Post #101698

2025-12-30 18:16 UTC

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.

Replies (4)

@angband@lemmy.world 2025-12-31 04:05

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

Open ##1183859
@CondorWonder@lemmy.ca 2025-12-30 18:56

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/?

Open ##1183860
@f4f4f4f4f4f4f4f4@sopuli.xyz 2025-12-31 01:28

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.

Open ##1183864
@bruhbeans@lemmy.ml 2025-12-30 18:28

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.

Open ##1183869