Made plugin input/output counts multi-typed (towards MIDI plugins, instruments, etc).

Cleaning up/genericification of Insert interface.
Fixed meter count for pre-fader metering (was # inputs, not # channels at end of pre-fader redirect list).
Work on redirect list stream handling, better error reporting (towards automatically adding 'adaptors' in the future?).


git-svn-id: svn://localhost/ardour2/trunk@2025 d708f5d6-7413-0410-9779-e7cbd77b26cf

7 files changed, 256 insertions, 184 deletions

diff --git a/libs/ardour/ardour/chan_count.h b/libs/ardour/ardour/chan_count.h
index a859c37b5a..1ed50f7abb 100644
--- a/libs/ardour/ardour/chan_count.h
+++ b/libs/ardour/ardour/chan_count.h
@@ -47,6 +47,8 @@ public:
 	// -1 is what to_index does.  inlined for speed.  this should maybe be changed..
 	inline size_t n_audio() const { return _counts[DataType::AUDIO-1]; }
 	inline size_t n_midi()  const { return _counts[DataType::MIDI-1]; }
+	inline void set_audio(size_t a) { _counts[DataType::AUDIO-1] = a; }
+	inline void set_midi(size_t m)  { _counts[DataType::MIDI-1] = m; }
 	
 	size_t n_total() const
 	{
diff --git a/libs/ardour/ardour/insert.h b/libs/ardour/ardour/insert.h
index e58cb71754..10902a76b0 100644
--- a/libs/ardour/ardour/insert.h
+++ b/libs/ardour/ardour/insert.h
@@ -55,9 +55,13 @@ class Insert : public Redirect
 	virtual void activate () {}
 	virtual void deactivate () {}
 
-	virtual int32_t can_support_input_configuration (int32_t in) const = 0;
-	virtual int32_t configure_io (int32_t magic, int32_t in, int32_t out) = 0;
-	virtual int32_t compute_output_streams (int32_t cnt) const = 0;
+	virtual bool      can_support_input_configuration (ChanCount in) const = 0;
+	virtual ChanCount output_for_input_configuration (ChanCount in) const = 0;
+	virtual bool      configure_io (ChanCount in, ChanCount out) = 0;
+
+protected:
+	bool      _configured;
+	ChanCount _configured_input;
 };
 
 class PortInsert : public Insert 
@@ -81,9 +85,9 @@ class PortInsert : public Insert
 	ChanCount output_streams() const;
 	ChanCount input_streams() const;
 
-	int32_t can_support_input_configuration (int32_t) const;
-	int32_t configure_io (int32_t magic, int32_t in, int32_t out);
-	int32_t compute_output_streams (int32_t cnt) const;
+	virtual bool      can_support_input_configuration (ChanCount in) const;
+	virtual ChanCount output_for_input_configuration (ChanCount in) const;
+	virtual bool      configure_io (ChanCount in, ChanCount out);
 
 	uint32_t bit_slot() const { return bitslot; }
 
@@ -118,12 +122,12 @@ class PluginInsert : public Insert
 	ChanCount natural_output_streams() const;
 	ChanCount natural_input_streams() const;
 
-	int      set_count (uint32_t num);
+	bool     set_count (uint32_t num);
 	uint32_t get_count () const { return _plugins.size(); }
 
-	int32_t can_support_input_configuration (int32_t) const;
-	int32_t configure_io (int32_t magic, int32_t in, int32_t out);
-	int32_t compute_output_streams (int32_t cnt) const;
+	virtual bool      can_support_input_configuration (ChanCount in) const;
+	virtual ChanCount output_for_input_configuration (ChanCount in) const;
+	virtual bool      configure_io (ChanCount in, ChanCount out);
 
 	bool is_generator() const;
 
@@ -166,6 +170,8 @@ class PluginInsert : public Insert
 	void auto_state_changed (uint32_t which);
 	void automation_list_creation_callback (uint32_t, AutomationList&);
 
