add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
Have you ever rented a DVD from the video store, or bought one used, only to be rudely surprised by a crippling scratch one hour into the film that makes the disc unplayable?
Scratch Catcher is a simple application for use with any computer that has a DVD drive. Before watching a movie, let Scratch
Catcher give the disc a quick scan for errors. If the disc passes the test, you may enjoy your movie with confidence. If the disc has a nasty scratch, well, at least you didn't find out the hard way.
Scratch Catcher can also be used on compact discs, so you can check out a used CD you've just bought. If you own a video store or a music shop that deals in used discs, Scratch Catcher will help with the quality control of your inventory. If you're a customer with a laptop, you can check a disc even before buying it!
***
A big part of Scratch Cather's usefulness depends on how fast it's possible to scan a disc. Frankly, I don't know what the technical limitations are for something like this. I'd say 8X would be the minimum acceptable speed - you'd have to be able to check a two hour film in no more than fifteen minutes.
Please log in.
If you're not logged in,
you can see what this page
looks like, but you will
not be able to add anything.
Annotation:
|
|
I wonder if perhaps scanning could be done by a portable device with the form factor of a sony discman, but not by attempting to read the contents of the disk but by either physically or optically just checking the surface for damage. I know I've fixed scratched disks with turtle wax before, and I think something w/ just a smooth surface and an array of pressure sensors could find a depression in a disk based only on "touch". Doing so would take only a second or so and be do-able before one leaves the video store. |
|
|
i didnt know we needed a seperate program with a fancy name for this. baked. |
|
|
ry4an - Not a bad suggestion, but what if you got a disc that someone had *unsuccessfully* tried to fix with Turtle Wax? There would be no scratch to detect, since the wax would have filled it in, but the disc would still be unplayable. |
|
|
ironfroggy - I'm clueless. What the heck is bash$ fsck /dev/dvd ? |
|
|
Unix command to run a check on a drive. |
|
|
If you had lots of parallel (or even independent) read heads you cold probably beat the 8x barrier fairly easily. |
|
|
ironfroggy -- Does fsck do a full surface check? I thought it only checked for the validity of the directory and inode structures. Of course, since I don't think dvd's have inodes, I'm not quite sure what it would do; does fsck adapt itself suitably to other file systems? |
|
|
Fascinating. I usually use a bright light (such as the sun). |
|
|
Of course, if there's an error in the encoding or something like that, my "Scratch Catcher" wouldn't work... |
|
|
just copy the movie to the disk and look if there are errors. |
|
|
also, fsck usually ist just a wrapper for different file systems' fsck tools. |
|
|
Certainly most of the data on the disc is still intact. If
so, then there should be an online service to allow auto-
matic downloading of the corrupt portions.
They would probably want to require users to provide a
cryptographic hash of randomly selected parts of the disc
to make sure you actually have the disc and aren't just
trying to download the data a little at a time.
|
|
|
When the played movie hit the part with the scratch it could just flash an advertisement for the correct amount of missing time. |
|
| |