when augmenting images with error correction data

dvdisaster Version 0.72.6 / 0.79 (devel-3) | To the Internet version

Contents
News
Overview
Howtos
· | The big picture
· | Scanning media for errors
· | Putting error correction data on a separate file
· | Putting error correction data on the medium
· | Recovering media images
· | Getting information about images and error correction data
· | Testing image compatibility
| - | with error correction files
| - | when augmenting images with error correction data
· | Dialogs and buttons
Download
Questions and Answers
Bug reporting
|  | ### 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.
|  | 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).
|  | 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.
|  | 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.
|  | Start the evaluation by clicking on the "Verify" button.
|  | 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.
Possible error causes and remedy:
|  | 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:
|  | Start a recovery process.
|  | Confirm the dialog. A dialog will appear asking you if it is okay to remove the superflous sectors from the image. Answer "OK".
|  | Stop the recovery process, as after truncating the image there is nothing more to do.
|  | Start the verification again by clicking on the "Verify" button.
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.
Screen shot: Show Information.
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.

Copyright 2004-2014 Carsten Gnörlich. Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.