Primitive auto-crop (#1477).

21 files changed, 385 insertions, 17 deletions

diff --git a/src/lib/config.cc b/src/lib/config.cc
index bf294aec9..da7082a8e 100644
--- a/src/lib/config.cc
+++ b/src/lib/config.cc
@@ -183,6 +183,7 @@ Config::set_defaults ()
 	_audio_mapping = boost::none;
 	_custom_languages.clear ();
 	_add_files_path = boost::none;
+	_auto_crop_threshold = 0.1;
 
 	_allowed_dcp_frame_rates.clear ();
 	_allowed_dcp_frame_rates.push_back (24);
@@ -583,6 +584,7 @@ try
 	}
 
 	_add_files_path = f.optional_string_child("AddFilesPath");
+	_auto_crop_threshold = f.optional_number_child<double>("AutoCropThreshold").get_value_or(0.1);
 
 	if (boost::filesystem::exists (_cinemas_file)) {
 		cxml::Document f ("Cinemas");
@@ -1014,6 +1016,7 @@ Config::write_config () const
 		/* [XML] AddFilesPath The default path that will be offered in the picker when adding files to a film. */
 		root->add_child("AddFilesPath")->add_child_text(_add_files_path->string());
 	}
+	root->add_child("AutoCropThreshold")->add_child_text(raw_convert<string>(_auto_crop_threshold));
 
 	auto target = config_write_file();
 
diff --git a/src/lib/config.h b/src/lib/config.h
index 5289656e3..bdf6c8395 100644
--- a/src/lib/config.h
+++ b/src/lib/config.h
@@ -84,6 +84,7 @@ public:
 		HISTORY,
 		SHOW_EXPERIMENTAL_AUDIO_PROCESSORS,
 		AUDIO_MAPPING,
+		AUTO_CROP_THRESHOLD,
 		OTHER
 	};
 
@@ -547,6 +548,10 @@ public:
 		return _add_files_path;
 	}
 
+	double auto_crop_threshold () const {
+		return _auto_crop_threshold;
+	}
+
 	/* SET (mostly) */
 
 	void set_master_encoding_threads (int n) {
@@ -1055,6 +1060,10 @@ public:
 		changed ();
 	}
 
+	void set_auto_crop_threshold (double threshold) {
+		maybe_set (_auto_crop_threshold, threshold, AUTO_CROP_THRESHOLD);
+	}
+
 	void changed (Property p = OTHER);
 	boost::signals2::signal<void (Property)> Changed;
 	/** Emitted if read() failed on an existing Config file.  There is nothing
@@ -1268,6 +1277,7 @@ private:
 	boost::optional<AudioMapping> _audio_mapping;
 	std::vector<dcp::LanguageTag> _custom_languages;
 	boost::optional<boost::filesystem::path> _add_files_path;
+	double _auto_crop_threshold;
 
 	static int const _current_version;
 
diff --git a/src/lib/player.cc b/src/lib/player.cc
index 01413115b..f1fd060f4 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -1384,7 +1384,7 @@ Player::set_dcp_decode_reduction (optional<int> reduction)
 
 
 optional<DCPTime>
-Player::content_time_to_dcp (shared_ptr<Content> content, ContentTime t)
+Player::content_time_to_dcp (shared_ptr<const Content> content, ContentTime t)
 {
 	boost::mutex::scoped_lock lm (_mutex);
 
@@ -1399,6 +1399,22 @@ Player::content_time_to_dcp (shared_ptr<Content> content, ContentTime t)
 }
 
 
+optional<ContentTime>
+Player::dcp_to_content_time (shared_ptr<const Content> content, DCPTime t)
+{
+	boost::mutex::scoped_lock lm (_mutex);
+
+	for (auto i: _pieces) {
+		if (i->content == content) {
+			return dcp_to_content_time (i, t);
+		}
+	}
+
+	/* We couldn't find this content; perhaps things are being changed over */
+	return {};
+}
+
+
 shared_ptr<const Playlist>
 Player::playlist () const
 {
diff --git a/src/lib/player.h b/src/lib/player.h
index 0d0116e92..3bd293889 100644
--- a/src/lib/player.h
+++ b/src/lib/player.h
@@ -101,7 +101,8 @@ public:
 	void set_play_referenced ();
 	void set_dcp_decode_reduction (boost::optional<int> reduction);
 
