(I am not looking for any programs or ways to copy disks!)
As I know almost nothing about disks it would seem easy to copy any disk by simply taking the raw data off the disk and putting straight back unchanged on another disk without trying to decode or decrypt it. As this is not done AFAIK I can only imagine that either the disk drive manufacturers dont allow this low level access, or there is some formatting reason why this doesnt work.
Not sure but I think a low level copy would be very slow so that is why they don’t do it that way.
Because copy protection schemes put things like bad sectors in specific places and other low level tricks to fool raw reads and writes.
These things throw off Joe Average, but a determined hacker can get through them. A lot of gamers end up virtualizing their cd’s so they arent always messing with physical discs. So its been done, at least with some drm schemes.
I don’t get it either. If the disk is an exact copy of the original, byte for byte, how can any protection scheme tell them apart? I’m assuming the only information the protection has to go on is contained on the disk itself, and if both are identical how can it distinguish them?
You can read guides about copying these discs here:
Most of it is about getting around securerom protected discs.
Generally, most disk support in OS isn’t designed to work on a low level. It’s more useful to take a given filesystem for granted and work within it.
I assume that a protected DVD doesn’t really have a standard filesystem - not before you decode the encryption, which the standard ‘copy disk’ features do not do, though DVD player software can.
I would tend to suspect that providing a low-level copy wouldn’t be that difficult perhaps, but since an obvious use for it would be piracy, there are vested interests in not not making that standard with all DVD writers. It might even fall under a stretch of the DMCA as ‘technology to circumvent a copy protection scheme.’
The people who would be most interested in writing a tool like that are probably the software firms that have already ‘cracked’ the DVD encryption scheme, and at that point it probably is worth decrypting even for a disk to disk copy, in that they can verify that the data being copied is valid and hasn’t degraded to uselessness.
There are areas of a dvd that are coded at manufacture, and cannot be copied. Commercial DVD players (hardware and software) are required to honour these fields, as well as region encoding and no-skip flags.
Game discs use bad sectors to create a disk signature that influences read timings - these bad sectors can be copied with sophisticated software, but it is hard to get the same results. Disk images (iso files) can be more accurate, but they have a different timing pattern, so this needs to be imposed by scanning the original disk to capture this data. And the virtual disk needs to be hidden from the anti-copying tools.
Si
To make a copy of a HOME-MADE (not copy protected) DVD that you created from your own home movies, of your own authorship etc etc, it is indeed true that all you need do is copy all the files from one to another.
Without in any shape way or form condoning the practice or even asserting that it is indeed possible to rip a copy-protected DVD, I can tell you that I have the distinct impression that were such a rip possible, it would be equally easy to make yet another copy from the rip simply by copying all the files.
Furthermore, it is not possible to make an exact copy of a commercial DVD using consumer equipment. There’s an area of the disc that contains encryption keys or some such, which is not writeable on consumer recordable DVDs. Consumer DVD drives can read the data, but not write it.
Part of it is the use of redundant data that makes it hard to exactly cooy a DVD or CD.
But that doesn’t mean you can’t get a perfect play rip.
Before CDs were first introduced it was decided it would be utterly foolish (I always wanted to use that phrase :)) to have a CD fail if there was a flaw in it. So manufacturers and makers of CDs decided that they would put redundant data on a CD so if it fails in one place it still works.
Now when it comes to DVDs they started to be popular after it became obvious consumers would have access to cheap copying devices.
Sony for instance tried to sneak in a copy protection scheme on its CDs and it screwed up and not only failed to securely protect the CDs but it messed up people’s computers and it caused a lot of flack.
Consumers refused to accept a CD with protection on it. Consumers however grew up with DVD protections. But some countries allow you to make copies of disks you own for your own personal use, there for schemes to defeat the copy protect are on the Internet.
Lastly there never has been a way to defeat the analog hole. What that is, is simple a computer or device must be able to play your CD or DVD, so it must be converted. If it can be converted it can be recorded. Now granted an analog recording isn’t an exact copy, but with a book on tape or a DVD you can use programs that get very close, or at least “close enough.”
Another issue is the simple fact that you need different hardware to burn a DVD (or, I’m guessing, most game disks) than for a CD. The laser needs to be both higher power and higher frequency to burn a DVD (and higher yet for a Blu-Ray). This wouldn’t, in principle, stop you from copying a DVD onto a CD, but since the former has a much higher capacity, you’d either need to compress the data more or use multiple CDs.
Something else that hasn’t been mentioned explicitly…
A CD (or DVD) has error-correction built-in. This is done through a checksum of sorts. If bits are missing, it’s possible to replace them on-the-fly. Your CD player handles this correction. The CD has the responsibility of having its data encoded to comply with this error-correction scheme.
In all likelihood, every CD you’ve ever used has had some error on it, as seen from the point of view of the player. You just don’t know about it because the correction is automatic. The error could be caused from a scratch, dust, vibration, manufacturing error, electrical noise… basically anything that might interfere with the processor interpreting a binary value from analog data.
The point is that you can’t actually get a physical reproduction of the disc. You get the analog pits & bumps turned into digital form, and then burnt back into an analog equivalent. When the pits & bumps are corrected, the corrections are the ones burnt onto the new disc.
So your video game console may have a specification that says that every 5th packet will contain a corruption*. So the drive in the console knows whether or not to correct the packet and can take action based on the presence of that corruption. If you were to copy the disc in your CD burner, that CD burner doesn’t realize that the error is intentional, so you get a copy that has the errors corrected. You put that disc in your video game console and when it realizes that the error isn’t there, it locks you out (or stops loading the game, or makes pink bunnies cover the screen… whatever they want to do, really).
oh, and if the schema is known, it’s (probably) possible to massage the buffered data so that when it’s burnt out to the disc, it burns the intentional errors. This is what happens when you get pirated/copied media that can be played in an unmodified player. Alternatively, one could modify the player to not expect the intentional errors / ignore those errors.
When I learned the basics behind this, the cost/benefit and ethical issues kept me from looking into it further. My posts are meant as a high-level overview, and not instructions on how any encryption schemas are setup. In fact, they might not even be all that accurate.
tx for teh replies. I understand now the problems involved.
One thing that hasn’t been mentioned yet is that most commercial DVDs are dual-layer media, which has a capacity roughly twice that of a single-layer disc (8.5 GB vs. 4.7 GB). The issue is that writeable dual-layer discs are more expensive than single-layer discs and require DVD drives capable of writing them, also more expensive. Now, I’ll give the caveat that this was the case as of a year or two ago and maybe technology is catching up now and the prices have become more competitive, but historically, this is another reason that DVDs are more difficult to copy. Of course, you can get around the DL issue by compressing the video file and dropping some of the extras (ie: other language tracks, extra scenes, etc.) in order to fit it into a SL disc, however this requires more sophistication on the part of the copier.