fix merge errors with master

19 files changed, 692 insertions, 41 deletions

diff --git a/libs/ardour/ardour/panner.h b/libs/ardour/ardour/panner.h
index cee59923ef..47b102989b 100644
--- a/libs/ardour/ardour/panner.h
+++ b/libs/ardour/ardour/panner.h
@@ -175,8 +175,11 @@ protected:
 extern "C" {
 struct LIBARDOUR_API PanPluginDescriptor {
 	std::string name;
+	std::string panner_uri;
+	std::string gui_uri;
 	int32_t in;
 	int32_t out;
+	uint32_t priority;
 	ARDOUR::Panner* (*factory)(boost::shared_ptr<ARDOUR::Pannable>, boost::shared_ptr<ARDOUR::Speakers>);
 };
 }
diff --git a/libs/ardour/ardour/panner_manager.h b/libs/ardour/ardour/panner_manager.h
index e47ed36ec3..619beb454f 100644
--- a/libs/ardour/ardour/panner_manager.h
+++ b/libs/ardour/ardour/panner_manager.h
@@ -49,7 +49,8 @@ public:
 	void discover_panners ();
 	std::list<PannerInfo*> panner_info;
 
-	PannerInfo* select_panner (ChanCount in, ChanCount out);
+	PannerInfo* select_panner (ChanCount in, ChanCount out, std::string const uri = "");
+	PannerInfo* get_by_uri (std::string uri);
 
 private:
 	PannerManager();
diff --git a/libs/ardour/ardour/panner_shell.h b/libs/ardour/ardour/panner_shell.h
index b78573212a..76df20489f 100644
--- a/libs/ardour/ardour/panner_shell.h
+++ b/libs/ardour/ardour/panner_shell.h
@@ -37,6 +37,7 @@
 namespace ARDOUR {
 
 class Session;
+class Route;
 class Panner;
 class BufferSet;
 class AudioBuffer;
@@ -71,11 +72,23 @@ public:
 	bool bypassed () const;
 	void set_bypassed (bool);
 
+	std::string current_panner_uri() const { return _current_panner_uri; }
+	std::string user_selected_panner_uri() const { return _user_selected_panner_uri; }
+	std::string panner_gui_uri() const { return _panner_gui_uri; }
+
   private:
+	friend class Route;
 	void distribute_no_automation (BufferSet& src, BufferSet& dest, pframes_t nframes, gain_t gain_coeff);
+	bool set_user_selected_panner_uri (std::string const uri);
+
 	boost::shared_ptr<Panner> _panner;
 	boost::shared_ptr<Pannable> _pannable;
 	bool _bypassed;
+
+	std::string _current_panner_uri;
+	std::string _user_selected_panner_uri;
+	std::string _panner_gui_uri;
+	bool _force_reselect;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/ardour/route.h b/libs/ardour/ardour/route.h
index fb2b18f177..5cd17ee24e 100644
--- a/libs/ardour/ardour/route.h
+++ b/libs/ardour/ardour/route.h
@@ -256,6 +256,7 @@ class LIBARDOUR_API Route : public SessionObject, public Automatable, public Rou
 	int remove_processor (boost::shared_ptr<Processor>, ProcessorStreams* err = 0, bool need_process_lock = true);
 	int remove_processors (const ProcessorList&, ProcessorStreams* err = 0);
 	int reorder_processors (const ProcessorList& new_order, ProcessorStreams* err = 0);
+	void set_custom_panner_uri (std::string const panner_uri);
 	void disable_processors (Placement);
 	void disable_processors ();
 	void disable_plugins (Placement);
diff --git a/libs/ardour/panner_manager.cc b/libs/ardour/panner_manager.cc
index 94e8d4ff2f..24fa10e225 100644
--- a/libs/ardour/panner_manager.cc
+++ b/libs/ardour/panner_manager.cc
@@ -24,7 +24,8 @@
 
 #include "pbd/error.h"
 #include "pbd/compose.h"
-#include "pbd/file_utils.h"
+#include "pbd/pathscanner.h"
+#include "pbd/stl_delete.h"
 
 #include "ardour/debug.h"
 #include "ardour/panner_manager.h"
@@ -59,25 +60,30 @@ PannerManager::instance ()
 	return *_instance;
 }
 
+static bool panner_filter (const string& str, void */*arg*/)
+{
+#ifdef __APPLE__
+	return str[0] != '.' && (str.length() > 6 && str.find (".dylib") == (str.length() - 6));
+#else
+	return str[0] != '.' && (str.length() > 3 && str.find (".so") == (str.length() - 3));
+#endif
+}
+
 void
 PannerManager::discover_panners ()
 {
-	vector<std::string> panner_modules;
-
-	Glib::PatternSpec so_extension_pattern("*.so");
-	Glib::PatternSpec dylib_extension_pattern("*.dylib");
+	PathScanner scanner;
+	std::vector<std::string *> *panner_modules;
+	std::string search_path = panner_search_path().to_string();
 
-	find_matching_files_in_search_path (panner_search_path (),
-	                                    so_extension_pattern, panner_modules);
+	DEBUG_TRACE (DEBUG::Panning, string_compose (_("looking for panners in %1\n"), search_path));
 
-	find_matching_files_in_search_path (panner_search_path (),
-	                                    dylib_extension_pattern, panner_modules);
+	panner_modules = scanner (search_path, panner_filter, 0, false, true, 1, true);
 
