QuickTime File Format is a computer file format

File format

A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

 used natively by the 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...

 framework.

Design

The format specifies a multimedia container file that contains one or more tracks, each of which stores a particular type of data: audio, video, effects, or text (e.g. for subtitles). Each track either contains a digitally-encoded media stream (using a specific format) or a data reference to the media stream located in another file. Tracks are maintained in a hierarchical data structure consisting of objects called atoms. An atom can be a parent to other atoms or it can contain media or edit data, but it cannot do both.

The ability to contain abstract data references for the media data, and the separation of the media data from the media offsets and the track edit lists means that QuickTime is particularly suited for editing, as it is capable of importing and editing in place (without data copying). Other later-developed media container formats such as Microsoft's Advanced Systems Format

Advanced Systems Format

Advanced Systems Format is Microsoft's proprietary digital audio/digital video container format, especially meant for streaming media...

 or the Matroska

Matroska

The Matroska Multimedia Container is an open standard free container format, a file format that can hold an unlimited number of video, audio, picture or subtitle tracks in one file. It is intended to serve as a universal format for storing common multimedia content, like movies or TV shows...

 and 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...

 containers lack this abstraction, and require all media data to be rewritten after editing.

Correlation with MP4

Because both the QuickTime and MP4 container formats can use the same MPEG-4 formats, they are mostly interchangeable in a QuickTime-only environment. MP4, being an international standard, has more support. This is especially true on hardware devices, such as the Sony PSP and various DVD players; on the software side, most DirectShow

DirectShow

DirectShow , codename Quartz, is a multimedia framework and API produced by Microsoft for software developers to perform various operations with media files or streams. It is the replacement for Microsoft's earlier Video for Windows technology...

 / 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:...

 codec packs include an MP4 parser, but not one for QTFF.

In QuickTime Pro's MPEG-4 Export dialog, an option called "Passthrough" allows a clean export to MP4 without affecting the audio or video streams. One recent discrepancy ushered in by QuickTime 7 is that the QuickTime file format now supports multichannel audio (used, for example, in the high-definition trailers on Apple's site).

Extensions

The International Organization for Standardization

International Organization for Standardization

The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

 approved the QuickTime file format as the basis of the MPEG-4 file format. The MPEG-4 file format specification was created on the basis of the QuickTime format specification published in 2001. The MP4 (.mp4) file format was published in 2001 as the revision of the MPEG-4 Part 1: Systems specification published in 1999 (ISO/IEC 14496-1:2001). In 2003, the first version of MP4 format was revised and replaced by MPEG-4 Part 14

MPEG-4 Part 14

MPEG-4 Part 14 or MP4 is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital video and digital audio streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images...

: MP4 file format (ISO/IEC 14496-14:2003). The MP4 file format was generalized into the ISO Base Media File Format

ISO base media file format

ISO base media file format defines a general structure for time-based multimedia files such as video and audio. It is used as the basis for other media file formats...

 ISO/IEC 14496-12:2004, which defines a general structure for time-based media files. It in turn is used as the basis for other multimedia file formats (for example 3GP

3GP

3GP is a multimedia container format defined by the Third Generation Partnership Project for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones....

, Motion JPEG 2000). A list of all registered extensions for ISO Base Media File Format is published on the official registration authority website www.mp4ra.org. This registration authority for code-points in "MP4 Family" files is Apple Computer Inc. and it is named in Annex D (informative) in MPEG-4 Part 12.