I'm trying to figure out how to record a video stream into a buffer of sorts, so that it contains the last hour of the stream.

Why you say?
I need to be able to do "post" cutting on this file with the use of timecodes to generate clips that might overlap.
Clip1: 14:30 - 14:40
Clip2: 14:35 - 14:50

Hopefully I manged to explain that so people can understand what I'm after.
Any pointers or ideas on how to achieve this will be highly appreciated.