Sustainability of Digital Formats: Planning for Library of Congress Collections

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QuickTime Video, Sorenson Codec

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name QuickTime Video, Sorenson Codec
Description QuickTime file format wrapping a Sorenson video bitstream with other data chunks, e.g., audio.
Production phase Used as a final-state format for enduser delivery; may also be used as a middle-state format, e.g., as the video source when producing lower-resolution streaming versions.
Relationship to other formats
    Subtype of QuickTime, QuickTime File Format
    Contains Sorenson_3, Sorenson Video Codec, Version 3
    May contain Audio streams not documented at this time

Local use Explanation of format description terms

LC experience or existing holdings See QuickTime
LC preference See QuickTime

Sustainability factors Explanation of format description terms

Disclosure See QuickTime and Sorenson_3
    Documentation See QuickTime and Sorenson_3
Adoption Appears to be widely adopted for video filemaking.
    Licensing and patents See QuickTime and Sorenson_3
Transparency See Sorenson_3
Self-documentation See QuickTime
External dependencies See QuickTime
Technical protection considerations See QuickTime

Quality and functionality factors Explanation of format description terms

Moving Image
Normal rendering Good support.
Clarity (high image resolution) Moderate, given that this is a format typically used for compression and does not support interlaced video. Outcome will depend on the type and extent of compression, and the encoder used. Several commentators state that the quality of QTV_Sorenson surpasses that of QTV_AppleVideo and QTV_Cinepak, at the same bitrate. At higher bitrates, QTV_MJPEG is likely to provide the highest quality of the QuickTime codecs described at this web site.
Functionality beyond normal rendering See QuickTime.

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension mov
Internet Media Type See related format.  See QuickTime
Magic numbers See related format.  See QuickTime
Apple Video Sample Description svqi
Four-character code identifying the Sorenson video codec, from QuickTime File Format, p. 92 or p.96.1

Notes Explanation of format description terms


Format specifications Explanation of format description terms

Useful references


1There seem to have been at least two printings of the specification carrying the same date. These were not systematically compared by the compiler of this Web page. Pagination varies between these two printings.

Last Updated: 08/04/2021