wip: audio meters.

15 files changed, 512 insertions, 2 deletions

diff --git a/src/lib/butler.cc b/src/lib/butler.cc
index 14f342045..57c891404 100644
--- a/src/lib/butler.cc
+++ b/src/lib/butler.cc
@@ -24,6 +24,7 @@
 #include "cross.h"
 #include "dcpomatic_log.h"
 #include "exceptions.h"
+#include "level_calculator.h"
 #include "log.h"
 #include "player.h"
 #include "util.h"
@@ -33,6 +34,7 @@
 using std::cout;
 using std::function;
 using std::make_pair;
+using std::make_shared;
 using std::pair;
 using std::shared_ptr;
 using std::string;
@@ -88,6 +90,7 @@ Butler::Butler(
 	, _alignment(alignment)
 	, _fast(fast)
 	, _prepare_only_proxy(prepare_only_proxy)
+	, _level_calculator(make_shared<LevelCalculator>())
 {
 	_player_video_connection = _player.Video.connect(bind(&Butler::video, this, _1, _2));
 	_player_audio_connection = _player.Audio.connect(bind(&Butler::audio, this, _1, _2, _3));
@@ -312,6 +315,7 @@ Butler::seek_unlocked(DCPTime position, bool accurate)
 
 	_video.clear();
 	_audio.clear();
+	_level_calculator->clear();
 	_closed_caption.clear();
 
 	_summon.notify_all();
@@ -370,6 +374,8 @@ Butler::audio(shared_ptr<AudioBuffers> audio, DCPTime time, int frame_rate)
 		return;
 	}
 
+	_level_calculator->put(audio, time, frame_rate);
+
 	_audio.put(remap(audio, _audio_channels, _audio_mapping), time, frame_rate);
 }
 
@@ -481,3 +487,10 @@ Butler::Error::summary() const
 	return "";
 }
 
+
+shared_ptr<LevelCalculator>
+Butler::level_calculator() const
+{
+	return _level_calculator;
+}
+
diff --git a/src/lib/butler.h b/src/lib/butler.h
index ad2552769..dd04e7b86 100644
--- a/src/lib/butler.h
+++ b/src/lib/butler.h
@@ -37,6 +37,7 @@
 #include <boost/thread/condition.hpp>
 
 
+class LevelCalculator;
 class Player;
 class PlayerVideo;
 
@@ -94,6 +95,8 @@ public:
 	boost::optional<dcpomatic::DCPTime> get_audio(Behaviour behaviour, float* out, Frame frames);
 	boost::optional<TextRingBuffers::Data> get_closed_caption();
 
+	std::shared_ptr<LevelCalculator> level_calculator() const;
+
 	std::pair<size_t, std::string> memory_used() const;
 
 private:
@@ -154,6 +157,8 @@ private:
 	*/
 	boost::optional<dcpomatic::DCPTime> _awaiting;
 
