PART 1: Technical Discussion; Questions CDDA Ripping, PerfectTUNES etc.

[Edward3]

Hi Spoon,

Thank you for your continued work—I’ve been following your forums for many years.

Apologies for the length and number of questions. I’ve consolidated them here for efficiency, and due to text limits, had to post in multiple parts. I hope that’s okay.

By background, I previously worked as a developer on CDDA DRM (with brief involvement in DVD DRM) and contributed to several related patents. While this work was commercially motivated at the time, I no longer support DRM. I...

[Spoon]

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[Spoon]

SUBJECT: Technical Discussion/Questions: CDDA Ripping with PerfectTUNES, ECC/CIRC Limitations, and AccurateRip Reliability

Hi Spoon,

Thank you for your continued work—I’ve been following your forums for many years.

Apologies for the length and number of questions. I’ve consolidated them here for efficiency, but I’m happy to split them into separate posts in the proper forum categories if preferred.

By background, I previously worked as a developer on CDDA DRM (with brief involvement in DVD DRM) and contributed to several related patents. While this work was commercially motivated at the time, I no longer support DRM, as I do not believe it effectively prevents piracy and instead disproportionately impacts legitimate users. I also recognize its negative impact on archival integrity. For example, I no longer have access to original masters (e.g., Final Fantasy X-2 VGM), and in some cases lossy-deleted samples replaced with interpolation artifacts are effectively unrecoverable (it's impossible). My prior replication and plant contacts are also no longer available, so I am now limited to consumer-level tools and analysis.

Historically, I experimented with hardware consumer modified drives that intentionally wrote CU/E32-level errors to mask data (forcing interpolation in players while confusing rippers). As expected, this approach was ultimately ineffective.

As we know, CDDA sectors (2352 bytes) allocate all space to audio data, with no additional room for sector addressing or higher-level ECC/EDC. Error handling relies entirely on CIRC, which is inherently limited. When errors exceed correction capability (C2), interpolation occurs, breaking bit-perfect extraction. Compounding this, many drives that support C2 error reporting may fail to reliably report a C2 error and cause interpolation (damaged data).

Professional mastering/replication equipment appears to provide deeper error visibility and control, but such tools are not accessible to consumers. Given a large archive (~10,000 discs), exhaustive multi-drive ripping is impractical despite having a substantial collection of drives including my favorite PlexWriter Premium2 and Yamaha units are my second pick).

From my understanding, CDDA structure includes TOC, subchannel data, PCM frames, and CIRC-based error correction.

I have the following questions:

1. Pre-emphasis (NR flag detection):
   Both EAC and dBpoweramp appear to rely solely on TOC flags. Some early discs reportedly store the flags only in subchannel data instead. The issue is that when pre-emphasis flags exist outside the TOC (e.g., in subchannel data), EAC and dBpoweramp may not detect them. Obviously I do not want de-emphasis applied during extraction, but I am concerned the software may misidentify the disc as having no pre-emphasis at all but yet apply it due to the subchannel because it is not listed in the TOC. My goal is to preserve exact, 1:1 PCM data.
2. AccurateRip error handling (downloaded FLACs):
   When AccurateRip reports mismatches on a small number of tracks, is there any mechanism to reconstruct minor errors (e.g., limited byte-level discrepancies) using redundancy or ECC-like methods? Or would this require a complete reference database, making it impractical?

[Spoon]

1. There are not many discs with Pre-emphasis, there are lists out there which list all the known discs and weather it is signaled in the TOC and subcodes.
2. No, there is CueTools which can do this with its CueTools DB, we will implement this in dBpoweramp hopefully soon.