Detect conditon to play a relevant video file

Hello, I am using the latest version of WordPress and have embedded two video files on on a page. One is a .flv file which plays perfectly on a laptop or desktop computer but does not on a mobile device and the second file is a .mp4 which plays on a mobile device and not on a desktop etc.
My website is already set up for responsive but this isn’t the case for the playback of videos.

Can some please advise on how to detect which device (e.g. an iPad or iPhone or laptop is being used on my videos page only.

I am using the “Video Embed & Thumbnail Generator” plug-in which is great and my two lines of code are:

[KGVID]https://www.mywebsite.co.uk/wp-content/uploads/2016/video/myvideo.mp4[/KGVID]

[KGVID]https://www.mywebsite.co.uk/wp-content/uploads/2016/02/myvideo.flv[/KGVID]

Thank you, Steve