Subtitle "to" times used to be stored against their "from" times.

Sadly an example shows that from times are not unique.  This patch
uses a hash of stuff from the first AVSubtitle as the key.

9 files changed, 101 insertions, 43 deletions

diff --git a/src/lib/ffmpeg.cc b/src/lib/ffmpeg.cc
index 6103ccd50..df708d923 100644
--- a/src/lib/ffmpeg.cc
+++ b/src/lib/ffmpeg.cc
@@ -26,6 +26,7 @@
 #include "log.h"
 #include "ffmpeg_subtitle_stream.h"
 #include "ffmpeg_audio_stream.h"
+#include "md5_digester.h"
 #include "compose.hpp"
 extern "C" {
 #include <libavcodec/avcodec.h>
@@ -268,6 +269,27 @@ FFmpeg::subtitle_period (AVSubtitle const & sub)
 		);
 }
 
+string
+FFmpeg::subtitle_id (AVSubtitle const & sub)
+{
+	MD5Digester digester;
+	digester.add (sub.start_display_time);
+	digester.add (sub.end_display_time);
+	digester.add (sub.pts);
+	for (unsigned int i = 0; i < sub.num_rects; ++i) {
+		AVSubtitleRect* rect = sub.rects[i];
+		digester.add (rect->x);
+		digester.add (rect->y);
+		digester.add (rect->w);
+		digester.add (rect->h);
+		int const line = rect->pict.linesize[0];
+		for (int j = 0; j < rect->h; ++j) {
+			digester.add (rect->pict.data[0] + j * line, line);
+		}
+	}
+	return digester.get ();
+}
+
 /** Compute the pts offset to use given a set of audio streams and some video details.
  *  Sometimes these parameters will have just been determined by an Examiner, sometimes
  *  they will have been retrieved from a piece of Content, hence the need for this method
diff --git a/src/lib/ffmpeg.h b/src/lib/ffmpeg.h
index b3bc13e5c..0b195268a 100644
--- a/src/lib/ffmpeg.h
+++ b/src/lib/ffmpeg.h
@@ -56,7 +56,8 @@ protected:
 		std::vector<boost::shared_ptr<FFmpegAudioStream> > audio_streams, boost::optional<ContentTime> first_video, double video_frame_rate
 		) const;
 
-	static FFmpegSubtitlePeriod subtitle_period (AVSubtitle const &);
+	static FFmpegSubtitlePeriod subtitle_period (AVSubtitle const & sub);
+	static std::string subtitle_id (AVSubtitle const & sub);
 
 	boost::shared_ptr<const FFmpegContent> _ffmpeg_content;
 
diff --git a/src/lib/ffmpeg_content.cc b/src/lib/ffmpeg_content.cc
index a317ec35f..ba799be72 100644
--- a/src/lib/ffmpeg_content.cc
+++ b/src/lib/ffmpeg_content.cc
@@ -75,7 +75,7 @@ FFmpegContent::FFmpegContent (shared_ptr<const Film> film, cxml::ConstNodePtr no
 {
 	list<cxml::NodePtr> c = node->node_children ("SubtitleStream");
 	for (list<cxml::NodePtr>::const_iterator i = c.begin(); i != c.end(); ++i) {
-		_subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (*i)));
+		_subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (*i, version)));
 		if ((*i)->optional_number_child<int> ("Selected")) {
 			_subtitle_stream = _subtitle_streams.back ();
 		}
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index c393067ce..c25efa463 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2016 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
@@ -34,6 +34,7 @@
 #include "ffmpeg_content.h"
 #include "raw_image_proxy.h"
 #include "film.h"
+#include "md5_digester.h"
 #include "compose.hpp"
 extern "C" {
 #include <libavcodec/avcodec.h>
@@ -426,7 +427,7 @@ FFmpegDecoder::decode_subtitle_packet ()
 		period.to = sub_period.to.get() + _pts_offset;
 	} else {
 		/* We have to look up the `to' time in the stream's records */
-		period.to = ffmpeg_content()->subtitle_stream()->find_subtitle_to (period.from);
+		period.to = ffmpeg_content()->subtitle_stream()->find_subtitle_to (subtitle_id (sub));
 	}
 
 	for (unsigned int i = 0; i < sub.num_rects; ++i) {
diff --git a/src/lib/ffmpeg_examiner.cc b/src/lib/ffmpeg_examiner.cc
index 719e7a2b0..48738b917 100644
--- a/src/lib/ffmpeg_examiner.cc
+++ b/src/lib/ffmpeg_examiner.cc
@@ -142,11 +142,13 @@ FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c, shared_ptr<Jo
 		}
 	}
 
