Collect player subtitle processing into a Subtitle class.

1 files changed, 106 insertions, 0 deletions

diff --git a/src/lib/subtitle.cc b/src/lib/subtitle.cc
new file mode 100644
index 000000000..f348833b0
--- /dev/null
+++ b/src/lib/subtitle.cc
@@ -0,0 +1,106 @@
+/*
+    Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
+
+    This program 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.
+
+    This program 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 this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "subtitle.h"
+#include "subtitle_content.h"
+#include "piece.h"
+#include "image.h"
+#include "scaler.h"
+#include "film.h"
+
+using boost::shared_ptr;
+using boost::dynamic_pointer_cast;
+using boost::weak_ptr;
+
+Subtitle::Subtitle (shared_ptr<const Film> film, libdcp::Size video_container_size, weak_ptr<Piece> weak_piece, shared_ptr<Image> image, dcpomatic::Rect<double> rect, Time from, Time to)
+	: _piece (weak_piece)
+	, _in_image (image)
+	, _in_rect (rect)
+	, _in_from (from)
+	, _in_to (to)
+{
+	update (film, video_container_size);
+}
+
+void
+Subtitle::update (shared_ptr<const Film> film, libdcp::Size video_container_size)
+{
+	shared_ptr<Piece> piece = _piece.lock ();
+	if (!piece) {
+		return;
+	}
+
+	if (!_in_image) {
+		_out_image.reset ();
+		return;
+	}
+
+	shared_ptr<SubtitleContent> sc = dynamic_pointer_cast<SubtitleContent> (piece->content);
+	assert (sc);
+
+	dcpomatic::Rect<double> in_rect = _in_rect;
+	libdcp::Size scaled_size;
+
+	in_rect.x += sc->subtitle_x_offset ();
+	in_rect.y += sc->subtitle_y_offset ();
+
+	/* We will scale the subtitle up to fit _video_container_size, and also by the additional subtitle_scale */
+	scaled_size.width = in_rect.width * video_container_size.width * sc->subtitle_scale ();
+	scaled_size.height = in_rect.height * video_container_size.height * sc->subtitle_scale ();
+
+	/* Then we need a corrective translation, consisting of two parts:
+	 *
+	 * 1.  that which is the result of the scaling of the subtitle by _video_container_size; this will be
+	 *     rect.x * _video_container_size.width and rect.y * _video_container_size.height.
+	 *
+	 * 2.  that to shift the origin of the scale by subtitle_scale to the centre of the subtitle; this will be
+	 *     (width_before_subtitle_scale * (1 - subtitle_scale) / 2) and
+	 *     (height_before_subtitle_scale * (1 - subtitle_scale) / 2).
+	 *
+	 * Combining these two translations gives these expressions.
+	 */
+	
+	_out_position.x = rint (video_container_size.width * (in_rect.x + (in_rect.width * (1 - sc->subtitle_scale ()) / 2)));
+	_out_position.y = rint (video_container_size.height * (in_rect.y + (in_rect.height * (1 - sc->subtitle_scale ()) / 2)));
+	
+	_out_image = _in_image->scale (
+		scaled_size,
+		Scaler::from_id ("bicubic"),
+		_in_image->pixel_format (),
+		true
+		);
+
+	/* XXX: hack */
+	Time from = _in_from;
+	Time to = _in_to;
+	shared_ptr<VideoContent> vc = dynamic_pointer_cast<VideoContent> (piece->content);
+	if (vc) {
+		from = rint (from * vc->video_frame_rate() / film->video_frame_rate());
+		to = rint (to * vc->video_frame_rate() / film->video_frame_rate());
+	}
+	
+	_out_from = from + piece->content->position ();
+	_out_to = to + piece->content->position ();
+}
+
+bool
+Subtitle::covers (Time t) const
+{
+	return _out_from <= t && t <= _out_to;
+}