+	int32_t count_for_configuration (ChanCount in, ChanCount out) const;
+
 	boost::shared_ptr<Plugin> plugin_factory (boost::shared_ptr<Plugin>);
 };
 
diff --git a/libs/ardour/ardour/plugin.h b/libs/ardour/ardour/plugin.h
index feb86f1b7b..b1a2823b33 100644
--- a/libs/ardour/ardour/plugin.h
+++ b/libs/ardour/ardour/plugin.h
@@ -28,6 +28,7 @@
 
 #include <jack/types.h>
 #include <ardour/types.h>
+#include <ardour/chan_count.h>
 #include <ardour/plugin_state.h>
 #include <ardour/cycles.h>
 
@@ -60,8 +61,8 @@ class PluginInfo {
 
 	string name;
 	string category;
-	uint32_t n_inputs;
-	uint32_t n_outputs;
+	ChanCount n_inputs;
+	ChanCount n_outputs;
 	ARDOUR::PluginType type;
 
 	long unique_id;
diff --git a/libs/ardour/ardour/route.h b/libs/ardour/ardour/route.h
index ed839f091b..b5d1fa03d6 100644
--- a/libs/ardour/ardour/route.h
+++ b/libs/ardour/ardour/route.h
@@ -159,15 +159,23 @@ class Route : public IO
 	}
 	
 	ChanCount max_redirect_outs () const { return redirect_max_outs; }
+	ChanCount pre_fader_streams() const;
 	
-	// FIXME: remove/replace err_streams parameters with something appropriate
-	// they are used by 'wierd_plugin_dialog'(sic) to display the number of input streams
-	// at the insertion point if the insert fails
-	int add_redirect (boost::shared_ptr<Redirect>, void *src, uint32_t* err_streams = 0);
-	int add_redirects (const RedirectList&, void *src, uint32_t* err_streams = 0);
-	int remove_redirect (boost::shared_ptr<Redirect>, void *src, uint32_t* err_streams = 0);
-	int copy_redirects (const Route&, Placement, uint32_t* err_streams = 0);
-	int sort_redirects (uint32_t* err_streams = 0);
+	/** A record of the stream configuration at some point in the redirect list.
+	 * Used to return where and why a redirect list configuration request failed.
+	 */
+	struct InsertStreams {
+		InsertStreams(size_t i=0, ChanCount c=ChanCount()) : index(i), count(c) {}
+
+		size_t    index; ///< Index of redirect where configuration failed
+		ChanCount count; ///< Input requested of redirect
+	};
+
+	int add_redirect (boost::shared_ptr<Redirect>, void *src, InsertStreams* err = 0);
+	int add_redirects (const RedirectList&, void *src, InsertStreams* err = 0);
+	int remove_redirect (boost::shared_ptr<Redirect>, void *src, InsertStreams* err = 0);
+	int copy_redirects (const Route&, Placement, InsertStreams* err = 0);
+	int sort_redirects (InsertStreams* err = 0);
 	void disable_redirects (Placement);
 	void disable_redirects ();
 	void disable_plugins (Placement);
@@ -347,22 +355,21 @@ class Route : public IO
 	void output_change_handler (IOChange, void *src);
 
 	bool legal_redirect (Redirect&);
-	int reset_plugin_counts (uint32_t*); /* locked */
-	int _reset_plugin_counts (uint32_t*); /* unlocked */
+	int reset_plugin_counts (InsertStreams*); /* locked */
+	int _reset_plugin_counts (InsertStreams*); /* unlocked */
 
-	/* plugin count handling */
+	/* insert I/O channels and plugin count handling */
 
 	struct InsertCount {
 	    boost::shared_ptr<ARDOUR::Insert> insert;
-	    int32_t cnt;
-	    int32_t in;
-	    int32_t out;
+	    ChanCount in;
+	    ChanCount out;
 
