API to count max multi-channel plugin outputs

libs/ardour/ardour/audio_unit.h

@@ -245,7 +245,7 @@ struct LIBARDOUR_API AUPluginCachedInfo {
 class LIBARDOUR_API AUPluginInfo : public PluginInfo {
   public:
 	 AUPluginInfo (boost::shared_ptr<CAComponentDescription>);
-	~AUPluginInfo ();
+	~AUPluginInfo () {}
 
 	PluginPtr load (Session& session);
 
@@ -263,6 +263,7 @@ class LIBARDOUR_API AUPluginInfo : public PluginInfo {
 	AUPluginCachedInfo cache;
 
 	bool reconfigurable_io() const { return true; }
+	uint32_t max_configurable_ouputs () const { return max_outputs; }
 
 	static void clear_cache ();
 	static PluginInfoList* discover (bool scan_only);
@@ -274,6 +275,7 @@ class LIBARDOUR_API AUPluginInfo : public PluginInfo {
   private:
 	boost::shared_ptr<CAComponentDescription> descriptor;
 	UInt32 version;
+	uint32_t max_outputs;
 	static FILE * _crashlog_fd;
 	static bool _scan_only;
 

libs/ardour/ardour/luaproc.h

@@ -211,6 +211,12 @@ class LIBARDOUR_API LuaPluginInfo : public PluginInfo
 	std::vector<Plugin::PresetRecord> get_presets (bool user_only) const;
 
 	bool reconfigurable_io() const { return true; }
+	uint32_t max_configurable_ouputs () const {
+		return _max_outputs;
+	}
+
+	private:
+	uint32_t _max_outputs;
 };
 
 typedef boost::shared_ptr<LuaPluginInfo> LuaPluginInfoPtr;

libs/ardour/ardour/plugin.h

@@ -496,6 +496,12 @@ public:
 	/* @return true if the plugin can change its inputs or outputs on demand. */
 	virtual bool reconfigurable_io () const { return false; }
 
+	/* max [re]configurable outputs (if finite, 0 otherwise) */
+	virtual uint32_t max_configurable_ouputs () const
+	{
+		return n_outputs.n_audio();
+	}
+
 protected:
 	friend class PluginManager;
 	uint32_t index; //< used for LADSPA, index in module

libs/ardour/audio_unit.cc

@@ -2549,11 +2549,7 @@ AUPlugin::has_editor () const
 AUPluginInfo::AUPluginInfo (boost::shared_ptr<CAComponentDescription> d)
 	: descriptor (d)
 	, version (0)
-{
-	type = ARDOUR::AudioUnit;
-}
-
-AUPluginInfo::~AUPluginInfo ()
+	, max_outputs (0)
 {
 	type = ARDOUR::AudioUnit;
 }
@@ -2922,6 +2918,8 @@ AUPluginInfo::discover_by_description (PluginInfoList& plugs, CAComponentDescrip
 
 		const int rv = cached_io_configuration (info->unique_id, info->version, cacomp, info->cache, info->name);
 
+		info.max_outputs = 0;
+
 		if (rv == 0) {
 			/* here we have to map apple's wildcard system to a simple pair
 			   of values. in ::can_do() we use the whole system, but here
@@ -2936,8 +2934,18 @@ AUPluginInfo::discover_by_description (PluginInfoList& plugs, CAComponentDescrip
 			   info to the user, which should perhaps be revisited.
 			*/
 
-			int32_t possible_in = info->cache.io_configs.front().first;
-			int32_t possible_out = info->cache.io_configs.front().second;
+			const vector<pair<int,int> >& ioc (info->cache.io_configs);
+			for (vector<pair<int,int> >::const_iterator i = ioc.begin(); i != ioc.end(); ++i) {
+				int32_t possible_out = i->second;
+				if (possible_out < 0) {
+					continue;
+				} else if (possible_out > info.max_outputs) {
+					info.max_outputs = possible_out;
+				}
+			}
+
+			int32_t possible_in = ioc.front().first;
+			int32_t possible_out = ioc.font().second;
 
 			if (possible_in > 0) {
 				info->n_inputs.set (DataType::AUDIO, possible_in);

libs/ardour/luaproc.cc

@@ -1232,6 +1232,8 @@ LuaPluginInfo::LuaPluginInfo (LuaScriptInfoPtr lsi) {
 	n_outputs.set (DataType::AUDIO, 1);
 	type = Lua;
 
+	// TODO, parse script, get 'dsp_ioconfig', see can_support_io_configuration()
+	_max_outputs = 0;
 }
 
 PluginPtr

libs/ardour/plugin_manager.cc

@@ -286,7 +286,7 @@ PluginManager::detect_name_ambiguities (PluginInfoList* pil)
 				* by listing number of audio outputs.
 				* This is used in the instrument selector.
 				*/
-			 bool r = p->n_outputs.n_audio() != (*i)->n_outputs.n_audio();
+			 bool r = p->max_configurable_ouputs () != (*i)->max_configurable_ouputs ();
 			 p->multichannel_name_ambiguity = r;
 			 (*i)->multichannel_name_ambiguity = r;
 		 }