Basic implementation of <Space> tag in subtitles.v1.8.3

14 files changed, 228 insertions, 66 deletions

diff --git a/src/subtitle_asset.cc b/src/subtitle_asset.cc
index a8636368..2793772a 100644
--- a/src/subtitle_asset.cc
+++ b/src/subtitle_asset.cc
@@ -286,14 +286,28 @@ SubtitleAsset::parse_subtitles (xmlpp::Element const * node, vector<ParseState>&
 		throw XMLError ("unexpected node " + node->get_name());
 	}
 
+	float space_before = 0;
+
 	for (auto i: node->get_children()) {
 		auto const v = dynamic_cast<xmlpp::ContentNode const *>(i);
 		if (v) {
-			maybe_add_subtitle (v->get_content(), state, standard);
+			maybe_add_subtitle (v->get_content(), state, space_before, standard);
+			space_before = 0;
 		}
 		auto const e = dynamic_cast<xmlpp::Element const *>(i);
 		if (e) {
-			parse_subtitles (e, state, tcr, standard);
+			if (e->get_name() == "Space") {
+				if (node->get_name() != "Text") {
+					throw XMLError ("Space node found outside Text");
+				}
+				auto size = optional_string_attribute(e, "Size").get_value_or("0.5");
+				if (standard == dcp::Standard::INTEROP) {
+					boost::replace_all(size, "em", "");
+				}
+				space_before += raw_convert<float>(size);
+			} else {
+				parse_subtitles (e, state, tcr, standard);
+			}
 		}
 	}
 
@@ -302,7 +316,7 @@ SubtitleAsset::parse_subtitles (xmlpp::Element const * node, vector<ParseState>&
 
 
 void
-SubtitleAsset::maybe_add_subtitle (string text, vector<ParseState> const & parse_state, Standard standard)
+SubtitleAsset::maybe_add_subtitle (string text, vector<ParseState> const & parse_state, float space_before, Standard standard)
 {
 	if (empty_or_white_space (text)) {
 		return;
@@ -398,7 +412,8 @@ SubtitleAsset::maybe_add_subtitle (string text, vector<ParseState> const & parse
 				ps.effect.get_value_or (Effect::NONE),
 				ps.effect_colour.get_value_or (dcp::Colour (0, 0, 0)),
 				ps.fade_up_time.get_value_or(Time()),
-				ps.fade_down_time.get_value_or(Time())
+				ps.fade_down_time.get_value_or(Time()),
+				space_before
 				)
 			);
 		break;
@@ -684,7 +699,7 @@ SubtitleAsset::subtitles_as_xml (xmlpp::Element* xml_root, int time_code_rate, S
 			    fabs(last_v_position - is->v_position()) > ALIGN_EPSILON ||
 			    last_direction != is->direction()
 				) {
-				text.reset (new order::Text (subtitle, is->h_align(), is->h_position(), is->v_align(), is->v_position(), is->direction()));
+				text = make_shared<order::Text>(subtitle, is->h_align(), is->h_position(), is->v_align(), is->v_position(), is->direction());
 				subtitle->children.push_back (text);
 
 				last_h_align = is->h_align ();
@@ -694,7 +709,7 @@ SubtitleAsset::subtitles_as_xml (xmlpp::Element* xml_root, int time_code_rate, S
 				last_direction = is->direction ();
 			}
 
-			text->children.push_back (make_shared<order::String>(text, order::Font (is, standard), is->text()));
+			text->children.push_back (make_shared<order::String>(text, order::Font (is, standard), is->text(), is->space_before()));
 		}
 
 		auto ii = dynamic_pointer_cast<SubtitleImage>(i);
diff --git a/src/subtitle_asset.h b/src/subtitle_asset.h
index 8ec57fce..f51906e2 100644
--- a/src/subtitle_asset.h
+++ b/src/subtitle_asset.h
@@ -156,6 +156,7 @@ protected:
 			IMAGE
 		};
 		boost::optional<Type> type;
+		float space_before = 0;
 	};
 
 	void parse_subtitles (xmlpp::Element const * node, std::vector<ParseState>& state, boost::optional<int> tcr, Standard standard);
@@ -205,7 +206,7 @@ private:
 	friend struct ::pull_fonts_test2;
 	friend struct ::pull_fonts_test3;
 