+	std::shared_ptr<LevelCalculator> _level_calculator;
+
 	boost::signals2::scoped_connection _player_video_connection;
 	boost::signals2::scoped_connection _player_audio_connection;
 	boost::signals2::scoped_connection _player_text_connection;
diff --git a/src/lib/level_calculator.cc b/src/lib/level_calculator.cc
new file mode 100644
index 000000000..0563d4ed8
--- /dev/null
+++ b/src/lib/level_calculator.cc
@@ -0,0 +1,127 @@
+/*
+    Copyright (C) 2025 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "audio_buffers.h"
+#include "level_calculator.h"
+
+
+using std::make_pair;
+using std::shared_ptr;
+using boost::optional;
+
+
+constexpr int frames_per_measurement = 48000 / 30;
+
+
+LevelCalculator::LevelCalculator()
+	: _enabled(false)
+{
+
+}
+
+
+void
+LevelCalculator::put(shared_ptr<const AudioBuffers> audio, dcpomatic::DCPTime time, int frame_rate)
+{
+	if (!_enabled) {
+		std::cout << "no calcs for me.\n";
+		return;
+	}
+
+	boost::mutex::scoped_lock lm(_current_mutex);
+
+	auto const channels = audio->channels();
+
+	if (static_cast<int>(_current_peaks.size()) != channels) {
+		_current_peaks.resize(channels);
+	}
+
+	auto const data = audio->data();
+	auto const frames = audio->frames();
+	for (auto frame = 0; frame < frames; ++frame) {
+		for (auto channel = 0; channel < channels; ++channel) {
+			_current_peaks[channel] = std::max(std::abs(data[channel][frame]), _current_peaks[channel]);
+		}
+
+		++_current_frames;
+		if (_current_frames == frames_per_measurement) {
+			{
+				boost::mutex::scoped_lock lm(_store_mutex);
+				_peaks.emplace_back(time + dcpomatic::DCPTime::from_frames(frame, frame_rate), _current_peaks);
+			}
+			std::fill(_current_peaks.begin(), _current_peaks.end(), 0.0f);
+			_current_frames = 0;
+		}
+	}
+
+}
+
+
+void
+LevelCalculator::clear()
+{
+	boost::mutex::scoped_lock slm(_store_mutex);
+	_peaks.clear();
+
+	boost::mutex::scoped_lock clm(_current_mutex);
+	std::fill(_current_peaks.begin(), _current_peaks.end(), 0.0f);
+	_current_frames = 0;
+}
+
+
+std::vector<float>
+LevelCalculator::get(dcpomatic::DCPTime time)
+{
+	boost::mutex::scoped_lock slm(_store_mutex);
+
+	auto iter = _peaks.begin();
+	optional<dcpomatic::DCPTime> last_delta;
+	std::list<Measurement>::iterator last_iter;
+	while (iter != _peaks.end()) {
+		auto const delta = dcpomatic::DCPTime(time - iter->time).abs();
+		if (last_delta) {
+			if (delta > *last_delta) {
+				/* This is worse than the last - use the last one */
+				return last_iter->value;
+			} else {
+				/* This is better - keep looking */
+				_peaks.erase(last_iter);
+			}
+		}
+		last_delta = delta;
+		last_iter = iter;
+		++iter;
+	}
+
+	if (iter == _peaks.end()) {
+		return {};
+	}
+
+	return iter->value;
+}
+
+
+void
+LevelCalculator::enable(bool e)
+{
+	_enabled = e;
+}
+
diff --git a/src/lib/level_calculator.h b/src/lib/level_calculator.h
new file mode 100644
index 000000000..9eeb5b9b8
--- /dev/null
+++ b/src/lib/level_calculator.h
@@ -0,0 +1,74 @@
+/*
+    Copyright (C) 2025 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#ifndef DCPOMATIC_LEVEL_CALCULATOR_H
+#define DCPOMATIC_LEVEL_CALCULATOR_H
+
+
+#include "dcpomatic_time.h"
+#include <boost/thread.hpp>
+#include <memory>
+
+
+class AudioBuffers;
+
+
+class LevelCalculator
+{
+public:
+	LevelCalculator();
+
+	LevelCalculator(LevelCalculator const&) = delete;
+	LevelCalculator& operator=(LevelCalculator const&) = delete;
+
+	void put(std::shared_ptr<const AudioBuffers> audio, dcpomatic::DCPTime time, int frame_rate);
+	void clear();
+	std::vector<float> get(dcpomatic::DCPTime time);
+
+	void enable(bool e);
+
+private:
+	boost::mutex _current_mutex;
+	std::vector<float> _current_peaks;
+	int _current_frames = 0;
+
+	struct Measurement
+	{
+		Measurement(dcpomatic::DCPTime t, std::vector<float> v)
+			: time(t)
+			, value(std::move(v))
+		{
+
+		}
+
+		dcpomatic::DCPTime time;
+		std::vector<float> value;
+	};
+
+	mutable boost::mutex _store_mutex;
+	std::list<Measurement> _peaks;
+
+	boost::atomic<bool> _enabled;
+};
+
+
+#endif
+
diff --git a/src/lib/wscript b/src/lib/wscript
index dafd655fe..4b0002f04 100644
--- a/src/lib/wscript
+++ b/src/lib/wscript
@@ -156,6 +156,7 @@ sources = """
           kdm_recipient.cc
           kdm_with_metadata.cc
           kdm_util.cc
+          level_calculator.cc
           log.cc
           log_entry.cc
           make_dcp.cc
diff --git a/src/tools/dcpomatic_player.cc b/src/tools/dcpomatic_player.cc
index c5242c310..98fa6517a 100644
--- a/src/tools/dcpomatic_player.cc
+++ b/src/tools/dcpomatic_player.cc
@@ -133,6 +133,7 @@ enum {
 	ID_view_full_screen = DCPOMATIC_MAIN_MENU + 200,
 	ID_view_dual_screen,
 	ID_view_closed_captions,
+	ID_view_meters,
 	ID_view_eye,
 	ID_view_eye_left,
 	ID_view_eye_right,
@@ -241,6 +242,7 @@ public:
 		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_full_screen, this), ID_view_full_screen);
 		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_dual_screen, this), ID_view_dual_screen);
 		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_closed_captions, this), ID_view_closed_captions);
+		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_meters, this), ID_view_meters);
 		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_cpl, this, _1), ID_view_cpl, ID_view_cpl + MAX_CPLS);
 		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_eye_changed, this, _1), ID_view_eye_left);
 		Bind (wxEVT_MENU, boost::bind (&DOMFrame::view_eye_changed, this, _1), ID_view_eye_right);
@@ -644,6 +646,7 @@ private:
 		setup_menu ();
 		view->AppendSeparator();
 		view->Append(ID_view_closed_captions, _("Closed captions..."));
+		view->Append(ID_view_meters, _("Audio meters..."));
 		_view_eye_menu = new wxMenu;
 		_view_eye_left = _view_eye_menu->AppendRadioItem(ID_view_eye_left, _("Left"));
 		_view_eye_menu->AppendRadioItem(ID_view_eye_right, _("Right"));
@@ -989,6 +992,11 @@ private:
 		_viewer.show_closed_captions();
 	}
 
