The FLV extension identifies Flash video files. By using it on Youtube and similar sites, it has become the standard format for streaming Internet video.
The format was developed by Macromedia and is being further developed by Adobe today. It's a proprietary format, but it's also made available to other developers.
Like MOV, FLV is a container format. The files contain a video and audio stream as well as metadata. The included audio and video data may be encoded using various compression techniques. Which ones are depends on the desired compatibility with the Flashplayer plugin. With higher versions, other methods are available that also support HD resolutions.
Any browser with Adobe Flashplayer plugin can play FLV files.
Most often resolving problems with opening FLV files is very simple. Just install an appropriate program that supports such files. All of the listed programs support FLV files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of FLV files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate FLV files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe Flash applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe Flash has been installed.
Sometimes problems with opening FLV files may not lie with the application itself, but can arise due to other causes, such as: