C1 and C2 errors

Daniel Prince wrote:

My understanding is that if there are too many C1 errors on a CDR disc
sector, I will get a C2 error and that if there are too many C2 errors I
will get a DOS/Windows error. Is this correct? If it is correct, how
many C1 errors are too many and how many C2 errors are too many?


You've got the right idea. The important thing to remember is that if
you get too many consecutive C1 errors (3 I think) then you'll get a C2
error.

The red book specification calls for a maximum error rate of 220 per
second but, in my experience, a good burn will give far fewer C1 errors
and no C2 errors.

I have a Cendyne 16x10x40 CD-RW drive which is a Lite-On LTR 16101B
Firmware revision TS0L. I have tested several of the discs I have
written on this drive for C1 and C2 errors. None of them have any C2
errors. They all have some C1 errors. Most of them have between 3,000
and 4,000 total C1 errors, a maximum (per sector?) of between 20 and 30
and an average of around 0.8. How bad is this?


That's a reasonable result but could possibly be bettered. Different
drives have different preferences so it is difficult to recommend media
for your drive. I would try burning a few different brands of disc - see
if you can get hold of some Taiyo Yuden discs and some Mitsui discs. Try
burning at different speeds - I'd suggest 8X and 12X are most likely to
give the lowest error rates.

I'd aim for an average error rate of 0.4 with decent media but if you
are lucky you could get as low as 0.1 with the right drive and media.

Cheers.

James.

G'day James,

Can you recommend decent software tool (preferably freeware for
analysing error rates on CDRs please?

In article ,
James Perrett wrote:
Daniel Prince wrote:
My understanding is that if there are too many C1 errors on a CDR disc
sector, I will get a C2 error and that if there are too many C2 errors I
will get a DOS/Windows error. Is this correct? If it is correct, how
many C1 errors are too many and how many C2 errors are too many?

You've got the right idea. The important thing to remember is that if
you get too many consecutive C1 errors (3 I think) then you'll get a C2
error.

The red book specification calls for a maximum error rate of 220 per
second but, in my experience, a good burn will give far fewer C1 errors
and no C2 errors.

I have a Cendyne 16x10x40 CD-RW drive which is a Lite-On LTR 16101B
Firmware revision TS0L. I have tested several of the discs I have
written on this drive for C1 and C2 errors. None of them have any C2
errors. They all have some C1 errors. Most of them have between 3,000
and 4,000 total C1 errors, a maximum (per sector?) of between 20 and 30
and an average of around 0.8. How bad is this?

That's a reasonable result but could possibly be bettered. Different
drives have different preferences so it is difficult to recommend media
for your drive. I would try burning a few different brands of disc - see
if you can get hold of some Taiyo Yuden discs and some Mitsui discs. Try
burning at different speeds - I'd suggest 8X and 12X are most likely to
give the lowest error rates.

I'd aim for an average error rate of 0.4 with decent media but if you
are lucky you could get as low as 0.1 with the right drive and media.


Cheers, Phred.

--
LID

(Phred) wrote:

Can you recommend decent software tool (preferably freeware for
analysing error rates on CDRs please?

I used Nero CD-DVD Speed V2.11. http://www.cdspeed2000.com/ It is
freeware.
--
Whenever I hear or think of the song "Great green gobs of greasy
grimey gopher guts" I imagine my cat saying; "That sounds REALLY,
REALLY good. I'll have some of that!"

James Perrett wrote:

You've got the right idea. The important thing to remember is that if
you get too many consecutive C1 errors (3 I think) then you'll get a C2
error.

Do you know how many C2 errors you can have before you get a Dos/Windows
error?
--
Whenever I hear or think of the song "Great green gobs of greasy
grimey gopher guts" I imagine my cat saying; "That sounds REALLY,
REALLY good. I'll have some of that!"

"Daniel Prince" wrote:

Do you know how many C2 errors you can have before
you get a Dos/Windows error?

My understanding is that C2 errors are completely and seamlessly corrected
before the operating system ever sees the data. By definition, no amount of
C2 errors will cause a DOS/Windows error. I've seen CDs in which more than
half the sectors were reported as having C2 errors and it was still a simple
matter to copy the data off and re-burn to a new disc.

