dvdisaster Version 0.72 | To the Internet version

Contents

News
Overview
Howtos
· | The big picture
· | Scanning media for errors
· | Putting error correction data on a separate file
| - | Decision help
| - | Basic settings for reading
| - | Creating the error correction file
| - | Archiving error correction files
| - | Advanced settings
· | Putting error correction data on the medium
· | Recovering media images
· | Getting information about images and error correction data
· | Testing image compatibility
· | Dialogs and buttons
Download
Questions and Answers
Bug reporting

Creating error correction files |
Basic settings

| The following tabs are found in the configuration dialog. Open the dialog by selecting the symbol marked green in the screen shot (click the image to expand it). The symbol may look different due to the symbol theme you are using.

Opening the configuration dialog.

Settings for reading the image from the medium

| If you already have an ISO image available you can skip the next two tabs and proceed with the error correction settings. But make sure that you really have an ISO type image; other formats like ".nrg" do not produce usable error correction data.

"Image" tab. Make sure that the image size is determined using the "ISO/UDF" setting and that the linear reading strategy is selected. The required selections are marked green. Leave the other settings at their defaults.

"Image" tab.

"Drive" tab. Reading data from the drive while it is spinning up can generate spurious error reports. Adjust the spin up time for your drive (typically 5-10 seconds) in the field marked green to make dvdisaster wait for the appropriate time.

Leave the other settings at the shown values.

"Drive" tab.

"Read attempts". The option "Read and analyse raw sectors" (marked green) uses additional information provided by the drive to check the integrity of read data. This is recommended as we are interested in creating error correction data from a properly read image. On the other hand since error correction data can only be created from fully readable media we do not need multiple reading attempts and caching of raw sectors as shown in the screen shot.

Screen shot: "Read attempts".

Error correction settings

"Error correction" tab. First choose "Error correction file (RS01)" in the "Storage method" list (green marking). By picking the redundancy you will determine the maximum error correction capability: An error correction file with x% redundancy can correct up to x% of read errors under optimal circumstances. Since the best case is usually not encountered you should add some safety margin to the redundancy by picking one of the following choices (see yellow markings);

- The "normal" and "high" presets provide a redundancy of 14.3% and 33.5% respectively. These two settings are very fast in creating error correction files due to optimized program code.
- You can freely choose the redundancy by activating the "other" item and dragging the slider.
- By activating the "Use at most" button you can specify the error correction file size in MB. dvdisaster will choose a suitable redundancy so that the error correction file will be close to but not larger than the specified size.

The redundancy will also determine the size of the error correction file; using x% redundancy will create an error correction file of about x% the size of the image. Using redundancies lower than the "normal" setting (14.3%) is not recommended as the error correction might be overloaded too quickly.

"Error correction" tab.

"Files" tab. If your operating system can not create files larger than 2GB then you must choose the "Split files " setting (marked green). In that case dvdisaster will create up to 100 segments called "medium00.iso", "medium01.iso" etc. instead of a single "medium.iso" file. Using this option results in a small performance hit. This option is mostly useful under Windows if the old FAT32 file system is still used. Leave the other settings off for the moment; suggestions for further optimization follow later.

"Files" tab.

Not used tabs

The "Misc" tab currently has only functions for creating log files. This is helpful for sending in bug reports but should be left off during normal operation. The "Appearance" tab allows you to adapt the output colors to your taste, but these have no further effects on the error correction data creation.

Creating the error correction data...

Old documentation (V0.70)

Copyright 2004-2009 Carsten Gnörlich. Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.