Chapter 10 Reverse Engineering in an OOM

Reverse engineering encoding format

If the applications you want to reverse contain source files written with Unicode or MBCS (Multibyte character set), you should use the encoding parameters provided to you in the File Encoding box.

If you want to change these parameters because you know which encoding is used within the sources, you can select the appropriate encoding parameter by clicking the Ellipsis button beside the File Encoding box. This opens the Text Input Encoding Format dialog box in which you can select the encoding format of your choice.

The Text Input Encoding Format dialog box includes the following options:

Option	Description
Encoding hint	Encoding format to be used as hint when reversing the file
Detection mode	Indicates whether text encoding detection is to be attempted and specifies how much of each file should be analyzed
On ambiguous detection	Specifies what action should be taken in case of ambiguity
Abort on character loss	Allows you to stop reverse engineering if characters cannot be identified and are to be lost in current encoding

Here is an example on how to read encoding formats from the list:

Detection Mode

The Detection Mode specifies which buffer size is used during text encoding detection. When it is set to some other value than 'No Detection', it analyzes a given portion at the beginning of the text, and from some heuristic based on illegal bytes sequences in the various possible encoding and/or the presence of some tags that can identify encoding, it tries to detect the appropriate encoding that should be used for reading the text.

The Detection Mode dropdown listbox includes the following options:

Option	Description
No detection	Turns off the detection feature. Select this option when you know what the encoding format is
Quick detection	Analyzes a small buffer to perform detection. Select this option when you think that the encoding format will be easy to detect
Full detection	Analyzes the whole file to perform detection. Select this option when you think that the number of characters that determine the encoding format is very small

On Ambiguous Detection

Whenever a detection mode (other than No Detection) has been selected, you can choose to fine tune the way the encoding should be processed in case the detection yields an ambiguous result.

On ambiguous detection, you can select one of the following options:

Option	Description
Use encoding hint and display warning	Means that there are several valid code pages but that can produce different results, in this case the encoding hint is used and a warning message is displayed in the Reverse Page of the Output window, located in the lower part of the main window
Use encoding hint	If possible, uses the encoding format selected in the Encoding Hint box. No warning message is displayed
Use detected encoding	Uses the encoding format detected by PowerDesigner

Under Windows 98 and Millenium, the auto-detect Microsoft method is not available, therefore you should select the encoding format you need rather than let the detection feature that lacks this functionality, try to detect the encoding format.