View source for Flash Video

{{mux|id=flv|encoder=n}}
'''Flash Video''' is a file format mainly used for playing data in a Flash player on a webpage. It has the extension '''.flv'''.

There are two types of flv files, the one based on [[H.263]] (which exists since Flash 6) and another based on [[VP6]] (which was introduced in Flash 8).
In Flash 9 Update 3 Adobe added support for MPEG-4, thus since this version flv files may also contain [[H.264]] and HE-[[AAC]].

==Compatibility==

H.263 flash video is supported by the latest VLC, with some bugs. There is a [[Fixing .flv to .avi with FFmpeg|workaround]] using [[ffmpeg]] for this. VP6 is also supported by VLC from version 0.8.6b and above.

However, seeking, (that is, jumping to a position in the video) is not supported until 0.9.0 in either codecs.

==Streaming Flash Video With VLC==

Starting from VLC revision 18876 (which means 0.9.0-svn after 17/02/2007), you can stream flash with VLC. You also need to build VLC with a fairly recent ffmpeg version (r7593 21/01/2007 or newer).

You can then use the following command line to do HTTP Flash Video streaming:
 % ./vlc <input> --sout "#transcode{vcodec=FLV1,acodec=mp3}:std{access=http,dst=/stream.flv}"
You can then point any flash based player to that stream using <nowiki>http://192.2.0.1:8080/stream.flv</nowiki> where 192.2.0.1 is the server IP address.

Note that flash only accepts 3 audio sample rates (44.1 kHz, 22.05 kHz and 11.025 kHz). If your source audio uses something else, muxing will fail. You can change the sampling rate by adding samplerate=44100 in transcode.

Note: this and many other video codecs appear to be disabled and silently not working on Windows binaries, the system won't complain, but all you find is a container with no video stream in it.