EAC CIRC and C1 error

[PO3c]

Revisitting and old topic as we learn 'new' things from the past.

C1 Errors​

C1 Errors are anomalies in the block error rate (BLER), which are bit-burning errors at the lowest measurable level, making these the least serious of the error types. This rate is rendered as errors per second. EVERY CD and CD-R contains THIS TYPE OF ERROR. These usually result from the CD burning process, but faulty media can also cause these to occur. Keeping these errors below an acceptable average of 220 errors per second is the standard here. https://www.blantonemusic.com/redbook-standard

Now using EAC we know it makes a great effort in cloning bits of data as accurate as possible, but does it confirm these bits as valid music data?

Reading though its documentation I can not find any mention of how EAC interact with CIRC correction code on the RedBook CD. More specific I try to learn if EAC correct C1 errors on the CD pressing, or rather extrac these errors as valid bits without confirming with CIRC code?

 

[kchap]

I think C1 errors below 220 are considered correctable. A high C1 error rate may indicate the pressing was poor or the CD is degrading, but they should not result errors in the data stream.

 

[PO3c]

Yes, this is how I understand the RedBook standard also. When playing on a normal audio CD player the CIRC error code interleaved over several frames will help mitigate many of the bit errors. But EAC do not mention any use of C1 error correction, only refers to C2.

I'm guessing this is due to CD-Rom station also read RedBook CD and CD-R utilizing the CIRC code. Hence no need for the EAC manual to talk about it. But would be nice to know for sure.

If this is not true this might actually explain why some say they hear a difference playing CD rather than the ripped version.

 

[AnalogSteph]

Reading though its documentation I can not find any mention of how EAC interact with CIRC correction code on the RedBook CD.

To my understanding, it doesn't. The optical drive itself handles all of that internally. Some drives are able to output C2 error indications, but otherwise the only way to find out whether anything went wrong is reading things multiple times and comparing the results. That's what EAC does in secure mode until it's gotten the same data back enough times to feel confident to continue.

If you need to verify that the rip is 100% perfect, your best chance is an online database (AccurateRip DB or CTDB).

 

[PO3c]

The optical drive itself handles all of that internally.

Thats what I've concluded also. And this is done using CIRC kode from the disk to correct the high amount of C1 errors RedBook allows for.

If not EAC could actually be reading and repeatedly verifying production errors from the media. Which then possible would make 100% match with the AccurateRip database less frequent than we are custom to.