From 6a68937320fa76ce213c648845abc73983fc1849 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Wed, 13 Dec 2017 22:04:49 +0000
Subject: [PATCH] Setup SubtitleDecoder::_position correctly (in some cases).

---
 src/lib/dcp_decoder.cc           | 3 ++-
 src/lib/dcp_subtitle_decoder.cc  | 8 ++++++--
 src/lib/ffmpeg_decoder.cc        | 3 ++-
 src/lib/subtitle_decoder.cc      | 4 +++-
 src/lib/subtitle_decoder.h       | 7 ++-----
 src/lib/text_subtitle_decoder.cc | 6 +++++-
 6 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/src/lib/dcp_decoder.cc b/src/lib/dcp_decoder.cc
index 44053c5df..1a4896fe7 100644
--- a/src/lib/dcp_decoder.cc
+++ b/src/lib/dcp_decoder.cc
@@ -59,7 +59,8 @@ DCPDecoder::DCPDecoder (shared_ptr<const DCPContent> c, shared_ptr<Log> log, boo
 		audio.reset (new AudioDecoder (this, c->audio, log, fast));
 	}
 	if (c->subtitle) {
-		subtitle.reset (new SubtitleDecoder (this, c->subtitle, log));
+		/* XXX: this time here should be the time of the first subtitle, not 0 */
+		subtitle.reset (new SubtitleDecoder (this, c->subtitle, log, ContentTime()));
 	}
 
 	shared_ptr<dcp::CPL> cpl;
diff --git a/src/lib/dcp_subtitle_decoder.cc b/src/lib/dcp_subtitle_decoder.cc
index 04b264192..965f9db61 100644
--- a/src/lib/dcp_subtitle_decoder.cc
+++ b/src/lib/dcp_subtitle_decoder.cc
@@ -30,11 +30,15 @@ using boost::bind;
 
 DCPSubtitleDecoder::DCPSubtitleDecoder (shared_ptr<const DCPSubtitleContent> content, shared_ptr<Log> log)
 {
-	subtitle.reset (new SubtitleDecoder (this, content->subtitle, log));
-
 	shared_ptr<dcp::SubtitleAsset> c (load (content->path (0)));
 	_subtitles = c->subtitles ();
 	_next = _subtitles.begin ();
+
+	ContentTime first;
+	if (_next != _subtitles.end()) {
+		first = content_time_period(*_next).from;
+	}
+	subtitle.reset (new SubtitleDecoder (this, content->subtitle, log, first));
 }
 
 void
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 378b59901..0d6ac383f 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -98,7 +98,8 @@ FFmpegDecoder::FFmpegDecoder (shared_ptr<const FFmpegContent> c, shared_ptr<Log>
 	}
 
 	if (c->subtitle) {
-		subtitle.reset (new SubtitleDecoder (this, c->subtitle, log));
+		/* XXX: this time here should be the time of the first subtitle, not 0 */
+		subtitle.reset (new SubtitleDecoder (this, c->subtitle, log, ContentTime()));
 	}
 
 	_next_time.resize (_format_context->nb_streams);
diff --git a/src/lib/subtitle_decoder.cc b/src/lib/subtitle_decoder.cc
index 802c9ef84..5838d167b 100644
--- a/src/lib/subtitle_decoder.cc
+++ b/src/lib/subtitle_decoder.cc
@@ -40,10 +40,12 @@ using boost::function;
 SubtitleDecoder::SubtitleDecoder (
 	Decoder* parent,
 	shared_ptr<const SubtitleContent> c,
-	shared_ptr<Log> log
+	shared_ptr<Log> log,
+	ContentTime first
 	)
 	: DecoderPart (parent, log)
 	, _content (c)
+	, _position (first)
 {
 
 }
diff --git a/src/lib/subtitle_decoder.h b/src/lib/subtitle_decoder.h
index 9740b06e8..c1f171b1f 100644
--- a/src/lib/subtitle_decoder.h
+++ b/src/lib/subtitle_decoder.h
@@ -38,14 +38,11 @@ class Image;
 class SubtitleDecoder : public DecoderPart
 {
 public:
-	/** Second parameter to the _during functions is true if we
-	 *  want only subtitles that start during the period,
-	 *  otherwise we want subtitles that overlap the period.
-	 */
 	SubtitleDecoder (
 		Decoder* parent,
 		boost::shared_ptr<const SubtitleContent>,
-		boost::shared_ptr<Log> log
+		boost::shared_ptr<Log> log,
+		ContentTime first
 		);
 
 	ContentTime position () const {
diff --git a/src/lib/text_subtitle_decoder.cc b/src/lib/text_subtitle_decoder.cc
index 846c3016e..6188d524f 100644
--- a/src/lib/text_subtitle_decoder.cc
+++ b/src/lib/text_subtitle_decoder.cc
@@ -38,7 +38,11 @@ TextSubtitleDecoder::TextSubtitleDecoder (shared_ptr<const TextSubtitleContent>
 	: TextSubtitle (content)
 	, _next (0)
 {
-	subtitle.reset (new SubtitleDecoder (this, content->subtitle, log));
+	ContentTime first;
+	if (!_subtitles.empty()) {
+		first = content_time_period(_subtitles[0]).from;
+	}
+	subtitle.reset (new SubtitleDecoder (this, content->subtitle, log, first));
 }
 
 void
-- 
2.30.2