retains VHS's conventional linear (baseband) and high fidelity (Hi-Fi) – Audio Frequency Modulation (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 (PCM) digital audio 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 Mbit/s. 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; 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 recordings to contain Teletext 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.
S-VHS video cassette recorders (VCRs) and cassette tapes are nearly identical in appearance and operation, and backward compatible 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 recordings that use either the full-size S-VHS cassette or the smaller S-VHS-C cassette.
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S-VHS AI simulator
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S-VHS
Super VHS, commonly abbreviated as S-VHS, is an analog video cassette format introduced by JVC in 1987 as a more developed version of the VHS (Video Home System) format. S-VHS improved image quality by increasing the bandwidth of the luminance (brightness) signal, allowing for a resolution of approximately 400 horizontal 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 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.
Like VHS, the S-VHS format uses a color under A modulation scheme. S-VHS improves luminance (luma) resolution by increasing luminance bandwidth. Increased bandwidth is possible because of the increased luminance carrier from 3.4 megahertz (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 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 analog cable and broadcast TV, which is limited to about 330 television lines (TVL). In practice, when time-shifting TV programs on S-VHS equipment, the improvement over VHS is noticeable. Yet, the trained eye can easily spot the difference between live television 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 (chroma) signal. In VHS, the chroma carrier is both severely bandlimited 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 and ED-Beta – all of which were limited to 0.4 megahertz or 30 TVL resolution.
In audio recording, S-VHS retains VHS's conventional linear (baseband) and high fidelity (Hi-Fi) – Audio Frequency Modulation (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 (PCM) digital audio 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 Mbit/s. 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; 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 recordings to contain Teletext 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.
S-VHS video cassette recorders (VCRs) and cassette tapes are nearly identical in appearance and operation, and backward compatible 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 recordings that use either the full-size S-VHS cassette or the smaller S-VHS-C cassette.