All of these compression formats are restricted by patents.
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Flash Video is a container file format used to deliver video over the Internet using Adobe Flash Player version 6 and newer.
Flash Video content may also be embedded within SWF files.
There are two different video file formats known as Flash Video: FLV and F4V.
The audio and video data within FLV files are encoded in the same manner as they are within SWF files.
The F4V file format is based on the ISO base media file format and is starting with Flash Player 9 update 3.
Both formats are supported in Adobe Flash Player and developed by Adobe Systems. Flash Video used to be the de facto standard for web-based streaming video (over RTMP). Video, metacafe, Reuters.com, and many other news providers.
Flash Video FLV files usually contain material encoded with codecs following the Sorenson Spark or VP6 video compression formats.
The most recent public releases of Flash Player (collaboration between Adobe Systems and Main Concept) also support H.264 video and HE-AAC audio.
In 2003, Flash Player 7 added direct support for FLV file format.
Because of restrictions in the FLV file format, Adobe Systems has created in 2007 new file formats listed below, based on the ISO base media file format (MPEG-4 Part 12).
Flash Player does not check the extension of the file, but rather looks inside the file to detect which format it is.