-	    InsertCount (boost::shared_ptr<ARDOUR::Insert> ins) : insert (ins), cnt (-1) {}
+	    InsertCount (boost::shared_ptr<ARDOUR::Insert> ins) : insert(ins) {}
 	};
 	
 	int32_t apply_some_plugin_counts (std::list<InsertCount>& iclist);
-	int32_t check_some_plugin_counts (std::list<InsertCount>& iclist, int32_t required_inputs, uint32_t* err_streams);
+	bool    check_some_plugin_counts (std::list<InsertCount>& iclist, ChanCount required_inputs, InsertStreams* err_streams);
 
 	void set_deferred_state ();
 	void add_redirect_from_xml (const XMLNode&);
diff --git a/libs/ardour/insert.cc b/libs/ardour/insert.cc
index f08661b06a..88a5c1a14d 100644
--- a/libs/ardour/insert.cc
+++ b/libs/ardour/insert.cc
@@ -53,11 +53,13 @@ using namespace PBD;
  * Inserts are still definitely audio only */
 Insert::Insert(Session& s, string name, Placement p)
 	: Redirect (s, name, p)
+	, _configured(false)
 {
 }
 
 Insert::Insert(Session& s, string name, Placement p, int imin, int imax, int omin, int omax)
 	: Redirect (s, name, p, imin, imax, omin, omax)
+	, _configured(false)
 {
 }
 
@@ -121,7 +123,7 @@ PluginInsert::PluginInsert (const PluginInsert& other)
 	RedirectCreated (this); /* EMIT SIGNAL */
 }
 
-int
+bool
 PluginInsert::set_count (uint32_t num)
 {
 	bool require_state = !_plugins.empty();
@@ -131,7 +133,7 @@ PluginInsert::set_count (uint32_t num)
 	*/
 
 	if (num == 0) { 
-		return -1;
+		return false;
 	} else if (num > _plugins.size()) {
 		uint32_t diff = num - _plugins.size();
 
@@ -150,7 +152,7 @@ PluginInsert::set_count (uint32_t num)
 		}
 	}
 
-	return 0;
+	return true;
 }
 
 void
@@ -185,29 +187,31 @@ PluginInsert::auto_state_changed (uint32_t which)
 ChanCount
 PluginInsert::output_streams() const
 {
-	// FIXME: TYPE
-	return ChanCount(DataType::AUDIO, _plugins[0]->get_info()->n_outputs * _plugins.size());
+	if (_configured)
+		return output_for_input_configuration(_configured_input);
+	else
+		return natural_output_streams();
 }
 
 ChanCount
 PluginInsert::input_streams() const
 {
-	// FIXME: TYPE
-	return ChanCount(DataType::AUDIO, _plugins[0]->get_info()->n_inputs * _plugins.size());
+	if (_configured)
+		return _configured_input;
+	else
+		return natural_input_streams();
 }
 
 ChanCount
 PluginInsert::natural_output_streams() const
 {
-	// FIXME: TYPE
-	return ChanCount(DataType::AUDIO, _plugins[0]->get_info()->n_outputs);
+	return _plugins[0]->get_info()->n_outputs;
 }
 
 ChanCount
 PluginInsert::natural_input_streams() const
 {
-	// FIXME: TYPE
-	return ChanCount(DataType::AUDIO, _plugins[0]->get_info()->n_inputs);
+	return _plugins[0]->get_info()->n_inputs;
 }
 
 bool
@@ -217,7 +221,7 @@ PluginInsert::is_generator() const
 	   a specific "instrument" flag, for example.
 	 */
 
-	return _plugins[0]->get_info()->n_inputs == 0;
+	return _plugins[0]->get_info()->n_inputs.n_audio() == 0;
 }
 
 void
@@ -349,12 +353,9 @@ PluginInsert::silence (nframes_t nframes, nframes_t offset)
 	uint32_t in_index = 0;
 	uint32_t out_index = 0;
 
-	uint32_t n;
-
 	if (active()) {
 		for (vector<boost::shared_ptr<Plugin> >::iterator i = _plugins.begin(); i != _plugins.end(); ++i) {
-			n = (*i) -> get_info()->n_inputs;
-			(*i)->connect_and_run (_session.get_silent_buffers (ChanCount(DataType::AUDIO, n)), in_index, out_index, nframes, offset);
+			(*i)->connect_and_run (_session.get_silent_buffers ((*i)->get_info()->n_inputs), in_index, out_index, nframes, offset);
 		}
 	}
 }
@@ -370,8 +371,8 @@ PluginInsert::run (BufferSet& bufs, nframes_t start_frame, nframes_t end_frame,
 			connect_and_run (bufs, nframes, offset, false);
 		}
 	} else {
-		uint32_t in = _plugins[0]->get_info()->n_inputs;
-		uint32_t out = _plugins[0]->get_info()->n_outputs;
+		uint32_t in = _plugins[0]->get_info()->n_inputs.n_audio();
+		uint32_t out = _plugins[0]->get_info()->n_outputs.n_audio();
 
 		if (out > in) {
 
@@ -382,7 +383,7 @@ PluginInsert::run (BufferSet& bufs, nframes_t start_frame, nframes_t end_frame,
 			}
 		}
 
