Make sure we round properly when deciding how many audio frames to discard.

3 files changed, 10 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 6e343d2f3..b5a6ba3d9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2015-09-29  Carl Hetherington  <cth@carlh.net>
+
+	* Improve fix for failure to analyse some audio.
+
 2015-09-28  Carl Hetherington  <cth@carlh.net>
 
 	* Version 2.3.9 released.
diff --git a/src/lib/dcpomatic_time.h b/src/lib/dcpomatic_time.h
index 7d755a46c..a5a0684e5 100644
--- a/src/lib/dcpomatic_time.h
+++ b/src/lib/dcpomatic_time.h
@@ -140,6 +140,11 @@ public:
 		return floor (_t * r / HZ);
 	}
 
+	template <typename T>
+	int64_t frames_ceil (T r) const {
+		return ceil (_t * r / HZ);
+	}
+
 	/** @param r Frames per second */
 	template <typename T>
 	void split (T r, int& h, int& m, int& s, int& f) const
diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 7923be59b..c23d56b42 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -337,7 +337,7 @@ FFmpegDecoder::decode_audio_packet ()
 
 			if (ct < ContentTime ()) {
 				/* Discard audio data that comes before time 0 */
-				Frame const remove = min (int64_t (data->frames()), -ct.frames_round ((*stream)->frame_rate ()));
+				Frame const remove = min (int64_t (data->frames()), (-ct).frames_ceil(double((*stream)->frame_rate ())));
 				data->move (remove, 0, data->frames() - remove);
 				data->set_frames (data->frames() - remove);
 				ct += ContentTime::from_frames (remove, (*stream)->frame_rate ());