From bf494092b03f107e35ab6ad70be324f23a193c2b Mon Sep 17 00:00:00 2001
From: Neil Brown <neilb@suse.de>
Date: Sat, 18 Aug 2007 00:45:44 +0000
Subject: [PATCH] There is no guarantee that every stream will have a
 start_time found (though it is likely), so check that the start_time is
 defined before calculating a duration.  (patch by neilb suse de)

Originally committed as revision 10138 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/utils.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 9663a99f88..0eba3e619c 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1551,7 +1551,8 @@ static void av_estimate_timings_from_pts(AVFormatContext *ic, offset_t old_offse
             break;
         read_size += pkt->size;
         st = ic->streams[pkt->stream_index];
-        if (pkt->pts != AV_NOPTS_VALUE) {
+        if (pkt->pts != AV_NOPTS_VALUE &&
+            st->start_time != AV_NOPTS_VALUE) {
             end_time = pkt->pts;
             duration = end_time - st->start_time;
             if (duration > 0) {