Once the error density is high enough to cause an unrecoverable data error,
it's no longer a C2 error.

There, now someone please correct me. :-)

Rick.
-+---

http://www.alienshore.com/seeking/

Daniel Prince wrote:

James Perrett wrote:

You've got the right idea. The important thing to remember is that if
you get too many consecutive C1 errors (3 I think) then you'll get a C2
error.

Do you know how many C2 errors you can have before you get a Dos/Windows
error?

On an audio CD you are allowed 2 consecutive C2 errors before you get an
E32 which is generally considered uncorrectable. However, data CD's have
a further level of error correction and I'm not sure how many errors are
allowed before this correction gives up. Audio CD players also
incorporate an interpolation stage so some E32's are disguised by this
interpolation.

Cheers.

James.

Daniel Prince wrote:

(Phred) wrote:

Can you recommend decent software tool (preferably freeware for
analysing error rates on CDRs please?

I used Nero CD-DVD Speed V2.11. http://www.cdspeed2000.com/ It is
freeware.

The versions of CDSpeed that I've seen will only detect C2 errors (and
worse). Some CD writer manufacturers produce their own in-house software
for their particular drives but only Plextor officially support C1 error
checking for end users with the Premium drive.

Cheers.

James.

James Perrett wrote:

Daniel Prince wrote:

(Phred) wrote:

Can you recommend decent software tool (preferably freeware for
analysing error rates on CDRs please?

I used Nero CD-DVD Speed V2.11. http://www.cdspeed2000.com/ It is
freeware.

The versions of CDSpeed that I've seen will only detect C2 errors (and
worse). Some CD writer manufacturers produce their own in-house software
for their particular drives but only Plextor officially support C1 error
checking for end users with the Premium drive.

Nero CD-DVD Speed V2.11 claims to detect C1 errors on my CD-RW drive.
If you do not believe me, I can send you the screen dump with the C1
errors listed.

When I run Nero CD-DVD Speed V2.11 on my DVD rom drive I get an error
message if "Report C1 errors" is checked. The help file says that not
all drives can report C1 errors.
--
Whenever I hear or think of the song "Great green gobs of greasy
grimey gopher guts" I imagine my cat saying; "That sounds REALLY,
REALLY good. I'll have some of that!"

James Perrett wrote:
You've got the right idea. The important thing to remember is that if
you get too many consecutive C1 errors (3 I think) then you'll get a C2
error.

Do you know how many C2 errors you can have before you get a Dos/Windows
error?

On an audio CD you are allowed 2 consecutive C2 errors before you get an
E32 which is generally considered uncorrectable. However, data CD's have
a further level of error correction and I'm not sure how many errors are
allowed before this correction gives up. Audio CD players also
incorporate an interpolation stage so some E32's are disguised by this
interpolation.

For a quick explanation, see:

Subject: [2-47] What are C2 errors? What do they say about disc quality?

For a longer explanation, see:

Subject: [2-43-3] What's a frame? CIRC encoding? How does ECC work?

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Daniel Prince wrote:

James Perrett wrote:

Daniel Prince wrote:

(Phred) wrote:

Can you recommend decent software tool (preferably freeware for
analysing error rates on CDRs please?

I used Nero CD-DVD Speed V2.11. http://www.cdspeed2000.com/ It is
freeware.

The versions of CDSpeed that I've seen will only detect C2 errors (and
worse). Some CD writer manufacturers produce their own in-house software
for their particular drives but only Plextor officially support C1 error
checking for end users with the Premium drive.

Nero CD-DVD Speed V2.11 claims to detect C1 errors on my CD-RW drive.
If you do not believe me, I can send you the screen dump with the C1
errors listed.

When I run Nero CD-DVD Speed V2.11 on my DVD rom drive I get an error
message if "Report C1 errors" is checked. The help file says that not
all drives can report C1 errors.

I took a look at this version and it certainly appears to support C1
testing although it didn't appear to work with one drive that I know
supports these flags.

Cheers.

James.