I done these C1/C2 test now, but I really don't know what values that are acceptable.
I heard that the C1 vaule "acceptable" limit is an average of 220 errors, but this sounds very high since most my burns are from 3.00-5.00 in average.
Are there diffrent acceptable values for CD&DVD?
IF so what are the acceptable values for Audio CDs & Video DVDs?
Full Version: Acceptable Values?
QUOTE(AudiophileSD @ Mar 17 2006, 02:07 AM)
I done these C1/C2 test now, but I really don't know what values that are acceptable.
I heard that the C1 vaule "acceptable" limit is an average of 220 errors, but this sounds very high since most my burns are from 3.00-5.00 in average.
Are there diffrent acceptable values for CD&DVD?
IF so what are the acceptable values for Audio CDs & Video DVDs?
I heard that the C1 vaule "acceptable" limit is an average of 220 errors, but this sounds very high since most my burns are from 3.00-5.00 in average.
Are there diffrent acceptable values for CD&DVD?
IF so what are the acceptable values for Audio CDs & Video DVDs?
It depends on the drive and program you use to measure. I can only speak for the Plextor drive / Plextools combination.
C1: the 220 limit is the official one, but as you have seen for yourself, with a good burner/media combination, you get nowhere near this limit, so no need to worry. I'd certainly reburn a disc that shows >100 C1 average, because CD-R are cheap and natural degradation usually leads to increasing error levels over time, which means the disc might become unreadable.
DVDs have a different form of error correction and don't use C1/C2 terminology, you have PIE/PIF there. The more important value is PIF ("parity inner failure"), which should stay below 4 over the whole disc.
To what sTisTi said I'll add that Redbook does not specify the acceptable limit on C2s. Pio2001 mentioned it was 1 C2 per hour in an earlier post.
<edit: spelling>
<edit: spelling>
my personally limits it that a new burned cd should not peak beyond 20 c1 errors an have no c2 errors
QUOTE(sven_Bent @ Mar 19 2006, 03:10 PM)
my personally limits it that a new burned cd should not peak beyond 20 c1 errors an have no c2 errors
Total of 20 C1 errors? Per disc? Is that possible at all?
Even Plextor CD-Rs burned with my PX-712A at 24x have at least 100 in total (but less than 0.5 on average and less than 5 maximum).
For C2, I though you don't want to get ANY C2 errors, meaning it should be zero because C2 error is not correctable, while C1 error is still correctable.
QUOTE(pika2000 @ Mar 19 2006, 07:34 PM)
For C2, I though you don't want to get ANY C2 errors, meaning it should be zero because C2 error is not correctable, while C1 error is still correctable.
Huh, where do you have that from? A certain number of C2 errors are correctable.
The limits are the following:
C1: 220 max. (equals up to 3% of the total data being unreadable)
C2: 7 max.
CU (uncorrectable): 0
Not total, but at any given point, meaning that there should be no spikes that go above that.
AudiophileSD, here's some more proof that the scanning speed influences the results:
QUOTE(CiTay @ Mar 19 2006, 10:54 PM)
AudiophileSD, here's some more proof that the scanning speed influences the results:
depends on the drive, i would say. here's a scan of one of my burned CDs and either my LITEON 16P9SV DVD-ROM isn't good for C1/C2 scanning or all my recently burned CDs have top notch quility, because they all look more or less the same, like this one:
-andy-
QUOTE(AndyMutz @ Mar 19 2006, 11:28 PM)
depends on the drive, i would say. here's a scan of one of my burned CDs and either my LITEON 16P9SV DVD-ROM isn't good for C1/C2 scanning or all my recently burned CDs have top notch quility, because they all look more or less the same, like this one:
c't once wrote that Lite-On's DVD-ROM drives are completely unusable for CD quality scans, only the CD-RW drives are acceptable for that (they compared the values to professional analyzers).
QUOTE(CiTay @ Mar 19 2006, 01:54 PM)
The limits are the following:
C1: 220 max. (equals up to 3% of the total data being unreadable)
C2: 7 max.
CU (uncorrectable): 0
C1: 220 max. (equals up to 3% of the total data being unreadable)
C2: 7 max.