-	void maybe_add_subtitle (std::string text, std::vector<ParseState> const & parse_state, Standard standard);
+	void maybe_add_subtitle (std::string text, std::vector<ParseState> const & parse_state, float space_before, Standard standard);
 
 	static void pull_fonts (std::shared_ptr<order::Part> part);
 };
diff --git a/src/subtitle_asset_internal.cc b/src/subtitle_asset_internal.cc
index bf73fcc3..7a10f472 100644
--- a/src/subtitle_asset_internal.cc
+++ b/src/subtitle_asset_internal.cc
@@ -134,9 +134,17 @@ order::Part::as_xml (xmlpp::Element* parent, Context &) const
 
 
 xmlpp::Element*
-order::String::as_xml (xmlpp::Element* parent, Context &) const
+order::String::as_xml (xmlpp::Element* parent, Context& context) const
 {
-	parent->add_child_text (text);
+	if (fabs(_space_before) > SPACE_BEFORE_EPSILON) {
+		auto space = parent->add_child("Space");
+		auto size = raw_convert<string>(_space_before, 2);
+		if (context.standard == Standard::INTEROP) {
+			size += "em";
+		}
+		space->set_attribute("Size", size);
+	}
+	parent->add_child_text (_text);
 	return 0;
 }
 
diff --git a/src/subtitle_asset_internal.h b/src/subtitle_asset_internal.h
index f24ed58a..55880797 100644
--- a/src/subtitle_asset_internal.h
+++ b/src/subtitle_asset_internal.h
@@ -127,14 +127,17 @@ public:
 class String : public Part
 {
 public:
-	String (std::shared_ptr<Part> parent, Font font, std::string text_)
+	String (std::shared_ptr<Part> parent, Font font, std::string text, float space_before)
 		: Part (parent, font)
-		, text (text_)
+		, _text (text)
+		, _space_before (space_before)
 	{}
 
 	virtual xmlpp::Element* as_xml (xmlpp::Element* parent, Context &) const override;
 
-	std::string text;
+private:
+	std::string _text;
+	float _space_before;
 };
 
 
diff --git a/src/subtitle_string.cc b/src/subtitle_string.cc
index acd35691..5e2c6251 100644
--- a/src/subtitle_string.cc
+++ b/src/subtitle_string.cc
@@ -69,7 +69,8 @@ SubtitleString::SubtitleString (
 	Effect effect,
 	Colour effect_colour,
 	Time fade_up_time,
-	Time fade_down_time
+	Time fade_down_time,
+	float space_before
 	)
 	: Subtitle (in, out, h_position, h_align, v_position, v_align, fade_up_time, fade_down_time)
 	, _font (font)
@@ -83,6 +84,7 @@ SubtitleString::SubtitleString (
 	, _text (text)
 	, _effect (effect)
 	, _effect_colour (effect_colour)
+	, _space_before (space_before)
 {
 	_aspect_adjust = max(min(_aspect_adjust, 4.0f), 0.25f);
 }
@@ -122,7 +124,8 @@ dcp::operator== (SubtitleString const & a, SubtitleString const & b)
 		a.effect() == b.effect() &&
 		a.effect_colour() == b.effect_colour() &&
 		a.fade_up_time() == b.fade_up_time() &&
-		a.fade_down_time() == b.fade_down_time()
+		a.fade_down_time() == b.fade_down_time() &&
+		fabs (a.space_before() - b.space_before()) < SPACE_BEFORE_EPSILON
 		);
 }
 
@@ -163,7 +166,8 @@ dcp::operator<< (ostream& s, SubtitleString const & sub)
 	  << ", hpos " << sub.h_position() << ", halign " << ((int) sub.h_align())
 	  << ", direction " << ((int) sub.direction())
 	  << ", effect " << ((int) sub.effect())
-	  << ", effect colour (" << sub.effect_colour().r << ", " << sub.effect_colour().g << ", " << sub.effect_colour().b << ")";
+	  << ", effect colour (" << sub.effect_colour().r << ", " << sub.effect_colour().g << ", " << sub.effect_colour().b << ")"
+	  << ", space before " << sub.space_before();
 
