QuickTime
In computing, QuickTime is the name of the US company Apple's software product, and a file format popular on the Macintosh operating system platform. It is also widely used by web developers to create cross-platform video clips that can be downloaded from the Internet.
It is a standard for displaying video, audio, virtual reality and almost any kind of multimedia content on computers. The format is designed by Apple Computer.
The tracks in turn contain track media which rely on specific codecs, like the Sorenson codec, Motion JPEG, AC3 etc. It also has an "edit list" indicating what parts of the media are to be used.
The track media in turn contain several samples of the media stream. These samples may be in the same file, another file, or out on a network.
Internally, this format is maintained as a tree-structure of "atoms", each of which has 4 bytes of size, a 4-byte identifier, and then content whose structure is determined by its identifier. An atom can be a parent to other atoms or contain data, but not both.
Developers can use the QuickTime Application framework to develop multimedia applications for Mac or Windows with the C programming language or the Java programming language.
Independent players for QuickTime 6 (MPEG-4) exist for many operating systems, and the FFmpeg library even supports the Sorenson video compression format. Apple is however the exclusive licensee of Sorenson technology.
See also: NATO.0+55+3dArchitecture
A QuickTime file contains tracks with particular types, such as audio, video, effects, or text (eg for subtitles).QuickTime and MPEG-4
In 1998, the ISO approved the QuickTime file format as the basis of the MPEG-4 file format, with supporters noting that it was a good "life-cycle" format, well-suited to capture, editing, archiving, distribution and playback (as opposed to the simple file-as-stream approach of MPEG-1 and MPEG-2, which are poorly suited to editing). MPEG-4 compatibility was added QuickTime 6 in 2002. However, Apple delayed the release of this version for months in a dispute with the MPEG-4 licensing body, claiming that proposed license fees were prohibitive for many users and content providers. A compromise was reached and QuickTime 6 was released in July of that year.Platforms and versions
Apple has released official media player software for Mac OS and Microsoft Windows under the brand QuickTime Player. Apple also has a version of the software that can create "QuickTime" brand files, under the brand QuickTime Pro.