-		bufs.count().set(DataType::AUDIO, out);
+		bufs.count().set(_default_type, out);
 	}
 }
 
@@ -534,36 +535,98 @@ PluginInsert::plugin_factory (boost::shared_ptr<Plugin> other)
 	return boost::shared_ptr<Plugin> ((Plugin*) 0);
 }
 
-int32_t
-PluginInsert::compute_output_streams (int32_t cnt) const
+bool
+PluginInsert::configure_io (ChanCount in, ChanCount out)
 {
-	return _plugins[0]->get_info()->n_outputs * cnt;
+	ChanCount matching_out = output_for_input_configuration(out);
+	if (matching_out != out) {
+		_configured = false;
+		return false;
+	} else {
+		bool success = set_count (count_for_configuration(in, out));
+		if (success) {
+			_configured = true;
+			_configured_input = in;
+		}
+		return success;
+	}
 }
 
-int32_t
-PluginInsert::configure_io (int32_t magic, int32_t in, int32_t out)
+bool
+PluginInsert::can_support_input_configuration (ChanCount in_count) const
 {
-	return set_count (magic);
+	int32_t outputs = _plugins[0]->get_info()->n_outputs.get(_default_type);
+	int32_t inputs = _plugins[0]->get_info()->n_inputs.get(_default_type);
+	int32_t in = in_count.get(_default_type);
+
+	/* see output_for_input_configuration below */
+	if ((inputs == 0)
+			|| (outputs == 1 && inputs == 1)
+			|| (inputs == in)
+			|| ((inputs < in) && (inputs % in == 0))) {
+		return true;
+	} else {
+		return false;
+	}
 }
 
-int32_t 
-PluginInsert::can_support_input_configuration (int32_t in) const
+ChanCount
+PluginInsert::output_for_input_configuration (ChanCount in) const
 {
-	int32_t outputs = _plugins[0]->get_info()->n_outputs;
-	int32_t inputs = _plugins[0]->get_info()->n_inputs;
+	ChanCount outputs = _plugins[0]->get_info()->n_outputs;
+	ChanCount inputs = _plugins[0]->get_info()->n_inputs;
+
+	if (inputs.n_total() == 0) {
+		/* instrument plugin, always legal, but throws away any existing streams */
+		return outputs;
+	}
+
+	if (inputs.n_total() == 1 && outputs == inputs) {
+		/* mono plugin, replicate as needed to match in */
+		return in;
+	}
+
+	if (inputs == in) {
+		/* exact match */
+		return outputs;
+	}
 
-	if (inputs == 0) {
+	// FIXME: single type plugins only.  can we do this for instruments?
+	if ((inputs.n_total() == inputs.get(_default_type))
+			&& ((in.n_total() == in.get(_default_type))
+			&& (inputs.n_total() < in.n_total())
+			&& (inputs.n_total() % in.n_total() == 0))) {
 
-		/* instrument plugin, always legal, but it throws
-		   away any existing active streams.
+		/* number of inputs is a factor of the requested input
+		   configuration, so we can replicate.
 		*/
 
+		return ChanCount(_default_type, in.n_total() / inputs.n_total());
+	}
+
+	/* sorry */
+	return ChanCount();
+}
+
+/* Number of plugin instances required to support a given channel configuration.
+ * (private helper)
+ */
+int32_t
+PluginInsert::count_for_configuration (ChanCount in, ChanCount out) const
+{
+	// FIXME: take 'out' into consideration
+	
+	ChanCount outputs = _plugins[0]->get_info()->n_outputs;
+	ChanCount inputs = _plugins[0]->get_info()->n_inputs;
+
+	if (inputs.n_total() == 0) {
+		/* instrument plugin, always legal, but throws away any existing streams */
 		return 1;
 	}
 