 	return s;
 }
diff --git a/src/subtitle_string.h b/src/subtitle_string.h
index bf9c87d9..f6d0974b 100644
--- a/src/subtitle_string.h
+++ b/src/subtitle_string.h
@@ -76,6 +76,7 @@ public:
 	 *  @param effect_colour Colour of the effect
 	 *  @param fade_up_time Time to fade the text in
 	 *  @param fade_down_time Time to fade the text out
+	 *  @param space_before Space to add before this string, in ems (could be negative to remove space).
 	 */
 	SubtitleString (
 		boost::optional<std::string> font,
@@ -96,7 +97,8 @@ public:
 		Effect effect,
 		Colour effect_colour,
 		Time fade_up_time,
-		Time fade_down_time
+		Time fade_down_time,
+		float space_before
 		);
 
 	/** @return font ID */
@@ -142,6 +144,10 @@ public:
 
 	int size_in_pixels (int screen_height) const;
 
+	float space_before () const {
+		return _space_before;
+	}
+
 	/** @return Aspect ratio `adjustment' of the font size.
 	 *  Values greater than 1 widen each character, values less than 1 narrow each character,
 	 *  and the value must be between 0.25 and 4.
@@ -202,6 +208,7 @@ private:
 	std::string _text;
 	Effect _effect;
 	Colour _effect_colour;
+	float _space_before;
 };
 
 bool operator== (SubtitleString const & a, SubtitleString const & b);
diff --git a/src/types.h b/src/types.h
index caa28dd5..be9ba1b3 100644
--- a/src/types.h
+++ b/src/types.h
@@ -349,6 +349,12 @@ constexpr float ASPECT_ADJUST_EPSILON = 1e-3;
 constexpr float ALIGN_EPSILON = 1e-3;
 
 
+/** Maximum absolute difference between dcp::SubtitleString space_before values that
+ *  are considered equal.
+ */
+constexpr float SPACE_BEFORE_EPSILON = 1e-3;
+
+
 enum class Marker {
 	FFOC, ///< first frame of composition
 	LFOC, ///< last frame of composition
diff --git a/test/data/subs1.xml b/test/data/subs1.xml
index ee57db02..2262449a 100644
--- a/test/data/subs1.xml
+++ b/test/data/subs1.xml
@@ -7,7 +7,7 @@
   <LoadFont Id="theFontId" URI="arial.ttf"/>
   <Font Id="theFontId" Color="FFFFFFFF" Effect="border" EffectColor="FF000000" Italic="no" Size="39" Script="normal" Underlined="no" Weight="normal">
     <Subtitle SpotNumber="1" TimeIn="00:00:05:198" TimeOut="00:00:07:115" FadeUpTime="1" FadeDownTime="1">
-      <Text VAlign="bottom" VPosition="15.0">My jacket was Idi Amin's</Text>
+      <Text VAlign="bottom" VPosition="15.0">My jacket was <Space Size="6em"/>Idi Amin's</Text>
     </Subtitle>
     <Font Italic="yes">
       <Subtitle SpotNumber="2" TimeIn="00:00:07:177" TimeOut="00:00:11:031" FadeUpTime="1" FadeDownTime="1">
diff --git a/test/decryption_test.cc b/test/decryption_test.cc
index 708f222b..eb305c6a 100644
--- a/test/decryption_test.cc
+++ b/test/decryption_test.cc
@@ -193,7 +193,7 @@ BOOST_AUTO_TEST_CASE (decryption_test2)
 		"Hello world",
 		dcp::Effect::NONE,
 		dcp::Colour(0, 0, 0),
-		dcp::Time(), dcp::Time()
+		dcp::Time(), dcp::Time(), 0
 		));
 	subs_asset->write (dir / "subs.mxf");
 
diff --git a/test/interop_subtitle_test.cc b/test/interop_subtitle_test.cc
index d0d44bb8..ff0940b0 100644
--- a/test/interop_subtitle_test.cc
+++ b/test/interop_subtitle_test.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-202]1 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of libdcp.
 
