Instant rewind

Firstly can you nip over to Introductions and introduce yourself per forum rules?

Now - just consider the practicality of what you are wanting. Consider the amount of channels, and think about how much HDD space it would take, and not to mention resources (processing) needed to record every single channel while you are watching another, and also that you would need multiple tuners and feeds.

There are features to rewind the channel you are watching, record one channel while watching another, but consider how difficult it would be to get what you are wanting.

Quote from Bardinho

Thanks for the clafications.
I'm asking because I have a box from a telecommunication company that contain this feature even if it works only for few channels. I was thinking about doing the same thing so it doesn't seize a lot of space in th HDD. Thus, I don't know if this could possible by connecting to certain server or somehow else...

the permanent time shift plugin will be the nearest thing you would come across for what you are after. I don't use it myself but it is configurable to a point, but you simply can't just rewind a random channel to an earlier point, this would require hundreds of channels to be recorded at the same time.

musogeek is correct, you simply can not turn to a channel mid way through and expect to be able to rewind it past the point at which you started viewing unless you have a huge server recording every single channel in real time all the time.

PTS would be the nearest you are going to get depending in the image you use.