-	DEBUG_TRACE (DEBUG::Panning, string_compose (_("looking for panners in %1"), panner_search_path().to_string()));
-
-	for (vector<std::string>::iterator i = panner_modules.begin(); i != panner_modules.end(); ++i) {
-		panner_discover (*i);
+	for (vector<std::string *>::iterator i = panner_modules->begin(); i != panner_modules->end(); ++i) {
+		panner_discover (**i);
 	}
+	vector_delete (panner_modules);
 }
 
 int
@@ -97,7 +103,7 @@ PannerManager::panner_discover (string path)
 
 		if (i == panner_info.end()) {
 			panner_info.push_back (pinfo);
-			DEBUG_TRACE (DEBUG::Panning, string_compose(_("Panner discovered: \"%1\" in %2"), pinfo->descriptor.name, path));
+			DEBUG_TRACE (DEBUG::Panning, string_compose(_("Panner discovered: \"%1\" in %2\n"), pinfo->descriptor.name, path));
 		}
 	}
 
@@ -138,53 +144,87 @@ PannerManager::get_descriptor (string path)
 }
 
 PannerInfo*
-PannerManager::select_panner (ChanCount in, ChanCount out)
+PannerManager::select_panner (ChanCount in, ChanCount out, std::string const uri)
 {
+	PannerInfo* rv = NULL;
 	PanPluginDescriptor* d;
 	int32_t nin = in.n_audio();
 	int32_t nout = out.n_audio();
+	uint32_t priority = 0;
+
+	/* look for user-preference -- check if channels match */
+	for (list<PannerInfo*>::iterator p = panner_info.begin(); p != panner_info.end(); ++p) {
+		d = &(*p)->descriptor;
+		if (d->panner_uri != uri) continue;
+		if (d->in != nin && d->in != -1) continue;
+		if (d->out != nout && d->out != -1) continue;
+		return *p;
+	}
 
 	/* look for exact match first */
 
 	for (list<PannerInfo*>::iterator p = panner_info.begin(); p != panner_info.end(); ++p) {
 		d = &(*p)->descriptor;
 
-		if (d->in == nin && d->out == nout) {
-			return *p;
+		if (d->in == nin && d->out == nout && d->priority > priority) {
+			priority = d->priority;
+			rv = *p;
 		}
 	}
+	if (rv) { return rv; }
 
 	/* no exact match, look for good fit on inputs and variable on outputs */
 
+	priority = 0;
 	for (list<PannerInfo*>::iterator p = panner_info.begin(); p != panner_info.end(); ++p) {
 		d = &(*p)->descriptor;
 
-		if (d->in == nin && d->out == -1) {
-			return *p;
+		if (d->in == nin && d->out == -1 && d->priority > priority) {
+			priority = d->priority;
+			rv = *p;
 		}
 	}
+	if (rv) { return rv; }
 
 	/* no exact match, look for good fit on outputs and variable on inputs */
 
+	priority = 0;
 	for (list<PannerInfo*>::iterator p = panner_info.begin(); p != panner_info.end(); ++p) {
 		d = &(*p)->descriptor;
 
-		if (d->in == -1 && d->out == nout) {
-			return *p;
+		if (d->in == -1 && d->out == nout && d->priority > priority) {
+			priority = d->priority;
+			rv = *p;
 		}
 	}
+	if (rv) { return rv; }
 
 	/* no exact match, look for variable fit on inputs and outputs */
 
+	priority = 0;
 	for (list<PannerInfo*>::iterator p = panner_info.begin(); p != panner_info.end(); ++p) {
 		d = &(*p)->descriptor;
 
-		if (d->in == -1 && d->out == -1) {
-			return *p;
+		if (d->in == -1 && d->out == -1 && d->priority > priority) {
+			priority = d->priority;
+			rv = *p;
 		}
 	}
+	if (rv) { return rv; }
 
 	warning << string_compose (_("no panner discovered for in/out = %1/%2"), nin, nout) << endmsg;
 
 	return 0;
 }
+
+PannerInfo*
+PannerManager::get_by_uri (std::string uri)
+{
+	PannerInfo* pi = NULL;
+	for (list<PannerInfo*>::iterator p = panner_info.begin(); p != panner_info.end(); ++p) {
+		if ((*p)->descriptor.panner_uri != uri) continue;
+		pi = (*p);
+		break;
+	}
+	return pi;
+}
diff --git a/libs/ardour/panner_search_path.cc b/libs/ardour/panner_search_path.cc
index 63802ffc4e..49349238e4 100644
--- a/libs/ardour/panner_search_path.cc
+++ b/libs/ardour/panner_search_path.cc
@@ -37,7 +37,6 @@ panner_search_path ()
 	SearchPath spath(user_config_directory ());
 	spath += ardour_dll_directory ();
 	spath.add_subdirectory_to_paths(panner_dir_name);
-
 	spath += SearchPath(Glib::getenv(panner_env_variable_name));
 	return spath;
 }
diff --git a/libs/ardour/panner_shell.cc b/libs/ardour/panner_shell.cc
index 1aeb94eb7e..a25cb49ab5 100644
--- a/libs/ardour/panner_shell.cc
+++ b/libs/ardour/panner_shell.cc
@@ -63,6 +63,10 @@ PannerShell::PannerShell (string name, Session& s, boost::shared_ptr<Pannable> p
 	: SessionObject (s, name)
 	, _pannable (p)
 	, _bypassed (false)
+	, _current_panner_uri("")
+	, _user_selected_panner_uri("")
+	, _panner_gui_uri("")
+	, _force_reselect (false)
 {
 	set_name (name);
 }
@@ -82,7 +86,7 @@ PannerShell::configure_io (ChanCount in, ChanCount out)
 	   the config hasn't changed, we're done.
 	*/
 