-	if (outputs == 1 && inputs == 1) {
-		/* mono plugin, replicate as needed */
-		return in;
+	if (inputs.n_total() == 1 && outputs == inputs) {
+		/* mono plugin, replicate as needed to match in */
+		return in.n_total();
 	}
 
 	if (inputs == in) {
@@ -571,18 +634,21 @@ PluginInsert::can_support_input_configuration (int32_t in) const
 		return 1;
 	}
 
-	if ((inputs < in) && (inputs % in == 0)) {
+	// FIXME: single type plugins only.  can we do this for instruments?
+	if ((inputs.n_total() == inputs.get(_default_type))
+			&& ((in.n_total() == in.get(_default_type))
+			&& (inputs.n_total() < in.n_total())
+			&& (inputs.n_total() % in.n_total() == 0))) {
 
 		/* number of inputs is a factor of the requested input
 		   configuration, so we can replicate.
 		*/
 
-		return in/inputs;
+		return in.n_total() / inputs.n_total();
 	}
 
 	/* sorry */
-
-	return -1;
+	return 0;
 }
 
 XMLNode&
@@ -970,14 +1036,14 @@ PortInsert::latency()
 	return _session.engine().frames_per_cycle() + input_latency();
 }
 
-int32_t
-PortInsert::can_support_input_configuration (int32_t in) const
+bool
+PortInsert::can_support_input_configuration (ChanCount in) const
 {
 	if (input_maximum() == ChanCount::INFINITE && output_maximum() == ChanCount::INFINITE) {
 
 		/* not configured yet */
 
-		return 1; /* we can support anything the first time we're asked */
+		return true; /* we can support anything the first time we're asked */
 
 	} else {
 
@@ -985,16 +1051,23 @@ PortInsert::can_support_input_configuration (int32_t in) const
 		   many output ports it will have.
 		*/
 
-		if (output_maximum().get(_default_type) == static_cast<uint32_t>(in)) {
-			return 1;
+		if (output_maximum() == in) {
+
+			return true;
 		} 
 	}
 
-	return -1;
+	return false;
 }
 
-int32_t
-PortInsert::configure_io (int32_t ignored_magic, int32_t in, int32_t out)
+ChanCount
+PortInsert::output_for_input_configuration (ChanCount in) const
+{
+	return in;
+}
+
+bool
+PortInsert::configure_io (ChanCount in, ChanCount out)
 {
 	/* do not allow configuration to be changed outside the range of
 	   the last request config. or something like that.
@@ -1010,27 +1083,12 @@ PortInsert::configure_io (int32_t ignored_magic, int32_t in, int32_t out)
 	   to the number of input ports we need.
 	*/
 
-	set_output_maximum (ChanCount(_default_type, in));
-	set_output_minimum (ChanCount(_default_type, in));
-	set_input_maximum (ChanCount(_default_type, out));
-	set_input_minimum (ChanCount(_default_type, out));
-
-	if (in < 0) {
-		in = n_outputs ().get(_default_type);
-	} 
+	set_output_maximum (in);
+	set_output_minimum (in);
+	set_input_maximum (out);
+	set_input_minimum (out);
 
-	if (out < 0) {
-		out = n_inputs ().get(_default_type);
-	}
-
-	return ensure_io (ChanCount(_default_type, out), ChanCount(_default_type, in), false, this);
-}
-
-int32_t
-PortInsert::compute_output_streams (int32_t cnt) const
-{
-	/* puzzling, eh? think about it ... */
-	return n_inputs ().get(_default_type);
+	return (ensure_io (out, in, false, this) == 0);
 }
 