+	void view_meters ()
+	{
+		_viewer.show_meters();
+	}
+
 	void tools_verify ()
 	{
 		DCPOMATIC_ASSERT(!_film->content().empty());
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index b77ff987c..5e1caa1bf 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -28,6 +28,7 @@
 #include "closed_captions_dialog.h"
 #include "film_viewer.h"
 #include "gl_video_view.h"
+#include "meters_dialog.h"
 #include "nag_dialog.h"
 #include "playhead_to_frame_dialog.h"
 #include "playhead_to_timecode_dialog.h"
@@ -89,6 +90,7 @@ rtaudio_callback(void* out, void *, unsigned int frames, double, RtAudioStreamSt
 
 FilmViewer::FilmViewer(wxWindow* p)
 	: _closed_captions_dialog(new ClosedCaptionsDialog(p, this))
+	, _meters_dialog(new MetersDialog(p))
 {
 #if wxCHECK_VERSION(3, 1, 0)
 	switch (Config::instance()->video_view_type()) {
@@ -96,11 +98,17 @@ FilmViewer::FilmViewer(wxWindow* p)
 		_video_view = std::make_shared<GLVideoView>(this, p);
 		break;
 	case Config::VIDEO_VIEW_SIMPLE:
-		_video_view = std::make_shared<SimpleVideoView>(this, p);
+	{
+		auto simple = std::make_shared<SimpleVideoView>(this, p);
+		_meters_dialog->set_meters(simple->get_meters());
+		_video_view = simple;
+	}
 		break;
 	}
 #else
-	_video_view = std::make_shared<SimpleVideoView>(this, p);
+	auto simple = std::make_shared<SimpleVideoView>(this, p);
+	_meters_dialog->set_meters(simple->get_meters());
+	_video_view = simple;
 #endif
 
 	_video_view->Sized.connect(boost::bind(&FilmViewer::video_view_sized, this));
@@ -808,6 +816,13 @@ FilmViewer::show_closed_captions()
 
 
 void
+FilmViewer::show_meters()
+{
+	_meters_dialog->Show();
+}
+
+
+void
 FilmViewer::seek_by(DCPTime by, bool accurate)
 {
 	seek(_video_view->position() + by, accurate);
diff --git a/src/wx/film_viewer.h b/src/wx/film_viewer.h
index 2a6239d7d..31fdbe0c7 100644
--- a/src/wx/film_viewer.h
+++ b/src/wx/film_viewer.h
@@ -48,6 +48,7 @@ class FFmpegPlayer;
 class Image;
 class Player;
 class PlayerVideo;
+class MetersDialog;
 class RGBPlusAlphaImage;
 class wxToggleButton;
 
@@ -71,6 +72,7 @@ public:
 	}
 
 	void show_closed_captions();
+	void show_meters();
 
 	void set_film(std::shared_ptr<Film>);
 	std::shared_ptr<Film> film() const {
@@ -212,6 +214,7 @@ private:
 	Optimisation _optimisation = Optimisation::NONE;
 