+	/* Finish off any hanging subtitles at the end */
 	for (LastSubtitleMap::const_iterator i = _last_subtitle_start.begin(); i != _last_subtitle_start.end(); ++i) {
 		if (i->second) {
 			i->first->add_subtitle (
+				i->second->id,
 				ContentTimePeriod (
-					i->second.get (),
+					i->second->time,
 					ContentTime::from_frames (video_length(), video_frame_rate().get_value_or (24))
 					)
 				);
@@ -203,24 +205,25 @@ FFmpegExaminer::subtitle_packet (AVCodecContext* context, shared_ptr<FFmpegSubti
 	int frame_finished;
 	AVSubtitle sub;
 	if (avcodec_decode_subtitle2 (context, &sub, &frame_finished, &_packet) >= 0 && frame_finished) {
+		string id = subtitle_id (sub);
 		FFmpegSubtitlePeriod const period = subtitle_period (sub);
 		LastSubtitleMap::iterator last = _last_subtitle_start.find (stream);
 		if (last != _last_subtitle_start.end() && last->second) {
 			/* We have seen the start of a subtitle but not yet the end.  Whatever this is
 			   finishes the previous subtitle, so add it */
-			stream->add_subtitle (ContentTimePeriod (last->second.get (), period.from));
+			stream->add_subtitle (last->second->id, ContentTimePeriod (last->second->time, period.from));
 			if (sub.num_rects == 0) {
 				/* This is a `proper' end-of-subtitle */
-				_last_subtitle_start[stream] = optional<ContentTime> ();
+				_last_subtitle_start[stream] = optional<SubtitleStart> ();
 			} else {
 				/* This is just another subtitle, so we start again */
-				_last_subtitle_start[stream] = period.from;
+				_last_subtitle_start[stream] = SubtitleStart (id, period.from);
 			}
 		} else if (sub.num_rects == 1) {
 			if (period.to) {
-				stream->add_subtitle (ContentTimePeriod (period.from, period.to.get ()));
+				stream->add_subtitle (id, ContentTimePeriod (period.from, period.to.get ()));
 			} else {
-				_last_subtitle_start[stream] = period.from;
+				_last_subtitle_start[stream] = SubtitleStart (id, period.from);
 			}
 		}
 		avsubtitle_free (&sub);
diff --git a/src/lib/ffmpeg_examiner.h b/src/lib/ffmpeg_examiner.h
index 6e2185129..e87e11d1c 100644
--- a/src/lib/ffmpeg_examiner.h
+++ b/src/lib/ffmpeg_examiner.h
@@ -86,6 +86,17 @@ private:
 	Frame _video_length;
 	bool _need_video_length;
 
-	typedef std::map<boost::shared_ptr<FFmpegSubtitleStream>, boost::optional<ContentTime> > LastSubtitleMap;
+	struct SubtitleStart
+	{
+		SubtitleStart (std::string id_, ContentTime time_)
+			: id (id_)
+			, time (time_)
+		{}
+
+		std::string id;
+		ContentTime time;
+	};
+
+	typedef std::map<boost::shared_ptr<FFmpegSubtitleStream>, boost::optional<SubtitleStart> > LastSubtitleMap;
 	LastSubtitleMap _last_subtitle_start;
 };
diff --git a/src/lib/ffmpeg_subtitle_stream.cc b/src/lib/ffmpeg_subtitle_stream.cc
index e12075581..466032b37 100644
--- a/src/lib/ffmpeg_subtitle_stream.cc
+++ b/src/lib/ffmpeg_subtitle_stream.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2016 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
@@ -32,16 +32,33 @@ using std::cout;
  *  @param t String returned from to_string().
  *  @param v State file version.
  */
-FFmpegSubtitleStream::FFmpegSubtitleStream (cxml::ConstNodePtr node)
+FFmpegSubtitleStream::FFmpegSubtitleStream (cxml::ConstNodePtr node, int version)
 	: FFmpegStream (node)
 {
-	BOOST_FOREACH (cxml::NodePtr i, node->node_children ("Period")) {
-		add_subtitle (
-			ContentTimePeriod (
-				ContentTime (i->number_child<ContentTime::Type> ("From")),
-				ContentTime (i->number_child<ContentTime::Type> ("To"))
-				)
-			);
+	if (version == 32) {
+		BOOST_FOREACH (cxml::NodePtr i, node->node_children ("Period")) {
+			/* In version 32 we assumed that from times were unique, so they weer
+			   used as identifiers.
+			*/
+			add_subtitle (
+				raw_convert<string> (i->string_child ("From")),
+				ContentTimePeriod (
+					ContentTime (i->number_child<ContentTime::Type> ("From")),
+					ContentTime (i->number_child<ContentTime::Type> ("To"))
+					)
+				);
+		}
+	} else {
+		/* In version 33 we use a hash of various parts of the subtitle as the id */
+		BOOST_FOREACH (cxml::NodePtr i, node->node_children ("Subtitle")) {
+			add_subtitle (
+				raw_convert<string> (i->string_child ("Id")),
+				ContentTimePeriod (
+					ContentTime (i->number_child<ContentTime::Type> ("From")),
+					ContentTime (i->number_child<ContentTime::Type> ("To"))
+					)
+				);
+		}
 	}
 }
 