 ChanCount
diff --git a/libs/ardour/plugin_manager.cc b/libs/ardour/plugin_manager.cc
index 9af7ad0451..02cba7dd94 100644
--- a/libs/ardour/plugin_manager.cc
+++ b/libs/ardour/plugin_manager.cc
@@ -253,18 +253,18 @@ PluginManager::ladspa_discover (string path)
 		info->category = get_ladspa_category(descriptor->UniqueID);
 		info->path = path;
 		info->index = i;
-		info->n_inputs = 0;
-		info->n_outputs = 0;
+		info->n_inputs = ChanCount();
+		info->n_outputs = ChanCount();
 		info->type = ARDOUR::LADSPA;
 		info->unique_id = descriptor->UniqueID;
 		
 		for (uint32_t n=0; n < descriptor->PortCount; ++n) {
 			if ( LADSPA_IS_PORT_AUDIO (descriptor->PortDescriptors[n]) ) {
 				if ( LADSPA_IS_PORT_INPUT (descriptor->PortDescriptors[n]) ) {
-					info->n_inputs++;
+					info->n_inputs.set_audio(info->n_inputs.n_audio() + 1);
 				}
 				else if ( LADSPA_IS_PORT_OUTPUT (descriptor->PortDescriptors[n]) ) {
-					info->n_outputs++;
+					info->n_outputs.set_audio(info->n_outputs.n_audio() + 1);
 				}
 			}
 		}
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index 49870abf37..d77dc46b0c 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -773,7 +773,7 @@ Route::set_mute (bool yn, void *src)
 }
 
 int
-Route::add_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_t* err_streams)
+Route::add_redirect (boost::shared_ptr<Redirect> redirect, void *src, InsertStreams* err)
 {
 	ChanCount old_rmo = redirect_max_outs;
 
@@ -792,7 +792,7 @@ Route::add_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_t*
 		if ((pi = boost::dynamic_pointer_cast<PluginInsert>(redirect)) != 0) {
 			pi->set_count (1);
 
-			if (pi->input_streams() == ChanCount::ZERO) {
+			if (pi->natural_input_streams() == ChanCount::ZERO) {
 				/* generator plugin */
 				_have_internal_generator = true;
 			}
@@ -814,18 +814,19 @@ Route::add_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_t*
 			porti->ensure_io (n_outputs (), n_inputs(), false, this);
 		}
 		
-		// Ensure peak vector sizes before the plugin is activated
-		ChanCount potential_max_streams = max(redirect->input_streams(), redirect->output_streams());
-		_meter->setup(potential_max_streams);
-
 		_redirects.push_back (redirect);
 
-		if (_reset_plugin_counts (err_streams)) {
+		// Set up redirect list channels.  This will set redirect->[input|output]_streams()
+		if (_reset_plugin_counts (err)) {
 			_redirects.pop_back ();
 			_reset_plugin_counts (0); // it worked before we tried to add it ...
 			return -1;
 		}
 
+		// Ensure peak vector sizes before the plugin is activated
+		ChanCount potential_max_streams = max(redirect->input_streams(), redirect->output_streams());
+		_meter->setup(potential_max_streams);
+
 		redirect->activate ();
 		redirect->active_changed.connect (mem_fun (*this, &Route::redirect_active_proxy));
 	}
@@ -840,7 +841,7 @@ Route::add_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_t*
 }
 
 int
-Route::add_redirects (const RedirectList& others, void *src, uint32_t* err_streams)
+Route::add_redirects (const RedirectList& others, void *src, InsertStreams* err)
 {
 	ChanCount old_rmo = redirect_max_outs;
 
@@ -873,7 +874,7 @@ Route::add_redirects (const RedirectList& others, void *src, uint32_t* err_strea
 
 			_redirects.push_back (*i);
 			
-			if (_reset_plugin_counts (err_streams)) {
+			if (_reset_plugin_counts (err)) {
 				++existing_end;
 				_redirects.erase (existing_end, _redirects.end());
 				_reset_plugin_counts (0); // it worked before we tried to add it ...
@@ -996,6 +997,28 @@ Route::ab_plugins (bool forward)
 		}
 	}
 }
+	
+	
+/* Figure out the streams that will feed into PreFader */
+ChanCount
+Route::pre_fader_streams() const
+{
+	boost::shared_ptr<Redirect> redirect;
+
+	// Find the last pre-fader redirect
+	for (RedirectList::const_iterator r = _redirects.begin(); r != _redirects.end(); ++r) {
+		if ((*r)->placement() == PreFader) {
+			redirect = *r;
+		}
+	}
+	
+	if (redirect) {
+		return redirect->output_streams();
+	} else {
+		return n_inputs ();
+	}
+}
+
 
