Requirements
------------

This plugin requires an external source code project, SpanDSP.

Spandsp is a LGPL library and suite of programs that implement a faxmodem. A
known version, compatible with OPAL, is available from the following URL:

    http://www.soft-switch.org/downloads/spandsp/spandsp-0.0.6pre21.tgz



Building on Windows
-------------------

After getting the spandsp tar file, unpack it so it is called "spandsp" in
the same directory is the plug in, e.g.

	opal\plugins\fax\fax_spandsp\spandsp-0.0.6

After installing SpanDSP, simply then use the spandsp_fax_2005.sln or
spandsp_fax_2008.sln file to build the plug in. Note Visual Studio 2003 is
not supported.

Note, this will automatically try and download libtiff, another open source
library for TIFF file operations. Thus the first time you build it you should
be connected to the Internet so the download can proceed.

Then copy the following two files from:
	opal\bin\plugins\Release\SpanDSPFax_ptplugin.dll
	opal\plugins\fax\fax_spandsp\Release\libspandsp.dll

to C:\PTLib_Plugins, or wherever you have set the PTPLUGINDIR environment
variable. It should work in the same directory as your application as well.

Additional note: If you get errors building libtiff, you may need to edit
tiff-3.8.2\libtiff\tiffconf.h and comment out the entries for JPEG_SUPPORT,
LZW_SUPPORT, PIXARLOG_SUPPORT and ZIP_SUPPORT.

Another note: if using Visual Studio 2010 or 2012, the spandsp_fax_2008.sln
file will upgrade. Normally we would provide the later solution/project
files, but in this case the spandsp tar ball only has 2008 versions, and
they cannot be converted if already in a 2010/2012 solution. It is
recommended that you rename spandsp_fax_2008.sln to spandsp_fax_2010.sln
after conversion to avoid SVN always reporting a modified file.


Building on Linux
-----------------

After getting the spandsp tar file, unpack it and go:

	./configure
	make
	make install

then go to the opal directory and go:

	./configure

then go to the opal/plugins/fax/fax_spandsp directory and go:

	make

Note: you must have libtiff installed on your system.


IMPORTANT NOTE
--------------

The spandsp and libtiff libraries are released under the LGPL license. The
spandsp_fax plugin is released under the MPL license. This means that
distribution of aggregated source code is somewhat murky, which is why we
have instructions on downloading the components and their compilation.

This is also why the libspandsp.dll library is separate, to abide by
the terms of an LGPL library.


   Craig Southeren, 
   craigs@postincrement.com

   Robert Jongbloed
   robertj@voxlucida.com.au
