Support PNG subs in DCPSubtitleDecoder (#1479).

4 files changed, 66 insertions, 37 deletions

diff --git a/src/lib/dcp_decoder.cc b/src/lib/dcp_decoder.cc
index 1098bb87a..85dd28006 100644
--- a/src/lib/dcp_decoder.cc
+++ b/src/lib/dcp_decoder.cc
@@ -259,45 +259,20 @@ DCPDecoder::pass_texts (
 				strings.push_back (*is);
 			}
 
+			/* XXX: perhaps these image subs should also be collected together like the string ones are;
+			   this would need to be done both here and in DCPSubtitleDecoder.
+			*/
+
 			shared_ptr<dcp::SubtitleImage> ii = dynamic_pointer_cast<dcp::SubtitleImage> (i);
 			if (ii) {
-				FFmpegImageProxy proxy (ii->png_image());
-				shared_ptr<Image> image = proxy.image().first;
-				/* set up rect with height and width */
-				dcpomatic::Rect<double> rect(0, 0, image->size().width / double(size.width), image->size().height / double(size.height));
-
-				/* add in position */
-
-				switch (ii->h_align()) {
-				case dcp::HALIGN_LEFT:
-					rect.x += ii->h_position();
-					break;
-				case dcp::HALIGN_CENTER:
-					rect.x += 0.5 + ii->h_position() - rect.width / 2;
-					break;
-				case dcp::HALIGN_RIGHT:
-					rect.x += 1 - ii->h_position() - rect.width;
-					break;
-				}
-
-				switch (ii->v_align()) {
-				case dcp::VALIGN_TOP:
-					rect.y += ii->v_position();
-					break;
-				case dcp::VALIGN_CENTER:
-					rect.y += 0.5 + ii->v_position() - rect.height / 2;
-					break;
-				case dcp::VALIGN_BOTTOM:
-					rect.y += 1 - ii->v_position() - rect.height;
-					break;
-				}
-
-				decoder->emit_bitmap (
+				emit_subtitle_image (
 					ContentTimePeriod (
 						ContentTime::from_frames (_offset - entry_point, vfr) + ContentTime::from_seconds (i->in().as_seconds ()),
 						ContentTime::from_frames (_offset - entry_point, vfr) + ContentTime::from_seconds (i->out().as_seconds ())
 						),
-					image, rect
+					*ii,
+					size,
+					decoder
 					);
 			}
 		}
diff --git a/src/lib/dcp_subtitle_decoder.cc b/src/lib/dcp_subtitle_decoder.cc
index 6c95b8b1f..5d5e1f631 100644
--- a/src/lib/dcp_subtitle_decoder.cc
+++ b/src/lib/dcp_subtitle_decoder.cc
@@ -64,12 +64,13 @@ DCPSubtitleDecoder::pass ()
 
 	/* Gather all subtitles with the same time period that are next
 	   on the list.  We must emit all subtitles for the same time
-	   period with the same plain_text() call otherwise the
+	   period with the same emit*() call otherwise the
 	   TextDecoder will assume there is nothing else at the
-	   time of emit the first.
+	   time of emitting the first.
 	*/
 
 	list<dcp::SubtitleString> s;
+	list<dcp::SubtitleImage> i;
 	ContentTimePeriod const p = content_time_period (*_next);
 
 	while (_next != _subtitles.end () && content_time_period (*_next) == p) {
@@ -79,7 +80,15 @@ DCPSubtitleDecoder::pass ()
 			++_next;
 		}
 