CU (uncorrectable): 0
Uh, where does that 7 come from ?
QUOTE(spath @ Mar 19 2006, 11:37 PM)
QUOTE(CiTay @ Mar 19 2006, 01:54 PM)
The limits are the following:
C1: 220 max. (equals up to 3% of the total data being unreadable)
C2: 7 max.
CU (uncorrectable): 0
C1: 220 max. (equals up to 3% of the total data being unreadable)
C2: 7 max.
CU (uncorrectable): 0
Uh, where does that 7 come from ?
Another c't article about this topic
QUOTE(CiTay @ Mar 19 2006, 11:31 PM)
c't once wrote that Lite-On's DVD-ROM drives are completely unusable for CD quality scans, only the CD-RW drives are acceptable for that (they compared the values to professional analyzers).
what's a good drive for scanning CDs then?
here's the same disc, scanned with a BENQ DW1620 DVD burner.
i know the drive cannot report C2 errors, but the C1 errors seem more realistic..?
-andy-
QUOTE(AndyMutz @ Mar 20 2006, 02:54 AM)
what's a good drive for scanning CDs then?
here's the same disc, scanned with a BENQ DW1620 DVD burner.
i know the drive cannot report C2 errors, but the C1 errors seem more realistic..?
here's the same disc, scanned with a BENQ DW1620 DVD burner.
i know the drive cannot report C2 errors, but the C1 errors seem more realistic..?
There is really no "good" drive, we discussed this before in some other threads. The results are a combination of the drive's reading ability and the media quality, but the media quality is actually obscured by how well the drive reads it. The only thing i would say is, make as many measurements on the same drive as you can, then you can compare good/bad ones and make a rough quality estimation between them. You can't, however, compare scans from different drives, or different programs (Plextools/Nero), and the results also can't be compared to professional analyzer results.
QUOTE(CiTay @ Mar 19 2006, 03:45 PM)
QUOTE(spath @ Mar 19 2006, 11:37 PM)
Uh, where does that 7 come from ?
Another c't article about this topic
Hehe, why am I not surprised ?
No such thing in the Red Book though.
QUOTE(Sebastian Mares @ Mar 19 2006, 06:15 PM)
Total of 20 C1 errors? Per disc? Is that possible at all?
Even Plextor CD-Rs burned with my PX-712A at 24x have at least 100 in total (but less than 0.5 on average and less than 5 maximum).
Even Plextor CD-Rs burned with my PX-712A at 24x have at least 100 in total (but less than 0.5 on average and less than 5 maximum).
sorry theire. i didnt clarify.
peak value of 20 with nero cd/dvd speed
it's not a total number for a CD but a peak value for some certain time intervall
But if I make a Redbook Master AudioCD do I really need a correct C1 figure?
Isn't the C2 the important thing to have correct? Cause it's C2 errors that can cause problems.
I mean I don't think my new Lite-On burner reaches the C1 threshold level for Redbook.
I did the advanced DAE test in Nero CD/DVD Speed and it got good figures on the C2 Test.
It got 100% on C2 Thoroughness it didn't miss any C2 errors so that mean that the C2 scan on my Lite-On drive is accurate.
So if I do get a C2 error on any Master CD I make I will know it, that sounds like the most important thing to know.
C1 analysis sound more like a good to know value but not as crucial as C2, or am I wrong here?
Isn't the C2 the important thing to have correct? Cause it's C2 errors that can cause problems.
I mean I don't think my new Lite-On burner reaches the C1 threshold level for Redbook.
I did the advanced DAE test in Nero CD/DVD Speed and it got good figures on the C2 Test.
It got 100% on C2 Thoroughness it didn't miss any C2 errors so that mean that the C2 scan on my Lite-On drive is accurate.
So if I do get a C2 error on any Master CD I make I will know it, that sounds like the most important thing to know.
C1 analysis sound more like a good to know value but not as crucial as C2, or am I wrong here?
C1 errors are those that can be completely corrected by the system, before data reaches the DAC. C2 errors are those uncorrectable at the C1 level. At the time they are declared C2 it is unknown whether or not they will be correctable. Therefore, if testing only reports the C1 level errors, you just don't know if there are worse ones.
