1 Topic by fuzzball (edited by fuzzball 2020-10-11 03:35:02)

  • From: Llylgamyn
  • Registered: 2007-12-05
  • Posts: 1,656

case 1:

Number of sector(s) where user data doesn't match the expected ECC/EDC: 1
Number of sector(s) where while user data does match the expected ECC/EDC there is no EDC: 1337

Error count is 1? or 1337? or 1+1337=1338?

case 2:

Number of sector(s) where while user data does match the expected ECC/EDC there is no EDC: 46113

Error count is 0? or 46113?

Region Extractor
  • Registered: 2014-10-06
  • Posts: 701

From code:

                    //
                    // Might be Mode 2, Form 2
                    //
                    if (
                        edc_compute(0, sector + 0x10, 0x91C) == get32lsb(sector + 0x10 + 0x91C)
                        ) {
                        return 3; // Mode 2, Form 2
                    }
                    else {
                        return 4; // Mode 2, No EDC (for PlayStation)
                    }

What you're asking is if return 4 is in error path. Yes. EDC doesn't match for the sector. What does CDmage report?
So I think it's 1338 and 46113.

  • From: Llylgamyn
  • Registered: 2007-12-05
  • Posts: 1,656

reentrant wrote:

What does CDmage report?

1 and 0.

Region Extractor
  • Registered: 2014-10-06
  • Posts: 701

What's the value of EDC for such sectors: 0 or different than 0? Maybe value of 0 is a special case...
Are the sectors readable in simple imaging tools like IsoBuster?

  • From: Llylgamyn
  • Registered: 2007-12-05
  • Posts: 1,656

reentrant wrote:

Are the sectors readable in simple imaging tools like IsoBuster?

Yes. Both are PlayStation disc.

case 1:
http://redump.org/disc/29762/

case 2:
http://redump.org/disc/15196/
http://redump.org/disc/15257/

Region Extractor
  • Registered: 2006-12-24
  • Posts: 3,846

"Number of sector(s) where while user data does match the expected ECC/EDC there is no EDC" -- most likely these numbers just show the number of Mode 2 Form 1 sectors in the NoEDC image, these are not errors.

I think it's better to report the number of errors from CDMage, because edcchhk treats many cases as "warnings", that's confusing.

  • Jackal
  • Moderator (Retired)
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  • Registered: 2006-12-23
  • Posts: 4,130

F1ReB4LL wrote:

I think it's better to report the number of errors from CDMage, because edcchhk treats many cases as "warnings", that's confusing.

I agree.. but I think the 1337 and 46113 are the sectors with modified subheaders. They do show as errors in CDMage?

  • Registered: 2006-12-24
  • Posts: 3,846

Jackal wrote:

They do show as errors in CDMage?

He says "no" (3rd post).

"while user data does match the expected ECC/EDC there is no EDC" -- IMO, it says "there's no ECC/EDC error, but EDC itself is null" and nothing about subheaders at all, that's normal for NoEDC images.

  • iR0b0t
  • iR0b0t
  • Administrator
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  • From: Research equipment
  • Registered: 2008-02-21
  • Posts: 6,703

edcchhk returns a correct amount of ERRORS, just look for that line and not for total.

CDmage (at least the last version i was ever using) returns any "errors" you can ever have: moddified subheaders, ECC/EDC error etc. Where moddified subheaders and ECC/EDC mismatch is not an actual ERROR and should not be included into final errors count.

case1 = 1
case2 = 0

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)
  • Registered: 2006-12-24
  • Posts: 3,846

iR0b0t wrote:

Where moddified subheaders and ECC/EDC mismatch is not an actual ERROR and should not be included into final errors count.

Disagree. IMO, we should include any imperfections into the total errors count. Otherwise, there should be a "Warnings" count field as well.
I'm not talking about NoEDC sectors in NoEDC images, of course, I don't understand the reason to warn there.