[FFmpeg-cvslog] avcodec/mpeg4videodec: Fix runtime error: signed integer overflow: 53098 * 40448 cannot be represented in type 'int'

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Tue Jun  6 16:28:57 2017 +0200| [faa104541d36fa081cc56eeb8eb679e956fad54d] | committer: Michael Niedermayer

avcodec/mpeg4videodec: Fix runtime error: signed integer overflow: 53098 * 40448 cannot be represented in type 'int'

Fixes: 2106/clusterfuzz-testcase-minimized-6136503639998464

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 18bca25adbae9d010d75f9fc197c0af656af758d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=faa104541d36fa081cc56eeb8eb679e956fad54d
---

 libavcodec/mpeg4videodec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 52ec688ce8..0da925c4f8 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -2333,7 +2333,7 @@ static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
     if (s->pict_type != AV_PICTURE_TYPE_B) {
         s->last_time_base = s->time_base;
         s->time_base     += time_incr;
-        s->time = s->time_base * s->avctx->framerate.num + time_increment;
+        s->time = s->time_base * (int64_t)s->avctx->framerate.num + time_increment;
         if (s->workaround_bugs & FF_BUG_UMP4) {
             if (s->time < s->last_non_b_time) {
                 /* header is not mpeg-4-compatible, broken encoder,
@@ -2345,7 +2345,7 @@ static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
         s->pp_time         = s->time - s->last_non_b_time;
         s->last_non_b_time = s->time;
     } else {
-        s->time    = (s->last_time_base + time_incr) * s->avctx->framerate.num + time_increment;
+        s->time    = (s->last_time_base + time_incr) * (int64_t)s->avctx->framerate.num + time_increment;
         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
         if (s->pp_time <= s->pb_time ||
             s->pp_time <= s->pp_time - s->pb_time ||