QUOTE(AndyH-ha @ Mar 20 2006, 06:13 PM)
C1 errors are those that can be completely corrected by the system, before data reaches the DAC. C2 errors are those uncorrectable at the C1 level. At the time they are declared C2 it is unknown whether or not they will be correctable. Therefore, if testing only reports the C1 level errors, you just don't know if there are worse ones.
So you're saying i'm ok just by knowing that my Lite-On dive has 100% accuracy in spoting the C2 errors?
I don't need to worry about it being inaccurate in analyzing C1 statistics?
The drive isn't inaccurate. The errors are not absolute things, they are a measure of how well THAT drive reads that CD. If another drive reports fewer errors, it means it read the disk more easily. If it reports more errors, that means it had more trouble with the disk. Quite possibly the errors don't exist, any more than errors exist on the eye doctor's chart. The error is in the reader, not the source.
This in not to say that unreadable conditions never exist on a CD, they certainly do. The testing however, is not about the CD per se but about the reading process. The CD might be very good by objective standards but a particular drive reports errors, not because it is wrong or inacurate in its reporting, but because, by goodness, it just had trouble reading that disk. Likewise, a poorer quality disk (e.g. less contrast between the dye marks and the background) might be read with few reported errors because the drive just read well in spite of that difficulty.
The real value of the test, as had been reported a great many times, is to use it to find out which media, at which write speed, gives you the fewest errors. Then you create all your CD-R with those disks at that speed.
A second great value is to make a record of the read errors soon after creating the disk. Save the record. Later, a year, or three, or whenever, test it again. If the errors are significantly higher, the disk is probably deteriorating. Maybe you used poor quality blanks and should consider another brand. Maybe something else is wrong, but you probably want to fix it so your CDs don't all die.
This test presumes that the drive you are testing with hasn't itself changed greatly over that time. you can somewhat verify this by comparing very recently made CD-Rs with your saved results from earlier times.
This in not to say that unreadable conditions never exist on a CD, they certainly do. The testing however, is not about the CD per se but about the reading process. The CD might be very good by objective standards but a particular drive reports errors, not because it is wrong or inacurate in its reporting, but because, by goodness, it just had trouble reading that disk. Likewise, a poorer quality disk (e.g. less contrast between the dye marks and the background) might be read with few reported errors because the drive just read well in spite of that difficulty.
The real value of the test, as had been reported a great many times, is to use it to find out which media, at which write speed, gives you the fewest errors. Then you create all your CD-R with those disks at that speed.
A second great value is to make a record of the read errors soon after creating the disk. Save the record. Later, a year, or three, or whenever, test it again. If the errors are significantly higher, the disk is probably deteriorating. Maybe you used poor quality blanks and should consider another brand. Maybe something else is wrong, but you probably want to fix it so your CDs don't all die.
This test presumes that the drive you are testing with hasn't itself changed greatly over that time. you can somewhat verify this by comparing very recently made CD-Rs with your saved results from earlier times.
QUOTE(AndyH-ha @ Mar 20 2006, 10:02 PM)
The drive isn't inaccurate. The errors are not absolute things, they are a measure of how well THAT drive reads that CD. If another drive reports fewer errors, it means it read the disk more easily. If it reports more errors, that means it had more trouble with the disk. Quite possibly the errors don't exist, any more than errors exist on the eye doctor's chart. The error is in the reader, not the source.
This in not to say that unreadable conditions never exist on a CD, they certainly do. The testing however, is not about the CD per se but about the reading process. The CD might be very good by objective standards but a particular drive reports errors, not because it is wrong or inacurate in its reporting, but because, by goodness, it just had trouble reading that disk. Likewise, a poorer quality disk (e.g. less contrast between the dye marks and the background) might be read with few reported errors because the drive just read well in spite of that difficulty.
The real value of the test, as had been reported a great many times, is to use it to find out which media, at which write speed, gives you the fewest errors. Then you create all your CD-R with those disks at that speed.
