Question Multiple files of 3.3gb on the same dvd - please help

[Jimboss99]

Hi all, just wondering if you can help me with copying my files of this dvd.
I used it to store my old ipod photos (don't know why I did that) but for some reason after a certain point the files are all around 3.3GB -there are nearly 300 files like this. The filenames and dates are are shown but nothing more and I cannot open them. If I try and copy those files it copies the whole 3.3GB for each file. The dvd still has space left on it though. Also using the program "recover disc 2.0" it only finds the files that are not 3.3GB.
Are they corrupted? Is there any way to recover the files? If not I'll just throw the disc away and forget about it but any help appreciated.

 

[fzabkar]

Examine the files with a hex editor, eg HxD (freeware).

https://mh-nexus.de/en/hxd/

JPEGs have a header which begins with 0xFF 0xD8.

PNG files usually (?) have a "PNG" header.

 

[Jimboss99]

Examine the files with a hex editor, eg HxD (freeware).

https://mh-nexus.de/en/hxd/

JPEGs have a header which begins with 0xFF 0xD8.

PNG files usually (?) have a "PNG" header.

Thanks for the info,
I have used the program for one of the 3.3GB JPG files. All values are "00" up to offset CE7993B0. After that there is a small amount of data. There is no "FF D8"
header and after looking at a normal JPG file, it seems the 3.3GB one has the start of the data missing.
Do you know why this might be?

(Left image: start of data, Right image: end of data).

 

[fzabkar]

The last two bytes are 0xFF 0xD9. That's the end of a JPEG.

Obviously the file system is corrupt. I would make a byte-by-byte image of the DVD (as an ISO file) and then run data recovery software against the image file. You could also run the data recovery software against the DVD, but that may be slower, especially if you can copy the image to an SSD.

 

[Jimboss99]

I have used recovery software "recover disc 2.0" on the disc, I can copy the non corrupt files fine but it doesn't even show the 3.3GB ones. Is there recovery software you could recommend that might recover the rest of the data or is it too corrupt to save?
Thanks in advance

 

[fzabkar]

There are free tools/methods to create an ISO image file of your DVD. Start with that.

I would think that files on a working DVD would be unfragmented, so any file carving tool should be able to extract all the available files from the ISO image without relying on the file system's metadata (which are obviously corrupt). PhotoRec is a free tool that can do this.

Alternatively, DMDE is a good data recovery tool whose free version will probably be all you need. I would use this tool, but that's because I'm very comfortable with it.

R-Photo is another good, free tool, but I don't know if it will work on an ISO image.

JPEGSnoop (free) can extract JPEG files from within other files, so I expect that it should find all the JPEGs in your ISO image.

 

[Jimboss99]

I used MagicISO to make the ISO file - it said it was a multi-session disc and exported entire disc. I used DMDE, R-Photo(on the disc) and PhotoRec - they all find the same files as I can already open on the dvd. JPEGSnoop couldn't extract the image from a 3.3gb jpeg file. I tried Isobuster too and that showed multiple sessions and tracks and the last 3 sessions show the same files as in windows explorer. I can't seem to get access to the 3.3GB files. I think I might be out of luck.

(First image: DMDE scan, 2nd image: isobuster screenshot)

Thank-you for your help.

 

[fzabkar]

I forgot about IsoBuster.

Each file in the IsoBuster directory listing has a starting LBA and a size in blocks. For example, IMG_2004.PNG starts at LBA 94448 and has a size of 342 blocks. All the previous files have the same starting LBA, namely 94224, so something is wrong at this point. Since each block is 2048 bytes, we can then calculate the position in the ISO file where the problem appears. This should be viewable in DMDE or HxD.

I suspect that the "recovered" 3.3GB files may be essentially identical, after accounting for their slightly different lengths.

I would have expected that the end LBA of IMG_2004.PNG would have been 944789 (= 94448 + 342 - 1), instead of 94805. For all the other good files ...

start LBA + size in blocks - 1 = end LBA​

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