 /** Remove redirects with a given placement.
  * @param p Placement of redirects to remove.
@@ -1037,7 +1060,7 @@ Route::clear_redirects (Placement p, void *src)
 }
 
 int
-Route::remove_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_t* err_streams)
+Route::remove_redirect (boost::shared_ptr<Redirect> redirect, void *src, InsertStreams* err)
 {
 	ChanCount old_rmo = redirect_max_outs;
 
@@ -1093,7 +1116,7 @@ Route::remove_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_
 			return 1;
 		}
 
-		if (_reset_plugin_counts (err_streams)) {
+		if (_reset_plugin_counts (err)) {
 			/* get back to where we where */
 			_redirects.insert (i, redirect);
 			/* we know this will work, because it worked before :) */
@@ -1127,92 +1150,52 @@ Route::remove_redirect (boost::shared_ptr<Redirect> redirect, void *src, uint32_
 }
 
 int
-Route::reset_plugin_counts (uint32_t* lpc)
+Route::reset_plugin_counts (InsertStreams* err)
 {
 	Glib::RWLock::WriterLock lm (redirect_lock);
-	return _reset_plugin_counts (lpc);
+	return _reset_plugin_counts (err);
 }
 
 
 int
-Route::_reset_plugin_counts (uint32_t* err_streams)
+Route::_reset_plugin_counts (InsertStreams* err)
 {
 	RedirectList::iterator r;
-	uint32_t i_cnt;
-	uint32_t s_cnt;
 	map<Placement,list<InsertCount> > insert_map;
-	nframes_t initial_streams;
-
-	redirect_max_outs.reset();
-	i_cnt = 0;
-	s_cnt = 0;
+	ChanCount initial_streams;
 
+	/* Process each placement in order, checking to see if we 
+	   can really do what has been requested.
+	*/
+	
 	/* divide inserts up by placement so we get the signal flow
 	   properly modelled. we need to do this because the _redirects
-	   list is not sorted by placement, and because other reasons may 
-	   exist now or in the future for this separate treatment.
+	   list is not sorted by placement
 	*/
+
+	/* ... but it should/will be... */
 	
 	for (r = _redirects.begin(); r != _redirects.end(); ++r) {
 
 		boost::shared_ptr<Insert> insert;
 
-		/* do this here in case we bomb out before we get to the end of
-		   this function.
-		*/
-
-		redirect_max_outs = max ((*r)->output_streams (), redirect_max_outs);
-
 		if ((insert = boost::dynamic_pointer_cast<Insert>(*r)) != 0) {
-			++i_cnt;
 			insert_map[insert->placement()].push_back (InsertCount (insert));
-
-			/* reset plugin counts back to one for now so
-			   that we have a predictable, controlled
-			   state to try to configure.
-			*/
-
-			boost::shared_ptr<PluginInsert> pi;
-		
-			if ((pi = boost::dynamic_pointer_cast<PluginInsert>(insert)) != 0) {
-				pi->set_count (1);
-			}
-
-		} else if (boost::dynamic_pointer_cast<Send> (*r) != 0) {
-			++s_cnt;
 		}
 	}
 	
-	if (i_cnt == 0) {
-		if (s_cnt) {
-			goto recompute;
-		} else {
-			return 0;
-		}
-	}
-
-	/* Now process each placement in order, checking to see if we 
-	   can really do what has been requested.
-	*/
 
 	/* A: PreFader */
 	
-	if (check_some_plugin_counts (insert_map[PreFader], n_inputs ().get(_default_type), err_streams)) {
+	if ( ! check_some_plugin_counts (insert_map[PreFader], n_inputs (), err)) {
 		return -1;
 	}
 
-	/* figure out the streams that will feed into PreFader */
-
-	if (!insert_map[PreFader].empty()) {
-		InsertCount& ic (insert_map[PreFader].back());
-		initial_streams = ic.insert->compute_output_streams (ic.cnt);
-	} else {
-		initial_streams = n_inputs ().get(_default_type);
-	}
+	ChanCount post_fader_input = (err ? err->count : n_inputs());
 