A second great value is to make a record of the read errors soon after creating the disk. Save the record. Later, a year, or three, or whenever, test it again. If the errors are significantly higher, the disk is probably deteriorating. Maybe you used poor quality blanks and should consider another brand. Maybe something else is wrong, but you probably want to fix it so your CDs don't all die.
This test presumes that the drive you are testing with hasn't itself changed greatly over that time. you can somewhat verify this by comparing very recently made CD-Rs with your saved results from earlier times.
This in not to say that unreadable conditions never exist on a CD, they certainly do. The testing however, is not about the CD per se but about the reading process. The CD might be very good by objective standards but a particular drive reports errors, not because it is wrong or inacurate in its reporting, but because, by goodness, it just had trouble reading that disk. Likewise, a poorer quality disk (e.g. less contrast between the dye marks and the background) might be read with few reported errors because the drive just read well in spite of that difficulty.
The real value of the test, as had been reported a great many times, is to use it to find out which media, at which write speed, gives you the fewest errors. Then you create all your CD-R with those disks at that speed.
A second great value is to make a record of the read errors soon after creating the disk. Save the record. Later, a year, or three, or whenever, test it again. If the errors are significantly higher, the disk is probably deteriorating. Maybe you used poor quality blanks and should consider another brand. Maybe something else is wrong, but you probably want to fix it so your CDs don't all die.
This test presumes that the drive you are testing with hasn't itself changed greatly over that time. you can somewhat verify this by comparing very recently made CD-Rs with your saved results from earlier times.
So I get so low C1 errors because my Lite-On drive has very easy to read my burnt CD-R discs?
I did a analyze of a Kodak CD-R Ultima that was burnt in October 2001, and I got higher numbers for sure but they are still good:
When writing a AudioCD you should have 0 C2 errors and I always do, but when I burn a Video DVD I can never get the C2 levels down to 0.
Can't C2 levels be 0 on a DVD? Are there any guidelines how many C2 errors that is acceptable on a DVD?
QUOTE(AudiophileSD @ Mar 21 2006, 09:29 AM)
Can't C2 levels be 0 on a DVD? Are there any guidelines how many C2 errors that is acceptable on a DVD?
*sigh* Did you 1) read what the first answer in this thread said about DVD
and 2) ever try to use google before posting questions to a messageboard ?
The following should give you some insight into disc quality (and spare us
a few dozen questions
) :http://club.cdfreaks.com/showthread.php?t=80545
http://www.cdfreaks.com/article/202
QUOTE(spath @ Mar 21 2006, 12:47 PM)
QUOTE(AudiophileSD @ Mar 21 2006, 09:29 AM)
Can't C2 levels be 0 on a DVD? Are there any guidelines how many C2 errors that is acceptable on a DVD?
*sigh* Did you 1) read what the first answer in this thread said about DVD
and 2) ever try to use google before posting questions to a messageboard ?
The following should give you some insight into disc quality (and spare us
a few dozen questions
) :http://club.cdfreaks.com/showthread.php?t=80545
http://www.cdfreaks.com/article/202
Yeah sure I read it but cause I just started with this I would think it's kind of ok to ask questions since many things on the web makes little sence to me.
I just wan't to be sure, if I knew this stuff I wouldn't be in here.
QUOTE(spath @ Mar 20 2006, 02:58 PM)
QUOTE(CiTay @ Mar 19 2006, 03:45 PM)
QUOTE(spath @ Mar 19 2006, 11:37 PM)
Uh, where does that 7 come from ?
Another c't article about this topic :)
Hehe, why am I not surprised ? :) No such thing in the Red Book though.
QUOTE(AudiophileSD @ Mar 21 2006, 05:08 PM)
I would think it's kind of ok to ask questions since many things on the web makes little sence to me.
It's OK to ask questions. It's not OK to repeat the same questions while ignoring the answers that have already been given.
QUOTE(AudiophileSD @ Mar 21 2006, 05:08 PM)
I just wan't to be sure, if I knew this stuff I wouldn't be in here.
I imagine that a lot of ppl are here because they can learn a thing or two; but you make it sound like this is some kind of hospital. Sheesh... This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.