Video format not supported under Linux Mint 17 "Qiana"

I am using Linux Mint 17 Qiana and downloaded Libreoffice using the download manager. I cannot load video into Libreoffice. Keeps telling me format not supported. How do I fix this? I have changed formats and tried other suggestions by linking but still get the same results.

I will be teaching Linux to Year 7 students very soon as i hope to convert them away from their Apples and into the share ware world. I find Linux is much more suitable for learning than all the others.

I you can help

Please edit your question to indicate the extension of the video file you are attempting to insert and the audio / video stream codecs used in the file. Thanks.

Refer this answer. You may also want to consider installing mpv or vlc.