@@ -50,18 +67,19 @@ FFmpegSubtitleStream::as_xml (xmlpp::Node* root) const
 {
 	FFmpegStream::as_xml (root);
 
-	for (map<ContentTime, ContentTime>::const_iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
-		xmlpp::Node* node = root->add_child ("Period");
-		node->add_child("From")->add_child_text (raw_convert<string> (i->first.get ()));
-		node->add_child("To")->add_child_text (raw_convert<string> (i->second.get ()));
+	for (map<string, ContentTimePeriod>::const_iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
+		xmlpp::Node* node = root->add_child ("Subtitle");
+		node->add_child("Id")->add_child_text (i->first);
+		node->add_child("From")->add_child_text (raw_convert<string> (i->second.from.get ()));
+		node->add_child("To")->add_child_text (raw_convert<string> (i->second.to.get ()));
 	}
 }
 
 void
-FFmpegSubtitleStream::add_subtitle (ContentTimePeriod period)
+FFmpegSubtitleStream::add_subtitle (string id, ContentTimePeriod period)
 {
-	DCPOMATIC_ASSERT (_subtitles.find (period.from) == _subtitles.end ());
-	_subtitles[period.from] = period.to;
+	DCPOMATIC_ASSERT (_subtitles.find (id) == _subtitles.end ());
+	_subtitles[id] = period;
 }
 
 list<ContentTimePeriod>
@@ -70,9 +88,9 @@ FFmpegSubtitleStream::subtitles_during (ContentTimePeriod period, bool starting)
 	list<ContentTimePeriod> d;
 
 	/* XXX: inefficient */
-	for (map<ContentTime, ContentTime>::const_iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
-		if ((starting && period.contains (i->first)) || (!starting && period.overlaps (ContentTimePeriod (i->first, i->second)))) {
-			d.push_back (ContentTimePeriod (i->first, i->second));
+	for (map<string, ContentTimePeriod>::const_iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
+		if ((starting && period.contains (i->second.from)) || (!starting && period.overlaps (i->second))) {
+			d.push_back (i->second);
 		}
 	}
 
@@ -80,20 +98,19 @@ FFmpegSubtitleStream::subtitles_during (ContentTimePeriod period, bool starting)
 }
 
 ContentTime
-FFmpegSubtitleStream::find_subtitle_to (ContentTime from) const
+FFmpegSubtitleStream::find_subtitle_to (string id) const
 {
-	map<ContentTime, ContentTime>::const_iterator i = _subtitles.find (from);
+	map<string, ContentTimePeriod>::const_iterator i = _subtitles.find (id);
 	DCPOMATIC_ASSERT (i != _subtitles.end ());
-	return i->second;
+	return i->second.to;
 }
 
 /** Add some offset to all the times in the stream */
 void
 FFmpegSubtitleStream::add_offset (ContentTime offset)
 {
-	map<ContentTime, ContentTime> fixed;
-	for (map<ContentTime, ContentTime>::iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
-		fixed[i->first + offset] = i->second + offset;
+	for (map<string, ContentTimePeriod>::iterator i = _subtitles.begin(); i != _subtitles.end(); ++i) {
+		i->second.from += offset;
+		i->second.to += offset;
 	}
-	_subtitles = fixed;
 }
diff --git a/src/lib/ffmpeg_subtitle_stream.h b/src/lib/ffmpeg_subtitle_stream.h
index 0809b359a..6cd5318d0 100644
--- a/src/lib/ffmpeg_subtitle_stream.h
+++ b/src/lib/ffmpeg_subtitle_stream.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2016 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
@@ -27,15 +27,15 @@ public:
 		: FFmpegStream (n, i)
 	{}
 
-	FFmpegSubtitleStream (cxml::ConstNodePtr);
+	FFmpegSubtitleStream (cxml::ConstNodePtr, int version);
 
 	void as_xml (xmlpp::Node *) const;
 
-	void add_subtitle (ContentTimePeriod period);
+	void add_subtitle (std::string id, ContentTimePeriod period);
 	std::list<ContentTimePeriod> subtitles_during (ContentTimePeriod period, bool starting) const;
-	ContentTime find_subtitle_to (ContentTime from) const;
+	ContentTime find_subtitle_to (std::string id) const;
 	void add_offset (ContentTime offset);
 
 private:
-	std::map<ContentTime, ContentTime> _subtitles;
+	std::map<std::string, ContentTimePeriod> _subtitles;
 };
diff --git a/src/lib/film.cc b/src/lib/film.cc
index 20b959dd0..9320cf5d2 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -103,8 +103,11 @@ using boost::is_any_of;
  *
  * Bumped to 32 for 2.0 branch; some times are expressed in Times rather
  * than frames now.
+ *
+ * 32 -> 33
+ * Changed <Period> to <Subtitle> in FFmpegSubtitleStream
  */
-int const Film::current_state_version = 32;
+int const Film::current_state_version = 33;
 
 /** Construct a Film object in a given directory.
  *