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Cinepak

Cinepak

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Cinepak is a video codec
Video codec
A video codec is a device or software that enables video compression and/or decompression for digital video. The compression usually employs lossy data compression. Historically, video was stored as an analog signal on magnetic tape...

 developed by Peter Barrett at SuperMac Technologies
Supermac
Supermac may refer to:* Harold Macmillan, , Prime Minister of the United Kingdom from 1957 to 1963* Malcolm "Supermac" Macdonald, , a retired English football player and pundit...

, and released in 1991 with the Video Spigot, and then in 1992 as part of Apple Computer's QuickTime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...

 video suite. It was designed to encode 320x240 resolution video at 1x (150 kbyte
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

/s) CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

 transfer rates. The codec was ported to the Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 platform in 1993. It was also used on first-generation and some second-generation CD-ROM game consoles, such as the Atari Jaguar CD
Atari Jaguar CD
The Atari Jaguar CD or Jag CD is a CD-ROM peripheral for the Atari Jaguar video game console.Late in the life span of the company, Atari released this long-promised CD-ROM unit. The unit hit shelves on September 11, 1995 and retailed for $149.95. The device sat atop the Jaguar console, snapping...

, Sega CD, Sega Saturn
Sega Saturn
The is a 32-bit fifth-generation video game console that was first released by Sega on November 22, 1994 in Japan, May 11, 1995 in North America, and July 8, 1995 in Europe...

, and 3DO
3DO Interactive Multiplayer
The 3DO Interactive Multiplayer is a video game console originally produced by Panasonic in 1993. Further renditions of the hardware were released in 1994 by Sanyo and Goldstar. The consoles were manufactured according to specifications created by The 3DO Company, and were originally designed by...

.

It was the primary video codec of early versions of QuickTime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...

 and Microsoft Video for Windows
Video for Windows
Video for Windows was a multimedia framework developed by Microsoft that allowed Microsoft Windows to play digital video.-Overview:...

, but was later superseded by Sorenson Video, Intel Indeo
Indeo
Indeo Video is a video codec developed by Intel in 1992. It was sold to Ligos Corporation in 2000. While its original version was related to Intel's DVI video stream format, a hardware-only codec for the compression of television-quality video onto compact disks, Indeo was distinguished by being...

, and most recently MPEG-4
MPEG-4
MPEG-4 is a method of defining compression of audio and visual digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group under the formal standard ISO/IEC...

 and H.264. However, movies compressed with Cinepak are generally still playable in most media players.

Cinepak is based on vector quantization
Vector quantization
Vector quantization is a classical quantization technique from signal processing which allows the modeling of probability density functions by the distribution of prototype vectors. It was originally used for data compression. It works by dividing a large set of points into groups having...

, which is a significantly different algorithm from the discrete cosine transform
Discrete cosine transform
A discrete cosine transform expresses a sequence of finitely many data points in terms of a sum of cosine functions oscillating at different frequencies. DCTs are important to numerous applications in science and engineering, from lossy compression of audio and images A discrete cosine transform...

 (DCT) algorithm used by most current codecs (in particular the MPEG family, as well as JPEG
JPEG
In computing, JPEG . The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality....

). This permitted implementation on relatively slow CPUs (video encoded in Cinepak will usually play fine even on a 25 MHz Motorola 68030
Motorola 68030
The Motorola 68030 is a 32-bit microprocessor in Motorola's 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general Motorola naming, this CPU is often referred to as the 030 .The 68030 features on-chip...

), but tended to result in blocky artifacting at low bitrate
Bitrate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....

s, which explained the criticism levelled at the FMV-based
Full motion video
Full motion video based games are video games that rely upon pre-recorded TV-quality movie or animation rather than sprites, vectors, or 3D models to display action in the game. In the early 1990s a diverse set of games utilized this format...

 video games.

Cinepak divides a movie into key images and intra-coded images. Each image is divided into a number of horizontal bands which have individual 256-color palettes transferred in the key images. Each band is subdivided into 4x4 pixel blocks. The compressor uses vector quantization
Vector quantization
Vector quantization is a classical quantization technique from signal processing which allows the modeling of probability density functions by the distribution of prototype vectors. It was originally used for data compression. It works by dividing a large set of points into groups having...

 to determine the one or two band palette colors which best match each block and encodes runs of blocks as either one color byte or two color bytes plus a 16-bit vector which determines which pixel gets which color, similarly to S3 Texture Compression
S3 Texture Compression
S3 Texture Compression is a group of related lossy texture compression algorithms originally developed by Iourcha et al. of S3 Graphics, Ltd. for use in their Savage 3D computer graphics accelerator...

. The data rate can be controlled within a narrow range by adjusting the rate of key versus intra-coded frames and by adjusting the permitted error in each block and the block run-length.

The original name of this codec was CompactVideo, which is why its FourCC
FourCC
A FourCC is a sequence of four bytes used to uniquely identify data formats.The concept originated in the OSType scheme used in the Macintosh system software and was adopted for the Amiga/Electronic Arts Interchange File Format and derivatives...

 identifier is "CVID".

Cinepak files tend to be about 70% larger than similar quality MPEG-4
MPEG-4
MPEG-4 is a method of defining compression of audio and visual digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group under the formal standard ISO/IEC...

 or Ogg
Ogg
Ogg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high quality digital multimedia.The Ogg container format can multiplex...

 files.

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