From 29790c6d88d028db7874e98f92ec5ec23a3310c8 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Sun, 6 Jan 2013 23:43:40 +0000
Subject: [PATCH] Try to postpone linking of duplicate video frames to stop
 copies failing on Windows.

---
 src/lib/encoder.cc | 15 ++++++++++++---
 src/lib/encoder.h  |  8 +++++++-
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/lib/encoder.cc b/src/lib/encoder.cc
index 6e1209d83..693bd5bc8 100644
--- a/src/lib/encoder.cc
+++ b/src/lib/encoder.cc
@@ -42,6 +42,7 @@ using std::stringstream;
 using std::vector;
 using std::list;
 using std::cout;
+using std::make_pair;
 using namespace boost;
 
 int const Encoder::_history_size = 25;
@@ -207,6 +208,12 @@ Encoder::process_end ()
 			_film->log()->log (String::compose ("Local encode failed (%1)", e.what ()));
 		}
 	}
+
+	/* Now do links (or copies on windows) to duplicate frames */
+	for (list<pair<int, int> >::iterator i = _links_required.begin(); i != _links_required.end(); ++i) {
+		link (_opt->frame_out_path (i->first, false), _opt->frame_out_path (i->second, false));
+		link (_opt->hash_out_path (i->first, false), _opt->hash_out_path (i->second, false));
+	}
 }	
 
 /** @return an estimate of the current number of frames we are encoding per second,
@@ -305,9 +312,11 @@ Encoder::process_video (shared_ptr<Image> image, bool same, boost::shared_ptr<Su
 	}
 
 	if (same && _last_real_frame) {
-		/* Use the last frame that we encoded */
-		link (_opt->frame_out_path (_last_real_frame.get(), false), _opt->frame_out_path (_video_frame, false));
-		link (_opt->hash_out_path (_last_real_frame.get(), false), _opt->hash_out_path (_video_frame, false));
+		/* Use the last frame that we encoded.  We need to postpone doing the actual link,
+		   as on windows the link is really a copy and the reference frame might not have
+		   finished encoding yet.
+		*/
+		_links_required.push_back (make_pair (_last_real_frame.get(), _video_frame));
 	} else {
 		/* Queue this new frame for encoding */
 		pair<string, string> const s = Filter::ffmpeg_strings (_film->filters());
diff --git a/src/lib/encoder.h b/src/lib/encoder.h
index e5916ad3a..52ccfc166 100644
--- a/src/lib/encoder.h
+++ b/src/lib/encoder.h
@@ -121,7 +121,13 @@ private:
 
 #if HAVE_SWRESAMPLE	
 	SwrContext* _swr_context;
-#endif	
+#endif
+
+	/** List of links that we need to create when all frames have been processed;
+	 *  such that we need to call link (first, second) for each member of this list.
+	 *  In other words, `first' is a `real' frame and `second' should be a link to `first'.
+	 */
+	std::list<std::pair<int, int> > _links_required;
 
 	std::vector<SNDFILE*> _sound_files;
 	int64_t _audio_frames_written;
-- 
2.30.2