@@ -43,7 +43,6 @@
 
 
 using std::dynamic_pointer_cast;
-using std::list;
 using std::make_shared;
 using std::shared_ptr;
 using std::string;
@@ -68,7 +67,7 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test1)
 	BOOST_CHECK_EQUAL (interop_lfn->uri, "arial.ttf");
 
 	auto s = subs.subtitles_during (dcp::Time (0, 0, 6, 1, 250), dcp::Time (0, 0, 6, 2, 250), false);
-	BOOST_REQUIRE_EQUAL (s.size(), 1);
+	BOOST_REQUIRE_EQUAL (s.size(), 2);
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.front()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.front()), dcp::SubtitleString (
 				   string ("theFontId"),
@@ -85,11 +84,35 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test1)
 				   0.15,
 				   dcp::VAlign::BOTTOM,
 				   dcp::Direction::LTR,
-				   "My jacket was Idi Amin's",
+				   "My jacket was ",
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 1, 250),
-				   dcp::Time (0, 0, 0, 1, 250)
+				   dcp::Time (0, 0, 0, 1, 250),
+				   0
+				   ));
+	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
+	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
+				   string ("theFontId"),
+				   false,
+				   false,
+				   false,
+				   dcp::Colour (255, 255, 255),
+				   39,
+				   1.0,
+				   dcp::Time (0, 0, 5, 198, 250),
+				   dcp::Time (0, 0, 7, 115, 250),
+				   0,
+				   dcp::HAlign::CENTER,
+				   0.15,
+				   dcp::VAlign::BOTTOM,
+				   dcp::Direction::LTR,
+				   "Idi Amin's",
+				   dcp::Effect::BORDER,
+				   dcp::Colour (0, 0, 0),
+				   dcp::Time (0, 0, 0, 1, 250),
+				   dcp::Time (0, 0, 0, 1, 250),
+				   6
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 0, 7, 190, 250), dcp::Time (0, 0, 7, 191, 250), false);
@@ -114,7 +137,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test1)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 1, 250),
-				   dcp::Time (0, 0, 0, 1, 250)
+				   dcp::Time (0, 0, 0, 1, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -136,7 +160,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test1)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 1, 250),
-				   dcp::Time (0, 0, 0, 1, 250)
+				   dcp::Time (0, 0, 0, 1, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 0, 11, 95, 250), dcp::Time (0, 0, 11, 96, 250), false);
@@ -161,7 +186,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test1)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 1, 250),
-				   dcp::Time (0, 0, 0, 1, 250)
+				   dcp::Time (0, 0, 0, 1, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 0, 14, 42, 250), dcp::Time (0, 0, 14, 43, 250), false);
@@ -186,7 +212,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test1)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 1, 250),
-				   dcp::Time (0, 0, 0, 1, 250)
+				   dcp::Time (0, 0, 0, 1, 250),
+				   0
 				   ));
 }
 
@@ -217,7 +244,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 0, 250),
-				   dcp::Time (0, 0, 0, 0, 250)
+				   dcp::Time (0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -239,7 +267,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 0, 250),
-				   dcp::Time (0, 0, 0, 0, 250)
+				   dcp::Time (0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 0, 50, 50, 250), dcp::Time (0, 0, 50, 51, 250), false);
@@ -264,7 +293,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 0, 250),
-				   dcp::Time (0, 0, 0, 0, 250)
+				   dcp::Time (0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -286,7 +316,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour (0, 0, 0),
 				   dcp::Time (0, 0, 0, 0, 250),
-				   dcp::Time (0, 0, 0, 0, 250)
+				   dcp::Time (0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 1, 2, 300, 250), dcp::Time (0, 1, 2, 301, 250), false);
@@ -311,7 +342,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -333,7 +365,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 1, 15, 50, 250), dcp::Time (0, 1, 15, 51, 250), false);
@@ -358,7 +391,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -380,7 +414,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 1, 27, 200, 250), dcp::Time (0, 1, 27, 201, 250), false);
@@ -405,7 +440,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -427,7 +463,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 1, 42, 300, 250), dcp::Time (0, 1, 42, 301, 250), false);
@@ -452,7 +489,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -474,7 +512,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 1, 45, 200, 250), dcp::Time (0, 1, 45, 201, 250), false);
@@ -499,7 +538,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -521,7 +561,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 1, 47, 249, 250), dcp::Time (0, 1, 47, 250, 250), false);
@@ -546,7 +587,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -568,7 +610,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 
 	s = subs.subtitles_during (dcp::Time (0, 2, 6, 210, 250), dcp::Time (0, 2, 6, 211, 250), false);
@@ -593,7 +636,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(s.back()));
 	BOOST_CHECK_EQUAL (*dynamic_pointer_cast<const dcp::SubtitleString>(s.back()), dcp::SubtitleString (
@@ -615,7 +659,8 @@ BOOST_AUTO_TEST_CASE (read_interop_subtitle_test2)
 				   dcp::Effect::BORDER,
 				   dcp::Colour(0, 0, 0),
 				   dcp::Time(0, 0, 0, 0, 250),
-				   dcp::Time(0, 0, 0, 0, 250)
+				   dcp::Time(0, 0, 0, 0, 250),
+				   0
 				   ));
 }
 