 	ClosedCaptionsDialog* _closed_captions_dialog = nullptr;
+	MetersDialog* _meters_dialog = nullptr;
 
 	bool _outline_content = false;
 	boost::optional<dcpomatic::Rect<double>> _outline_subtitles;
diff --git a/src/wx/meters_dialog.cc b/src/wx/meters_dialog.cc
new file mode 100644
index 000000000..e95fb65f2
--- /dev/null
+++ b/src/wx/meters_dialog.cc
@@ -0,0 +1,44 @@
+/*
+    Copyright (C) 2019-2021 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "meters_dialog.h"
+#include <wx/wx.h>
+
+
+MetersDialog::MetersDialog(wxWindow* parent)
+	: wxDialog(parent, wxID_ANY, _("Meters"))
+{
+
+}
+
+void
+MetersDialog::set_meters(wxWindow* meters)
+{
+	meters->Reparent(this);
+
+	auto sizer = new wxBoxSizer(wxVERTICAL);
+	sizer->Add(meters, 1, wxEXPAND);
+	SetSizer(sizer);
+
+	SetSize({640, 480});
+	sizer->Layout();
+}
+
diff --git a/src/wx/meters_dialog.h b/src/wx/meters_dialog.h
new file mode 100644
index 000000000..84e2f0504
--- /dev/null
+++ b/src/wx/meters_dialog.h
@@ -0,0 +1,40 @@
+/*
+    Copyright (C) 2019-2021 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "simple_meters.h"
+#include "lib/dcpomatic_time.h"
+#include <wx/wx.h>
+#include <memory>
+
+
+class Butler;
+class LevelCalculator;
+class wxWindow;
+
+
+class MetersDialog : public wxDialog
+{
+public:
+	MetersDialog(wxWindow* parent);
+
+	void set_meters(wxWindow* meters);
+};
+
diff --git a/src/wx/simple_meters.cc b/src/wx/simple_meters.cc
new file mode 100644
index 000000000..b719f93f9
--- /dev/null
+++ b/src/wx/simple_meters.cc
@@ -0,0 +1,103 @@
+/*
+    Copyright (C) 2025 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "simple_meters.h"
+#include "wx_util.h"
+#include "lib/level_calculator.h"
+#include <dcp/types.h>
+#include <wx/wx.h>
+#include <algorithm>
+
+
+static auto constexpr min_db = -70.0f;
+
+
+using std::shared_ptr;
+#if BOOST_VERSION >= 106100
+using namespace boost::placeholders;
+#endif
+
+
+SimpleMeters::SimpleMeters(wxWindow* parent)
+	: _panel(new wxPanel(parent, wxID_ANY))
+{
+	_panel->Bind(wxEVT_PAINT, boost::bind(&SimpleMeters::paint, this));
+}
+
+
+wxWindow*
+SimpleMeters::get() const
+{
+	return _panel;
+}
+
+
+void
+SimpleMeters::paint()
+{
+	wxPaintDC dc(_panel);
+
+	dc.SetBackground(*wxBLACK_BRUSH);
+	dc.Clear();
+
+	if (_peaks.empty()) {
+		return;
+	}
+
+	auto const scale = 1 / dpi_scale_factor(_panel);
+	dc.SetLogicalScale(scale, scale);
+
+	auto const panel_size = dcp::Size(_panel->GetSize().GetWidth() / scale, _panel->GetSize().GetHeight() / scale);
+
+	auto const channel_width = panel_size.width / _peaks.size();
+
+	int x = 0;
+	dc.SetBrush(*wxGREEN_BRUSH);
+	for (auto peak: _peaks) {
+		auto const peak_db = std::max(min_db, 20 * log10(peak));
+		dc.DrawRectangle(x, panel_size.height, channel_width, (1 - (peak_db - min_db)) * panel_size.height / (-min_db));
+		x += channel_width;
+	}
+}
+
+
+bool
+SimpleMeters::update(shared_ptr<LevelCalculator> calculator, dcpomatic::DCPTime time)
+{
+	if (!_panel->GetParent()->IsShown()) {
+		return false;
+	}
+
+	_peaks = calculator->get(time);
+	_panel->Refresh();
+	_panel->Update();
+
+	return true;
+}
+
+
+void
+SimpleMeters::clear()
+{
+	_peaks.clear();
+	_panel->Refresh();
+	_panel->Update();
+}
diff --git a/src/wx/simple_meters.h b/src/wx/simple_meters.h
new file mode 100644
index 000000000..6b3843f3c
--- /dev/null
+++ b/src/wx/simple_meters.h
@@ -0,0 +1,63 @@
+/*
+    Copyright (C) 2025 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#ifndef DCPOMATIC_SIMPLE_METERS_H
+#define DCPOMATIC_SIMPLE_METERS_H
+
+
+#include "lib/dcpomatic_time.h"
+#include <memory>
+#include <vector>
+
+
+class Butler;
+class LevelCalculator;
+class wxPanel;
+class wxShowEvent;
+class wxWindow;
+
+
+class SimpleMeters
+{
+public:
+	SimpleMeters(wxWindow* parent);
+
+	SimpleMeters(SimpleMeters const&) = delete;
+	SimpleMeters& operator=(SimpleMeters const&) = delete;
+
+	wxWindow* get() const;
+
+	bool update(std::shared_ptr<LevelCalculator> calculator, dcpomatic::DCPTime time);
+	void clear();
+
+private:
+	void paint();
+	void shown(wxShowEvent& ev);
+
+	wxPanel* _panel;
+	std::vector<float> _peaks;
+
+	std::weak_ptr<LevelCalculator> _level_calculator;
+};
+
+
+#endif
+
diff --git a/src/wx/simple_video_view.cc b/src/wx/simple_video_view.cc
index 665cee117..fe0ea42e0 100644
--- a/src/wx/simple_video_view.cc
+++ b/src/wx/simple_video_view.cc
@@ -26,6 +26,7 @@
 #include "lib/butler.h"
 #include "lib/dcpomatic_log.h"
 #include "lib/image.h"
+#include "lib/level_calculator.h"
 #include "lib/video_filter_graph.h"
 #include "lib/video_filter_graph_set.h"
 #include <dcp/util.h>
@@ -50,6 +51,7 @@ SimpleVideoView::SimpleVideoView (FilmViewer* viewer, wxWindow* parent)
 	: VideoView (viewer)
 	, _rec2020_filter("convert", "convert", "", "colorspace=all=bt709:iall=bt2020")
 	, _rec2020_filter_graph({ _rec2020_filter }, dcp::Fraction(24, 1))
+	, _meters(parent)
 {
 	_panel = new wxPanel (parent);
 
