X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=nageru%2Fdelay_analyzer.cpp;fp=nageru%2Fdelay_analyzer.cpp;h=b3127c4630567db073871b7f1505218a1028999b;hb=4c23038d9c18d22a9bfe577244a2d0fc293a7e6a;hp=9e8206015de30a80ce74455a0efdd9d12ff6f19f;hpb=5b1f88aa6f4e44f497e951f572a0fe2987389330;p=nageru

diff --git a/nageru/delay_analyzer.cpp b/nageru/delay_analyzer.cpp
index 9e82060..b3127c4 100644
--- a/nageru/delay_analyzer.cpp
+++ b/nageru/delay_analyzer.cpp
@@ -2,6 +2,7 @@
 
 #include "audio_mixer.h"
 #include "ui_delay_analyzer.h"
+#include "shared/post_to_main_thread.h"
 
 #include <bmusb/bmusb.h>
 
@@ -53,6 +54,7 @@ void DelayAnalyzer::grab_clicked()
 	grab_timeout->start(milliseconds(2000));
 	clip1.clear();
 	clip2.clear();
+	ui->delay_estimate_label->clear();
 	ui->peak_display_1->reset_base();
 	ui->peak_display_2->reset_base();
 	ui->peak_display_1->audio_clip_updated();
@@ -90,6 +92,7 @@ void DelayAnalyzer::card_selected(QComboBox *card_combo, int selected_index)
 		clip2.clear();
 		ui->peak_display_2->audio_clip_updated();
 	}
+	ui->delay_estimate_label->clear();
 }
 
 void DelayAnalyzer::channel_selected(QComboBox *channel_combo)
@@ -101,6 +104,7 @@ void DelayAnalyzer::channel_selected(QComboBox *channel_combo)
 		clip2.clear();
 		ui->peak_display_2->audio_clip_updated();
 	}
+	ui->delay_estimate_label->clear();
 }
 
 DeviceSpec DelayAnalyzer::get_selected_device(QComboBox *card_combo)
@@ -152,7 +156,29 @@ void DelayAnalyzer::add_audio(DeviceSpec device_spec, const uint8_t *data, unsig
 			grab_timeout->stop();
 		});
 		grabbing = false;
+
+		// The delay estimation is cheap, but it's not free, and we're on the main mixer thread,
+		// so fire it off onto a background thread.
+		std::thread(&DelayAnalyzer::estimate_delay, this).detach();
+	}
+}
+
+void DelayAnalyzer::estimate_delay()
+{
+	AudioClip::BestCorrelation corr = clip1.find_best_correlation(&clip2);
+	char buf[256];
+	if (isnan(corr.correlation) || fabs(corr.correlation) < 0.1) {  // Very loose bound, basically to guard against digital silence.
+		snprintf(buf, sizeof(buf), "Could not estimate delay.\n");
+	} else if (corr.correlation < 0.0) {
+		snprintf(buf, sizeof(buf), "Best estimate: Channel is %.1f ms delayed compared to reference <em>and inverted</em> (correlation = %.3f)\n",
+			corr.delay_ms, corr.correlation);
+	} else {
+		snprintf(buf, sizeof(buf), "Best estimate: Channel is %.1f ms delayed compared to reference (correlation = %.3f)\n",
+			corr.delay_ms, corr.correlation);
 	}
+	post_to_main_thread([this, buf] {
+		ui->delay_estimate_label->setText(buf);
+	});
 }
 
 void DelayAnalyzer::grab_timed_out()