FLV / MPG ?

Hello I have a question when I go to / public_html / flash / modules / video / files /
I see by expl

10.flv
10.jpg
10.mp4
10.mpg

I send the files are in flv each time, so what I want to know in what format are the videos, if it is in mpg, I can simply remove the flv? is that nothing is changed is to save disk space

Thank you

I believe the FLV files are what is actually streamed, and the MPG files are the ones used for the download option on the player.

So what do I do, because by now expl size of each of its file - FLV (14.05) and MPG (13.53)

If the file is twice as heavy or + size two sizes will be the same, is it a file that is used initially to convert the flv file, then sends it over or not?