From 832683cb01b5e18dbceea5e36e80fd91afbee9cb Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Sun, 10 Aug 2025 07:35:48 -0600
Subject: [PATCH] region tempo and meter are optional

---
 libs/ardour/ardour/region.h |  9 +++++----
 libs/ardour/audioregion.cc  |  4 +++-
 libs/ardour/region.cc       | 18 +++++++++++-------
 libs/ardour/triggerbox.cc   |  6 ++++--
 4 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index ea0f9cd248..ff0c358df3 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -24,6 +24,7 @@
 #pragma once
 
 #include <memory>
+#include <optional>
 #include <vector>
 
 #include "temporal/domain_swap.h"
@@ -544,9 +545,9 @@ public:
 		}
 	}
 
-	Temporal::Tempo tempo() const { return _tempo; }
+	std::optional<Temporal::Tempo> tempo() const { return _tempo; }
 	void set_tempo (Temporal::Tempo const &);
-	Temporal::Meter meter() const { return _meter; }
+	std::optional<Temporal::Meter> meter() const { return _meter; }
 	void set_meter (Temporal::Meter const &);
 
 protected:
@@ -601,8 +602,8 @@ protected:
 	uint32_t                      _fx_tail;
 	RegionFxList                  _plugins;
 
-	Temporal::Tempo _tempo;
-	Temporal::Meter _meter;
+	std::optional<Temporal::Tempo> _tempo;
+	std::optional<Temporal::Meter> _meter;
 
 	PBD::Property<bool>      _sync_marked;
 	PBD::Property<bool>      _left_of_split;
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 0637e91126..44ff2a5792 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -442,9 +442,11 @@ AudioRegion::set_tempo_stuff_from_source ()
 	if (read (data.get(), 0, data_size, 0) == data_size) {
 		double tempo;
 		double beatcount;
+		Temporal::Meter m (4, 4);
 
-		estimate_audio_tempo (shared_from_this(), data.get(), data_size, _session.sample_rate(), tempo, _meter, beatcount);
+		estimate_audio_tempo (shared_from_this(), data.get(), data_size, _session.sample_rate(), tempo, m, beatcount);
 		_tempo = Temporal::Tempo (tempo, 4);
+		_meter = m;
 	}
 }
 
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 4326e70eed..241e68ddac 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -230,9 +230,7 @@ Region::register_properties ()
 }
 
 #define REGION_DEFAULT_STATE(s,l) \
-	  _tempo (120, 4) \
-	, _meter (4, 4) \
-	, _sync_marked (Properties::sync_marked, false) \
+	  _sync_marked (Properties::sync_marked, false) \
 	, _left_of_split (Properties::left_of_split, false) \
 	, _right_of_split (Properties::right_of_split, false) \
 	, _valid_transients (Properties::valid_transients, false) \
@@ -1426,8 +1424,12 @@ Region::state () const
 	node->set_property ("id", id ());
 	node->set_property ("type", _type);
 
-	node->add_child_nocopy (_tempo.get_state());
-	node->add_child_nocopy (_meter.get_state());
+	if (_tempo) {
+		node->add_child_nocopy (_tempo.value().get_state());
+	}
+	if (_meter) {
+		node->add_child_nocopy (_meter.value().get_state());
+	}
 
 	std::string fe;
 
@@ -1629,9 +1631,11 @@ Region::_set_state (const XMLNode& node, int version, PropertyChange& what_chang
 				_plugins.push_back (rfx);
 				changed = true;
 			} else  if (child->name() == Temporal::Tempo::xml_node_name) {
-				_tempo.set_state (*child, version);
+				Temporal::Tempo t (*child);
+				_tempo = t;
 			} else  if (child->name() == Temporal::Meter::xml_node_name) {
-				_meter.set_state (*child, version);
+				Temporal::Meter m (*child);
+				_meter = m;
 			}
 		}
 		lm.release ();
diff --git a/libs/ardour/triggerbox.cc b/libs/ardour/triggerbox.cc
index d3c1b729c8..41a7d4b9a6 100644
--- a/libs/ardour/triggerbox.cc
+++ b/libs/ardour/triggerbox.cc
@@ -2646,8 +2646,10 @@ MIDITrigger::get_segment_descriptor () const
 {
 	SegmentDescriptor sd;
 
-	sd.set_extent (Temporal::Beats(), _region->length().beats());
-	sd.set_tempo (_region->tempo());
+	if (_region->tempo()) {
+		sd.set_extent (Temporal::Beats(), _region->length().beats());
+		sd.set_tempo (_region->tempo().value());
+	}
 	return sd;
 }