From c11f8532ca5b6bd874db2f67daa1fe0b1803c40e Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 24 May 2023 01:53:45 +0200
Subject: [PATCH] Add API to query backend/driver/device ID

---
 libs/ardour/ardour/audioengine.h |  2 ++
 libs/ardour/audioengine.cc       | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/libs/ardour/ardour/audioengine.h b/libs/ardour/ardour/audioengine.h
index 2c60157f52..e93980dcd1 100644
--- a/libs/ardour/ardour/audioengine.h
+++ b/libs/ardour/ardour/audioengine.h
@@ -134,6 +134,8 @@ class LIBARDOUR_API AudioEngine : public PortManager, public SessionHandlePtr
 	bool freewheeling() const { return _freewheeling; }
 	bool running() const { return _running; }
 
+	std::string backend_id (bool for_input);
+
 	Glib::Threads::Mutex& process_lock() { return _process_lock; }
 	Glib::Threads::Mutex& latency_lock() { return _latency_lock; }
 
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index ea14191b2d..18154151e5 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -1778,3 +1778,27 @@ AudioEngine::add_pending_port_deletion (Port* p)
 		delete p;
 	}
 }
+
+std::string
+AudioEngine::backend_id (bool for_input)
+{
+	if (!_backend) {
+		return "";
+	}
+	if (!setup_required ()) {
+		return "JACK";
+	}
+
+	std::stringstream ss;
+	ss << _backend->name() << ";" << _backend->driver_name () << ";";
+	if (_backend->use_separate_input_and_output_devices ()) {
+		if (for_input) {
+			ss << _backend->input_device_name ();
+		} else {
+			ss << _backend->output_device_name ();
+		}
+	} else {
+		ss << _backend->device_name ();
+	}
+	return ss.str ();
+}