Checking compatibility for images augmented with error correction data
Motivation: dvdisaster can put error correction data
together with the user data on the medium.
The error correction data is appended to the ISO image in a way invisible
to most applications in order to not interfere with them.
Possible incompatibility: The CD/DVD/BD writing software may also
be unable to see the error correction data. While being unlikely it is
possible that the writing software will truncate or damage the error
correction data while creating the medium. In that case the error correction
will not work.
How to test compatibility:
Please note that some steps are only sketched out here;
follow the links to the respective sections to find detailed instructions
and examples.
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First create a medium which was augmented with
error correction data. Do not forget
to use the proper settings and follow the
step by step instructions.
Do not use rewriteable DVD or BD media as they may influence the test
under some circumstances (see item 3.4 in the
questions and answers).
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Create a second image from the written
medium.
Use the same settings and steps as in
reading a medium for creating an error
correction file; however you can stop after the reading has finished as
we do not need the error correction file.
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Enter the name of the second ISO image
which you have just read from the medium. Please note that the following
test is useless when working with the image which was initially created
using the CD/DVD/BD authoring software and augmented with dvdisaster.
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Start the evaluation by clicking
on the "Verify" button. |
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Look at the verification results.
If you get the green messages "Good image." and "Good error correction data."
your authoring software and dvdisaster are compatible with respect to
the augmented images.
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Possible error causes and remedy:
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Typical problem: wrong image size.
The verification may find out that the image is larger as expected.
Typically the difference is 150 or 300 sectors for CD media and
1-15 sectors for DVD/BD media. These might simply be zero padding sectors
appended by the writing software. To find out if this really is the case
do the following:
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Start a recovery process.
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Confirm the dialog.
A dialog will appear asking you if it is okay to remove the superflous
sectors from the image. Answer "OK".
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Stop the recovery process,
as after truncating the image there is nothing more to do.
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Start the verification again
by clicking on the "Verify" button. |
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Consider the new results.
If you now get the green messages "Good image." and "Good error correction
data." your problem is purely cosmetic: The writing software has indeed
added zero padding sectors while writing the medium.
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If the problem persists after carrying out the above
steps you can not use the CD/DVD/BD writing software
for creating media from augmented images.
Perform the test again using a software from a different vendor.
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