Cope with AVSubtitles having no AVSubtitleRects.

2 files changed, 8 insertions, 1 deletions

diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index 828934604..554188343 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -254,7 +254,12 @@ FFmpegDecoder::do_pass ()
 		int got_subtitle;
 		AVSubtitle sub;
 		if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) {
-			process_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
+			/* I'm not entirely sure why, but sometimes we get an AVSubtitle with
+			   no AVSubtitleRects.
+			*/
+			if (sub.num_rects > 0) {
+				process_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
+			}
 			avsubtitle_free (&sub);
 		}
 	}
diff --git a/src/lib/subtitle.cc b/src/lib/subtitle.cc
index 451d83691..f851d5643 100644
--- a/src/lib/subtitle.cc
+++ b/src/lib/subtitle.cc
@@ -35,6 +35,8 @@ using namespace boost;
  */
 TimedSubtitle::TimedSubtitle (AVSubtitle const & sub)
 {
+	assert (sub.rects > 0);
+	
 	/* subtitle PTS in seconds */
 	float const packet_time = (sub.pts / AV_TIME_BASE) + float (sub.pts % AV_TIME_BASE) / 1e6;