Questions about functionality

[lcoughey]

In windows atm, so grabbed demo's of disk Tuna / Klennet Carver and noticed the same interface.
is this just a cosmetic feature? are they the same program "under the hood",
and are there options to reduce minimum file size, as some go under the radar on other programs?

Good question. I'm sure Joep has the answer.

[Joep]

They're the same.

What type of file you want to carve then?

If corrupt RAW photos rather than fragmented, no software will un-corrupt them. So Klennet, JRL and whatever will recover the corrupt RAWs.

Carvers typically carve from cluster/sector boundaries and that's not where you will find the smaller embedded JPEG previews. My other tool JpegDigger will detect TIFF based RAW photos, but rather than recovering those it will try for find and recover embedded JPEGs from those. These often survive even when the RAW is corrupted for whatever reason. However to trigger these it will still need to detect start of a TIFF based file at a cluster/sector boundary.

In JpegDigger you can set minimum resolution but this is to make the software skip lower resolution JPEGs inside RAW photos. It will also skip low res JPEGs at sector/cluster boundaries though.

To a degree it will repair corrupted JPEGs to the point where they can at least be rendered by a photo viewer or editor by taking care of invalid JPEG markers. And also if JPEG bitstream is interrupted at sector/cluster boundaries it will assume the file is fragmented and will try to find the rest of the file.

If you explain in greater detail what it is you're doing then I may be able to tweak it a little to fit your needs.

[kern]

Joe, thanks for the prompt reply. my bad, i expect these files are fragmented, not corrupted although that can't be ruled out either.

backstory:
The chap doing this appealed for help in hddguru saying he couldn't get anything back, and that it's a pro bono / charity job for his local LEA (india).
In this particular instance i have been given a few files which are from some sort of security camera setup.
they are labelled as .asf but have recognizable .wmv file headers. None will play in their current state.

Others, including myself, concluded that it's lkely they are fragmented files with a header and not much after them.
I tried a number of software options, the usual file fixers and data recovery programs, to no avail.
UFS Explorer did identify one as .wmv but it was the same as the original file length, minus a little. (~720MB)

Further to this, the guy has found at least one jpg so far, a single frame from the video file maybe, which degenerates into random block shapes at the very end.
That might be all there is total, or there are other small files scattered around.
He now has also found files (again might only be headers) in a .dav format, but hasn't managed to get any to play.

a number of years ago i had something similar, and adapted Photorec, (which found nothing in the first pass) to reduce it's minimum filesize.
I'm wondering if there's a chance that the video files might be made up of smaller jpg files and, given that with fragmentation the larger files essentially just disintegrate, maybe having an option to configure for the smallest possible size might render files that are smaller than the actual fragments they are contained in?

Does this sound feasible?

I tried jpeg-digger to no avail.
Ideally he should have taken a clone of the original device, a memory card, but he has only been given a small number of timestamped files.
It's possible the first responders and the police handling are non technical and may not have followed any sort of standard procedure to protect the device or its files.

thanks again for taking time out to answer

regards
K

[Joep]

Finding actual JPEGs or JPEG headers inside that file is a good indication the file is fragmented specially if the position of the JPEG header is (pos mod 512 = 0). To my knowledge you will not find JPEGs embedded in a WMV file at least in the ones I checked.

This is a bit hopeless if you ask me, without original drive.

[kern]

collectively, that seems to be the opinon.

given he's somehow extracted image and movie data, from what he had been given, I wondered though.
Certainly would be more favourable given a cloned device.
also wondered if its because it's some proprietary format used, particular to that camera setup.

thanks for the input

K

[boblee]

Thanks, @Joep. Sorry to see there's no more free version but your Technician license is a steal!

And that includes JpegDigger too!

Hi Joep, sorry for bothering you but I have a question... I just downloaded Disk Tuna defragmenter/optimizer... It did a defragment in less than an hour... But I started the "optomize" setting two hours ago and the progress bar is moving so slowly that it has gone only 5% of the way in two hours... My Question is - will it hurt my computer if I just press "Stop" ? Please let me know... I'd be very happy for your reply... Bob Lee, from Montana USA...

[Joep]

Thanks, @Joep. Sorry to see there's no more free version but your Technician license is a steal!

And that includes JpegDigger too!

Hi Joep, sorry for bothering you but I have a question... I just downloaded Disk Tuna defragmenter/optimizer... It did a defragment in less than an hour... But I started the "optomize" setting two hours ago and the progress bar is moving so slowly that it has gone only 5% of the way in two hours... My Question is - will it hurt my computer if I just press "Stop" ? Please let me know... I'd be very happy for your reply... Bob Lee, from Montana USA...

It's okay to press stop. I typically let optimize run over night and if it isn't finished yet when I need the PC, I stop it. It will just finish the current file. I can not stop that because as soon it tells the Windows defrag API, go move these clusters over here, it has to wait for that to finish. Or even if the program crashes or you forcefully end the task, this defrag API will finish that, update the file system etc..

And so, on topic of defragging I must admit I hardly ever do it anymore even on conventional disks. Optimize does offer advantages but question is if they outweigh the time needed for the defrag. Optimize moves stuff from the fastest area on the disk to make room for file and structures you want to profit from that speed because they're frequently needed. Not only files, but the MFT and folders too. So once freed up, which often indeed takes a huge amount of time, it starts moving files and structures that could benefit most from the relatively better speeds towards that area. Once it is done boot times improve but also things like explorer showing a large directory listing. Back then I frequently rebooted (XP), now I hardly ever. So some of those advantages back then put less weight in now. In fact, it made booting faster than any of the commercial tools back then except for Perfect Disk which gave a similar result.

Problem with the current version is that each time you do this it starts from scratch. Time I wrote the tool it didn't appear to be a problem, always worked fast on the PCs I then tested on. On one of my current laptops with spinners, it takes ages.

To address that I have an more up to date version that allows to selectively free up that fast area, move frequently used files, move folders etc.. Also it doesn't move out of the fastest area that it will be moving back later. if I use DIskTuna it is this version I use myself. Thing is, I never really finished it. Interface is still quirky, as I also decided to go from this little disk map bar to a higher resolution diskmap which is kind of slow in it's current state. Anyway I was getting so little feedback on the tool, and with the shift towards SSD, at some point I started questioning if it was worth putting much more time into this tool.

This is an example of the new disk map. The 'options' menu item is where you select what you want optimize to do. You can still see the area at the start of the disk that is less populated than what comes after it, and how the MFT (pink-ish) is moved towards the start of the disk: