Revert "Write one TTI block per subtitle line for binary STL."

It's wrong as where multiple TTI blocks are used only the first
block of the subtitle carries relevant information for time in/out,
position, justification and comment.

This reverts commit c18e3a2e54f992245feeac384a41792b82f698aa.

1 files changed, 86 insertions, 64 deletions

diff --git a/src/stl_binary_writer.cc b/src/stl_binary_writer.cc
index 9931985..baed8d8 100644
--- a/src/stl_binary_writer.cc
+++ b/src/stl_binary_writer.cc
@@ -170,9 +170,10 @@ sub::write_stl_binary (
 	ofstream output (file_name.string().c_str ());
 	STLBinaryTables tables;
 
-	/* Find the longest subtitle in characters and count the number of lines we have */
+	/* Find the longest subtitle in characters */
+
 	int longest = 0;
-	int lines = 0;
+
 	BOOST_FOREACH (Subtitle const& i, subtitles) {
 		BOOST_FOREACH (Line const& j, i.lines) {
 			int t = 0;
@@ -180,7 +181,6 @@ sub::write_stl_binary (
 				t += k.text.size ();
 			}
 			longest = std::max (longest, t);
-			++lines;
 		}
 	}
 
@@ -205,7 +205,7 @@ sub::write_stl_binary (
 	put_string (buffer + 230, revision_date);
 	put_int_as_string (buffer + 236, revision_number, 2);
 	/* TTI blocks */
-	put_int_as_string (buffer + 238, lines, 5);
+	put_int_as_string (buffer + 238, subtitles.size(), 5);
 	/* Total number of subtitles */
 	put_int_as_string (buffer + 243, subtitles.size(), 5);
 	/* Total number of subtitle groups */
@@ -233,53 +233,76 @@ sub::write_stl_binary (
 
