If you are an owner of one of the Samsung PVR enabled devices, you'll probably thought about how to make these videos playable on other devices (of course in case of a mainboard switch). There was a tool from SamyGo removing the encryption when executed on the device.
There was a port of that tool for Windows called DRMDecrypter wich was able to extract the key from the .mdb file and decrypt the .srf to an simple transportstream (.ts).
I managed to port it on Unix based systems because it was quite annoying to read the harddisk on Linux (XFS filesystem) and copy it to a Windows machine for processing. You'll now have all on one box.
Download the source from GitHub.