Tagged: Rainbow Books

Enhanced CD (1994 – )

An enhanced CD (or ECD) is a Compact Disc that contains both audio content playable on a standard CD audio player, and multimedia content playable on a computer CD-ROM.

Introduced in 1994, the idea behind enhanced CDs was to offer the music buyer some extra bonus features using space on the disc that was unfilled by the music. This might take the form of music videos (similar to the earlier idea of CD Video), interviews, wallpapers, pictures, lyrics, or links to an artists website.

Rather confusingly, there were three different ways on combining the different content on the disc. Prior to 1996, enhanced CDs were created in one of two ways. One was to have the multimedia content in the first track, but this meant that track 1 needed to be skipped when played in a standard CD audio player or else the multimedia track could cause an unpleasant noise to be heard. A subsequent solution was to have the multimedia content in the pre-gap before track 1 (rather like the way a CD-i Ready disc worked). Both of these methods were known as ‘mixed-mode’, combining Red Book Digital Audio and Yellow Book CD-ROM information in a single ‘session’ on the same disc.

To get around the problems of mixed-mode discs, Philips and Sony released the Blue Book standards in 1995, and worked with Apple, Microsoft and the Recording Industry Association of America (RIAA) to develop them. This new standard specified multisession technology that used two sessions on the disc, the first one containing audio tracks, and the second one containing data that is invisible to CD audio players. In 1996, most enhanced CDs used mixed-mode with the multimedia in the pre-gap, but by 1997 most were using Blue Book standards. The only downside to the newer multisession technology was that CD-ROM drives made before 1996 might not recognise them if they were not multisession capable.

Enhanced CDs can usually be recognised the official ‘Enhanced CD’ logo recommended by the RIAA. They may also have the CD EXTRA logo (previously known as CD Plus), which was trademarked by Sony for use on Blue Book discs.

Later technologies like DVD-Audio or DualDisc tried to perform the same function of offering the music album with bonus material such as videos, but later albums often came instead with the videos on a separate DVD-Video.

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Photo CD (1992 – 2004)

Photo CD was an optical disc system based on the Compact Disc that allowed the storage of up to 100 high quality images in a proprietary format. It was introduced by Kodak in 1992, and the format is defined in the Biege Book standard (one of the Rainbow Books covering Compact Disc standards). Kodak’s Photo CD system also included the scanners for photo processing labs that could take scans from film negatives or slides. Photographers could take exposed film to a Photo CD processing lab, where the film would be developed and scanned to a Photo CD, or they could have previously developed film scanned to Photo CD.

Photo CDs were designed to be played on a dedicated standalone Photo CD player connected to a domestic television, but they could also be played in a CD-i player. It was possible to play them on a computer with suitable software, but at the time CD-ROM drives were still uncommon.

The system was not popular with consumers, though it was more accepted by professional photographers.  Although there were around 140 Photo CD processing labs in the US alone by 2000, by this time domestic scanners enabled consumers to scan their own photographs. In 1999, Kodak had also introduced the more affordable Picture CD system, with images in JPEG format burned onto a recordable CD that also held the software required to the view and edit the images on a computer.

Kodak had completely abandoned the Photo CD business by 2004, but never released the image specifications. However, it has been reverse-engineered so it is possible to convert images to other formats.

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XRCD (1995 – )

XRCD (eXtended Resolution Compact Disc) was introduced by JVC in 1995. XRCD discs conform to Red Book standards and will play on any Compact Disc player, but claim to use much higher quality mastering and manufacturing processes to produce a sound as close as possible to the original master tape.

Subsequent versions of XRCD are called XRCD2 and XRCD24.

All versions of XRCD disc are encoded at 16 bits; the 24 in XRCD24 refers to the use of 24 bit encoding when digitising the original analogue source (XRCD and XRCD2 used 20 bit encoding of the original source).

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CD-i Digital Video (1993 – 1994)

CD-i Digital Video was a short-lived video disc format introduced by Philips in 1993 that was designed to be played in CD-i players equipped with an optional Digital Video Cartridge. This expansion unit contained a 32 bit RISC processor and 1 MB of RAM to provide MPEG-1 decoding.

CD-i Digital Video followed the Green Book standard for CD-i discs, making it incompatible with the Video CD format introduced shortly afterwards that followed the White Book standard. However, whilst Video CD players could not play CD-i Digital Video, CD-i players with the optional Digital Video Cartridge could play both formats. Some other CD-i discs such as games also made use of the Digital Video Cartridge to play video.

One of the two differences between the formats was the resolution, that was slightly higher on CD-i Digital Video (384×288 instead of 352×288 for Video CD). When a Video CD is played on a CD-i player, slightly larger pixels are displayed to fill the screen.

Only around 20 movies were released on CD-i Digital Video before Philips switched to Video CD for distributing movies in 1994.

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Mini CD-R / CD-RW (1990s – )

Mini CD-R (CD-Recordable) and Mini CD-RW (CD-Rewritable) are 8cm versions of CD-R/CD-RW. They can hold anything from 156 MB (18 minutes of music) to 210 MB (24 minutes of music).

