CentraDoc 6.7.2 - Summary of Changes since 6.5.5

Table Of Contents


It has been two years since the official release of CentraDoc, 6.5.5. The 6.5 branch has been very successful, and received regular updates until fairly recently, when the 6.7 branch started being used in production. There is far too much to cover all the details of what has changed, but here are some highlights.

Latest Third Party Libraries

PDF XFA - XML Forms Architecture

PDF XFA is an XML file format that uses PDF as a wrapper, similar to the way that Adobe Illustrator embeds AI files inside the PDF format. XFA support has been implemented as a JavaScript library and uses a plug-in wrapper for the V8 JavaScript engine, primarily because XFA itself contains embedded JavaScript.

The XFA specification is very slippery; in practice XFA is whatever Adobe LiveCycle supports. Although the current implementation works well with most of the examples encountered, it is likely to have ongoing issues. If you would like to integrate XFA handling, Liberty can provide more information about building the plug-in and distributing the library. At the moment, the plug-in is only built for Windows.

PDF XFA required the addition of libpng to handled embedded PNG images; there is also a minimal implementation of the GIF format, and a portable implementation of the DIB format, also required by XFA. These formats are not used by regular PDF or PostScript, although portable DIB output is supported by the RIP.

PDF Linearization

The PDF output library has an extension to produce web-optimized PDF Files (#551).

PDF/A-1a and PDF/E

The PDF output library has extensions to mark files for PDF/A-1a and PDF/E compliance. We do not verify PDF/A-1a compliance - please refer to the specifications for more information or contact Liberty for assistance.

PDF Files > 2gb

The 64 bit build of CentraDoc can now support PDF files larger than 2gb. This also requires manually installing Windows file system support at some point during initialization:

#if defined(_WIN64)
    FFsWin32_Install();     /* large file support */

The default FFS implementation uses stdio for portability.

While it would be possible to support large files in the 32 bit Windows build, this is not considered a priority.

Incremental updates for PDF file format > 1.4

CentraDoc has support for incremental updates of PDF files (append to file vs. create new file and re-write) but this didn't work correctly for files using the XRefStm structures from PDF 1.5 and later. This has been repaired. PDF files created from scratch do not use the XRefStm format.

Repairs and Enhancements by Ticket #