-	if (_panner && (_panner->in().n_audio() == nins) && (_panner->out().n_audio() == nouts)) {
+	if (!_force_reselect && _panner && (_panner->in().n_audio() == nins) && (_panner->out().n_audio() == nouts)) {
 		return;
 	}
 
@@ -90,17 +94,21 @@ PannerShell::configure_io (ChanCount in, ChanCount out)
 		/* no need for panning with less than 2 outputs or no inputs */
 		if (_panner) {
 			_panner.reset ();
+			_current_panner_uri = "";
+			_panner_gui_uri = "";
 			Changed (); /* EMIT SIGNAL */
 		}
 		return;
 	}
 
-	PannerInfo* pi = PannerManager::instance().select_panner (in, out);
+	PannerInfo* pi = PannerManager::instance().select_panner (in, out, _user_selected_panner_uri);
 	if (!pi) {
 		cerr << "No panner found: check that panners are being discovered correctly during startup.\n";
 		assert (pi);
 	}
 
+	DEBUG_TRACE (DEBUG::Panning, string_compose (_("select panner: %1\n"), pi->descriptor.name.c_str()));
+
 	boost::shared_ptr<Speakers> speakers = _session.get_speakers ();
 
 	if (nouts != speakers->size()) {
@@ -116,6 +124,8 @@ PannerShell::configure_io (ChanCount in, ChanCount out)
 	// boost_debug_shared_ptr_mark_interesting (p, "Panner");
 	_panner.reset (p);
 	_panner->configure_io (in, out);
+	_current_panner_uri = pi->descriptor.panner_uri;
+	_panner_gui_uri = pi->descriptor.gui_uri;
 
 	Changed (); /* EMIT SIGNAL */
 }
@@ -126,6 +136,7 @@ PannerShell::get_state ()
 	XMLNode* node = new XMLNode ("PannerShell");
 
 	node->add_property (X_("bypassed"), _bypassed ? X_("yes") : X_("no"));
+	node->add_property (X_("user-panner"), _user_selected_panner_uri);
 
 	if (_panner) {
 		node->add_child_nocopy (_panner->get_state ());
@@ -146,12 +157,29 @@ PannerShell::set_state (const XMLNode& node, int version)
 		set_bypassed (string_is_affirmative (prop->value ()));
 	}
 
+	if ((prop = node.property (X_("user-panner"))) != 0) {
+		_user_selected_panner_uri = prop->value ();
+	}
+
 	_panner.reset ();
 	
 	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
 
 		if ((*niter)->name() == X_("Panner")) {
 
+			if ((prop = (*niter)->property (X_("uri")))) {
+				PannerInfo* p = PannerManager::instance().get_by_uri(prop->value());
+				if (p) {
+					_panner.reset (p->descriptor.factory (_pannable, _session.get_speakers ()));
+					_current_panner_uri = p->descriptor.panner_uri;
+					_panner_gui_uri = p->descriptor.gui_uri;
+					if (_panner->set_state (**niter, version) == 0) {
+						return -1;
+					}
+				}
+			}
+
+			else /* backwards compatibility */
 			if ((prop = (*niter)->property (X_("type")))) {
 
 				list<PannerInfo*>::iterator p;
@@ -166,6 +194,8 @@ PannerShell::set_state (const XMLNode& node, int version)
 						*/
 
 						_panner.reset ((*p)->descriptor.factory (_pannable, _session.get_speakers ()));
+						_current_panner_uri = (*p)->descriptor.panner_uri;
+						_panner_gui_uri = (*p)->descriptor.gui_uri;
 
 						if (_panner->set_state (**niter, version) == 0) {
 							return -1;
@@ -347,3 +377,19 @@ PannerShell::bypassed () const
 {
 	return _bypassed;
 }
+
+/* set custom-panner config
+ *
+ * This function is intended to be only called from
+ * Route::set_custom_panner()
+ * which will trigger IO-reconfigutaion if this fn return true
+ */
+bool
+PannerShell::set_user_selected_panner_uri (std::string const uri)
+{
+	if (uri == _user_selected_panner_uri) return false;
+	_user_selected_panner_uri = uri;
+	if (uri == _current_panner_uri) return false;
+	_force_reselect = true;
+	return true;
+}
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index c032b77eff..6f23e920d4 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -51,6 +51,7 @@
 #include "ardour/midi_port.h"
 #include "ardour/monitor_processor.h"
 #include "ardour/pannable.h"
+#include "ardour/panner.h"
 #include "ardour/panner_shell.h"
 #include "ardour/plugin_insert.h"
 #include "ardour/port.h"
@@ -1574,6 +1575,58 @@ Route::remove_processors (const ProcessorList& to_be_deleted, ProcessorStreams*
 }
 
