From d9de72215b85fb480bca948069d2c583aa342544 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 5 Jul 2016 00:38:52 +0200
Subject: [PATCH] fix bypassing plugins with sidechain i/o

---
 libs/ardour/ardour/plugin_insert.h |  1 +
 libs/ardour/plugin_insert.cc       | 34 +++++++++++++++++++++++-------
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/libs/ardour/ardour/plugin_insert.h b/libs/ardour/ardour/plugin_insert.h
index 5ec35d0589..9f1d56b811 100644
--- a/libs/ardour/ardour/plugin_insert.h
+++ b/libs/ardour/ardour/plugin_insert.h
@@ -96,6 +96,7 @@ class LIBARDOUR_API PluginInsert : public Processor
 	bool pre_seed (const ChanCount&, const ChanCount&, const ChanMapping&, const ChanMapping&, const ChanMapping&);
 
 	ChanMapping input_map () const; ///< combined (all instances) input map
+	ChanMapping no_sc_input_map () const; ///< combined (all instances) input map w/o sidechain sinks
 	ChanMapping output_map () const; ///< combined (all instances) output map
 	bool has_midi_bypass () const;
 	bool has_midi_thru () const;
diff --git a/libs/ardour/plugin_insert.cc b/libs/ardour/plugin_insert.cc
index 92d4897c6b..8c1fe8bac6 100644
--- a/libs/ardour/plugin_insert.cc
+++ b/libs/ardour/plugin_insert.cc
@@ -858,8 +858,8 @@ PluginInsert::bypass (BufferSet& bufs, pframes_t nframes)
 	 */
 
 	// TODO: atomically copy maps & _no_inplace
-	ChanMapping in_map (input_map ());
-	ChanMapping out_map (output_map ());
+	const ChanMapping in_map (no_sc_input_map ());
+	const ChanMapping out_map (output_map ());
 	if (_mapping_changed) {
 		_no_inplace = check_inplace ();
 		_mapping_changed = false;
@@ -988,15 +988,15 @@ PluginInsert::silence (framecnt_t nframes, framepos_t start_frame)
 void
 PluginInsert::run (BufferSet& bufs, framepos_t start_frame, framepos_t end_frame, double speed, pframes_t nframes, bool)
 {
+	if (_sidechain) {
+		// collect sidechain input for complete cycle (!)
+		// TODO we need delaylines here for latency compensation
+		_sidechain->run (bufs, start_frame, end_frame, speed, nframes, true);
+	}
+
 	if (_pending_active) {
 		/* run as normal if we are active or moving from inactive to active */
 
-		if (_sidechain) {
-			// collect sidechain input for complete cycle (!)
-			// TODO we need delaylines here for latency compensation
-			_sidechain->run (bufs, start_frame, end_frame, speed, nframes, true);
-		}
-
 		if (_session.transport_rolling() || _session.bounce_processing()) {
 			automation_run (bufs, start_frame, end_frame, speed, nframes);
 		} else {
@@ -1254,6 +1254,24 @@ PluginInsert::input_map () const
 	return rv;
 }
 
+
+ChanMapping
+PluginInsert::no_sc_input_map () const
+{
+	ChanMapping rv;
+	uint32_t pc = 0;
+	for (PinMappings::const_iterator i = _in_map.begin (); i != _in_map.end (); ++i, ++pc) {
+		ChanMapping m (i->second);
+		const ChanMapping::Mappings& mp ((*i).second.mappings());
+		for (ChanMapping::Mappings::const_iterator tm = mp.begin(); tm != mp.end(); ++tm) {
+			for (ChanMapping::TypeMapping::const_iterator i = tm->second.begin(); i != tm->second.end(); ++i) {
+				rv.set (tm->first, i->first + pc * (natural_input_streams().get(tm->first) - _cached_sidechain_pins.get(tm->first)), i->second);
+			}
+		}
+	}
+	return rv;
+}
+
 ChanMapping
 PluginInsert::output_map () const
 {