-	boost::optional<dcpomatic::DCPTime> content_time_to_dcp (std::shared_ptr<Content> content, dcpomatic::ContentTime t);
+	boost::optional<dcpomatic::DCPTime> content_time_to_dcp (std::shared_ptr<const Content> content, dcpomatic::ContentTime t);
+	boost::optional<dcpomatic::ContentTime> dcp_to_content_time (std::shared_ptr<const Content> content, dcpomatic::DCPTime t);
 
 	boost::signals2::signal<void (ChangeType, int, bool)> Change;
 
diff --git a/src/lib/rect.h b/src/lib/rect.h
index 5f807f499..a01e0f885 100644
--- a/src/lib/rect.h
+++ b/src/lib/rect.h
@@ -119,6 +119,13 @@ public:
 };
 
 
+template <class T>
+bool operator== (Rect<T> const& a, Rect<T> const& b)
+{
+	return a.x == b.x && a.y == b.y && a.width == b.width && a.height == b.height;
+}
+
+
 }
 
 
diff --git a/src/lib/video_content.cc b/src/lib/video_content.cc
index 27eb04fe0..1b24101f3 100644
--- a/src/lib/video_content.cc
+++ b/src/lib/video_content.cc
@@ -532,6 +532,12 @@ VideoContent::set_length (Frame len)
 
 
 void
+VideoContent::set_crop (Crop c)
+{
+	maybe_set (_crop, c, VideoContentProperty::CROP);
+}
+
+void
 VideoContent::set_left_crop (int c)
 {
 	maybe_set (_crop.left, c, VideoContentProperty::CROP);
diff --git a/src/lib/video_content.h b/src/lib/video_content.h
index 2adf941d9..d16af14d8 100644
--- a/src/lib/video_content.h
+++ b/src/lib/video_content.h
@@ -89,6 +89,7 @@ public:
 
 	void set_frame_type (VideoFrameType);
 
+	void set_crop (Crop crop);
 	void set_left_crop (int);
 	void set_right_crop (int);
 	void set_top_crop (int);
diff --git a/src/wx/auto_crop_dialog.cc b/src/wx/auto_crop_dialog.cc
new file mode 100644
index 000000000..bfc08beb3
--- /dev/null
+++ b/src/wx/auto_crop_dialog.cc
@@ -0,0 +1,76 @@
+/*
+    Copyright (C) 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 "auto_crop_dialog.h"
+#include "dcpomatic_spin_ctrl.h"
+#include "wx_util.h"
+#include "lib/config.h"
+#include "lib/types.h"
+
+
+AutoCropDialog::AutoCropDialog (wxWindow* parent, Crop crop)
+	: TableDialog (parent, _("Auto crop"), 2, 1, true)
+{
+	add (_("Left"), true);
+	_left = add(new SpinCtrl(this, DCPOMATIC_SPIN_CTRL_WIDTH));
+	add (_("Right"), true);
+	_right = add(new SpinCtrl(this, DCPOMATIC_SPIN_CTRL_WIDTH));
+	add (_("Top"), true);
+	_top = add(new SpinCtrl(this, DCPOMATIC_SPIN_CTRL_WIDTH));
+	add (_("Bottom"), true);
+	_bottom = add(new SpinCtrl(this, DCPOMATIC_SPIN_CTRL_WIDTH));
+	add (_("Threshold"), true);
+	_threshold = add(new SpinCtrl(this, DCPOMATIC_SPIN_CTRL_WIDTH));
+
+	_left->SetRange(0, 4096);
+	_right->SetRange(0, 4096);
+	_top->SetRange(0, 4096);
+	_bottom->SetRange(0, 4096);
+
+	set (crop);
+	_threshold->SetValue (std::round(Config::instance()->auto_crop_threshold() * 100));
+
+	layout ();
+
+	_left->Bind (wxEVT_SPINCTRL, [this](wxSpinEvent&) { Changed(get()); });
+	_right->Bind (wxEVT_SPINCTRL, [this](wxSpinEvent&) { Changed(get()); });
+	_top->Bind (wxEVT_SPINCTRL, [this](wxSpinEvent&) { Changed(get()); });
+	_bottom->Bind (wxEVT_SPINCTRL, [this](wxSpinEvent&) { Changed(get()); });
+	_threshold->Bind (wxEVT_SPINCTRL, [](wxSpinEvent& ev) { Config::instance()->set_auto_crop_threshold(ev.GetPosition() / 100.0); });
+}
+
+
+Crop
+AutoCropDialog::get () const
+{
+	return Crop(_left->GetValue(), _right->GetValue(), _top->GetValue(), _bottom->GetValue());
+}
+
+
+void
+AutoCropDialog::set (Crop crop)
+{
+	_left->SetValue (crop.left);
+	_right->SetValue (crop.right);
+	_top->SetValue (crop.top);
+	_bottom->SetValue (crop.bottom);
+}
+
diff --git a/src/wx/auto_crop_dialog.h b/src/wx/auto_crop_dialog.h
new file mode 100644
index 000000000..0615c14bb
--- /dev/null
+++ b/src/wx/auto_crop_dialog.h
@@ -0,0 +1,47 @@
+/*
+    Copyright (C) 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 "table_dialog.h"
+#include "lib/types.h"
+#include <boost/signals2.hpp>
+
+
+class SpinCtrl;
+
+
+class AutoCropDialog : public TableDialog
+{
+public:
+	AutoCropDialog (wxWindow* parent, Crop crop);
+
+	Crop get () const;
+	void set (Crop crop);
+
+	boost::signals2::signal<void (Crop)> Changed;
+
+private:
+	SpinCtrl* _left;
+	SpinCtrl* _right;
+	SpinCtrl* _top;
+	SpinCtrl* _bottom;
+	SpinCtrl* _threshold;
+};
+
diff --git a/src/wx/content_menu.cc b/src/wx/content_menu.cc
index 5d208acc5..48d5354ef 100644
--- a/src/wx/content_menu.cc
+++ b/src/wx/content_menu.cc
@@ -19,9 +19,11 @@
 */
 
