[FFmpeg-cvslog] ff_read_timestamp: check stream_index before using it as array index

[Michael Niedermayer]

ffmpeg | branch: release/1.1 | Michael Niedermayer <michaelni at gmx.at> | Mon Feb 18 19:48:44 2013 +0100| [2416eff5b9275e2e6e110f3ddbe7784586e4cd4f] | committer: Carl Eugen Hoyos

ff_read_timestamp: check stream_index before using it as array index

Fixes out of array read

Fixes ticket #2609.

Found-by: durandal_1707
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit 695a766bff4cd8414a84e58159506d72b4e44892)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2416eff5b9275e2e6e110f3ddbe7784586e4cd4f
---

 libavformat/utils.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index e85fa65..fc374f0 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1765,7 +1765,10 @@ int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp,
 static int64_t ff_read_timestamp(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit,
                                  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ))
 {
-    return wrap_timestamp(s->streams[stream_index], read_timestamp(s, stream_index, ppos, pos_limit));
+    int64_t ts = read_timestamp(s, stream_index, ppos, pos_limit);
+    if (stream_index >= 0)
+        ts = wrap_timestamp(s->streams[stream_index], ts);
+    return ts;
 }
 
 int ff_seek_frame_binary(AVFormatContext *s, int stream_index, int64_t target_ts, int flags)