Forward and backward in Kodi 17

Hello folks,

I play live stream like this in kodi (the video is a live conversion of a file) :

https://domain.com/path/to/my/flux.m3u8?t=0

In this url “t=0” is the timestamp from which the video as to start. If i want to backward/forward (+20s for example) if have to stop the current video and open a new stream with

https://domain.com/path/to/my/flux.m3u8?t=20

My problem is the “time line” in kodi start from 0 but the 0 correspond to the timestamp so if my timestamp is 280 and the total of my video is 3600, kodi will show a time line starting from 0 and a total time of my video 3320 … It is hard to explain, english is not my main language ..

Thanks for the help !