 
+#include "auto_crop_dialog.h"
 #include "content_advanced_dialog.h"
 #include "content_menu.h"
 #include "content_properties_dialog.h"
+#include "film_viewer.h"
 #include "repeat_dialog.h"
 #include "timeline_audio_content_view.h"
 #include "timeline_video_content_view.h"
@@ -36,9 +38,11 @@
 #include "lib/ffmpeg_content.h"
 #include "lib/film.h"
 #include "lib/find_missing.h"
+#include "lib/guess_crop.h"
 #include "lib/image_content.h"
 #include "lib/job_manager.h"
 #include "lib/playlist.h"
+#include "lib/video_content.h"
 #include <dcp/cpl.h>
 #include <dcp/decrypted_kdm.h>
 #include <dcp/exceptions.h>
@@ -61,6 +65,7 @@ using boost::optional;
 #if BOOST_VERSION >= 106100
 using namespace boost::placeholders;
 #endif
+using namespace dcpomatic;
 
 
 enum {
@@ -71,6 +76,7 @@ enum {
 	ID_properties,
 	ID_advanced,
 	ID_re_examine,
+	ID_auto_crop,
 	ID_kdm,
 	ID_ov,
 	ID_choose_cpl,
@@ -79,15 +85,17 @@ enum {
 };
 
 
-ContentMenu::ContentMenu (wxWindow* p)
+ContentMenu::ContentMenu (wxWindow* p, weak_ptr<FilmViewer> viewer)
 	: _menu (new wxMenu)
 	, _parent (p)
 	, _pop_up_open (false)
+	, _viewer (viewer)
 {
 	_repeat = _menu->Append (ID_repeat, _("Repeat..."));
 	_join = _menu->Append (ID_join, _("Join"));
 	_find_missing = _menu->Append (ID_find_missing, _("Find missing..."));
 	_re_examine = _menu->Append (ID_re_examine, _("Re-examine..."));
+	_auto_crop = _menu->Append (ID_auto_crop, _("Auto-crop..."));
 	_properties = _menu->Append (ID_properties, _("Properties..."));
 	_advanced = _menu->Append (ID_advanced, _("Advanced settings..."));
 	_menu->AppendSeparator ();
@@ -105,6 +113,7 @@ ContentMenu::ContentMenu (wxWindow* p)
 	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::properties, this), ID_properties);
 	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::advanced, this), ID_advanced);
 	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::re_examine, this), ID_re_examine);
+	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::auto_crop, this), ID_auto_crop);
 	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::kdm, this), ID_kdm);
 	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::ov, this), ID_ov);
 	_parent->Bind (wxEVT_MENU, boost::bind (&ContentMenu::set_dcp_settings, this), ID_set_dcp_settings);
@@ -139,6 +148,7 @@ ContentMenu::popup (weak_ptr<Film> film, ContentList c, TimelineContentViewList
 	_properties->Enable (_content.size() == 1);
 	_advanced->Enable (_content.size() == 1);
 	_re_examine->Enable (!_content.empty ());
+	_auto_crop->Enable (_content.size() == 1);
 
