Video codec

codecvideo decodingcodecsvideovideo encoding and decodinglossless video codecaudio/video codecsencode video streamsformatformats
A video codec is an electronic circuit or software that compresses or decompresses digital video.wikipedia
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Video quality

qualityfull reference metricmodels
There are complex relationships between the video quality, the amount of data used to represent the video (determined by the bit rate), the complexity of the encoding and decoding algorithms, sensitivity to data losses and errors, ease of editing, random access, and end-to-end delay (latency).
Such systems encode video streams and transmit them over various kinds of networks or channels.

Codec

codecsdecoderdecoders
In the context of video compression, "codec" is a concatenation of "encoder" and "decoder"—a device that only compresses is typically called an encoder, and one that only decompresses is a decoder.
A video codec accomplishes the same task for video signals.

Videotelephony

videoconferencingvideo conferencingvideo chat
Video codecs are used in DVD players, Internet video, video on demand, digital cable, digital terrestrial television, videotelephony and a variety of other applications.
Only in the late 20th century with the advent of powerful video codecs combined with high-speed Internet broadband and ISDN service did videotelephony become a practical technology for regular use.

Video coding format

video compression formatvideo compression standardvideo compression
The compressed data format usually conforms to a standard video compression specification.
A specific software or hardware implementation capable of video compression and/or decompression to/from a specific video coding format is called a video codec; an example of a video codec is Xvid, which is one of several different codecs which implements encoding and decoding videos in the MPEG-4 Part 2 video coding format in software.

Xvid

Xvid: Free/open-source implementation of MPEG-4 ASP, originally based on the OpenDivX project.
Xvid (formerly "XviD") is a video codec library following the MPEG-4 video coding standard, specifically MPEG-4 Part 2 Advanced Simple Profile (ASP).

Data compression

compressionvideo compressioncompressed
A video codec is an electronic circuit or software that compresses or decompresses digital video.
Most video compression formats and codecs exploit both spatial and temporal redundancy (e.g. through difference coding with motion compensation).

QuickTime

MOV.movMOV (QuickTime)
QuickTime H.264: H.264 implementation released by Apple.
Saving and exporting (encoding) to any of the codecs supported by QuickTime. QuickTime 7 includes presets for exporting video to a video-capable iPod, Apple TV, and the iPhone.

3ivx

3ivx MPEG-4
3ivx: A commercial MPEG-4 codec created by 3ivx Technologies.
3ivx is a video codec suite, created by 3ivx Technologies, based in Sydney, Australia, that allows the creation of MPEG-4 compliant data streams.

Windows Media Video

WMVWMV9.WMV
WMV (Windows Media Video): Microsoft's family of proprietary video codec designs including WMV 7, WMV 8, and WMV 9. The latest generation of WMV is standardized by SMPTE as the VC-1 standard.
Windows Media Video (WMV) is a series of video codecs and their corresponding video coding formats developed by Microsoft.

VP6

On2 VP66Truemotion VP6
VP6, VP6-E, VP6-S, VP7, VP8, VP9: Proprietary high definition video compression formats and codecs developed by On2 Technologies used in platforms such as Adobe Flash Player 8 and above, Adobe Flash Lite, Java FX and other mobile and desktop video platforms. Supports resolution up to 720p and 1080p. VP9 supports resolutions up to 2160p. VP8 and VP9 have been available under the New BSD License by Google with source code available as the libvpx VP8/VP9 codec SDK.
On2 TrueMotion VP6 is a proprietary lossy video compression format and video codec.

On2 Technologies

On257
VP6, VP6-E, VP6-S, VP7, VP8, VP9: Proprietary high definition video compression formats and codecs developed by On2 Technologies used in platforms such as Adobe Flash Player 8 and above, Adobe Flash Lite, Java FX and other mobile and desktop video platforms. Supports resolution up to 720p and 1080p. VP9 supports resolutions up to 2160p. VP8 and VP9 have been available under the New BSD License by Google with source code available as the libvpx VP8/VP9 codec SDK.
On2 Technologies, formerly known as The Duck Corporation, was a small publicly traded company (on the American Stock Exchange), founded in New York City in 1992 and headquartered in Clifton Park, New York, that designed video codec technology.