@@ -659,7 +704,8 @@ BOOST_AUTO_TEST_CASE (write_interop_subtitle_test)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -679,11 +725,37 @@ BOOST_AUTO_TEST_CASE (write_interop_subtitle_test)
 			0.4,
 			dcp::VAlign::BOTTOM,
 			dcp::Direction::LTR,
-			"What's going on",
+			"What's going ",
+			dcp::Effect::BORDER,
+			dcp::Colour (1, 2, 3),
+			dcp::Time (1, 2, 3, 4, 24),
+			dcp::Time (5, 6, 7, 8, 24),
+			0
+			)
+		);
+
+	c.add (
+		make_shared<dcp::SubtitleString>(
+			boost::optional<string> (),
+			true,
+			true,
+			true,
+			dcp::Colour (128, 0, 64),
+			91,
+			1.0,
+			dcp::Time (5, 41,  0, 21, 24),
+			dcp::Time (6, 12, 15, 21, 24),
+			0,
+			dcp::HAlign::CENTER,
+			0.4,
+			dcp::VAlign::BOTTOM,
+			dcp::Direction::LTR,
+			"on",
 			dcp::Effect::BORDER,
 			dcp::Colour (1, 2, 3),
 			dcp::Time (1, 2, 3, 4, 24),
-			dcp::Time (5, 6, 7, 8, 24)
+			dcp::Time (5, 6, 7, 8, 24),
+			9
 			)
 		);
 
@@ -702,7 +774,7 @@ BOOST_AUTO_TEST_CASE (write_interop_subtitle_test)
 		  "</Font>"
 		  "<Font AspectAdjust=\"1.0\" Color=\"FF800040\" Effect=\"border\" EffectColor=\"FF010203\" Italic=\"yes\" Script=\"normal\" Size=\"91\" Underlined=\"yes\" Weight=\"bold\">"
 		    "<Subtitle SpotNumber=\"2\" TimeIn=\"05:41:00:219\" TimeOut=\"06:12:15:219\" FadeUpTime=\"930792\" FadeDownTime=\"4591834\">"
-		      "<Text VAlign=\"bottom\" VPosition=\"40\">What's going on</Text>"
+		      "<Text VAlign=\"bottom\" VPosition=\"40\">What's going <Space Size=\"9em\"/>on</Text>"
 		    "</Subtitle>"
 		  "</Font>"
 		"</DCSubtitle>",
@@ -741,7 +813,8 @@ BOOST_AUTO_TEST_CASE (write_interop_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -765,7 +838,8 @@ BOOST_AUTO_TEST_CASE (write_interop_subtitle_test2)
 			dcp::Effect::BORDER,
 			dcp::Colour (1, 2, 3),
 			dcp::Time (1, 2, 3, 4, 24),
-			dcp::Time (5, 6, 7, 8, 24)
+			dcp::Time (5, 6, 7, 8, 24),
+			0
 			)
 		);
 
diff --git a/test/shared_subtitle_test.cc b/test/shared_subtitle_test.cc
index 4172db4f..f18b03db 100644
--- a/test/shared_subtitle_test.cc
+++ b/test/shared_subtitle_test.cc
@@ -157,7 +157,7 @@ BOOST_AUTO_TEST_CASE (pull_fonts_test3)
 	dcp::order::Font font;
 	font._values["font"] = "Inconsolata";
 	font._values["size"] = "42";
-	auto string1 = make_shared<dcp::order::String>(text1, font, "Hello world");
+	auto string1 = make_shared<dcp::order::String>(text1, font, "Hello world", 0);
 	text1->children.push_back (string1);
 