 	if (_content.size() == 1) {
 		auto dcp = dynamic_pointer_cast<DCPContent> (_content.front());
@@ -481,3 +491,84 @@ ContentMenu::cpl_selected (wxCommandEvent& ev)
 	DCPOMATIC_ASSERT (film);
 	JobManager::instance()->add (make_shared<ExamineContentJob>(film, dcp));
 }
+
+
+void
+ContentMenu::auto_crop ()
+{
+	DCPOMATIC_ASSERT (_content.size() == 1);
+
+	auto film = _film.lock ();
+	DCPOMATIC_ASSERT (film);
+	auto viewer = _viewer.lock ();
+	DCPOMATIC_ASSERT (viewer);
+
+	auto update_viewer = [this](Crop crop) {
+		auto film = _film.lock();
+		DCPOMATIC_ASSERT (film);
+		auto viewer = _viewer.lock ();
+		DCPOMATIC_ASSERT (viewer);
+		auto const content = _content.front();
+		auto const current_crop = content->video->actual_crop();
+		viewer->set_crop_guess (
+			Rect<float>(
+				static_cast<float>(std::max(0, crop.left - current_crop.left)) / content->video->size().width,
+				static_cast<float>(std::max(0, crop.top - current_crop.top)) / content->video->size().height,
+				1.0f - (static_cast<float>(std::max(0, crop.left - current_crop.left + crop.right - current_crop.right)) / content->video->size().width),
+				1.0f - (static_cast<float>(std::max(0, crop.top - current_crop.top + crop.bottom - current_crop.bottom)) / content->video->size().height)
+				));
+	};
+
+	auto guess_crop_for_content = [this, film, viewer]() {
+		auto position = viewer->position_in_content(_content.front()).get_value_or(
+			ContentTime::from_frames(_content.front()->video->length(), _content.front()->video_frame_rate().get_value_or(24))
+			);
+		return guess_crop(film, _content.front(), Config::instance()->auto_crop_threshold(), position);
+	};
+
+	/* Make an initial guess in the view and open the dialog */
+
+	auto const crop = guess_crop_for_content ();
+	update_viewer (crop);
+
+	if (_auto_crop_dialog) {
+		_auto_crop_dialog->Destroy();
+		_auto_crop_dialog = nullptr;
+	}
+	_auto_crop_dialog = new AutoCropDialog (_parent, crop);
+	_auto_crop_dialog->Show ();
+
+	/* Update the dialog and view when the crop threshold changes */
+	_auto_crop_config_connection = Config::instance()->Changed.connect([this, guess_crop_for_content, update_viewer](Config::Property property) {
+		auto film = _film.lock();
+		DCPOMATIC_ASSERT (film);
+		if (property == Config::AUTO_CROP_THRESHOLD) {
+			auto const crop = guess_crop_for_content();
+			_auto_crop_dialog->set(crop);
+			update_viewer(crop);
+		}
+	});
+
+	/* Also update the dialog and view when we're looking at a different frame */
+	_auto_crop_viewer_connection = viewer->ImageChanged.connect([this, guess_crop_for_content, update_viewer](shared_ptr<PlayerVideo>) {
+		auto const crop = guess_crop_for_content();
+		_auto_crop_dialog->set(crop);
+		update_viewer(crop);
+	});
+
+	/* Handle the user closing the dialog (with OK or cancel) */
+	_auto_crop_dialog->Bind (wxEVT_BUTTON, [this, viewer](wxCommandEvent& ev) {
+		if (ev.GetId() == wxID_OK) {
+			_content.front()->video->set_crop(_auto_crop_dialog->get());
+		}
+		_auto_crop_dialog->Show (false);
+		viewer->unset_crop_guess ();
+		_auto_crop_config_connection.disconnect ();
+		_auto_crop_viewer_connection.disconnect ();
+	});
+
+	/* Update the view when something in the dialog is changed */
+	_auto_crop_dialog->Changed.connect([this, update_viewer](Crop crop) {
+		update_viewer (crop);
+	});
+}
diff --git a/src/wx/content_menu.h b/src/wx/content_menu.h
index 03f657d38..147f95946 100644
--- a/src/wx/content_menu.h
+++ b/src/wx/content_menu.h
@@ -18,22 +18,28 @@
 
 */
 
+
 #ifndef DCPOMATIC_CONTENT_MENU_H
 #define DCPOMATIC_CONTENT_MENU_H
 
+
 #include "timeline_content_view.h"
 #include "lib/types.h"
 #include <wx/wx.h>
 #include <memory>
 
+
+class AutoCropDialog;
+class DCPContent;
 class Film;
+class FilmViewer;
 class Job;
-class DCPContent;
+
 
 class ContentMenu
 {
 public:
-	explicit ContentMenu (wxWindow* p);
+	ContentMenu (wxWindow* parent, std::weak_ptr<FilmViewer> viewer);
 
