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The CD format doesn't support DRM. Extremely few CDs tried to fiddle to add it by adding errors, but modern readers aren't stopped from reading the audio. CDs

The CD format doesn't support DRM. Extremely few CDs tried to fiddle to add it by adding errors, but modern readers aren't stopped from reading the audio. CDs are pure audio data with error correction.

boomboomsubban 4y ago
There's the whole Sony rootkit fiasco that shows that record labels have tried to put DRM on CD's. I have no idea how many continued to try, but if they did bypassing it is a crime, even if it's trivial to bypass. The DMCA is dumb.
- layer8 4y ago
  You can always play back the CD in a CD player with digital audio out and record the digital signal using an appropriate 44.1 kHz capable sound card, resulting in more or less a bit-perfect copy. That’s not bypassing DRM, because you’re just using regular consumer audio devices for their intended purpose.
- ChrisLomont 4y ago
  That was adding an executable for a PC, it had nothing to do with the audio, which was and is still perfectly copyable.
kevin_thibedeau 4y ago
CDs do have copy protection flags. This is unrelated to the intentionally corrupt pressed discs meant to subvert CD-R recorders.
- ChrisLomont 4y ago
  And it's so difficult to find any hardware anywhere that respects that flag that hacker forums are filled with questions asking if anyone ever saw such a device. Every modern copy or backup program ignores it, and it looks like none ever used it.
  - kevin_thibedeau 4y ago
    It was used on standalone audio recorders.
    - ChrisLomont 4y ago
      Yep, very few, and likely nothing anyone is using now to copy/backup CDs with. In forums where people look for such things out of curiosity people mention they existed, but I've not yet found someone that owns one to play with. And zero of them stopped the analog hole on those old devices. Now, as to the actual bit(s). There were two bits, one said copyrighted work, one said is this a copy. Almost all CDs shipped with the copyright bit set and the "is a copy" bit set to 0. This meant you can make one copy of the CD (by law). The copy should have the "is a copy" bit set, meaning no more copies of the copied disc. This means you can actually copy the original CD as many times as you want, since it always looked like an original, hence copyable. Remember Sony hardware sold an order of magnitude more in value than Sony music :) Again, a non-issue. To recap: 1. Very few CDs even bothered to set the bits. 2. None (?) set both bits, meaning you can copy any original CD, even with bit respecting hardware. 3. The bit(s) in no way changed the audio. 4. No copy software on PC I have ever heard of even looked at the bit. 5. Very few pieces of hardware respected the bit. Did I miss anything?

boomboomsubban 4y ago

There's the whole Sony rootkit fiasco that shows that record labels have tried to put DRM on CD's. I have no idea how many continued to try, but if they did bypassing it is a crime, even if it's trivial to bypass. The DMCA is dumb.

layer8 4y ago
You can always play back the CD in a CD player with digital audio out and record the digital signal using an appropriate 44.1 kHz capable sound card, resulting in more or less a bit-perfect copy. That’s not bypassing DRM, because you’re just using regular consumer audio devices for their intended purpose.
ChrisLomont 4y ago
That was adding an executable for a PC, it had nothing to do with the audio, which was and is still perfectly copyable.

kevin_thibedeau 4y ago

CDs do have copy protection flags. This is unrelated to the intentionally corrupt pressed discs meant to subvert CD-R recorders.

ChrisLomont 4y ago
And it's so difficult to find any hardware anywhere that respects that flag that hacker forums are filled with questions asking if anyone ever saw such a device. Every modern copy or backup program ignores it, and it looks like none ever used it.
- kevin_thibedeau 4y ago
  It was used on standalone audio recorders.
  - ChrisLomont 4y ago
    Yep, very few, and likely nothing anyone is using now to copy/backup CDs with. In forums where people look for such things out of curiosity people mention they existed, but I've not yet found someone that owns one to play with. And zero of them stopped the analog hole on those old devices. Now, as to the actual bit(s). There were two bits, one said copyrighted work, one said is this a copy. Almost all CDs shipped with the copyright bit set and the "is a copy" bit set to 0. This meant you can make one copy of the CD (by law). The copy should have the "is a copy" bit set, meaning no more copies of the copied disc. This means you can actually copy the original CD as many times as you want, since it always looked like an original, hence copyable. Remember Sony hardware sold an order of magnitude more in value than Sony music :) Again, a non-issue. To recap: 1. Very few CDs even bothered to set the bits. 2. None (?) set both bits, meaning you can copy any original CD, even with bit respecting hardware. 3. The bit(s) in no way changed the audio. 4. No copy software on PC I have ever heard of even looked at the bit. 5. Very few pieces of hardware respected the bit. Did I miss anything?