If you were trying to access files on a proprietary file system with no existing drivers or extraction programs, where would you start? In particular, I'm trying to access the recorded TV programs my Scientific Atlanta DVR. I know this kind of thing is possible as a program called TwinRip existed about ten years ago which did exactly this, but doesn't appear to work on newer systems - or at least I haven't gotten it to work. That file system was called STAVFS (STMicroelectronics Audio-Visual File System)
Yes, yes, I know. "Use a capture card to record TV! SO MUCH EASIER!!11!1!" I have been doing so for well over a year, but that shit is time consuming.
Do you think standard file recovery software (Easeus, Recuva, etc) would be effective? Do those sorts of programs have to know the file system, or do they just look for file headers?
I've spent the last month scouring every fucking tech/AVFS forum where people have discussed accessing the DVR's file system. The the farthest anyone gets is, "Gee, looks like a proprietary file system, I give up"
I'm asking how to go to the next step and actually extract files from that file system.
idk if you're using linux to check the drives but you should. It's much easier as windows refuses to acknowledge any file-system except for like fat ntfs vfat or whatever else microshit fs they make.
^ that link should help you out but most likely the DVR will be EXT or Fat.
and after you've mounted the drive in linux just copy the videos to a usb.
OR after you determine the FS you can just download some 3rd party Windows program for the FS like ext2fsd
I dual-boot Ubuntu/Windows, so checking out the drive in Linux was the first thing I tried. Admittedly, I didn't use the methods listed in your link; I just fired up Gparted and checked the drive that way. Gparted couldn't detect a file system of any kind.
I would start by finding out the codecs used in the hardware then looking for file header info and other metadata related to those codecs. Looks like MPEG so I would start looking for MPEG file identifiers and trying to find offsets. Maybe you could use IDA on TwinRip and try to find the filesystem functions to see what it knows about parsing the disk.
You could use heuristics if you had an idea of what you were trying to recover.
Asides from that, you'd need to check for the usual shit that filesystems typically store.
Since more and more things are being encrypted, we'll be fucked in the coming decades in this respect.