[FFmpeg-cvslog] avformat/rmdec.c: fix left shift of negative value in rm_sync()

[James Almer]

ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Sun Sep 15 00:06:34 2019 -0300| [78f52b4fe388bb63ed2ca674f7486edc11053f70] | committer: James Almer

avformat/rmdec.c: fix left shift of negative value in rm_sync()

Fixes ticket 8143.

Reviewed-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
Signed-off-by: James Almer <jamrial at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=78f52b4fe388bb63ed2ca674f7486edc11053f70
---

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

diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index c9abd38d33..e95cc9f858 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -724,8 +724,8 @@ static int rm_sync(AVFormatContext *s, int64_t *timestamp, int *flags, int *stre
 
             num = avio_rb16(pb);
             *timestamp = avio_rb32(pb);
-            mlti_id = (avio_r8(pb)>>1)-1<<16;
-            mlti_id = FFMAX(mlti_id, 0);
+            mlti_id = avio_r8((pb) >> 1) - 1;
+            mlti_id = FFMAX(mlti_id, 0) << 16;
             *flags = avio_r8(pb); /* flags */
         }
         for(i=0;i<s->nb_streams;i++) {