cannam@239: 
cannam@239: The Vamp Plugin SDK -- Platform Notes for Linux and other GNU platforms
cannam@239: =======================================================================
cannam@239: 
cannam@239: Building at the command line
cannam@239: ----------------------------
cannam@239: 
cannam@239: To build the SDK, example plugins, and command-line host, first edit
cannam@239: the Makefile to suit your platform according to the comments in it,
cannam@239: then run "make".
cannam@239: 
cannam@239: Note that you must have libsndfile
cannam@239: (http://www.mega-nerd.com/libsndfile/) installed in order to build the
cannam@239: command-line host successfully.  To build only the SDK and examples,
cannam@239: run "make sdk examples" instead of just "make".
cannam@239: 
cannam@239: 
cannam@239: Installing the Example Plugins
cannam@239: ------------------------------
cannam@239: 
cannam@239: To install the example plugins so you can load them in Vamp hosts,
cannam@239: copy the files
cannam@239: 
cannam@239:    examples/vamp-example-plugins.so
cannam@239: and
cannam@239:    examples/vamp-example-plugins.cat
cannam@239: 
cannam@239: to
cannam@239:    /usr/local/lib/vamp/
cannam@239: or 
cannam@239:    $HOME/vamp/
cannam@239: 
cannam@239: 
cannam@239: Plugin Linkage
cannam@239: --------------
cannam@239: 
cannam@239: Vamp plugins are distributed as dynamic libraries (.so files).  A
cannam@239: properly packaged Vamp plugin library should export exactly one public
cannam@239: symbol, namely the Vamp API entry point vampGetPluginDescriptor.
cannam@239: 
cannam@239: The default for the GNU linker is to export all of the symbols in the
cannam@239: library.  This will work (the host will be able to load the plugin),
cannam@239: but it unnecessarily pollutes the host's symbol namespace, it may
cannam@239: cause symbol collisions in some esoteric circumstances, and it
cannam@239: increases the amount of time the plugin takes to load.
cannam@239: 
cannam@239: To improve this behaviour, you can instruct the linker to export only
cannam@239: the one required symbol using a linker script.  To do this, place the
cannam@239: text
cannam@239: 
cannam@239: {
cannam@239: 	global: vampGetPluginDescriptor;
cannam@239: 	local: *;
cannam@239: };
cannam@239: 
cannam@239: into a text file, and then use the --version-script option to the
cannam@239: linker to tell it to refer to this file.  All other symbols will then
cannam@239: be properly hidden.
cannam@239: 
cannam@239: The Makefile included in this SDK uses this method to manage symbol
cannam@239: visibility for the included example plugins, using the file
cannam@239: build/vamp-plugin.map.  There are other methods that will work too,
cannam@239: but this one is simple and has the advantage of requiring no changes
cannam@239: to the code.
cannam@239: