QuickTime File Format

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QuickTime Movie
Filename extension .mov, .qt
Internet media type video/quicktime[1][2]
Type code MooV
Uniform Type Identifier com.apple.quicktime-movie
Developed by Apple Inc.
Type of format Media container
Container for Audio, video, text
Extended to MPEG-4 Part 12

QuickTime File Format (QTFF) is a computer file format used natively by the QuickTime framework.[3][4][5]

Design[edit]

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.[6]

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

Relation to MP4[edit]

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 and Video for Windows codec packs[7][8] 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[9]).

Extensions[edit]

The International Organization for Standardization 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.[10] 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).[11][12][13] In 2003, the first version of MP4 format was revised and replaced by MPEG-4 Part 14: MP4 file format (ISO/IEC 14496-14:2003).[14] The MP4 file format was generalized into the ISO Base Media File Format 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, Motion JPEG 2000).[15][16][17][18][19] 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 Inc. and it is named in Annex D (informative) in MPEG-4 Part 12.[18]

See also[edit]

References[edit]

  1. ^ "Video Media Types". IANA. 1993-06-04. Retrieved 2010-07-20. 
  2. ^ "The Codecs Parameter for "Bucket" Media Types". IETF. November 2005. Retrieved 2010-07-20. 
  3. ^ Apple Inc. "QuickTime File Format Specification: Introduction to QuickTime File Format Specification". Retrieved 2010-07-10. 
  4. ^ AfterDawn.com. "QuickTime - AfterDawn.com glossary". Retrieved 2010-07-20. 
  5. ^ "QuickTime container". MultimediaWiki. Retrieved 2010-07-20. 
  6. ^ Apple Inc. "QuickTime File Format Specification: Movie Atoms". Retrieved 2010-07-10. 
  7. ^ DefilerPak – A lightweight codec pack for Windows PCs
  8. ^ K-LiteCodecPack.com: Download Codecs, Videos and MP3s
  9. ^ Apple – Movie Trailers
  10. ^ Apple Inc. (2001). "Classic Version of the QuickTime File Format Specification". Retrieved 2009-06-14. 
  11. ^ Library of Congress (2001). "MPEG-4 File Format, Version 1". Retrieved 2009-06-14. 
  12. ^ Network Working Group (2006). "RFC 4337 – MIME Type Registration for MPEG-4". Retrieved 2009-06-14. 
  13. ^ International Organization for Standardization (2001). "MPEG-4 Part 1: Systems; ISO/IEC 14496-1:2001". Retrieved 2009-06-11. 
  14. ^ International Organization for Standardization (2003). "MPEG-4 Part 14: MP4 file format; ISO/IEC 14496-14:2003". Retrieved 2009-06-11. 
  15. ^ mp4ra.org – MP4 Registration authority. "References, MPEG-4 Registration authority". Retrieved 2009-06-14. 
  16. ^ ISO (April 2006). ISO Base Media File Format white paper – Proposal. archive.org. Archived from the original on 2008-07-14. Retrieved 2009-12-26. 
  17. ^ ISO (October 2009). ISO Base Media File Format white paper – Proposal. chiariglione.org. Retrieved 2009-12-26. 
  18. ^ a b ISO (2008). ISO/IEC 14496-12:2008, Information technology – Coding of audio-visual objects – Part 12: ISO base media file format (PDF). International Organization for Standardization. pp. 88, 94. Retrieved 2009-05-30. 
  19. ^ International Organization for Standardization (2004). "MPEG-4 Part 12: ISO base media file format; ISO/IEC 14496-12:2004". Retrieved 2009-06-11.