 	/* B: PostFader */
 
-	if (check_some_plugin_counts (insert_map[PostFader], initial_streams, err_streams)) {
+	if ( ! check_some_plugin_counts (insert_map[PostFader], post_fader_input, err)) {
 		return -1;
 	}
 
@@ -1223,8 +1206,6 @@ Route::_reset_plugin_counts (uint32_t* err_streams)
 
 	/* recompute max outs of any redirect */
 
-  recompute:
-
 	redirect_max_outs.reset();
 	RedirectList::iterator prev = _redirects.end();
 
@@ -1261,7 +1242,7 @@ Route::apply_some_plugin_counts (list<InsertCount>& iclist)
 
 	for (i = iclist.begin(); i != iclist.end(); ++i) {
 		
-		if ((*i).insert->configure_io ((*i).cnt, (*i).in, (*i).out)) {
+		if ((*i).insert->configure_io ((*i).in, (*i).out)) {
 			return -1;
 		}
 		/* make sure that however many we have, they are all active */
@@ -1271,38 +1252,55 @@ Route::apply_some_plugin_counts (list<InsertCount>& iclist)
 	return 0;
 }
 
-int32_t
-Route::check_some_plugin_counts (list<InsertCount>& iclist, int32_t required_inputs, uint32_t* err_streams)
+/** Returns whether \a iclist can be configured and run starting with
+ * \a required_inputs at the first insert's inputs.
+ * If false is returned, \a iclist can not be run with \a required_inputs, and \a err is set.
+ * Otherwise, \a err is set to the output of the list.
+ */
+bool
+Route::check_some_plugin_counts (list<InsertCount>& iclist, ChanCount required_inputs, InsertStreams* err)
 {
 	list<InsertCount>::iterator i;
-	
+	size_t index = 0;
+			
+	if (err) {
+		err->index = 0;
+		err->count = required_inputs;
+	}
+
 	for (i = iclist.begin(); i != iclist.end(); ++i) {
 
-		if (((*i).cnt = (*i).insert->can_support_input_configuration (required_inputs)) < 0) {
-			if (err_streams) {
-				*err_streams = required_inputs;
+		if ((*i).insert->can_support_input_configuration (required_inputs) < 0) {
+			if (err) {
+				err->index = index;
+				err->count = required_inputs;
 			}
-			return -1;
+			return false;
 		}
 		
 		(*i).in = required_inputs;
-		(*i).out = (*i).insert->compute_output_streams ((*i).cnt);
+		(*i).out = (*i).insert->output_for_input_configuration (required_inputs);
 
 		required_inputs = (*i).out;
+		
+		++index;
+	}
+			
+	if (err) {
+		if (!iclist.empty()) {
+			err->index = index;
+			err->count = iclist.back().insert->output_for_input_configuration(required_inputs);
+		}
 	}
 
-	return 0;
+	return true;
 }
 
 int
-Route::copy_redirects (const Route& other, Placement placement, uint32_t* err_streams)
+Route::copy_redirects (const Route& other, Placement placement, InsertStreams* err)
 {
 	ChanCount old_rmo = redirect_max_outs;
 
-	if (err_streams) {
-		*err_streams = 0;
-	}
-
 	RedirectList to_be_deleted;
 
 	{
@@ -1336,7 +1334,7 @@ Route::copy_redirects (const Route& other, Placement placement, uint32_t* err_st
 
 		/* reset plugin stream handling */
 
-		if (_reset_plugin_counts (err_streams)) {
+		if (_reset_plugin_counts (err)) {
 
 			/* FAILED COPY ATTEMPT: we have to restore order */
 
@@ -1421,7 +1419,7 @@ struct RedirectSorter {
 };
 
 int
-Route::sort_redirects (uint32_t* err_streams)
+Route::sort_redirects (InsertStreams* err)
 {
 	{
 		RedirectSorter comparator;
@@ -1434,7 +1432,7 @@ Route::sort_redirects (uint32_t* err_streams)
 
 		_redirects.sort (comparator);
 	
-		if (_reset_plugin_counts (err_streams)) {
+		if (_reset_plugin_counts (err)) {
 			_redirects = as_it_was_before;
 			redirect_max_outs = old_rmo;
 			return -1;