refine definition of "generator" plugins, and only send silence through the route is there is a REAL generator plugin (i.e. no inputs at all). Fixes #4144 (hopefully without breaking anything else)

git-svn-id: svn://localhost/ardour2/branches/3.0@9814 d708f5d6-7413-0410-9779-e7cbd77b26cf

3 files changed, 25 insertions, 9 deletions

diff --git a/libs/ardour/ardour/plugin_insert.h b/libs/ardour/ardour/plugin_insert.h
index ff2af9d150..e86e620273 100644
--- a/libs/ardour/ardour/plugin_insert.h
+++ b/libs/ardour/ardour/plugin_insert.h
@@ -72,7 +72,9 @@ class PluginInsert : public Processor
 	bool can_support_io_configuration (const ChanCount& in, ChanCount& out) const;
 	bool configure_io (ChanCount in, ChanCount out);
 
-	bool is_generator() const;
+	bool has_no_inputs() const;
+	bool has_no_audio_inputs() const;
+	bool is_midi_instrument() const;
 
 	void realtime_handle_transport_stopped ();
 
diff --git a/libs/ardour/plugin_insert.cc b/libs/ardour/plugin_insert.cc
index cdebd006fc..6c2add6c42 100644
--- a/libs/ardour/plugin_insert.cc
+++ b/libs/ardour/plugin_insert.cc
@@ -181,13 +181,27 @@ PluginInsert::natural_input_streams() const
 }
 
 bool
-PluginInsert::is_generator() const
+PluginInsert::has_no_inputs() const
+{
+	return _plugins[0]->get_info()->n_inputs == ChanCount::ZERO;
+}
+
+bool
+PluginInsert::has_no_audio_inputs() const
+{
+	return _plugins[0]->get_info()->n_inputs.n_audio() == 0;
+}
+
+bool
+PluginInsert::is_midi_instrument() const
 {
 	/* XXX more finesse is possible here. VST plugins have a
 	   a specific "instrument" flag, for example.
 	 */
+	PluginInfoPtr pi = _plugins[0]->get_info();
 
-	return _plugins[0]->get_info()->n_inputs.n_audio() == 0;
+	return pi->n_inputs.n_midi() != 0 &&
+		pi->n_outputs.n_audio() > 0;
 }
 
 void
@@ -414,7 +428,7 @@ PluginInsert::run (BufferSet& bufs, framepos_t /*start_frame*/, framepos_t /*end
 
 	} else {
 
-		if (is_generator()) {
+		if (has_no_audio_inputs()) {
 
 			/* silence all (audio) outputs. Should really declick
 			 * at the transitions of "active"
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index 81d85a8640..d4924d038d 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -909,7 +909,7 @@ Route::add_processor (boost::shared_ptr<Processor> processor, ProcessorList::ite
 
 		if ((pi = boost::dynamic_pointer_cast<PluginInsert>(processor)) != 0) {
 
-			if (pi->natural_input_streams() == ChanCount::ZERO) {
+			if (pi->has_no_inputs ()) {
 				/* generator plugin */
 				_have_internal_generator = true;
 			}
@@ -1062,7 +1062,7 @@ Route::add_processors (const ProcessorList& others, boost::shared_ptr<Processor>
 			boost::shared_ptr<PluginInsert> pi;
 
 			if ((pi = boost::dynamic_pointer_cast<PluginInsert>(*i)) != 0) {
-				if (pi->is_generator()) {
+				if (pi->has_no_inputs ()) {
 					_have_internal_generator = true;
 					break;
 				}
@@ -1361,7 +1361,7 @@ Route::remove_processor (boost::shared_ptr<Processor> processor, ProcessorStream
 			boost::shared_ptr<PluginInsert> pi;
 
 			if ((pi = boost::dynamic_pointer_cast<PluginInsert>(*i)) != 0) {
-				if (pi->is_generator()) {
+				if (pi->has_no_inputs ()) {
 					_have_internal_generator = true;
 					break;
 				}
@@ -1451,7 +1451,7 @@ Route::remove_processors (const ProcessorList& to_be_deleted, ProcessorStreams*
 			boost::shared_ptr<PluginInsert> pi;
 
 			if ((pi = boost::dynamic_pointer_cast<PluginInsert>(*i)) != 0) {
-				if (pi->is_generator()) {
+				if (pi->has_no_inputs ()) {
 					_have_internal_generator = true;
 					break;
 				}
@@ -2432,7 +2432,7 @@ Route::set_processor_state (const XMLNode& node)
 			boost::shared_ptr<PluginInsert> pi;
 
 			if ((pi = boost::dynamic_pointer_cast<PluginInsert>(*i)) != 0) {
-				if (pi->is_generator()) {
+				if (pi->has_no_inputs ()) {
 					_have_internal_generator = true;
 					break;
 				}