 void
+Route::set_custom_panner_uri (std::string const panner_uri)
+{
+	if (_in_configure_processors) {
+		DEBUG_TRACE (DEBUG::Panning, string_compose (_("Route::set_custom_panner_uri '%1' -- called while in_configure_processors\n"), name()));
+		return;
+	}
+
+	if (!_main_outs->panner_shell()->set_user_selected_panner_uri(panner_uri)) {
+		DEBUG_TRACE (DEBUG::Panning, string_compose (_("Route::set_custom_panner_uri '%1 '%2' -- no change needed\n"), name(), panner_uri));
+		/* no change needed */
+		return;
+	}
+
+	DEBUG_TRACE (DEBUG::Panning, string_compose (_("Route::set_custom_panner_uri '%1 '%2' -- reconfigure I/O\n"), name(), panner_uri));
+
+	/* reconfigure I/O -- re-initialize panner modules */
+	{
+		Glib::Threads::RWLock::WriterLock lm (_processor_lock);
+		Glib::Threads::Mutex::Lock lx (AudioEngine::instance()->process_lock ());
+
+		for (ProcessorList::iterator p = _processors.begin(); p != _processors.end(); ++p) {
+			boost::shared_ptr<Delivery> dl;
+			boost::shared_ptr<Panner> panner;
+			if ((dl = boost::dynamic_pointer_cast<Delivery> (*p)) == 0) {
+				continue;
+			}
+			if (!dl->panner_shell()) {
+				continue;
+			}
+			if (!(panner = dl->panner_shell()->panner())) {
+				continue;
+			}
+			/* _main_outs has already been set before the loop.
+			 * Ignore the return status here. It need reconfiguration */
+			if (dl->panner_shell() != _main_outs->panner_shell()) {
+				if (!dl->panner_shell()->set_user_selected_panner_uri(panner_uri)) {
+					continue;
+				}
+			}
+
+			ChanCount in = panner->in();
+			ChanCount out = panner->out();
+			dl->panner_shell()->configure_io(in, out);
+			dl->panner_shell()->pannable()->set_panner(dl->panner_shell()->panner());
+		}
+	}
+
+	processors_changed (RouteProcessorChange ()); /* EMIT SIGNAL */
+	_session.set_dirty ();
+}
+
+void
 Route::reset_instrument_info ()
 {
 	boost::shared_ptr<Processor> instr = the_instrument();
diff --git a/libs/audiographer/src/general/sample_format_converter.cc b/libs/audiographer/src/general/sample_format_converter.cc
index 5fe9a1185b..aaeda09477 100644
--- a/libs/audiographer/src/general/sample_format_converter.cc
+++ b/libs/audiographer/src/general/sample_format_converter.cc
@@ -54,10 +54,14 @@ template <>
 void
 SampleFormatConverter<int32_t>::init (framecnt_t max_frames, int type, int data_width)
 {
-	// GDither is broken with GDither32bit if the dither depth is bigger than 24
-	if(throw_level (ThrowObject) && data_width > 24) {
-		throw Exception (*this, "Trying to use SampleFormatConverter<int32_t> a data width > 24");
+	if(throw_level (ThrowObject) && data_width > 32) {
+		throw Exception (*this, "Trying to use SampleFormatConverter<int32_t> with a data width > 32");
 	}
+
+	// GDither is broken with GDither32bit if the dither depth is bigger than 24.
+	// And since floats only have 24 bits of data, we are fine with this.
+	data_width = std::min(data_width, 24);
+
 	init_common (max_frames);
 	dither = gdither_new ((GDitherType) type, channels, GDither32bit, data_width);
 }
@@ -68,7 +72,7 @@ SampleFormatConverter<int16_t>::init (framecnt_t max_frames, int type, int data_
 {
 	if (throw_level (ThrowObject) && data_width > 16) {
 		throw Exception (*this, boost::str(boost::format
-		    ("Data width (%1) too large for int16_t")
+		    ("Data width (%1%) too large for int16_t")
 		    % data_width));
 	}
 	init_common (max_frames);
@@ -81,7 +85,7 @@ SampleFormatConverter<uint8_t>::init (framecnt_t max_frames, int type, int data_
 {
 	if (throw_level (ThrowObject) && data_width > 8) {
 		throw Exception (*this, boost::str(boost::format
-		    ("Data width (%1) too large for uint8_t")
+		    ("Data width (%1%) too large for uint8_t")
 		    % data_width));
 	}
 	init_common (max_frames);
diff --git a/libs/audiographer/tests/general/sample_format_converter_test.cc b/libs/audiographer/tests/general/sample_format_converter_test.cc
index 9239564d5b..977e2b390a 100644
--- a/libs/audiographer/tests/general/sample_format_converter_test.cc
+++ b/libs/audiographer/tests/general/sample_format_converter_test.cc
@@ -31,27 +31,31 @@ class SampleFormatConverterTest : public CppUnit::TestFixture
 
