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Betacam is a family of half-inch professional videotape formats developed by Sony from 1982 onwards.
All use the same shape cassettes, meaning vaults and other storage facilities do not have to be changed when upgrading to a new format. The cassettes come in two sizes, S and L. The cassette shell and case for each Betacam cassette is colored differently depending on the format, this allows for easy visual identification. There is also a mechanical key that allows a video tape recorder to tell which format has been inserted.
Variants
Betacam
The original Betacam format launched in 1982. It is an analog component format, storing the luminance (Y) in one track and the chrominance (R-Y, B-Y) on another. This splitting of channels provides a crisp, true broadcast quality product with 300 lines of horizontal resolution.
Betacam tapes are usually grey.
Betacam SP
In 1986 Betacam SP was developed, which increased horizontal resolution to 340 lines. Beta SP (for "Superior Performance") became the industry standard for most TV stations and high-end production houses until the late 1990s.
Betacam SP tapes are usually grey.
Digital Betacam
Digital Betacam (commonly abbreviated to Digibeta or d-beta) was launched in 1993. It supersedes both Betacam and Betacam SP, while costing significantly less than the D1 format and providing high quality and reliability.
The Digital Betacam format records a DCT-compressed component video signal at YUV 4:2:2 sampling and 4 channels of uncompressed 48KHz PCM-encoded audio. A 5th audio track is available for cueing, and a linear timecode track is also used on the tape.
Some Digital Betacam equipment can also read Betacam and Betacam SP tapes. Along with the identical cassette size, this meant for easy upgrading.
Another key element which aided adoption was Sony's implementation of the Serial Digital Interface (SDI) coaxial digital connection on Digital Betacam decks. Facilities could begin using digital signals on their existing coaxial wiring without having to commit to an expensive re-installation.
Digital Betacam tapes are a muted blue.
Betacam SX
Betacam SX is a digital version of Betacam SP introduced in 1996, positioned as a cheaper alternative to Digital Betacam. It stores video using MPEG 4:2:2 Profile@ML compression, along with 4 channels of 48 KHz 16 bit PCM audio. All Betacam SX equipment is compatible with Betacam SP tapes.
Betacam SX tapes are bright yellow.
MPEG IMX
MPEG IMX is a 2001 development of the Digital Betacam format. It uses the MPEG compression system, but at a higher bitrate than Betacam SX. The IMX format allows for a CCIR 601 compliant video signal, with 8 channels of audio as well as cue and timecode tracks.
With its new IMX VTRs, Sony introduced some new technologies including SDTI and e-VTR. SDTI allows for audio, video, timecode, and remote control functions to be transported by a single coaxial cable, while e-VTR technology extends this by allowing the same data to be transported over IP by way of an ethernet interface on the VTR itself.
IMX VTRs such as the MSW-2100M are capable of playing back Digital Betacam cassettes as well as analog Betacam SP cassettes, but can only record to their native IMX cassettes.
MPEG IMX tapes are a muted green.
See also
External link
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