Have you checked the same file on Linux of different system? because if it is not playing there it means file is corrupt, not fir for linux but if it is played on other system's linux it means you have a less plugin on your system.

Try to install required plugin.

Have you tried playing the video in the browser with flash plugin? What happens?

In the XBMC wiki they mention FLV support so there should be some way to open the video, unless you have an older version that doesn't support FLV.

FLV is just the container type: are you sure it's h264 encoded video? There are other video compression formats that you can package into an FLV as mentioned here: http://en.wikipedia.org/wiki/Flash_Video. VLC and XBMC both specify they handle FLV so it makes me wonder if this specific video is using a different video compression format than h264.

Finally, do you have the non-free codecs installed?

Firefox with flash plugin does not play this file.

Yes. From offician mint repository.

The file plays in windows. So it is not corrupt. The file also plays (in VLC & also in other media players as mplayer & kaffeine) on an Archlinux system which has not been updated for about 2 months. So it seems to be a problem with codecs rather than VLC program.

Which plugin should I install?

Archlinux wiki states that the error goes away with gst-libav:
https://wiki.archlinux.org/index.php...n_Totem_Player
However, I could not find this package in Linux Mint 13 repository. There is gstreamer-libav in Debian Sid:
http://packages.debian.org/sid/i386/...libav/download
Can I download and install this?