 	ContentMenu (ContentMenu const &) = delete;
 	ContentMenu& operator= (ContentMenu const &) = delete;
@@ -47,6 +53,7 @@ private:
 	void properties ();
 	void advanced ();
 	void re_examine ();
+	void auto_crop ();
 	void kdm ();
 	void ov ();
 	void set_dcp_settings ();
@@ -59,6 +66,7 @@ private:
 	std::weak_ptr<Film> _film;
 	wxWindow* _parent;
 	bool _pop_up_open;
+	std::weak_ptr<FilmViewer> _viewer;
 	ContentList _content;
 	TimelineContentViewList _views;
 	wxMenuItem* _repeat;
@@ -67,11 +75,17 @@ private:
 	wxMenuItem* _properties;
 	wxMenuItem* _advanced;
 	wxMenuItem* _re_examine;
+	wxMenuItem* _auto_crop;
 	wxMenuItem* _kdm;
 	wxMenuItem* _ov;
 	wxMenuItem* _choose_cpl;
 	wxMenuItem* _set_dcp_settings;
 	wxMenuItem* _remove;
+
+	AutoCropDialog* _auto_crop_dialog = nullptr;
+	boost::signals2::scoped_connection _auto_crop_config_connection;
+	boost::signals2::scoped_connection _auto_crop_viewer_connection;
 };
 
+
 #endif
diff --git a/src/wx/content_panel.cc b/src/wx/content_panel.cc
index b2b72b216..e2a236937 100644
--- a/src/wx/content_panel.cc
+++ b/src/wx/content_panel.cc
@@ -84,7 +84,7 @@ ContentPanel::ContentPanel (wxNotebook* n, shared_ptr<Film> film, weak_ptr<FilmV
 	_splitter = new LimitedSplitter (n);
 	_top_panel = new wxPanel (_splitter);
 
-	_menu = new ContentMenu (_splitter);
+	_menu = new ContentMenu (_splitter, _film_viewer);
 
 	{
 		auto s = new wxBoxSizer (wxHORIZONTAL);
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index d91a9db9c..e2f09f238 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -118,7 +118,7 @@ FilmViewer::~FilmViewer ()
 }
 
 
-/** Ask for ::get() to be called next time we are idle */
+/** Ask for ::idle_handler() to be called next time we are idle */
 void
 FilmViewer::request_idle_display_next_frame ()
 {
@@ -712,6 +712,13 @@ FilmViewer::dcp_decode_reduction () const
 }
 
 
+optional<ContentTime>
+FilmViewer::position_in_content (shared_ptr<const Content> content) const
+{
+	return _player->dcp_to_content_time (content, position());
+}
+
+
 DCPTime
 FilmViewer::one_video_frame () const
 {
@@ -795,3 +802,21 @@ FilmViewer::set_optimise_for_j2k (bool o)
 	_video_view->set_optimise_for_j2k (o);
 }
 
+
+void
+FilmViewer::set_crop_guess (Rect<float> crop)
+{
+	if (crop != _crop_guess) {
+		_crop_guess = crop;
+		_video_view->update ();
+	}
+}
+
+
+void
+FilmViewer::unset_crop_guess ()
+{
+	_crop_guess = {};
+	_video_view->update ();
+}
+
diff --git a/src/wx/film_viewer.h b/src/wx/film_viewer.h
index 64ac885e3..af15ded94 100644
--- a/src/wx/film_viewer.h
+++ b/src/wx/film_viewer.h
@@ -80,6 +80,7 @@ public:
 	dcpomatic::DCPTime position () const {
 		return _video_view->position();
 	}
+	boost::optional<dcpomatic::ContentTime> position_in_content (std::shared_ptr<const Content> content) const;
 	dcpomatic::DCPTime one_video_frame () const;
 
 	void start ();
@@ -99,6 +100,8 @@ public:
 	void set_eyes (Eyes e);
 	void set_pad_black (bool p);
 	void set_optimise_for_j2k (bool o);
+	void set_crop_guess (dcpomatic::Rect<float> crop);
+	void unset_crop_guess ();
 
 	void slow_refresh ();
 
@@ -133,6 +136,9 @@ public:
 	}
 	void finished ();
 	void image_changed (std::shared_ptr<PlayerVideo> video);
+	boost::optional<dcpomatic::Rect<float>> crop_guess () const {
+		return _crop_guess;
+	}
 
 	bool pending_idle_get () const {
 		return _idle_get;
@@ -206,5 +212,7 @@ private:
 	/** true if an get() is required next time we are idle */
 	bool _idle_get = false;
 
