From c8db1d4012217ec295d2a77581cf0661543dc9af Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Tue, 5 Nov 2019 23:01:24 +0100
Subject: [PATCH] Differentiate between stop and suspend in player. This and
 the previous commit somewhat improve the previously terrible behaviour when
 seeking during playback, probably introduced by the idle update stuff.

---
 src/wx/controls.cc    |  9 +++------
 src/wx/controls.h     |  1 -
 src/wx/film_viewer.cc | 43 ++++++++++++++++++++++++++++++++++---------
 src/wx/film_viewer.h  |  3 +++
 4 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/src/wx/controls.cc b/src/wx/controls.cc
index 7cd31634d..a3360b262 100644
--- a/src/wx/controls.cc
+++ b/src/wx/controls.cc
@@ -59,7 +59,6 @@ Controls::Controls (wxWindow* parent, shared_ptr<FilmViewer> viewer, bool editor
 	, _slider (new wxSlider (this, wxID_ANY, 0, 0, 4096))
 	, _viewer (viewer)
 	, _slider_being_moved (false)
-	, _was_running_before_slider (false)
 	, _outline_content (0)
 	, _eye (0)
 	, _jump_to_selected (0)
@@ -203,7 +202,7 @@ Controls::slider_moved (bool page)
 
 	if (!page && !_slider_being_moved) {
 		/* This is the first event of a drag; stop playback for the duration of the drag */
-		_was_running_before_slider = _viewer->stop ();
+		_viewer->suspend ();
 		_slider_being_moved = true;
 	}
 
@@ -230,10 +229,8 @@ Controls::slider_moved (bool page)
 void
 Controls::slider_released ()
 {
-	if (_was_running_before_slider) {
-		/* Restart after a drag */
-		_viewer->start ();
-	}
+	/* Restart after a drag */
+	_viewer->resume ();
 	_slider_being_moved = false;
 }
 
diff --git a/src/wx/controls.h b/src/wx/controls.h
index 88d21defb..dfa11e6d7 100644
--- a/src/wx/controls.h
+++ b/src/wx/controls.h
@@ -93,7 +93,6 @@ private:
 	typedef std::pair<boost::shared_ptr<dcp::CPL>, boost::filesystem::path> CPL;
 
 	bool _slider_being_moved;
-	bool _was_running_before_slider;
 
 	wxCheckBox* _outline_content;
 	wxChoice* _eye;
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index 495b82567..9b01cd394 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -84,6 +84,7 @@ FilmViewer::FilmViewer (wxWindow* p)
 	, _audio_channels (0)
 	, _audio_block_size (1024)
 	, _playing (false)
+	, _suspended (0)
 	, _latency_history_count (0)
 	, _dropped (0)
 	, _closed_captions_dialog (new ClosedCaptionsDialog(p, this))
@@ -200,10 +201,11 @@ FilmViewer::set_film (shared_ptr<Film> film)
 void
 FilmViewer::recreate_butler ()
 {
-	bool const was_running = stop ();
+	suspend ();
 	_butler.reset ();
 
 	if (!_film) {
+		resume ();
 		return;
 	}
 
@@ -247,9 +249,7 @@ FilmViewer::recreate_butler ()
 
 	_closed_captions_dialog->set_film_and_butler (_film, _butler);
 
-	if (was_running) {
-		start ();
-	}
+	resume ();
 }
 
 void
@@ -312,7 +312,7 @@ FilmViewer::display_player_video ()
 		return;
 	}
 
-	if (_playing && (time() - _player_video.second) > one_video_frame()) {
+	if (_playing && !_suspended && (time() - _player_video.second) > one_video_frame()) {
 		/* Too late; just drop this frame before we try to get its image (which will be the time-consuming
 		   part if this frame is J2K).
 		*/
@@ -361,7 +361,7 @@ FilmViewer::display_player_video ()
 void
 FilmViewer::timer ()
 {
-	if (!_film || !_playing) {
+	if (!_film || !_playing || _suspended) {
 		return;
 	}
 
@@ -435,6 +435,28 @@ FilmViewer::calculate_sizes ()
 	_player->set_video_container_size (_out_size);
 }
 
+void
+FilmViewer::suspend ()
+{
+	++_suspended;
+	if (_audio.isStreamRunning()) {
+		_audio.abortStream();
+	}
+}
+
+void
+FilmViewer::resume ()
+{
+	--_suspended;
+	if (_playing && !_suspended) {
+		if (_audio.isStreamOpen()) {
+			_audio.setStreamTime (_video_position.seconds());
+			_audio.startStream ();
+		}
+		timer ();
+	}
+}
+
 void
 FilmViewer::start ()
 {
@@ -579,16 +601,19 @@ FilmViewer::seek (DCPTime t, bool accurate)
 		t = _film->length ();
 	}
 
-	bool const was_running = stop ();
+	suspend ();
 
 	_closed_captions_dialog->clear ();
 	_butler->seek (t, accurate);
 
-	if (!was_running) {
+	if (!_playing) {
 		request_idle_get ();
 	} else {
-		start ();
+		/* Make sure we get a frame so that _video_position is set up before we resume */
+		while (!get(true)) {}
 	}
+
+	resume ();
 }
 
 void
diff --git a/src/wx/film_viewer.h b/src/wx/film_viewer.h
index a37d7581e..1f20c3321 100644
--- a/src/wx/film_viewer.h
+++ b/src/wx/film_viewer.h
@@ -75,6 +75,8 @@ public:
 
 	void start ();
 	bool stop ();
+	void suspend ();
+	void resume ();
 	bool playing () const {
 		return _playing;
 	}
@@ -186,6 +188,7 @@ private:
 	int _audio_channels;
 	unsigned int _audio_block_size;
 	bool _playing;
+	int _suspended;
 	boost::shared_ptr<Butler> _butler;
 
 	std::list<Frame> _latency_history;
-- 
2.30.2