[FFmpeg-cvslog] mpegts: prevent division by zero

[Andreas Cadhalpun]

ffmpeg | branch: release/3.0 | Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com> | Mon Nov  7 23:37:59 2016 +0100| [3d82cebdd2bd5424b0eb37b0e39284da19fa0e5b] | committer: Andreas Cadhalpun

mpegts: prevent division by zero

Reviewed-by: Michael Niedermayer <michael at niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
(cherry picked from commit 1bbb18fe82fc77a10d45fa53bd2738d2c54de6c6)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3d82cebdd2bd5424b0eb37b0e39284da19fa0e5b
---

 libavformat/mpegts.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index e8f3889..c85c30d 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -2585,8 +2585,17 @@ static int mpegts_read_header(AVFormatContext *s)
                 packet_count[nb_pcrs] = nb_packets;
                 pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
                 nb_pcrs++;
-                if (nb_pcrs >= 2)
-                    break;
+                if (nb_pcrs >= 2) {
+                    if (pcrs[1] - pcrs[0] > 0) {
+                        /* the difference needs to be positive to make sense for bitrate computation */
+                        break;
+                    } else {
+                        av_log(ts->stream, AV_LOG_WARNING, "invalid pcr pair %"PRId64" >= %"PRId64"\n", pcrs[0], pcrs[1]);
+                        pcrs[0] = pcrs[1];
+                        packet_count[0] = packet_count[1];
+                        nb_pcrs--;
+                    }
+                }
             } else {
                 finished_reading_packet(s, ts->raw_packet_size);
             }