 	void testInit()
 	{
+		// Float never uses dithering and should always use full 32 bits of data
 		boost::shared_ptr<SampleFormatConverter<float> > f_converter (new SampleFormatConverter<float>(1));
 		f_converter->init (frames, D_Tri, 32); // Doesn't throw
 		CPPUNIT_ASSERT_THROW (f_converter->init (frames, D_Tri, 24), Exception);
 		CPPUNIT_ASSERT_THROW (f_converter->init (frames, D_Tri, 48), Exception);
-		
+
+		/* Test that too large data widths throw.
+		   We are fine with unnecessarily narrow data widths */
+
 		boost::shared_ptr<SampleFormatConverter<int32_t> > i_converter (new SampleFormatConverter<int32_t>(1));
 		i_converter->init (frames, D_Tri, 32); // Doesn't throw
 		i_converter->init (frames, D_Tri, 24); // Doesn't throw
-		CPPUNIT_ASSERT_THROW (i_converter->init (frames, D_Tri, 8), Exception);
-		CPPUNIT_ASSERT_THROW (i_converter->init (frames, D_Tri, 16), Exception);
+		i_converter->init (frames, D_Tri, 8); // Doesn't throw
+		i_converter->init (frames, D_Tri, 16); // Doesn't throw
 		CPPUNIT_ASSERT_THROW (i_converter->init (frames, D_Tri, 48), Exception);
-		
+
 		boost::shared_ptr<SampleFormatConverter<int16_t> > i16_converter (new SampleFormatConverter<int16_t>(1));
 		i16_converter->init (frames, D_Tri, 16); // Doesn't throw
-		CPPUNIT_ASSERT_THROW (i16_converter->init (frames, D_Tri, 8), Exception);
+		i16_converter->init (frames, D_Tri, 8); // Doesn't throw
 		CPPUNIT_ASSERT_THROW (i16_converter->init (frames, D_Tri, 32), Exception);
 		CPPUNIT_ASSERT_THROW (i16_converter->init (frames, D_Tri, 48), Exception);
-		
+
 		boost::shared_ptr<SampleFormatConverter<uint8_t> > ui_converter (new SampleFormatConverter<uint8_t>(1));
 		ui_converter->init (frames, D_Tri, 8); // Doesn't throw
-		CPPUNIT_ASSERT_THROW (ui_converter->init (frames, D_Tri, 4), Exception);
+		ui_converter->init (frames, D_Tri, 4); // Doesn't throw
 		CPPUNIT_ASSERT_THROW (ui_converter->init (frames, D_Tri, 16), Exception);
 	}
 
diff --git a/libs/gtkmm2ext/gtkmm2ext/utils.h b/libs/gtkmm2ext/gtkmm2ext/utils.h
index 112ca42e77..de9f7b765d 100644
--- a/libs/gtkmm2ext/gtkmm2ext/utils.h
+++ b/libs/gtkmm2ext/gtkmm2ext/utils.h
@@ -108,6 +108,7 @@ namespace Gtkmm2ext {
 	LIBGTKMM2EXT_API void rounded_top_half_rectangle (Cairo::RefPtr<Cairo::Context>, double x, double y, double w, double h, double r=10);
 	LIBGTKMM2EXT_API void rounded_bottom_half_rectangle (Cairo::RefPtr<Cairo::Context>, double x, double y, double w, double h, double r=10);
 	LIBGTKMM2EXT_API void rounded_right_half_rectangle (Cairo::RefPtr<Cairo::Context>, double x, double y, double w, double h, double r=10);
+	LIBGTKMM2EXT_API void rounded_left_half_rectangle (Cairo::RefPtr<Cairo::Context>, double x, double y, double w, double h, double r=10);
 
 	/* C API for rounded rectangles */
 
@@ -118,6 +119,7 @@ namespace Gtkmm2ext {
 	LIBGTKMM2EXT_API void rounded_top_half_rectangle (cairo_t*, double x, double y, double w, double h, double r=10);
 	LIBGTKMM2EXT_API void rounded_bottom_half_rectangle (cairo_t*, double x, double y, double w, double h, double r=10);
 	LIBGTKMM2EXT_API void rounded_right_half_rectangle (cairo_t*, double x, double y, double w, double h, double r=10);
+	LIBGTKMM2EXT_API void rounded_left_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r=10);
 
 	LIBGTKMM2EXT_API Gtk::Label* left_aligned_label (std::string const &);
 
diff --git a/libs/gtkmm2ext/utils.cc b/libs/gtkmm2ext/utils.cc
index 77ed843896..0f04b8cfe7 100644
--- a/libs/gtkmm2ext/utils.cc
+++ b/libs/gtkmm2ext/utils.cc
@@ -415,6 +415,13 @@ Gtkmm2ext::rounded_bottom_half_rectangle (Cairo::RefPtr<Cairo::Context> context,
 {
 	rounded_bottom_half_rectangle (context->cobj(), x, y, w, h, r);
 }
+
+void
+Gtkmm2ext::rounded_left_half_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
+{
+	rounded_left_half_rectangle (context->cobj(), x, y, w, h, r);
+}
+
 void
 Gtkmm2ext::rounded_right_half_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
 {
@@ -435,6 +442,19 @@ Gtkmm2ext::rounded_rectangle (cairo_t* cr, double x, double y, double w, double
 }
 
 void
+Gtkmm2ext::rounded_left_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
+{
+	double degrees = M_PI / 180.0;
+
+	cairo_new_sub_path (cr);
+	cairo_line_to (cr, x+w, y); // tr
+	cairo_line_to (cr, x+w, y + h); // br
+	cairo_arc (cr, x + r, y + h - r, r, 90 * degrees, 180 * degrees);  //bl
+	cairo_arc (cr, x + r, y + r, r, 180 * degrees, 270 * degrees);  //tl
+	cairo_close_path (cr);
+}
+
+void
 Gtkmm2ext::rounded_right_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
 {
 	double degrees = M_PI / 180.0;
diff --git a/libs/panners/1in2out/panner_1in2out.cc b/libs/panners/1in2out/panner_1in2out.cc
index 4524ed560b..12e7896cfb 100644
--- a/libs/panners/1in2out/panner_1in2out.cc
+++ b/libs/panners/1in2out/panner_1in2out.cc
@@ -63,7 +63,10 @@ using namespace PBD;
 
 static PanPluginDescriptor _descriptor = {
         "Mono to Stereo Panner",
+        "http://ardour.org/plugin/panner_1in2out",
+        "http://ardour.org/plugin/panner_1in2out#ui",
         1, 2, 
+        10000,
         Panner1in2out::factory
 };
 
