The FLV/F4V open specification documents
the file formats for storing media content used to
deliver streaming audio and video for playback in
Adobe® Flash® Player and Adobe AIR™ software. FLV
and F4V are the de facto standard for web video today;
80% of online videos are viewed worldwide using Adobe
An FLV file encodes synchronized audio
and video streams. The audio and video data within
FLV files are encoded in the same way as audio and
video within SWF files. Starting with SWF files published
for Flash Player 6, Flash Player can exchange audio,
video, and data over RTMP connections with Adobe Flash®
Media Server. One way to feed data to Flash Media
Server (and thus to Flash Player clients) is from
files in the FLV file format. Starting with SWF files
published for Flash Player 7, Flash Player can also
play FLV files directly with MIME type video/x-flv.
An FLV file encodes synchronized audio and video streams.
The F4V format is based on the format
specified by ISO/IEC 14496-12: ISO base media file
format. Starting with SWF files published for Flash
Player 9 Update 3 (9,0,115,0), Flash Player has been
able to play F4V files.
More details, please visit: http://www.adobe.com/devnet/flv/