@@ -265,4 +267,7 @@ SimpleVideoView::update ()
 	_inter_size = player_video().first->inter_size ();
 
 	refresh_panel ();
+
+	auto calculator = _viewer->butler()->level_calculator();
+	calculator->enable(_meters.update(calculator, _viewer->time()));
 }
diff --git a/src/wx/simple_video_view.h b/src/wx/simple_video_view.h
index e19068979..2c6ce7965 100644
--- a/src/wx/simple_video_view.h
+++ b/src/wx/simple_video_view.h
@@ -19,6 +19,7 @@
 */
 
 
+#include "simple_meters.h"
 #include "video_view.h"
 #include "lib/filter.h"
 #include "lib/position.h"
@@ -43,6 +44,10 @@ public:
 		return _panel;
 	}
 
+	wxWindow* get_meters() {
+		return _meters.get();
+	}
+
 	void update () override;
 	void start () override;
 	NextFrameResult display_next_frame (bool non_blocking) override;
@@ -60,4 +65,6 @@ private:
 
 	Filter _rec2020_filter;
 	VideoFilterGraphSet _rec2020_filter_graph;
+
+	SimpleMeters _meters;
 };
diff --git a/src/wx/wscript b/src/wx/wscript
index 6bb10511b..9a9a79d9c 100644
--- a/src/wx/wscript
+++ b/src/wx/wscript
@@ -125,6 +125,7 @@ sources = """
           markers_panel.cc
           message_dialog.cc
           metadata_dialog.cc
+          meters_dialog.cc
           move_to_dialog.cc
           nag_dialog.cc
           name_format_editor.cc
@@ -160,6 +161,7 @@ sources = """
           server_dialog.cc
           servers_list_dialog.cc
           short_kdm_output_panel.cc
+          simple_meters.cc
           simple_video_view.cc
           smpte_metadata_dialog.cc
           sound_preferences_page.cc