They can be written to in spindle-based or tray-loading CD-R / CD-RW burners (and read in spindle-based or tray-loading Compact Disc players) but there were also some devices that were specifically designed around the Mini CD-R/CD-RW.

One of these was a number of models in the Sony Mavica line of digital cameras. The first of these was the MVC-CD1000 released in 2000, which could record to Mini CD-Rs. Later models in the line (the last of which was released in 2003) could use either Mini CD-R or Mini CD-RW.

There was also a portable Mini CD-R burner called the Imation RipGo! that was introduced in 2001. This could burn MP3 files to disc, and also play them back. Sony also introduced a Mini CD burner (called the PhotoVault), allowing pictures to be saved from a Memory Stick, USB flash drive, or camera with a USB connection.

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CD-BGM (1989 – late 2000s)

Audio CDi (front)CD-BGM (CD-BackGround Music) was an audio format for background music systems, introduced by Philips in collaboration with several companies in the background music business in 1989.

Philips used a compression algorithm that was being developed for CD-i, ADPCM (Adaptive Delta Pulse Code Modulation). Audio is mono, and is stored at Level A – C compression, allowing up to 4,8 or 16 hours of music.

Because of Philips’ work on the CD-i at the time, all CD-BGM discs are compatible with the CD-i system even though the CD-i system wasn’t introduced until 1991, and can be played in CD-i players. CD-BGM is often referred as audio-only CD-i, and meets the Green Book specifications for CD-i.

It was not the intention for CD-BGM discs to be played on domestic CD-i players, and dedicated players were offered by companies working in the background music industry. Usually, these used a caddy system similar to early CD-ROMs, but much more secure as the discs were often used in unfavourable environments such as restaurants and planes. The discs were usually part of a subscription, and were returned to the supplier to get new ones.

Super High Material CD (2007 – )

Super High Material (SHM) CD is a type of Compact Disc that uses an improved transparency polycarbinate resin as its transparent substrate, and this is claimed to provide a clearer medium for the reading of the data and so reduce read errors and improve the sound quality.

The polycarbinate resin was developed by JVC and Universal Music Japan during research into LCD manufacturing, and SHM-CDs began to be released in 2007.

SHM-CDs are fully compliant with the Red Book standards and play in any Compact Disc player.

Almost all of the releases have come from Japan, and have mostly been re-releases.

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Video CD (1993 – 2000s)

Video CD (Compact Disc Digital Video or VCD) was a derivative of the Compact Disc, used for playback of video. The standard was created in 1993 by Sony, Philips, Matsushita and JVC, and is referred to as the White Book standard.

Like audio Compact Disc, it uses 120 mm optical discs. Dedicated Video CD player were available, but most DVD and Blu-ray players, personal computers, and some video game consoles will play them.

The older CD Video format could only store analogue video and was limited in its capacity to just 5 minutes of video, but new digital compression techniques allowed 74 minutes of audio and video on a Video CD. Overall quality is similar to VHS.

Video CD had a brief period of success, and some major feature films were released on it (usually as a 2 disc set). However it lacked copy protection so the increasing availability of recordable media such as CD-R meant unauthorised copies could be made, and DVD (which had copy protection and regional coding) became available in 1998. During the 2000s, DVD replaced it.

Video CD made considerable inroads into Asia and developing nations, where it is still in use today.

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Compact Disc-Recordable (CD-R) (1992 – )

Compact Disc-Recordable (CD-R) is an optical disc  format designed by Philips and Sony, and based on the Compact Disc. CD recorders became available in 1992 but were extremely expensive and it wasn’t until 1995 that they fell below $1000 (around £650).

CD-R discs can be used for audio or data recording, but only CD-R Audio discs can be used in standalone consumer audio recorders.

CD-Rs are a Write Once Read Many (WORM) medium, although the whole disk does not have to entirely written in the same session. Their specification is taken from the Orange Book standards. Properly written CD-Rs are fully compatible with audio (CD-DA) and data (CD-ROM) Compact Disc standards.

Standard CD-Rs are 120mm in diameter (although 8cm Mini CD-Rs are also available), and most can store 74 minutes of audio or 650 MB of data. Some CD-Rs have an 80 minute or 700 MB capacity, but anything over this means they are not fully compatible with CD standards.

A CD recorder writes data to a CD-R disc by pulsing its laser to heat areas of the organic dye layer. The writing process does not produce indentations (pits) – instead, the heat permanently changes the optical properties of the dye, changing the reflectivity of those areas. Various dyes have been used over the years, with cyanine being the earliest and less stable.

In general CD-Rs are expected to have an average life expectancy of 10 years. As well as degradation of the dye, failure of a CD-R can be due to the reflective surface. While silver is more widely used, it is more prone to oxidation. Gold-based CD-Rs do not suffer from this problem, but are more expensive.

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Preservation / Migration