Vapor: add option to sync processing to a 512 sample cycle

libs/ardour/ardour/surround_return.h

@@ -35,6 +35,7 @@
 #endif
 
 #include "ardour/chan_mapping.h"
+#include "ardour/fixed_delay.h"
 #include "ardour/lufs_meter.h"
 #include "ardour/monitor_processor.h"
 #include "ardour/processor.h"
@@ -109,6 +110,7 @@ public:
 
 	/* XXX this is only for testing */
 	void set_bed_mix (bool on, std::string const& ref, int* cmap = NULL);
+	void set_sync_and_return (bool on);
 
 	int set_state (XMLNode const&, int version);
 
@@ -124,6 +126,7 @@ private:
 	void evaluate (size_t id, std::shared_ptr<SurroundPannable> const&, timepos_t const& , pframes_t, bool force = false);
 
 	void reset_object_map ();
+	void latency_changed ();
 
 	std::shared_ptr<LV2Plugin> _surround_processor;
 
@@ -188,6 +191,8 @@ private:
 	bool             _rolling;
 	bool             _with_bed;
 	std::string      _export_reference;
+	bool             _sync_and_align;
+	FixedDelay       _delaybuffers;
 	std::atomic<int> _flush;
 };
 

libs/ardour/luabindings.cc

@@ -1922,6 +1922,7 @@ LuaBindings::common (lua_State* L)
 
 		.deriveWSPtrClass <SurroundReturn, Processor> ("SurroundReturn")
 		.addFunction ("set_bed_mix", &SurroundReturn::set_bed_mix)
+		.addFunction ("set_sync_and_return", &SurroundReturn::set_sync_and_return)
 		.addFunction ("have_au_renderer", &SurroundReturn::have_au_renderer)
 		.addFunction ("load_au_preset", &SurroundReturn::load_au_preset)
 		.addFunction ("set_au_param", &SurroundReturn::set_au_param)

libs/ardour/route.cc

@@ -299,6 +299,7 @@ Route::init ()
 	if (is_surround_master ()) {
 		_meter_point = _pending_meter_point = MeterPreFader;
 		_surround_return.reset (new SurroundReturn (_session, this));
+		_surround_return->set_owner (this);
 		_surround_return->activate ();
 		panner_shell()->set_bypassed (true);
 

libs/ardour/surround_return.cc

@@ -91,6 +91,7 @@ SurroundReturn::SurroundReturn (Session& s, Route* r)
 	, _export_end (0)
 	, _rolling (false)
 	, _with_bed (false)
+	, _sync_and_align (false)
 {
 #if !(defined(LV2_EXTENDED) && defined(HAVE_LV2_1_10_0))
 	throw failed_constructor ();
@@ -115,6 +116,9 @@ SurroundReturn::SurroundReturn (Session& s, Route* r)
 	_trim->configure_io (cca128, cca128);
 	_trim->activate ();
 
+	ChanCount cca20 (ChanCount (DataType::AUDIO, 20)); // 7.1.4 + binaural + 5.1
+	_delaybuffers.configure (cca20, 512);
+
 	for (size_t i = 0; i < max_object_id; ++i) {
 		_current_render_mode[i] = -1;
 		_channel_id_map[i] = i;
@@ -324,7 +328,7 @@ SurroundReturn::set_block_size (pframes_t nframes)
 samplecnt_t
 SurroundReturn::signal_latency () const
 {
-	return _surround_processor->signal_latency ();
+	return _surround_processor->signal_latency () + _delaybuffers.delay ();
 }
 
 void
@@ -333,6 +337,14 @@ SurroundReturn::flush ()
 	_flush.store (1);
 }
 
+void
+SurroundReturn::latency_changed ()
+{
+	LatencyChanged ();
+	assert (owner());
+	static_cast<Route*>(owner ())->processor_latency_changed (); /* EMIT SIGNAL */
+}
+
 void
 SurroundReturn::reset_object_map ()
 {
@@ -364,6 +376,15 @@ SurroundReturn::set_bed_mix (bool on, std::string const& ref, int* cmap)
 	}
 }
 
+void
+SurroundReturn::set_sync_and_return (bool on)
+{
+	if (_sync_and_align == on) {
+		return;
+	}
+	_sync_and_align = on;
+}
+
 void
 SurroundReturn::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, double speed, pframes_t nframes, bool)
 {
@@ -376,6 +397,27 @@ SurroundReturn::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_
 		_surround_processor->flush ();
 	}
 
+	if (_sync_and_align) {
+		if (!_rolling && start_sample != end_sample) {
+			_delaybuffers.flush ();
+			_surround_processor->deactivate();
+			_surround_processor->activate();
+		}
+		if (0 != (playback_offset() % 512)) {
+			ChanCount cca20 (ChanCount (DataType::AUDIO, 20)); // 7.1.4 + binaural + 5.1
+			if (_delaybuffers.delay () == 0) {
+				_delaybuffers.set (cca20, 512 - playback_offset() % 512);
+			} else {
+				_delaybuffers.set (cca20, 0);
+			}
+			latency_changed ();
+		}
+	} else if (_delaybuffers.delay () != 0) {
+		ChanCount cca20 (ChanCount (DataType::AUDIO, 20)); // 7.1.4 + binaural + 5.1
+		_delaybuffers.set (cca20, 0);
+		latency_changed ();
+	}
+
 	bool with_bed = _with_bed;
 
 	bufs.set_count (_configured_output);
@@ -438,7 +480,7 @@ SurroundReturn::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_
 					 * IOW: end_sample == next cycle's start_sample;
 					 */
 					if (nframes < 2) {
-						evaluate (id, p, timepos_t (start_sample), 0);
+						evaluate (id, p, timepos_t (start_sample + latency), 0);
 					} else {
 						bool found_event = false;
 						timepos_t start (start_sample + latency);
@@ -456,7 +498,7 @@ SurroundReturn::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_
 						}
 						/* inform live renderer */
 						if (!found_event && !_exporting) {
-							evaluate (id, p, end, nframes - 1);
+							evaluate (id, p, start, 0);
 						}
 					}
 				}
@@ -583,8 +625,9 @@ SurroundReturn::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_
 	_surround_processor->connect_and_run (_surround_bufs, start_sample, end_sample, speed, _in_map, _out_map, nframes, 0);
 
 	BufferSet::iterator i = _surround_bufs.begin (DataType::AUDIO);
-	for (BufferSet::iterator o = bufs.begin (DataType::AUDIO); o != bufs.end (DataType::AUDIO); ++i, ++o) {
+	uint32_t idx = 0;
-		o->read_from (*i, nframes);
+	for (BufferSet::iterator o = bufs.begin (DataType::AUDIO); o != bufs.end (DataType::AUDIO); ++i, ++o, ++idx) {
+		_delaybuffers.delay (DataType::AUDIO, idx, *o, *i, nframes);
 	}
 
 	if (_exporting) {