+	boost::optional<dcpomatic::Rect<float>> _crop_guess;
+
 	boost::signals2::scoped_connection _config_changed_connection;
 };
diff --git a/src/wx/gl_video_view.cc b/src/wx/gl_video_view.cc
index ed99e3430..39280c905 100644
--- a/src/wx/gl_video_view.cc
+++ b/src/wx/gl_video_view.cc
@@ -196,12 +196,14 @@ static constexpr char fragment_source[] =
 "\n"
 "uniform sampler2D texture_sampler;\n"
 /* type = 0: draw outline content rectangle
- * type = 1: draw XYZ image
- * type = 2: draw RGB image
+ * type = 1: draw crop guess rectangle
+ * type = 2: draw XYZ image
+ * type = 3: draw RGB image
  * See FragmentType enum below.
  */
 "uniform int type = 0;\n"
 "uniform vec4 outline_content_colour;\n"
+"uniform vec4 crop_guess_colour;\n"
 "uniform mat4 colour_conversion;\n"
 "\n"
 "out vec4 FragColor;\n"
@@ -263,6 +265,9 @@ static constexpr char fragment_source[] =
 "			FragColor = outline_content_colour;\n"
 "			break;\n"
 "		case 1:\n"
+"                       FragColor = crop_guess_colour;\n"
+"                       break;\n"
+"		case 2:\n"
 "			FragColor = texture_bicubic(texture_sampler, TexCoord);\n"
 "			FragColor.x = pow(FragColor.x, IN_GAMMA) / DCI_COEFFICIENT;\n"
 "			FragColor.y = pow(FragColor.y, IN_GAMMA) / DCI_COEFFICIENT;\n"
@@ -272,7 +277,7 @@ static constexpr char fragment_source[] =
 "			FragColor.y = pow(FragColor.y, OUT_GAMMA);\n"
 "			FragColor.z = pow(FragColor.z, OUT_GAMMA);\n"
 "			break;\n"
-"		case 2:\n"
+"		case 3:\n"
 "			FragColor = texture_bicubic(texture_sampler, TexCoord);\n"
 "			break;\n"
 "	}\n"
@@ -282,8 +287,9 @@ static constexpr char fragment_source[] =
 enum class FragmentType
 {
 	OUTLINE_CONTENT = 0,
-	XYZ_IMAGE = 1,
-	RGB_IMAGE = 2,
+	CROP_GUESS = 1,
+	XYZ_IMAGE = 2,
+	RGB_IMAGE = 3,
 };
 
 
@@ -308,6 +314,8 @@ static constexpr int indices_subtitle_texture_offset = indices_video_texture_off
 static constexpr int indices_subtitle_texture_number = 6;
 static constexpr int indices_outline_content_offset = indices_subtitle_texture_offset + indices_subtitle_texture_number;
 static constexpr int indices_outline_content_number = 8;
+static constexpr int indices_crop_guess_offset = indices_outline_content_offset + indices_outline_content_number;
+static constexpr int indices_crop_guess_number = 8;
 
 static constexpr unsigned int indices[] = {
 	0, 1, 3, // video texture triangle #1
@@ -318,12 +326,17 @@ static constexpr unsigned int indices[] = {
 	9, 10,   // outline content line #2
 	10, 11,  // outline content line #3
 	11, 8,   // outline content line #4
+	12, 13,  // crop guess line #1
+	13, 14,  // crop guess line #2
+	14, 15,  // crop guess line #3
+	15, 12,  // crop guess line #4
 };
 
 /* Offsets of things in the GL_ARRAY_BUFFER */
 static constexpr int array_buffer_video_offset = 0;
 static constexpr int array_buffer_subtitle_offset = array_buffer_video_offset + 4 * 5 * sizeof(float);
 static constexpr int array_buffer_outline_content_offset = array_buffer_subtitle_offset + 4 * 5 * sizeof(float);
+static constexpr int array_buffer_crop_guess_offset = array_buffer_outline_content_offset + 4 * 5 * sizeof(float);
 
 
 void
@@ -439,6 +452,7 @@ GLVideoView::setup_shaders ()
 	_fragment_type = glGetUniformLocation (program, "type");
 	check_gl_error ("glGetUniformLocation");
 	set_outline_content_colour (program);
+	set_crop_guess_colour (program);
 
 	auto conversion = dcp::ColourConversion::rec709_to_xyz();
 	boost::numeric::ublas::matrix<double> matrix = conversion.xyz_to_rgb ();
@@ -453,7 +467,7 @@ GLVideoView::setup_shaders ()
 	check_gl_error ("glGetUniformLocation");
 	glUniformMatrix4fv (colour_conversion, 1, GL_TRUE, gl_matrix);
 