Theora

libtheora.ogvOgg Theora
libtheora: A reference implementation of the Theora video compression format developed by the Xiph.org Foundation, based upon On2 Technologies' VP3 codec, and christened by On2 as the successor in VP3's lineage. Theora is targeted at competing with MPEG-4 video and similar lower-bitrate video compression schemes.
The libtheora video codec is the reference implementation of the Theora video compression format being developed by the Xiph.Org Foundation.

VP3

4VP4
libtheora: A reference implementation of the Theora video compression format developed by the Xiph.org Foundation, based upon On2 Technologies' VP3 codec, and christened by On2 as the successor in VP3's lineage. Theora is targeted at competing with MPEG-4 video and similar lower-bitrate video compression schemes.
On2 TrueMotion VP3 is a (royalty-free) lossy video compression format and video codec.

Indeo

Indeo 2, 3 and 5Intel Indeo 2
Indeo, an older video compression format and codec initially developed by Intel.
Indeo Video (commonly known now simply as "Indeo") is a video codec developed by Intel in 1992.

Cinepak

Cinepak: A very early codec used by Apple's QuickTime.
Cinepak is a lossy video codec 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.

Ultra-high-definition television

Ultra HDUHDUHDTV
Schrödinger and dirac-research: implementations of the Dirac compression format developed by BBC Research at the BBC. Dirac provides video compression from web video up to ultra HD and beyond.
Using a codec developed by NHK, the video was compressed from 24 Gbit/s to 180–600 Mbit/s and the audio was compressed from 28 Mbit/s to 7–28 Mbit/s.

K-Lite Codec Pack

K-Lite
Online video material is encoded by a variety of codecs, and this has led to the availability of codec packs — a pre-assembled set of commonly used codecs combined with an installer available as a software package for PCs, such as K-Lite Codec Pack.
The K-Lite Codec Pack is a collection of audio and video codecs for Microsoft Windows that enables an operating system and its software to play various audio and video formats generally not supported by the operating system itself.

Comparison of video codecs

video
Comparison of video codecs
Α video codec is software or a device that provides encoding and decoding for digital video, and which may or may not include the use of video compression and/or decompression.

X264

264libx264
x264: A GPL-licensed implementation of the H.264 video standard. x264 is only an encoder.

X265

libx265
*x265: A GPL-licensed implementation of the H.265 video standard.

Dirac (video compression format)

DiracDirac codecDirac video codec
Schrödinger and dirac-research: implementations of the Dirac compression format developed by BBC Research at the BBC. Dirac provides video compression from web video up to ultra HD and beyond.
Schrödinger and dirac-research (formerly just called "Dirac") are open and royalty-free software implementations (video codecs) of Dirac.

List of open-source codecs

freely-licensed data compression technologiesList of open-source audio codecs
List of open-source codecs
Daala – experimental Video codec which was under development by the Xiph.Org Foundation and finally merged into AV1.

Subjective video quality

psycho-visual optimizationsratings obtained by human viewerssubjective quality assessment
Subjective video quality
For example, to test the quality of a video codec, independent variables may be the video encoding software, a target bitrate, and the target resolution of the processed sequence.

Flash Video

FLVFlash.flv
Sorenson Spark: A codec and compression format that was licensed to Macromedia for use in its Flash Video starting with Flash Player 6. It is considered as an incomplete implementation of the H.263 standard.
Such video is displayed above all Flash content, and takes advantage of video codec chipsets installed on the user's device.

Libvpx

VP6, VP6-E, VP6-S, VP7, VP8, VP9: Proprietary high definition video compression formats and codecs developed by On2 Technologies used in platforms such as Adobe Flash Player 8 and above, Adobe Flash Lite, Java FX and other mobile and desktop video platforms. Supports resolution up to 720p and 1080p. VP9 supports resolutions up to 2160p. VP8 and VP9 have been available under the New BSD License by Google with source code available as the libvpx VP8/VP9 codec SDK.