[FFmpeg-devel] [PATCH 3/5] avformat/mpegts: Check pcr_incr before setting bitrate

[Michael Niedermayer]

Fixes: division by zero
Fixes: 26459/clusterfuzz-testcase-minimized-ffmpeg_dem_MPEGTSRAW_fuzzer-5666350112178176
Fixes: 28154/clusterfuzz-testcase-minimized-ffmpeg_dem_MPEGTSRAW_fuzzer-5195728439476224

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/mpegts.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 7549fc91c9..470fdf1272 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -3140,8 +3140,10 @@ static int mpegts_read_header(AVFormatContext *s)
         /* NOTE2: it is only the bitrate of the start of the stream */
         ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
         ts->cur_pcr  = pcrs[0] - ts->pcr_incr * packet_count[0];
-        s->bit_rate  = TS_PACKET_SIZE * 8 * 27000000LL / ts->pcr_incr;
-        st->codecpar->bit_rate = s->bit_rate;
+        if (ts->pcr_incr) {
+            s->bit_rate  = TS_PACKET_SIZE * 8 * 27000000LL / ts->pcr_incr;
+            st->codecpar->bit_rate = s->bit_rate;
+        }
         st->start_time      = ts->cur_pcr;
         av_log(ts->stream, AV_LOG_TRACE, "start=%0.3f pcr=%0.3f incr=%d\n",
                 st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);
-- 
2.17.1