1. Is it true that (at minimum) in any of the Secure modes EAC will read at least twice every thing it reads?
When, if ever, does EAC perform only one read of the audio?
How big is the chunk of data that is being read? 10x2352 bytes? 2352 bytes? 1 bit?
How sure can we be that EAC really does detect and "correct" errors?
the returned data is, say 0x2431. It reads again and the data is still 0x2431. [...] the scratch is done in such a way that the reflected information is always the same, AND wrong. How could EAC deal with this physical anomaly?
how sure are we of that?
should I go nuts with the offsets?
am I right to say that the digital extraction is successful anyway, that the offset only induces a time-shift (a very, very small one)?
When EAC commands the drive to read whatever amount it has to during its rip process, what error correction is performed by the drive? Is it using the Reed Salomon ECC error codes from the disc?
In DAE mode (... is it a 'mode' ?)
if the drive detects a problem on the disc (scratch, etc.) will it try to interpolate between two points or will it just send the data back unmodified?
Asked differently, in DAE mode does the drive treat the audio data as audio or as data?
The actual CD might have errors injected during its pressing (!).
When I perform a rip using EAC and this drive, will it be of the same quality from a rip performed from, say, a Plextor Ultraplex drive?
Great answer, Pio2001 - You should add this thread to the FAQ.
It is very rare that a scratch turns wrong just one byte. Such cases have been reported by BobHere ( http://www.digital-inn.de/showthread.php?t...?threadid=16578 ) and someone here (Tigre or Halcyon, I think).Most of the time, a scratch turns wrong several tens of bytes (see the increments of errors in Nero CD Speed quality check). When the reading is done again, some bytes that were wrong are right, and some that were right are wrong, and the difference is detected : http://www.digital-inn.de/showthread.php?t...?threadid=15838Quotehow sure are we of that?I'd say that the superiority of reading twice vs C2 has been tested about half a dozen times, and reading twice always came better than C2, that must have been at 99% accuracy. But remember it's before all a matter of drive, and of caching.
I personally would go with Secure, Test & Copy, C2 Enabled. This way, everything will be verified with CIRC *and* read twice (just in case..)If someone finds any weakness in this approach, I'd be happy to hear it.
QUOTE (Radetzky @ Mar 10 2003 - 03:55 AM) When, if ever, does EAC perform only one read of the audio? As soon as you check the "drive is capable of C2" checkbox
No, the quality directly depends on the drive.
I personally would go with Secure, Test & Copy, C2 Enabled. (...)If someone finds any weakness in this approach, I'd be happy to hear it.
Didn't Pio2001 just say that by enabling C2, it no longer reads twice but instead uses C2 error detection to find errors, thus making it less secure?
What do you mean by quality? Quality as in the # of errors picked/not picked up? Or quality as in how it sounds(too bright, no bass, etc)..
Seems I got it all wrong!
trying to recover damaged CDs, when error correction fails, but not by far, test and copy burst mode at low speed gives me the best results (same CRC), because in burst mode there is no risk of sync errors when the drives seeks back in order to try to correct errors.
Finally, EAC detects the following fatures for my drive : 'acurate stream', 'no caching', 'no C2'.If I select 'Drive caches audio data' anyway, will it force EAC to flush the inexistant cache and demand a second read _just in case_ there really is a cache and EAC couldn't detect it?
Would there be bad side effect of that?
"Burst mode" it's better with scratched CDs, but i've been trying also with the synchronized "Fast Mode" in EAC to try to copy damaged CDs; will "Burst Mode" will be better than "Fast Mode" in any case, or also depends on the drive?
QuoteWhy is it that Burst mode is regarded as better than Fast mode? (IIRC)Because it reads without repositioning the head, that increases the risk of loosing the track when there are scratches.
Why is it that Burst mode is regarded as better than Fast mode? (IIRC)
But if the drive always provide the same valuefrom it's interpolation technique... we have a problem, no?
I saw _ben_ questionned the term 'quality'. I too have aproblem understanding what you mean (even with the explanation yougave him).......................will I have the _exact_ same .wav file on myhdd (not taking into account the potentiel different offsets) ?
EAC will have received 12, 13, 15 both times but it will be froman interpolated value.
if the drive always provide the same valuefrom it's interpolation technique... we have a problem, no?if I extract a track with acheap drive and the same track with the best DAE capable drive andEAC reports that the extraction went by without any error, will I have the _exact_ same .wav file on myhdd ?
When you talked about the 'quality', you were referring to the way thedrive interpolates between points if an error is detected?
If not, what did you mean
and how would the sucessfully reported extraction from EAC differ when it is performed from a el-cheapo CD-ROM drive from a top of the line, made for DAE, CD-ROM drive?
will "Burst Mode" will be better than "Fast Mode" in any case, or also depends on the drive?
Finally, EAC detects the following features for my drive : 'acuratestream', 'no caching', 'no C2'.
Also, normally, if the drive has to interpolate or mute, I believe anerror should be detected by EAC. Unless we are very unlucky and adefect on the disc generates the same value twice.
* A drive that interpolates without reporting C2 errors may fool EAC into thinking there have been two good reads.
if we get a successful rip with EAC,it means we were able to extract the track ***perfectly***99.999999999% of the time
if the CRCs match between the two drives, the probability thatthe rip is correct must be growing a lot, no?
What do you mean by quality? Quality as in the # of errors picked/not picked up? Or quality as in how it sounds(too bright, no bass, etc).. I'm guessing you mean the former..
Can a badly extracted wav lack in bass, pitch, etc. ?I mean, an audio CD is full of 1's and 0's, so if the extracted wav has some 1's or 0's wrongit should have clicks or pops or not? It's not vinyl where a slightly deeper groove could produceslightly different sound... Am I wrong?