 	dcp::SubtitleAsset::pull_fonts (root);
diff --git a/test/smpte_subtitle_test.cc b/test/smpte_subtitle_test.cc
index e93efefb..b1ad4058 100644
--- a/test/smpte_subtitle_test.cc
+++ b/test/smpte_subtitle_test.cc
@@ -71,7 +71,8 @@ BOOST_AUTO_TEST_CASE (smpte_subtitle_id_test)
 			dcp::Effect::NONE,
 			dcp::Colour(),
 			dcp::Time(0, 0, 0, 0, 24),
-			dcp::Time(0, 0, 0, 0, 24)
+			dcp::Time(0, 0, 0, 0, 24),
+			0
 			)
 		);
 	subs.write("build/test/smpte_subtitle_id_test.mxf");
@@ -112,16 +113,18 @@ BOOST_AUTO_TEST_CASE (read_smpte_subtitle_test)
 	BOOST_REQUIRE_EQUAL (sc.subtitles().size(), 63);
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(sc.subtitles().front()));
 	BOOST_CHECK_EQUAL (dynamic_pointer_cast<const dcp::SubtitleString>(sc.subtitles().front())->text(), "Noch mal.");
+	BOOST_CHECK_EQUAL (dynamic_pointer_cast<const dcp::SubtitleString>(sc.subtitles().front())->space_before(), 0.0f);
 	BOOST_CHECK_EQUAL (sc.subtitles().front()->in(), dcp::Time (0, 0, 25, 12, 25));
 	BOOST_CHECK_EQUAL (sc.subtitles().front()->out(), dcp::Time (0, 0, 26, 4, 25));
 	BOOST_REQUIRE (dynamic_pointer_cast<const dcp::SubtitleString>(sc.subtitles().back()));
 	BOOST_CHECK_EQUAL (dynamic_pointer_cast<const dcp::SubtitleString>(sc.subtitles().back())->text(), "Prochainement");
+	BOOST_CHECK_EQUAL (dynamic_pointer_cast<const dcp::SubtitleString>(sc.subtitles().back())->space_before(), 0.0f);
 	BOOST_CHECK_EQUAL (sc.subtitles().back()->in(), dcp::Time (0, 1, 57, 17, 25));
 	BOOST_CHECK_EQUAL (sc.subtitles().back()->out(), dcp::Time (0, 1, 58, 12, 25));
 }
 
 
-/** And another one featuring <Font> within <Text> */
+/** And another one featuring <Font> within <Text> and some <Space> */
 BOOST_AUTO_TEST_CASE (read_smpte_subtitle_test2)
 {
 	dcp::SMPTESubtitleAsset sc (private_test / "olsson.xml");
@@ -133,31 +136,37 @@ BOOST_AUTO_TEST_CASE (read_smpte_subtitle_test2)
 	BOOST_REQUIRE (is);
 	BOOST_CHECK_EQUAL (is->text(), "Testing is ");
 	BOOST_CHECK (!is->italic());
+	BOOST_CHECK_CLOSE (is->space_before(), 0, 0.1);
 	++i;
 	is = dynamic_pointer_cast<const dcp::SubtitleString>(subs[i]);
 	BOOST_REQUIRE (is);
 	BOOST_CHECK_EQUAL (is->text(), "really");
 	BOOST_CHECK (is->italic());
+	BOOST_CHECK_CLOSE (is->space_before(), 0, 0.1);
 	++i;
 	is = dynamic_pointer_cast<const dcp::SubtitleString>(subs[i]);
 	BOOST_REQUIRE (is);
 	BOOST_CHECK_EQUAL (is->text(), " fun!");
 	BOOST_CHECK (!is->italic());
+	BOOST_CHECK_CLOSE (is->space_before(), 5, 0.1);
 	++i;
 	is = dynamic_pointer_cast<const dcp::SubtitleString>(subs[i]);
 	BOOST_REQUIRE (is);
 	BOOST_CHECK_EQUAL (is->text(), "This is the ");
 	BOOST_CHECK (!is->italic());
+	BOOST_CHECK_CLOSE (is->space_before(), 0, 0.1);
 	++i;
 	is = dynamic_pointer_cast<const dcp::SubtitleString>(subs[i]);
 	BOOST_REQUIRE (is);
 	BOOST_CHECK_EQUAL (is->text(), "second");
 	BOOST_CHECK (is->italic());
+	BOOST_CHECK_CLOSE (is->space_before(), 0, 0.1);
 	++i;
 	is = dynamic_pointer_cast<const dcp::SubtitleString>(subs[i]);
 	BOOST_REQUIRE (is);
 	BOOST_CHECK_EQUAL (is->text(), " line!");
 	BOOST_CHECK (!is->italic());
+	BOOST_CHECK_CLOSE (is->space_before(), 0, 0.1);
 }
 