@@ -332,6 +335,8 @@ XMLNode&
 Panner1in2out::get_state ()
 {
 	XMLNode& root (Panner::get_state ());
+	root.add_property (X_("uri"), _descriptor.panner_uri);
+	/* this is needed to allow new sessions to load with old Ardour: */
 	root.add_property (X_("type"), _descriptor.name);
 	return root;
 }
diff --git a/libs/panners/2in2out/panner_2in2out.cc b/libs/panners/2in2out/panner_2in2out.cc
index a316b764c7..f801a36ff4 100644
--- a/libs/panners/2in2out/panner_2in2out.cc
+++ b/libs/panners/2in2out/panner_2in2out.cc
@@ -63,7 +63,10 @@ using namespace PBD;
 
 static PanPluginDescriptor _descriptor = {
         "Equal Power Stereo",
+        "http://ardour.org/plugin/panner_2in2out",
+        "http://ardour.org/plugin/panner_2in2out#ui",
         2, 2,
+        10000,
         Panner2in2out::factory
 };
 
@@ -464,6 +467,8 @@ XMLNode&
 Panner2in2out::get_state ()
 {
 	XMLNode& root (Panner::get_state ());
+	root.add_property (X_("uri"), _descriptor.panner_uri);
+	/* this is needed to allow new sessions to load with old Ardour: */
 	root.add_property (X_("type"), _descriptor.name);
 	return root;
 }
diff --git a/libs/panners/stereobalance/panner_balance.cc b/libs/panners/stereobalance/panner_balance.cc
new file mode 100644
index 0000000000..d5ab96b73c
--- /dev/null
+++ b/libs/panners/stereobalance/panner_balance.cc
@@ -0,0 +1,333 @@
+/*
+    Copyright (C) 2004-2011 Paul Davis
+    adopted from 2in2out panner by Robin Gareus <robin@gareus.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <inttypes.h>
+
+#include <cmath>
+#include <cerrno>
+#include <fstream>
+#include <cstdlib>
+#include <string>
+#include <cstdio>
+#include <locale.h>
+#include <unistd.h>
+#include <float.h>
+#include <iomanip>
+
+#include <glibmm.h>
+
+#include "pbd/cartesian.h"
+#include "pbd/convert.h"
+#include "pbd/error.h"
+#include "pbd/failed_constructor.h"
+#include "pbd/xml++.h"
+#include "pbd/enumwriter.h"
+
+#include "evoral/Curve.hpp"
+
+#include "ardour/audio_buffer.h"
+#include "ardour/audio_buffer.h"
+#include "ardour/buffer_set.h"
+#include "ardour/pan_controllable.h"
+#include "ardour/pannable.h"
+#include "ardour/runtime_functions.h"
+#include "ardour/session.h"
+#include "ardour/utils.h"
+#include "ardour/mix.h"
+
+#include "panner_balance.h"
+
+#include "i18n.h"
+
+#include "pbd/mathfix.h"
+
+using namespace std;
+using namespace ARDOUR;
+using namespace PBD;
+
+static PanPluginDescriptor _descriptor = {
+	"Stereo Balance",
+	"http://ardour.org/plugin/panner_balance",
+	"http://ardour.org/plugin/panner_balance#ui",
+	2, 2,
+	2000,
+	Pannerbalance::factory
+};
+
+extern "C" { PanPluginDescriptor* panner_descriptor () { return &_descriptor; } }
+
+Pannerbalance::Pannerbalance (boost::shared_ptr<Pannable> p)
+	: Panner (p)
+{
+	if (!_pannable->has_state()) {
+		_pannable->pan_azimuth_control->set_value (0.5);
+	}
+
+	update ();
+
+	/* LEFT SIGNAL */
+	pos_interp[0] = pos[0] = desired_pos[0];
+	/* RIGHT SIGNAL */
+	pos_interp[1] = pos[1] = desired_pos[1];
+
+	_pannable->pan_azimuth_control->Changed.connect_same_thread (*this, boost::bind (&Pannerbalance::update, this));
+}
+
+Pannerbalance::~Pannerbalance ()
+{
+}
+
+double
+Pannerbalance::position () const
+{
+	return _pannable->pan_azimuth_control->get_value();
+}
+
+	void
+Pannerbalance::set_position (double p)
+{
+	if (clamp_position (p)) {
+		_pannable->pan_azimuth_control->set_value (p);
+	}
+}
+
+	void
+Pannerbalance::thaw ()
+{
+	Panner::thaw ();
+	if (_frozen == 0) {
+		update ();
+	}
+}
+
+void
+Pannerbalance::update ()
+{
+	if (_frozen) {
+		return;
+	}
+
+	float const pos = _pannable->pan_azimuth_control->get_value();
+
+	if (pos == .5) {
+		desired_pos[0] = 1.0;
+		desired_pos[1] = 1.0;
+	} else if (pos > .5) {
+		desired_pos[0] = 2 - 2. * pos;
+		desired_pos[1] = 1.0;
+	} else {
+		desired_pos[0] = 1.0;
+		desired_pos[1] = 2. * pos;
+	}
+}
+
+bool
+Pannerbalance::clamp_position (double& p)
+{
+	p = max (min (p, 1.0), 0.0);
+	return true;
+}
+
+pair<double, double>
+Pannerbalance::position_range () const
+{
+	return make_pair (0, 1);
+}
+
+void
+Pannerbalance::distribute_one (AudioBuffer& srcbuf, BufferSet& obufs, gain_t gain_coeff, pframes_t nframes, uint32_t which)
+{
+	assert (obufs.count().n_audio() == 2);
+
+	pan_t delta;
+	Sample* dst;
+	pan_t pan;
+
+	Sample* const src = srcbuf.data();
+
+	dst = obufs.get_audio(which).data();
+
+	if (fabsf ((delta = (pos[which] - desired_pos[which]))) > 0.002) { // about 1 degree of arc
+
+		/* we've moving the pan by an appreciable amount, so we must
+			 interpolate over 64 frames or nframes, whichever is smaller */
+
+		pframes_t const limit = min ((pframes_t) 64, nframes);
+		pframes_t n;
+
+		delta = -(delta / (float) (limit));
+
+		for (n = 0; n < limit; n++) {
+			pos_interp[which] = pos_interp[which] + delta;
+			pos[which] = pos_interp[which] + 0.9 * (pos[which] - pos_interp[which]);
+			dst[n] += src[n] * pos[which] * gain_coeff;
+		}
+
+		/* then pan the rest of the buffer; no need for interpolation for this bit */
+
+		pan = pos[which] * gain_coeff;
+
+		mix_buffers_with_gain (dst+n,src+n,nframes-n,pan);
+
+	} else {
+
+		pos[which] = desired_pos[which];
+		pos_interp[which] = pos[which];
+
+		if ((pan = (pos[which] * gain_coeff)) != 1.0f) {
+
+			if (pan != 0.0f) {
+
+				/* pan is 1 but also not 0, so we must do it "properly" */
+
+				//obufs.get_audio(1).read_from (srcbuf, nframes);
+				mix_buffers_with_gain(dst,src,nframes,pan);
+
+				/* mark that we wrote into the buffer */
+
+				// obufs[0] = 0;
+
+			}
+
+		} else {
+			/* pan is 1 so we can just copy the input samples straight in */
+			mix_buffers_no_gain(dst,src,nframes);
+		}
+	}
+}
+
+void
+Pannerbalance::distribute_one_automated (AudioBuffer& srcbuf, BufferSet& obufs,
+                                         framepos_t start, framepos_t end, pframes_t nframes,
+                                         pan_t** buffers, uint32_t which)
+{
+	assert (obufs.count().n_audio() == 2);
+
+	Sample* dst;
+	pan_t* pbuf;
+	Sample* const src = srcbuf.data();
+	pan_t* const position = buffers[0];
+
+	/* fetch positional data */
+
