Sustainability of Digital Formats
 Planning for Library of Congress Collections

Format Description Categories >> Browse Alphabetical List>> Back

Identification and description

Full name	Quicktime File Format with YUY2 (yuv2) Video Encoding
Description	Quicktime file format wrapping YUY2 (the Apple identifier is yuv2) uncompressed video essence, typically multiplexed with soundtrack audio.
Production phase	Generally employed in post-production or editing (middle phase) and in limited modes of dissemination (final phase).
Relationship to other formats
Subtype of	Quicktime, Quicktime File Format
Contains	YUY2, YUY2 Video Picture Encoding
May contain	Audio essences of various types, not discussed at this time.

Local use

LC experience or existing holdings	No extensive experience.
LC preference	None. For preservation reformatting, the Library of Congress' Packard Campus for Audio-Visual Conservation has chosen MXF_OP1a_JP2_LL (lossless JPEG 2000 wrapped in MXF operational pattern 1a).

Sustainability factors

Disclosure	See QT and YUY2.
Documentation	See QT and YUY2.
Adoption	Widely adopted.
Licensing and patents	None.
Transparency	Relatively transparent; requires tools to write and read.
Self-documentation	See QT.
External dependencies	None.
Technical protection considerations	None.

Quality and functionality factors

Moving Image
Normal rendering	Supported
Clarity (high image resolution)	See YUY2.
Functionality beyond normal rendering	See QT.

File type signifiers

Tag	Value	Note
Filename extension	See note.	See Quicktime.
Internet Media Type	See note.	See Quicktime.
Magic numbers	See note.	See Quicktime.
Other	yuv2	Apple Video Codec four-character code, referenced in a Quicktime file as the feature-values element in the QuickTime Video Codec Type. Comments welcome.

Notes

General

Appendix F of the Quicktime File Format Specification describes the QuickTime Video Codec Type. This type contains the elements profile atom [Track (video), movie]; part-ID [0x20202020 (universal feature)]; feature-code ['vfmt']; feature-value [Unsigned int(32) (a four-character-code) holding the QuickTime video codec type copied from the ImageDescription structure’s cType field."]. The "feature-values" is the four-character-code found in a video sample description. In this instance: yuv2. Comments welcome.

History

Format specifications

• See Disclosure under Sustainability factors.

Useful references

URLs

• QuickTime Video Codec Type (https://developer.apple.com/library/mac/#documentation/QuickTime/QTFF/QTFFAppenF/QTFFAppenF.html#//apple_ref/doc/uid/TP40000939-CH226-SW1). Includes description cited in Notes above.