-		/* XXX: image subtitles */
+		/* XXX: perhaps these image subs should also be collected together like the string ones are;
+		   this would need to be done both here and in DCPDecoder.
+		*/
+
+		shared_ptr<dcp::SubtitleImage> ni = dynamic_pointer_cast<dcp::SubtitleImage>(*_next);
+		if (ni) {
+			emit_subtitle_image (p, *ni, film()->frame_size(), only_text());
+			++_next;
+		}
 	}
 
 	only_text()->emit_plain (p, s);
diff --git a/src/lib/util.cc b/src/lib/util.cc
index 0b6f4be72..b52655194 100644
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2019 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -41,6 +41,9 @@
 #include "string_text.h"
 #include "font.h"
 #include "render_text.h"
+#include "ffmpeg_image_proxy.h"
+#include "image.h"
+#include "text_decoder.h"
 #include <dcp/locale_convert.h>
 #include <dcp/util.h>
 #include <dcp/raw_convert.h>
@@ -881,6 +884,45 @@ day_of_week_to_string (boost::gregorian::greg_weekday d)
 	return d.as_long_string ();
 }
 
+/** @param size Size of picture that the subtitle will be overlaid onto */
+void
+emit_subtitle_image (ContentTimePeriod period, dcp::SubtitleImage sub, dcp::Size size, shared_ptr<TextDecoder> decoder)
+{
+	/* XXX: this is rather inefficient; decoding the image just to get its size */
+	FFmpegImageProxy proxy (sub.png_image());
+	shared_ptr<Image> image = proxy.image().first;
+	/* set up rect with height and width */
+	dcpomatic::Rect<double> rect(0, 0, image->size().width / double(size.width), image->size().height / double(size.height));
+
+	/* add in position */
+
+	switch (sub.h_align()) {
+	case dcp::HALIGN_LEFT:
+		rect.x += sub.h_position();
+		break;
+	case dcp::HALIGN_CENTER:
+		rect.x += 0.5 + sub.h_position() - rect.width / 2;
+		break;
+	case dcp::HALIGN_RIGHT:
+		rect.x += 1 - sub.h_position() - rect.width;
+		break;
+	}
+
+	switch (sub.v_align()) {
+	case dcp::VALIGN_TOP:
+		rect.y += sub.v_position();
+		break;
+	case dcp::VALIGN_CENTER:
+		rect.y += 0.5 + sub.v_position() - rect.height / 2;
+		break;
+	case dcp::VALIGN_BOTTOM:
+		rect.y += 1 - sub.v_position() - rect.height;
+		break;
+	}
+
+	decoder->emit_bitmap (period, image, rect);
+}
+
 #ifdef DCPOMATIC_VARIANT_SWAROOP
 
 /* Make up a key from the machine UUID */
diff --git a/src/lib/util.h b/src/lib/util.h
index 86be99648..5ffdae450 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -29,6 +29,7 @@
 #include "dcpomatic_time.h"
 #include "audio_mapping.h"
 #include <dcp/util.h>
+#include <dcp/subtitle_image.h>
 #include <boost/shared_ptr.hpp>
 #include <boost/optional.hpp>
 #include <boost/filesystem.hpp>
@@ -68,6 +69,7 @@ extern bool is_batch_converter;
 
 struct AVSubtitle;
 class AudioBuffers;
+class TextDecoder;
 
 extern std::string seconds_to_hms (int);
 extern std::string time_to_hmsf (DCPTime time, Frame rate);
@@ -103,6 +105,7 @@ extern void checked_fread (void* ptr, size_t size, FILE* stream, boost::filesyst
 extern void checked_fwrite (void const * ptr, size_t size, FILE* stream, boost::filesystem::path path);
 extern size_t utf8_strlen (std::string s);
 extern std::string day_of_week_to_string (boost::gregorian::greg_weekday d);
+extern void emit_subtitle_image (ContentTimePeriod period, dcp::SubtitleImage sub, dcp::Size size, boost::shared_ptr<TextDecoder> decoder);
 #ifdef DCPOMATIC_VARIANT_SWAROOP
 extern boost::shared_ptr<dcp::CertificateChain> read_swaroop_chain (boost::filesystem::path path);
 extern void write_swaroop_chain (boost::shared_ptr<const dcp::CertificateChain> chain, boost::filesystem::path output);