+	if (!_pannable->pan_azimuth_control->list()->curve().rt_safe_get_vector (start, end, position, nframes)) {
+		/* fallback */
+		distribute_one (srcbuf, obufs, 1.0, nframes, which);
+		return;
+	}
+
+	for (pframes_t n = 0; n < nframes; ++n) {
+
+		float const pos = position[n];
+
+		if (which == 0) { // Left
+			if (pos > .5) {
+				buffers[which][n] = 2 - 2. * pos;
+			} else {
+				buffers[which][n] = 1.0;
+			}
+		} else { // Right
+			if (pos < .5) {
+				buffers[which][n] = 2. * pos;
+			} else {
+				buffers[which][n] = 1.0;
+			}
+		}
+	}
+
+	dst = obufs.get_audio(which).data();
+	pbuf = buffers[which];
+
+	for (pframes_t n = 0; n < nframes; ++n) {
+		dst[n] += src[n] * pbuf[n];
+	}
+
+	/* XXX it would be nice to mark the buffer as written to */
+}
+
+Panner*
+Pannerbalance::factory (boost::shared_ptr<Pannable> p, boost::shared_ptr<Speakers> /* ignored */)
+{
+	return new Pannerbalance (p);
+}
+
+	XMLNode&
+Pannerbalance::get_state ()
+{
+	XMLNode& root (Panner::get_state ());
+	root.add_property (X_("uri"), _descriptor.panner_uri);
+	/* this is needed to allow new sessions to load with old Ardour: */
+	root.add_property (X_("type"), _descriptor.name);
+	return root;
+}
+
+std::set<Evoral::Parameter>
+Pannerbalance::what_can_be_automated() const
+{
+	set<Evoral::Parameter> s;
+	s.insert (Evoral::Parameter (PanAzimuthAutomation));
+	return s;
+}
+
+string
+Pannerbalance::describe_parameter (Evoral::Parameter p)
+{
+	switch (p.type()) {
+		case PanAzimuthAutomation:
+			return _("L/R");
+		default:
+			return _pannable->describe_parameter (p);
+	}
+}
+
+string
+Pannerbalance::value_as_string (boost::shared_ptr<AutomationControl> ac) const
+{
+	/* DO NOT USE LocaleGuard HERE */
+	double val = ac->get_value();
+
+	switch (ac->parameter().type()) {
+		case PanAzimuthAutomation:
+			/* We show the position of the center of the image relative to the left & right.
+				 This is expressed as a pair of percentage values that ranges from (100,0)
+				 (hard left) through (50,50) (hard center) to (0,100) (hard right).
+
+				 This is pretty wierd, but its the way audio engineers expect it. Just remember that
+				 the center of the USA isn't Kansas, its (50LA, 50NY) and it will all make sense.
+
+				 This is designed to be as narrow as possible. Dedicated
+				 panner GUIs can do their own version of this if they need
+				 something less compact.
+				 */
+
+			return string_compose (_("L%1R%2"), (int) rint (100.0 * (1.0 - val)),
+					(int) rint (100.0 * val));
+
+		default:
+			return _pannable->value_as_string (ac);
+	}
+}
+
+void
+Pannerbalance::reset ()
+{
+	set_position (0.5);
+	update ();
+}
diff --git a/libs/panners/stereobalance/panner_balance.h b/libs/panners/stereobalance/panner_balance.h
new file mode 100644
index 0000000000..f381340888
--- /dev/null
+++ b/libs/panners/stereobalance/panner_balance.h
@@ -0,0 +1,83 @@
+/*
+    Copyright (C) 2004-2014 Paul Davis
+    adopted from 2in2out panner by Robin Gareus <robin@gareus.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __ardour_panner_balance_h__
+#define __ardour_panner_balance_h__
+
+#include <cmath>
+#include <cassert>
+#include <vector>
+#include <string>
+#include <iostream>
+
+#include "pbd/stateful.h"
+#include "pbd/controllable.h"
+#include "pbd/cartesian.h"
+
+#include "ardour/automation_control.h"
+#include "ardour/automatable.h"
+#include "ardour/panner.h"
+#include "ardour/types.h"
+
+namespace ARDOUR {
+
+class Pannerbalance : public Panner
+{
+	public:
+	Pannerbalance (boost::shared_ptr<Pannable>);
+	~Pannerbalance ();
+
+	ChanCount in() const { return ChanCount (DataType::AUDIO, 2); }
+	ChanCount out() const { return ChanCount (DataType::AUDIO, 2); }
+
+	void set_position (double);
+	bool clamp_position (double&);
+	std::pair<double, double> position_range () const;
+	double position () const;
+
+	std::set<Evoral::Parameter> what_can_be_automated() const;
+
+	static Panner* factory (boost::shared_ptr<Pannable>, boost::shared_ptr<Speakers>);
+
+	std::string describe_parameter (Evoral::Parameter);
+	std::string value_as_string (boost::shared_ptr<AutomationControl>) const;
+
+	XMLNode& get_state ();
+
+	void reset ();
+	void thaw ();
+
+	protected:
+	float pos[2];
+	float desired_pos[2];
+	float pos_interp[2];
+
+	void update ();
+
+	private:
+	void distribute_one (AudioBuffer& srcbuf, BufferSet& obufs, gain_t gain_coeff, pframes_t nframes, uint32_t which);
+	void distribute_one_automated (AudioBuffer& srcbuf, BufferSet& obufs,
+			framepos_t start, framepos_t end, pframes_t nframes,
+			pan_t** buffers, uint32_t which);
+};
+
+} // namespace
+
+#endif /* __ardour_panner_balance_h__ */
diff --git a/libs/panners/stereobalance/wscript b/libs/panners/stereobalance/wscript
new file mode 100644
index 0000000000..75eccca419
--- /dev/null
+++ b/libs/panners/stereobalance/wscript
@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+from waflib.extras import autowaf as autowaf
+import os
+
+# Library version (UNIX style major, minor, micro)
+# major increment <=> incompatible changes
+# minor increment <=> compatible changes (additions)
+# micro increment <=> no interface changes
+LIBARDOUR_PAN2IN2OUT_LIB_VERSION = '1.0.0'
+
+# Mandatory variables
+top = '.'
+out = 'build'
+
+def options(opt):
+    autowaf.set_options(opt)
+
+def configure(conf):
+    autowaf.configure(conf)
+
+def build(bld):
+    obj = bld(features = 'cxx cxxshlib')
+    obj.source = [ 'panner_balance.cc' ]
+    obj.export_includes = ['.']
+    obj.cxxflags     = '-DPACKAGE="libardour_panbalance"'
+    obj.includes     = ['.']
+    obj.name         = 'libardour_panbalance'
+    obj.target       = 'panbalance'
+    obj.use          = 'libardour libardour_cp libpbd'
+    obj.vnum         = LIBARDOUR_PAN2IN2OUT_LIB_VERSION
+    obj.install_path = os.path.join(bld.env['LIBDIR'], 'ardour3', 'panners')
+
+def shutdown():
+    autowaf.shutdown()
diff --git a/libs/panners/vbap/vbap.cc b/libs/panners/vbap/vbap.cc
index 1cef98fc7d..2241ab96e3 100644
--- a/libs/panners/vbap/vbap.cc
+++ b/libs/panners/vbap/vbap.cc
@@ -46,7 +46,10 @@ using namespace std;
 