 
@@ -190,7 +199,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -210,11 +220,37 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test)
 			0.4,
 			dcp::VAlign::BOTTOM,
 			dcp::Direction::RTL,
-			"What's going on",
+			"What's going ",
 			dcp::Effect::BORDER,
 			dcp::Colour (1, 2, 3),
 			dcp::Time (1, 2, 3, 4, 24),
-			dcp::Time (5, 6, 7, 8, 24)
+			dcp::Time (5, 6, 7, 8, 24),
+			0
+			)
+		);
+
+	c.add (
+		make_shared<dcp::SubtitleString>(
+			boost::optional<string> (),
+			true,
+			true,
+			true,
+			dcp::Colour (128, 0, 64),
+			91,
+			1.0,
+			dcp::Time (5, 41,  0, 21, 24),
+			dcp::Time (6, 12, 15, 21, 24),
+			0,
+			dcp::HAlign::CENTER,
+			0.4,
+			dcp::VAlign::BOTTOM,
+			dcp::Direction::RTL,
+			"on",
+			dcp::Effect::BORDER,
+			dcp::Colour (1, 2, 3),
+			dcp::Time (1, 2, 3, 4, 24),
+			dcp::Time (5, 6, 7, 8, 24),
+			4.2
 			)
 		);
 
@@ -238,7 +274,7 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test)
 		    "</Font>"
 		    "<Font AspectAdjust=\"1.0\" Color=\"FF800040\" Effect=\"border\" EffectColor=\"FF010203\" Italic=\"yes\" Script=\"normal\" Size=\"91\" Underline=\"yes\" Weight=\"bold\">"
 		      "<Subtitle SpotNumber=\"2\" TimeIn=\"05:41:00:21\" TimeOut=\"06:12:15:21\" FadeUpTime=\"01:02:03:04\" FadeDownTime=\"05:06:07:08\">"
-		        "<Text Valign=\"bottom\" Vposition=\"40\" Direction=\"rtl\">What's going on</Text>"
+		        "<Text Valign=\"bottom\" Vposition=\"40\" Direction=\"rtl\">What's going <Space Size=\"4.2\"/>on</Text>"
 		      "</Subtitle>"
 		    "</Font>"
 		  "</SubtitleList>"
@@ -279,7 +315,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -303,7 +340,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -327,7 +365,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -351,7 +390,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -375,7 +415,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
@@ -399,7 +440,8 @@ BOOST_AUTO_TEST_CASE (write_smpte_subtitle_test2)
 			dcp::Effect::NONE,
 			dcp::Colour (0, 0, 0),
 			dcp::Time (0, 0, 0, 0, 24),
-			dcp::Time (0, 0, 0, 0, 24)
+			dcp::Time (0, 0, 0, 0, 24),
+			0
 			)
 		);
 
diff --git a/test/test.cc b/test/test.cc
index f946c5dc..a6472540 100644
--- a/test/test.cc
+++ b/test/test.cc
@@ -410,7 +410,8 @@ simple_subtitle ()
 		dcp::Effect::NONE,
 		dcp::Colour(255, 255, 255),
 		dcp::Time(),
-		dcp::Time()
+		dcp::Time(),
+		0
 		);
 }
 
diff --git a/test/verify_test.cc b/test/verify_test.cc
index 707eed21..b4db6c5c 100644
--- a/test/verify_test.cc
+++ b/test/verify_test.cc
@@ -1257,7 +1257,8 @@ add_test_subtitle (shared_ptr<dcp::SubtitleAsset> asset, int start_frame, int en
 			dcp::Effect::NONE,
 			dcp::Colour(),
 			dcp::Time(),
-			dcp::Time()
+			dcp::Time(),
+			0
 		)
 	);
 }