| Author | Thread |
|
|
12/03/2008 04:27:30 PM · #26 |
Aren't discs divided into subdivisions anyway, and each "piece" of data takes a subdivision out of play, even if it doesn't actually fill it? Excuse my overly technical language :-)
R. |
|
|
|
12/03/2008 04:33:44 PM · #27 |
Originally posted by Bear_Music:
Aren't discs divided into subdivisions anyway, and each "piece" of data takes a subdivision out of play, even if it doesn't actually fill it? Excuse my overly technical language :-)
R. |
I think Blocks and Sectors are the usual subdivisions, a Sector being a group of Blocks.
Each disk has a "minimum allocation block" -- the minimum amount of space allocated to it regardless of the actual number of bytes comprising the file -- which is determined by the number of records which can be kept in that database Gordon mentioned. |
|
|
|
12/03/2008 04:35:35 PM · #28 |
Originally posted by stevieian:
you are awesome Shannon. It seems to be working. Now the question is, once all images are downloaded, and i'm lucky enough to find the one I need, where/who do I send it to here (since he's already been DQ-ed)??
Thanks again!!!! |
??? NO idea...
SC?? |
|
|
|
12/03/2008 04:36:44 PM · #29 |
Originally posted by Bear_Music:
Aren't discs divided into subdivisions anyway, and each "piece" of data takes a subdivision out of play, even if it doesn't actually fill it? Excuse my overly technical language :-)
R. |
Yes, but each piece of data gets put at the start of a subdivision, so they tend to overwrite each other.
More technically ( :) ) the disks are broken up into sectors, big enough to store 512 bytes of data. These sectors are combined into clusters of data. An image typically is stored across multiple clusters, which can be on different parts of the disk (this is what fragmentation is). The file allocation table keeps track of where all the bits of stuff is on the disk and tracks the end of one bit of file and where the start of the next bit of the same file is.
When the file allocation table (FAT) gets corrupted, you lose all that info about where things are - recovery software just assumes that the files are stored in order on the disk, starting at the first cluster and working up from there. If you delete images and add new ones this isn't true in general, as the new files might be bigger than the hole left when you deleted the old one.
Also, flash technology does all this sort of differently under the hood, but looks like a normal disk to anything using it.
The recovery software I wrote just looks at the bits at the start of a sector, decides if it looks like the start of a picture, or not. If it does, it starts writing it to a file, and gets the next sector, looks to see if it looks like the start of a picture, or not, and so on. Recovered every single RAW file and WAV file I lost - I was quite happy :) So when you pay the $29 or $49 or $109 for photo recovery software, you are paying for a more user friendly version of this, that knows about more formats than the ones I happened to need to recover.
Message edited by author 2008-12-03 16:42:08. |
|
|
|
12/03/2008 04:37:35 PM · #30 |
Originally posted by TCGuru:
Originally posted by stevieian:
you are awesome Shannon. It seems to be working. Now the question is, once all images are downloaded, and i'm lucky enough to find the one I need, where/who do I send it to here (since he's already been DQ-ed)??
Thanks again!!!! |
??? NO idea...
SC?? |
Taken care of. :) |
|
|
|
12/03/2008 04:37:54 PM · #31 |
| AFAIK the "original" has been received, and the photo in question has been (at least temporarily) "Un-DQd" and back in the voting pool while we go through the validation process again. |
|
|
|
12/03/2008 04:39:30 PM · #32 |
A hearty congratulations to everyone that helped or tried to help in this thread and so nice to see a ray of positivity shining through a morning that has been... less so, at DPC.
Warms the heart it does. |
|
|
|
12/03/2008 09:31:45 PM · #33 |
Originally posted by K10DGuy:
A hearty congratulations to everyone that helped or tried to help in this thread and so nice to see a ray of positivity shining through a morning that has been... less so, at DPC.
Warms the heart it does.
Second that. You guys are awesome! I don't care what anyone else says about 'cha ... ;) |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 08/24/2025 03:27:31 PM EDT.
