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Sorenson Video Codec, Version 3

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name Sorenson Video Codec, Version 3
Description

Bitstream encoding for video developed by Sorenson Media, Inc. The compiler of this description is uncertain about Sorenson's version numbers. Sorenson Media promotional information for version 4.5 of the Squeeze software application, consulted in February 2007, listed a number of possible output formats, including MPEG-, -2, and -4, and Flash Output (Spark). Spark may be the successor to the Sorenson codec, version 3, initially described at this Web site in 2004; comments welcome.

The matter of versioning may account for the fact that the Wikipedia article on the Sorenson codec associates the codec with both ITU-T H.263 (see MPEG-4_V) and H.264 (see MPEG-4_AVC). Macromedia (now Adobe) literature states that the FLV/SWF variant of Sorenson is related to H.263.

The SIGGRAPH education page states that the codec uses "advanced vector quantization with motion compensation," and that the Developer Edition of the Sorenson codec offers variable bitrate encoding, temporal scalability (sensitivity to the ability of the playing machine to process data), and the automatic determination of new keyframes (frames that contain all image information without reference to predictive or bidirectional frames that require adjacent frames for decoding).

Production phase Generally used as an end-user delivery format.
Relationship to other formats
    Used by QTV_Sorenson, QuickTime Video, Sorenson Codec
    Used by SWF_7, Macromedia Flash SWF File Format, Version 7
    Used by SWF_8, Macromedia Flash SWF File Format, Version 8
    Used by FLV, Macromedia Flash FLV File Format
    Used by Other formats, not documented at this time.

Local use Explanation of format description terms

LC experience or existing holdings American Memory produced QTV_Sorenson (QuickTime, Sorenson codec) for the Dance Instruction Manuals collection, where they offered endusers larger picture size and higher resolution than provided by QTV_Cinepak (QuickTime, Cinepak codec) files. The QTV_Sorenson files are encoded at 15 fps and 320x240 pixels; the audio stream employs IMA (Interactive Multimedia Association) 4:1 compression, based on PCM sampling at 22 kHz.
LC preference See QuickTime

Sustainability factors Explanation of format description terms

Disclosure Proprietary standard developed by Sorenson Media, Inc.
    Documentation Not a specification but modest, helpful documentation is provided by a SIGGRAPH education page.
Adoption Apparently widespread.
    Licensing and patents Codecs and software may be licensed from Sorenson Media, Inc.
Transparency Depends upon algorithms and tools to read; will require sophistication to build tools.
Self-documentation Not applicable; provided by wrapper formats.
External dependencies None.
Technical protection considerations The SIGGRAPH education page states that Sorenson encoding software offers watermarking and media keys that permit producers to limit viewing to users who have the required key. These or additional protections may also be provided by wrapper formats.

Quality and functionality factors Explanation of format description terms

Moving Image
Normal rendering Not applicable
Clarity (high image resolution) Moderate, given this is a compression format.
Functionality beyond normal rendering Not applicable

File type signifiers Explanation of format description terms

Tag Value Note
Filename extension Not applicable.   
Internet Media Type Not applicable.   
Magic numbers Not applicable.   

Notes Explanation of format description terms

General  
History  

Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: Friday, 03-Jan-2014 10:17:17 EST