6 files changed, 17 insertions, 3 deletions
diff --git a/libs/ardour/ardour/audio_unit.h b/libs/ardour/ardour/audio_unit.h
index b83798fd3e..63bd05b50d 100644
--- a/libs/ardour/ardour/audio_unit.h
+++ b/libs/ardour/ardour/audio_unit.h
@@ -74,6 +74,8 @@ class LIBARDOUR_API AUPlugin : public ARDOUR::Plugin
 	void set_parameter (uint32_t which, float val);
 	float get_parameter (uint32_t which) const;
 
+	PluginOutputConfiguration possible_output () const { return _output_configs; }
+
 	int get_parameter_descriptor (uint32_t which, ParameterDescriptor&) const;
 	uint32_t nth_parameter (uint32_t which, bool& ok) const;
 	void activate ();
@@ -172,6 +174,7 @@ class LIBARDOUR_API AUPlugin : public ARDOUR::Plugin
 	AudioBufferList* buffers;
 	bool _has_midi_input;
 	bool _has_midi_output;
+	PluginOutputConfiguration _output_configs;
 
 	/* despite all the cool work that apple did on their AU preset
 	   system, they left factory presets and user presets as two
diff --git a/libs/ardour/ardour/luaproc.h b/libs/ardour/ardour/luaproc.h
index 0f4f8d7d6d..a0f49d61bb 100644
--- a/libs/ardour/ardour/luaproc.h
+++ b/libs/ardour/ardour/luaproc.h
@@ -63,6 +63,8 @@ public:
 	std::string get_docs () const { return _docs; }
 	std::string get_parameter_docs (uint32_t) const;
 
+	PluginOutputConfiguration possible_output () const { return _output_configs; }
+
 	std::set<Evoral::Parameter> automatable() const;
 
 	void activate () { }
@@ -140,6 +142,7 @@ private:
 
 	ChanCount _configured_in;
 	ChanCount _configured_out;
+	PluginOutputConfiguration _output_configs;
 
 	bool _has_midi_input;
 	bool _has_midi_output;
diff --git a/libs/ardour/ardour/lv2_plugin.h b/libs/ardour/ardour/lv2_plugin.h
index f1907e80ae..34e68fdc7f 100644
--- a/libs/ardour/ardour/lv2_plugin.h
+++ b/libs/ardour/ardour/lv2_plugin.h
@@ -80,7 +80,7 @@ class LIBARDOUR_API LV2Plugin : public ARDOUR::Plugin, public ARDOUR::Workee
 	int         get_parameter_descriptor (uint32_t which, ParameterDescriptor&) const;
 	uint32_t    nth_parameter (uint32_t port, bool& ok) const;
 
-	IOPortDescription describe_io_port (DataType dt, bool input, uint32_t id);
+	IOPortDescription describe_io_port (DataType dt, bool input, uint32_t id) const;
 
 	const void* extension_data (const char* uri) const;
 
diff --git a/libs/ardour/ardour/plugin.h b/libs/ardour/ardour/plugin.h
index ec749281af..d284c2620d 100644
--- a/libs/ardour/ardour/plugin.h
+++ b/libs/ardour/ardour/plugin.h
@@ -22,6 +22,7 @@
 
 #include <boost/shared_ptr.hpp>
 #include <string>
+#include <set>
 
 #include "pbd/statefuldestructible.h"
 #include "pbd/controllable.h"
@@ -54,6 +55,7 @@ class AutomationControl;
 typedef boost::shared_ptr<Plugin> PluginPtr;
 typedef boost::shared_ptr<PluginInfo> PluginInfoPtr;
 typedef std::list<PluginInfoPtr> PluginInfoList;
+typedef std::set<uint32_t> PluginOutputConfiguration;
 
 /** A plugin is an external module (usually 3rd party provided) loaded into Ardour
  * for the purpose of digital signal processing.
@@ -124,7 +126,8 @@ class LIBARDOUR_API Plugin : public PBD::StatefulDestructible, public Latent
 		bool is_sidechain;
 	};
 
-	virtual IOPortDescription describe_io_port (DataType dt, bool input, uint32_t id);
+	virtual IOPortDescription describe_io_port (DataType dt, bool input, uint32_t id) const;
+	virtual PluginOutputConfiguration possible_output () const;
 
 	virtual void set_automation_control (uint32_t /*port_index*/, boost::shared_ptr<ARDOUR::AutomationControl>) { }
 
diff --git a/libs/ardour/ardour/plugin_insert.h b/libs/ardour/ardour/plugin_insert.h
index aa1164187d..c8f0a84222 100644
--- a/libs/ardour/ardour/plugin_insert.h
+++ b/libs/ardour/ardour/plugin_insert.h
@@ -134,7 +134,8 @@ class LIBARDOUR_API PluginInsert : public Processor
 		}
 	}
 
-	ChanCount required_buffers () const { return _required_buffers; }
+	const ChanCount& required_buffers () const { return _required_buffers; }
+	const ChanCount& preset_out () const { return _preset_out; }
 
 	// allow to override output_streams(), implies "Custom Mode"
 
@@ -144,6 +145,7 @@ class LIBARDOUR_API PluginInsert : public Processor
 	void set_outputs    (const ChanCount&);
 	void set_strict_io  (bool b);
 	void set_custom_cfg (bool b);
+	bool set_preset_out (const ChanCount&);
 	bool add_sidechain  (uint32_t n_audio = 1);
 	bool del_sidechain ();
 	boost::shared_ptr<SideChain> sidechain () const { return _sidechain; }
@@ -306,6 +308,7 @@ class LIBARDOUR_API PluginInsert : public Processor
 	ChanCount _configured_internal; // with side-chain
 	ChanCount _configured_out;
 	ChanCount _custom_out;
+	ChanCount _preset_out;
 	ChanCount _cached_sidechain_pins;
 	ChanCount _required_buffers;
 
@@ -317,6 +320,7 @@ class LIBARDOUR_API PluginInsert : public Processor
 	bool _mapping_changed;
 
 	Match private_can_support_io_configuration (ChanCount const &, ChanCount &) const;
+	Match internal_can_support_io_configuration (ChanCount const &, ChanCount &) const;
 	Match automatic_can_support_io_configuration (ChanCount const &, ChanCount &) const;
 
 	/** details of the match currently being used */
diff --git a/libs/ardour/ardour/route.h b/libs/ardour/ardour/route.h
index 7e7d5d55d4..c8f6005872 100644
--- a/libs/ardour/ardour/route.h
+++ b/libs/ardour/ardour/route.h
@@ -313,6 +313,7 @@ class LIBARDOUR_API Route : public SessionObject, public Automatable, public Rou
 	 */
 	bool customize_plugin_insert (boost::shared_ptr<Processor> proc, uint32_t count, ChanCount outs);
 	bool add_remove_sidechain (boost::shared_ptr<Processor> proc, bool);
+	bool plugin_preset_output (boost::shared_ptr<Processor> proc, ChanCount outs);
 
 	/* enable sidechain input for a given processor
 	 *