make use of measured latency values to set dialog controls, and use actual port latency to compute extra delay

1 files changed, 22 insertions, 1 deletions

diff --git a/gtk2_ardour/engine_dialog.cc b/gtk2_ardour/engine_dialog.cc
index 17ff0f7217..873498f6ec 100644
--- a/gtk2_ardour/engine_dialog.cc
+++ b/gtk2_ardour/engine_dialog.cc
@@ -249,6 +249,7 @@ and microphone.\n\n\
 	xopt = AttachOptions(0);
 
 	lm_measure_button.signal_toggled().connect (sigc::mem_fun (*this, &EngineControl::latency_button_toggled));
+	lm_use_button.signal_clicked().connect (sigc::mem_fun (*this, &EngineControl::use_latency_button_clicked));
 	lm_use_button.set_sensitive (false);
 		
 	lm_table.attach (lm_measure_button, 0, 2, row, row+1, xopt, (AttachOptions) 0);
@@ -972,7 +973,10 @@ EngineControl::check_latency_measurement ()
                 return false;
         }
 
-        snprintf (buf, sizeof (buf), "%10.3lf frames %10.3lf ms", mtdm->del (), mtdm->del () * 1000.0f/sample_rate);
+	uint32_t frames_total = mtdm->del();
+	uint32_t extra = frames_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
+
+        snprintf (buf, sizeof (buf), "%u samples %10.3lf ms", extra, extra * 1000.0f/sample_rate);
 
         bool solid = true;
 
@@ -1016,3 +1020,20 @@ EngineControl::latency_button_toggled ()
                 update_latency_display ();
         }
 }
+
+void
+EngineControl::use_latency_button_clicked ()
+{
+        MTDM* mtdm = ARDOUR::AudioEngine::instance()->mtdm ();
+
+	if (!mtdm) {
+		return;
+	}
+
+	uint32_t frames_total = mtdm->del();
+	uint32_t extra = frames_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
+	uint32_t one_way = extra/2;
+
+	input_latency_adjustment.set_value (one_way);
+	output_latency_adjustment.set_value (one_way);
+}