# Okapi Framework - Filters ## TTX Filter
- Overview - Processing Details - Limitations - Parameters |
Filters | Developer's Guide | Okapi Framework

If you are using an Okapi Tool after the M9 release, you should be using the wiki online help:
http://www.opentag.com/okapi/wiki/index.php?title=TTX_Filter

## Overview

The TTX Filter is an Okapi component that implements the `IFilter` interface for Trados TTX documents. The filter is implement in the class `net.sf.okapi.filters.ttx.TTXFilter` of the Okapi library.

TTX is a bilingual format used by some of the versions of the Trados tools, and supported by several other tools. There are no official public specifications available.

## Processing Details

### Input Encoding

The filter decides which encoding to use for the input document using the following logic:

- If the document has an encoding declaration it is used.
- Otherwise, UTF-8 is used as the default encoding (regardless the actual default encoding that was specified when opening the document).

### Output Encoding

If the output encoding is UTF-8:

- If the input encoding was also UTF-8, a Byte-Order-Mark is used for the output document only if one was detected in the input document.
- If the input encoding was not UTF-8, no Byte-Order-Mark is used in the output document.

### Line-Breaks

The type of line-breaks of the output is the same as the one of the original input.

### Segmentation

TTX is a format where the target text cannot be represented if the text is not segmented. To resolve that issue, the filter has an option to force un-segmented entires to be output as a segment. This option is set by default.

## Limitations

The `<DF>` TTX tag causes problems in some cases.

## Parameters

The filter offers the following options:

Force un-segmented entires to be output as a segment -- Set this option to force un-segmented entries to be written out with a translation part, as a single segment.

Escape the greater-than characters -- Set this option to have all greater-than characters ('`>`') escaped as "`&gt;`" in the output.