-	glLineWidth (1.0f);
+	glLineWidth (2.0f);
 	check_gl_error ("glLineWidth");
 	glEnable (GL_BLEND);
 	check_gl_error ("glEnable");
@@ -461,7 +475,7 @@ GLVideoView::setup_shaders ()
 	check_gl_error ("glBlendFunc");
 
 	/* Reserve space for the GL_ARRAY_BUFFER */
-	glBufferData(GL_ARRAY_BUFFER, 12 * 5 * sizeof(float), nullptr, GL_STATIC_DRAW);
+	glBufferData(GL_ARRAY_BUFFER, 16 * 5 * sizeof(float), nullptr, GL_STATIC_DRAW);
 	check_gl_error ("glBufferData");
 }
 
@@ -478,6 +492,17 @@ GLVideoView::set_outline_content_colour (GLuint program)
 
 
 void
+GLVideoView::set_crop_guess_colour (GLuint program)
+{
+	auto uniform = glGetUniformLocation (program, "crop_guess_colour");
+	check_gl_error ("glGetUniformLocation");
+	auto colour = crop_guess_colour ();
+	glUniform4f (uniform, colour.Red() / 255.0f, colour.Green() / 255.0f, colour.Blue() / 255.0f, 1.0f);
+	check_gl_error ("glUniform4f");
+}
+
+
+void
 GLVideoView::draw ()
 {
 	auto pad = pad_colour();
@@ -511,6 +536,11 @@ GLVideoView::draw ()
 		glDrawElements (GL_LINES, indices_outline_content_number, GL_UNSIGNED_INT, reinterpret_cast<void*>(indices_outline_content_offset * sizeof(int)));
 		check_gl_error ("glDrawElements");
 	}
+	if (auto guess = _viewer->crop_guess()) {
+		glUniform1i(_fragment_type, 1);
+		glDrawElements (GL_LINES, indices_crop_guess_number, GL_UNSIGNED_INT, reinterpret_cast<void*>(indices_crop_guess_offset * sizeof(int)));
+		check_gl_error ("glDrawElements");
+	}
 
 	glFlush();
 	check_gl_error ("glFlush");
@@ -553,6 +583,7 @@ GLVideoView::set_image (shared_ptr<const PlayerVideo> pv)
 	auto const inter_position = player_video().first->inter_position();
 	auto const inter_size = player_video().first->inter_size();
 	auto const out_size = player_video().first->out_size();
+	auto const crop_guess = _viewer->crop_guess();
 
 	auto x_offset = std::max(0, (canvas_width - out_size.width) / 2);
 	auto y_offset = std::max(0, (canvas_height - out_size.height) / 2);
@@ -562,6 +593,7 @@ GLVideoView::set_image (shared_ptr<const PlayerVideo> pv)
 	_last_inter_position.set_next (inter_position);
 	_last_inter_size.set_next (inter_size);
 	_last_out_size.set_next (out_size);
+	_last_crop_guess.set_next (crop_guess);
 
 	class Rectangle
 	{
@@ -631,8 +663,9 @@ GLVideoView::set_image (shared_ptr<const PlayerVideo> pv)
 		float _vertices[20];
 	};
 
-	if (_last_canvas_size.changed() || _last_inter_position.changed() || _last_inter_size.changed() || _last_out_size.changed()) {
+	auto const sizing_changed = _last_canvas_size.changed() || _last_inter_position.changed() || _last_inter_size.changed() || _last_out_size.changed();
 
+	if (sizing_changed) {
 		const auto video = _optimise_for_j2k ?
 			Rectangle(canvas_size, inter_position.x + x_offset, inter_position.y + y_offset, inter_size)
 			: Rectangle(canvas_size, x_offset, y_offset, out_size);
@@ -645,6 +678,17 @@ GLVideoView::set_image (shared_ptr<const PlayerVideo> pv)
 		check_gl_error ("glBufferSubData (outline_content)");
 	}
 
