World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000752851
Reproduction Date:

Title: Cinepak  
Author: World Heritage Encyclopedia
Language: English
Subject: Comparison of video codecs, Libavcodec, Libav, Audio Video Interleave, Qualcomm code-excited linear prediction
Collection: Video Codecs
Publisher: World Heritage Encyclopedia


Cinepak is a lossy video codec[1] developed by Peter Barrett at SuperMac Technologies, and released in 1991 with the Video Spigot, and then in 1992 as part of Apple Computer's QuickTime video suite. One of the first video compression tools to achieve full motion video on CD-ROM,[2] it was designed to encode 320×240 resolution video at 1× (150 kbyte/s) CD-ROM transfer rates. The original name of this codec was CompactVideo,[3] which is why its FourCC identifier is CVID. The codec was ported to the Microsoft Windows platform in 1993. It was also used on first-generation and some second-generation CD-ROM game consoles, such as the Atari Jaguar CD,[4] Sega CD, Sega Saturn, and 3DO.[2]


  • History 1
  • Technology 2
  • References 3
  • External links 4


It was the primary video codec of early versions of QuickTime and Microsoft Video for Windows, but was later superseded by Sorenson Video, Intel Indeo, and most recently MPEG-4 Part 2 and H.264/MPEG-4 AVC.[5][6] However, movies compressed with Cinepak are generally still playable in most media players.


Cinepak is based on vector quantization, which is a significantly different algorithm from the discrete cosine transform (DCT) algorithm used by most current codecs (in particular the MPEG family, as well as JPEG). This permitted implementation on relatively slow CPUs (video encoded in Cinepak will usually play fine even on a 25 MHz Motorola 68030, consoles like the Sega CD usually used even slower CPUs, e.g. a 12.5 MHz 68000), but tended to result in blocky artifacting at low bitrates, which explained the criticism leveled at the FMV-based video games. Cinepak files tend to be about 70% larger than similar quality MPEG-4 Part 2 or Theora files.

The vectors that are quantized in Cinepak are 2×2 pixel blocks. A block can consist of 4 luminance values (grayscale) or of 4 luminance and 2 chrominance values (4:2:0 chroma subsampling).[7][8] The quantized blocks are stored in two codebooks, named V1 and V4, each with up to 256 entries. The vectors in the V1 codebook represent downscaled 4×4 pixel blocks, while those in the V4 codebook represent 2×2 pixel blocks.

For processing, Cinepak divides a video into key (intra-coded) images and inter-coded images.[7] In key images the codebooks are transmitted from scratch, while in inter-coded images codebook entries are selectively updated.[7] Each image is further divided into a number of horizontal bands. The codebooks can be updated on a per-band basis. Each band is divided into 4×4 pixel blocks.[7][8] Each block can be coded either from the V1 or from the V4 codebook.[7][8] When coding from the V1 codebook, one codebook index per 4×4 block is written to the bitstream, and the corresponding 2×2 codebook entry is upscaled to 4×4 pixels.[7][8] When coding from the V4 codebook, four codebook indices per 4×4 block are written to the bitstream, one for each 2×2 subblock.[7][8] Alternatively to coding from the V1 or the V4 codebook, a 4×4 block in an inter-coded image can be skipped. A skipped block is copied unchanged from the previous frame in a conditional replenishment fashion.[7][8] The data rate can be controlled by adjusting the rate of key frames and by adjusting the permitted error in each block.


  1. ^ Bylund, Anders (22 December 2009). "From Cinepak to H.265: a brief history of video compression". Ars Technica. Retrieved 1 November 2012. 
  2. ^ a b "Rocket Science Blasts Off".  
  3. ^ "QuickTime 1.6.1: Read Me". Apple Knowledge Base. 19 February 2012. Retrieved 5 April 2013. 
  4. ^ "The Jaguar CD-ROM...".  
  5. ^ Jennifer Niederst Robbins (28 February 2006). Web Design in a Nutshell: A Desktop Quick Reference. O'Reilly Media, Inc. p. 627.  
  6. ^ Apple Computer, Inc (2004). QuickTime for the Web: For Windows and MacIntosh. Morgan Kaufmann. p. 328.  
  7. ^ a b c d e f g h Tim Ferguson (2001). "Cinepak (CVID) stream format for AVI and QT". Retrieved 5 April 2013. 
  8. ^ a b c d e f "cinepak.c". FFmpeg. Retrieved 5 April 2013. 

External links

  • Technical Description of the Cinepak Codec
  • Cinepak - MultimediaWiki
  • Cinepak Official Website
  • Cinepak Decoder - FFmpeg
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.