[gdal-dev] PDF: configure option --enable-pdf-plugin

[Even Rouault]

Andreas,

> I wonder what exactly the build option "--enable-pdf-plugin enable PDF
> driver as a plugin (included in libgdal by default)" means?

Plugin here means as a separate .so/.dll : gdal_PDF.so/dll
Mostly for licensing concerns if using the Poppler backend since Poppler is 
subject to the GPL. So you can make a libgdal build mostly subject to X/MIT or 
similar licenses, and in case you need it, use a gdal_PDF plugin subject to 
GPL

> How does this relate to the other options of building against
> poppler/podofo/pdfium ?

It is orthogonal to the poppler/podofo/pdfium backend(s) used.
For the pdfium backend, which is a bit involved to build (pdfium actually), 
there were also issues with symbol clashes between embedded libraries in 
pdfium and others used by GDAL, and making a plugin instead of linking in core 
GDAL library seemed to "solve" (workaround) issues. Was at least true on Linux 
with pdfium of a few years ago. I don't remember having had such issues with 
the recent upgrade I did in GDAL master.

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com