+	if ((sizing_changed || _last_crop_guess.changed()) && crop_guess) {
+		auto const crop_guess_rectangle = Rectangle(
+			canvas_size,
+			inter_position.x + x_offset + inter_size.width * crop_guess->x,
+			inter_position.y + y_offset + inter_size.height * crop_guess->y,
+			dcp::Size(inter_size.width * crop_guess->width, inter_size.height * crop_guess->height)
+			);
+		glBufferSubData (GL_ARRAY_BUFFER, array_buffer_crop_guess_offset, crop_guess_rectangle.size(), crop_guess_rectangle.vertices());
+		check_gl_error ("glBufferSubData (crop_guess_rectangle)");
+	}
+
 	if (_have_subtitle_to_render) {
 		const auto subtitle = Rectangle(canvas_size, inter_position.x + x_offset + text->position.x, inter_position.y + y_offset + text->position.y, text->image->size());
 		glBufferSubData (GL_ARRAY_BUFFER, array_buffer_subtitle_offset, subtitle.size(), subtitle.vertices());
diff --git a/src/wx/gl_video_view.h b/src/wx/gl_video_view.h
index 098b8ce8e..7a3aa41b0 100644
--- a/src/wx/gl_video_view.h
+++ b/src/wx/gl_video_view.h
@@ -100,6 +100,7 @@ private:
 	void size_changed (wxSizeEvent const &);
 	void setup_shaders ();
 	void set_outline_content_colour (GLuint program);
+	void set_crop_guess_colour (GLuint program);
 
 	wxGLCanvas* _canvas;
 	wxGLContext* _context;
@@ -130,6 +131,7 @@ private:
 	Last<Position<int>> _last_inter_position;
 	Last<dcp::Size> _last_inter_size;
 	Last<dcp::Size> _last_out_size;
+	Last<boost::optional<dcpomatic::Rect<float>>> _last_crop_guess;
 
 	boost::atomic<wxSize> _canvas_size;
 	std::unique_ptr<Texture> _video_texture;
diff --git a/src/wx/simple_video_view.cc b/src/wx/simple_video_view.cc
index 7f816c31d..45fcf4405 100644
--- a/src/wx/simple_video_view.cc
+++ b/src/wx/simple_video_view.cc
@@ -117,6 +117,19 @@ SimpleVideoView::paint ()
 		dc.DrawRectangle (subs->x * out_size.width, subs->y * out_size.height, subs->width * out_size.width, subs->height * out_size.height);
 	}
 
+	if (_viewer->crop_guess()) {
+		wxPen p (crop_guess_colour(), 2);
+		dc.SetPen (p);
+		dc.SetBrush (*wxTRANSPARENT_BRUSH);
+		auto const crop_guess = _viewer->crop_guess().get();
+		dc.DrawRectangle (
+			_inter_position.x + _inter_size.width * crop_guess.x,
+			_inter_position.y + _inter_size.height * crop_guess.y,
+			_inter_size.width * crop_guess.width,
+			_inter_size.height * crop_guess.height
+			);
+	}
+
         _state_timer.unset();
 }
 
diff --git a/src/wx/timeline.cc b/src/wx/timeline.cc
index 1c5937ae0..60b17c45c 100644
--- a/src/wx/timeline.cc
+++ b/src/wx/timeline.cc
@@ -77,7 +77,7 @@ Timeline::Timeline (wxWindow* parent, ContentPanel* cp, shared_ptr<Film> film, w
 	, _left_down (false)
 	, _down_view_position (0)
 	, _first_move (false)
-	, _menu (this)
+	, _menu (this, viewer)
 	, _snap (true)
 	, _tool (SELECT)
 	, _x_scroll_rate (16)
diff --git a/src/wx/video_view.cc b/src/wx/video_view.cc
index 1c645f11f..64226e88c 100644
--- a/src/wx/video_view.cc
+++ b/src/wx/video_view.cc
@@ -185,4 +185,3 @@ VideoView::pad_colour () const
 		return wxColour(240, 240, 240);
 	}
 }
-
diff --git a/src/wx/video_view.h b/src/wx/video_view.h
index 5353f213f..496888d43 100644
--- a/src/wx/video_view.h
+++ b/src/wx/video_view.h
@@ -146,6 +146,10 @@ protected:
 		return wxColour(0, 255, 0);
 	}
 
+	wxColour crop_guess_colour () const {
+		return wxColour(0, 0, 255);
+	}
+
 	int video_frame_rate () const {
 		boost::mutex::scoped_lock lm (_mutex);
 		return _video_frame_rate;
diff --git a/src/wx/wscript b/src/wx/wscript
index 1976397d1..8569872b7 100644
--- a/src/wx/wscript
+++ b/src/wx/wscript
@@ -31,6 +31,7 @@ sources = """
           audio_mapping_view.cc
           audio_panel.cc
           audio_plot.cc
+          auto_crop_dialog.cc
           barco_alchemy_certificate_panel.cc
           batch_job_view.cc
           check_box.cc