 static PanPluginDescriptor _descriptor = {
         "VBAP 2D panner",
+        "http://ardour.org/plugin/panner_vbap",
+        "http://ardour.org/plugin/panner_vbap#ui",
         -1, -1,
+        1000,
         VBAPanner::factory
 };
 
@@ -392,7 +395,9 @@ VBAPanner::distribute_one_automated (AudioBuffer& /*src*/, BufferSet& /*obufs*/,
 XMLNode&
 VBAPanner::get_state ()
 {
-        XMLNode& node (Panner::get_state());
+	XMLNode& node (Panner::get_state());
+	node.add_property (X_("uri"), _descriptor.panner_uri);
+	/* this is needed to allow new sessions to load with old Ardour: */
 	node.add_property (X_("type"), _descriptor.name);
 	return node;
 }
diff --git a/libs/panners/wscript b/libs/panners/wscript
index aec57eb40f..f3ce6e6f19 100644
--- a/libs/panners/wscript
+++ b/libs/panners/wscript
@@ -6,7 +6,7 @@ import os
 top = '.'
 out = 'build'
 
-panners = [ '2in2out', '1in2out', 'vbap' ]
+panners = [ '2in2out', '1in2out', 'vbap', 'stereobalance' ]
 
 def options(opt):
     autowaf.set_options(opt)