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Why does "ddrescue" fail for Audio Discs? (lemmy.ml)

submitted 2 days ago* (last edited 1 day ago) by doomsdayrs@lemmy.ml to c/asklemmy@lemmy.ml

7 comments fedilink hide all child comments

I have an audio disc that I want to produce a one to one ISO of (it has some marks).

When I try to use "ddrescue" to copy it, I get the following error message. ddrescue: /dev/sr0: Unaligned read error. Is sector size correct?.

What am I doing wrong? I would assume "ddrescue" would automatically figure out the sector size.

To note, I want to use "ddrescue" because "abcde" keeps hitting read errors on the disk.

Edit:

Seems that "ddrescue" does not support audio discs (https://unix.stackexchange.com/a/558628).

And "abcde" already uses "cdda paranoia".

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[–] angband@lemmy.world 4 points 1 day ago

audio cds are not a block format, they are a stream. dd works on block devices, where it can request blocks sequentially from the drive. audio cds can only be positioned by track, and even have to be oversampled to correct for jitter: https://www.cdroller.com/htm/readaudio.html

[–] CondorWonder@lemmy.ca 5 points 1 day ago (1 children)

ddrescue doesn’t work properly on audio discs (even if you use the correct sector size of 2048 bytes). Have you tried something like cdparanoia https://www.xiph.org/paranoia/?

[–] doomsdayrs@lemmy.ml 2 points 1 day ago

Am using "cdparanoia" (through "abcde") now.

[–] f4f4f4f4f4f4f4f4@sopuli.xyz 2 points 1 day ago

I've had success even on damaged discs with Exact Audio Copy on Windows, or fre:ac on Linux. Paranoia mode (or secure mode) is going to take a long time. It could be worth ripping with the fast burst mode and see if you can hear the errors/skips.

[–] bruhbeans@lemmy.ml 1 points 2 days ago (2 children)

Because audio CDs get written the opposite way to data CDs. I forget which is which but one gets written outside-in and the other inside-out.

[–] f4f4f4f4f4f4f4f4@sopuli.xyz 1 points 1 day ago

That's not right; both audio and data discs are burned and read inside to outside, which is the opposite of vinyl records.

[–] doomsdayrs@lemmy.ml 1 points 1 day ago* (last edited 1 day ago)

Passing "--reverse" to "ddrescue" does not help, leading to the same error message. 🙁