Idézet: DeadMeat - Dátum: 2004. aug. 9., hétfő - 1:19
"Valaki mondja már el végre a KProbe kék és piros grafikonjainak jelentését."
Erre vonatkozik a PLS.Kulonben azt tudtam h nem lehet az iroval hasznalni a tesztet.Engem az erdekelne h mennyi hibapontig ok a lemez.A segitsegert elore is thx!!!!!!!!!
Egy kis angol:
ECMA 267 Standard for DVD-ROM, ECMA 337 Standard for DVD+R/RW and ECMA 338 Standard for DVD-R/RW at
http://www.ecma-international.org if you want to look at the standards for yourself. Here is some data from the ECMA standards (same for DVD-ROM, DVD-R/RW and DVD+R/RW):
Random errors:
A row of an ECC Block that has at least 1 byte in error constitutes a PI error. In any 8 consecutive ECC Blocks the total number of PI errors before correction shall not exceed 280.
Here we see what a PI error is defined as a row in an ECC block having 1 byte or more containing errors. And that the sum of PI errors in 8 ECC blocks after each other should not exceed 280 PI errors.
But what is a row and what is an ECC block? Again we refer to the ECMA standards. We do not copy and paste everything but if interested look in the ECMA standards.
A row is 182 bytes long where the last 10 bytes contain PI (Parity Inner) information. An ECC block is 208 rows long where the last 16 rows contains the PO (Parity Outer) information. This gives us a maximum possible PI error amount of 208 errors per block and for 8 blocks after each other this sum is of course 8 times higher giving a maximum possible amount of 1664 PI errors. In practical use we have found that a disc with 1664 PI errors is unreadable.
According to our test the specified max PI sum of 280 for good discs seems to be a good guideline, as a few readers have problems reading discs when the PI failures is over 300 and many players starts to have problems when the PI failures reaches 600 and most players have problems with discs exceeding 900 PI errors or more.
But what are the PO errors that K-Probe reports? Actually the PO errors that K-Probe reports is the Parity Inner uncorrectable errors, meaning errors left after PI correction. Only the ECMA 337 standard describes the Parity Inner uncorrectable errors. So how is a Parity Inner uncorrectable error defined? Here are what ECMA 337 states:
“If a row of an ECC Block as defined in 13.3 contains more than 5 erroneous bytes, the row is said to be “PI-uncorrectable”.”
In theory an ECC block may in the worst case have 208 PI uncorrectable errors since every ECC block is 208 rows long. But the ECMA 337 standard goes further and specifies the max amount of accepted PI uncorrectable errors allowed on a good disc:
“- In any ECC Block the number of PI-uncorrectable rows should not exceed 4.”
This is where K-Probe gives us problems as for PI errors it have to be set to a PI/PO sum of 8 ECC blocks to show results that compares to the standard, but for PI uncorrectable errors (Called PO in K-Probe) the PI/PO sum have to be set to a sum of 1 ECC block.
A guideline is to calculate the Parity Inner Uncorrectable errors to 8 ECC sum, which is max 32 (4 x 8) Parity Inner uncorrectable errors, but now we can’t be sure if one of the 8 ECC blocks exceeds the specifications. But if the result exceeds 32 PI uncorrectable errors we know that at least one block have more than 4 PI uncorrectable errors. But if the PO error amount is between 5 and 32 there may still be a block that exceeds the standards.
But what makes a disc unreadable? A PO uncorrectable error will make the disc unreadable, but K-Probe does not display the PO uncorrectable errors.
Also these standards are probably when the disc is scanned at 1X reading speed.
So to get results directly comparable to the standards you have to scan a disc twice at 1X reading speed:
1 time with PI/PO sum set to 8 ECC to get a result comparable to the 280 PI errors per 8 blocks standard.
1 time with PI/PO sum set to 1 ECC to get a result comparable to the MAX 4 PI Uncorrectable (Called PO in K-Probe) per block standard.
Rövidebben és érthetőbben:
For the following recommendations to be true K-Probe must be set to 8 ECC PI/PO sum while scanning and preferably scanned by a Lite-On DVD-Writer (in other words NOT a DVD-ROM or Combo!).
Use this as a guideline for good discs:
PI (Parity Inner): No larger areas on the disc should exceed 280 PI errors, do not worry too much about high single spikes that exceeds 280.
PO (Parity Outer): No larger areas on the disc should exceed 32 PO (actually PI uncorrectable) errors, do not worry too much about high single spikes that exceeds 32. (Note that this is not completely correct according to the standards, but is still a good guideline, read the first technical post if you wonder why this is not a 100% correct way of reading the results compared to the standards).
Notice that there are other aspects such as disc reflectivity, jitter, tracking errors and so on that also will affect the readability of a DVD disc – but for this we do not have measuring equipment available.
And another note is that we normally scan/recommend scanning the discs at 4X CLV speed since this saves time compared to 2X/2.4X and 1X scanning and still offers CLV reading, but by lowering the speed to 2X(DVD-R/RW)/2.4X(DVD+R/RW) or 1X the amount of reported errors may drop on some discs.
Also using Nero CD/DVD-Speed to do a transfer rate test with a picky DVD-ROM (JLMS XJ-HD165H for example) and see if the reading speed drops is a good indication of the quality of the disc.
(CDfreaks fórumból ollózva, segítségképpen a Kprobe2 programhoz)