 	BOOST_FOREACH (Subtitle const& i, subtitles) {
 
-		size_t line = 0;
+		/* Find the top vertical position of this subtitle */
+		optional<int> top;
 		BOOST_FOREACH (Line const& j, i.lines) {
-
-			memset (buffer, 0, 128);
-
-			/* XXX: these should increment, surely! */
-			/* Subtitle group number */
-			put_int_as_int (buffer + 0, 1, 1);
-			/* Subtitle number */
-			put_int_as_int (buffer + 1, 0, 2);
-			/* Extension block number.  These are indexed from zero except the last one is 255 */
-			put_int_as_int (buffer + 3, line == (i.lines.size() - 1) ? 255 : line, 1);
-			/* Cumulative status */
-			put_int_as_int (buffer + 4, tables.cumulative_status_enum_to_file (CUMULATIVE_STATUS_NOT_CUMULATIVE), 1);
-			/* Time code in */
-			put_int_as_int (buffer + 5, i.from.hours(), 1);
-			put_int_as_int (buffer + 6, i.from.minutes(), 1);
-			put_int_as_int (buffer + 7, i.from.seconds(), 1);
-			put_int_as_int (buffer + 8, i.from.frames_at(sub::Rational(frames_per_second * 1000, 1000)), 1);
-			/* Time code out */
-			put_int_as_int (buffer + 9, i.to.hours(), 1);
-			put_int_as_int (buffer + 10, i.to.minutes(), 1);
-			put_int_as_int (buffer + 11, i.to.seconds(), 1);
-			put_int_as_int (buffer + 12, i.to.frames_at(sub::Rational(frames_per_second * 1000, 1000)), 1);
-			/* Vertical position */
-			put_int_as_int (buffer + 13, vertical_position(j), 1);
-
-			/* Justification code */
-			switch (j.horizontal_position.reference) {
-			case LEFT_OF_SCREEN:
-				put_int_as_int (buffer + 14, tables.justification_enum_to_file (JUSTIFICATION_LEFT), 1);
-				break;
-			case HORIZONTAL_CENTRE_OF_SCREEN:
-				put_int_as_int (buffer + 14, tables.justification_enum_to_file (JUSTIFICATION_CENTRE), 1);
-				break;
-			case RIGHT_OF_SCREEN:
-				put_int_as_int (buffer + 14, tables.justification_enum_to_file (JUSTIFICATION_RIGHT), 1);
-				break;
+			int const vp = vertical_position (j);
+			if (!top || vp < top.get ()) {
+				top = vp;
 			}
+		}
+
+		memset (buffer, 0, 128);
+
+		/* XXX: these should increment, surely! */
+		/* Subtitle group number */
+		put_int_as_int (buffer + 0, 1, 1);
+		/* Subtitle number */
+		put_int_as_int (buffer + 1, 0, 2);
+		/* Extension block number.  Use 0xff here to indicate that it is the last TTI
+		   block in this subtitle "set", as we only ever use one.
+		*/
+		put_int_as_int (buffer + 3, 255, 1);
+		/* Cumulative status */
+		put_int_as_int (buffer + 4, tables.cumulative_status_enum_to_file (CUMULATIVE_STATUS_NOT_CUMULATIVE), 1);
+		/* Time code in */
+		put_int_as_int (buffer + 5, i.from.hours(), 1);
+		put_int_as_int (buffer + 6, i.from.minutes(), 1);
+		put_int_as_int (buffer + 7, i.from.seconds(), 1);
+		put_int_as_int (buffer + 8, i.from.frames_at(sub::Rational(frames_per_second * 1000, 1000)), 1);
+		/* Time code out */
+		put_int_as_int (buffer + 9, i.to.hours(), 1);
+		put_int_as_int (buffer + 10, i.to.minutes(), 1);
+		put_int_as_int (buffer + 11, i.to.seconds(), 1);
+		put_int_as_int (buffer + 12, i.to.frames_at(sub::Rational(frames_per_second * 1000, 1000)), 1);
+		/* Vertical position */
+		put_int_as_int (buffer + 13, top.get(), 1);
+
+		/* Justification code */
+		/* XXX: this assumes the first line has the right value */
+		switch (i.lines.front().horizontal_position.reference) {
+		case LEFT_OF_SCREEN:
+			put_int_as_int (buffer + 14, tables.justification_enum_to_file (JUSTIFICATION_LEFT), 1);
+			break;
+		case HORIZONTAL_CENTRE_OF_SCREEN:
+			put_int_as_int (buffer + 14, tables.justification_enum_to_file (JUSTIFICATION_CENTRE), 1);
+			break;
+		case RIGHT_OF_SCREEN:
+			put_int_as_int (buffer + 14, tables.justification_enum_to_file (JUSTIFICATION_RIGHT), 1);
+			break;
+		}
+
+		/* Comment flag */
+		put_int_as_int (buffer + 15, tables.comment_enum_to_file (COMMENT_NO), 1);
+
+		/* Text */
+		string text;
+		bool italic = false;
+		bool underline = false;
+		optional<int> last_vp;
+
+		BOOST_FOREACH (Line const& j, i.lines) {
 
-			/* Comment flag */
-			put_int_as_int (buffer + 15, tables.comment_enum_to_file (COMMENT_NO), 1);
+			/* CR/LF down to this line */
+			int const vp = vertical_position (j);
 
-			/* Text */
-			string text;
-			bool italic = false;
-			bool underline = false;
+			if (last_vp) {
+				for (int k = last_vp.get(); k < vp; ++k) {
+					text += "\x8A";
+				}
+			}
+
+			last_vp = vp;
 
 			BOOST_FOREACH (Block const& k, j.blocks) {
 				if (k.underline && !underline) {
@@ -299,29 +322,28 @@ sub::write_stl_binary (
 
 				text += utf16_to_iso6937 (utf_to_utf<wchar_t> (k.text));
 			}
+		}
 
-			/* Turn italic/underline off before the end of this subtitle */
-
-			if (underline) {
-				text += "\x83";
-			}
+		/* Turn italic/underline off before the end of this subtitle */
 
-			if (italic) {
-				text += "\x81";
-			}
+		if (underline) {
+			text += "\x83";
+		}
 
-			if (text.length() > 111) {
-				text = text.substr (111);
-			}
+		if (italic) {
+			text += "\x81";
+		}
 
-			while (text.length() < 112) {
-				text += "\x8F";
-			}
+		if (text.length() > 111) {
+			text = text.substr (111);
+		}
 
-			put_string (buffer + 16, text);
-			output.write (buffer, 128);
-			++line;
+		while (text.length() < 112) {
+			text += "\x8F";
 		}
+
+		put_string (buffer + 16, text);
+		output.write (buffer, 128);
 	}
 
 	delete[] buffer;