[FFmpeg-cvslog] avutil/integer: Fix undefined left shifts of negative numbers

Andreas Rheinhardt git at videolan.org
Tue Oct 25 02:15:04 EEST 2022


ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Fri Oct 21 19:54:27 2022 +0200| [9a6cdd1ba3bd6fe592761dc7e9e6b5273495d048] | committer: Andreas Rheinhardt

avutil/integer: Fix undefined left shifts of negative numbers

Affected the integers FATE-test.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9a6cdd1ba3bd6fe592761dc7e9e6b5273495d048
---

 libavutil/integer.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/libavutil/integer.c b/libavutil/integer.c
index b709c6d487..3bc33dbca2 100644
--- a/libavutil/integer.c
+++ b/libavutil/integer.c
@@ -103,7 +103,7 @@ AVInteger av_shr_i(AVInteger a, int s){
     for(i=0; i<AV_INTEGER_SIZE; i++){
         unsigned int index= i + (s>>4);
         unsigned int v=0;
-        if(index+1<AV_INTEGER_SIZE) v = a.v[index+1]<<16;
+        if (index + 1 < AV_INTEGER_SIZE) v  = a.v[index + 1] * (1U << 16);
         if(index  <AV_INTEGER_SIZE) v+= a.v[index  ];
         out.v[i]= v >> (s&15);
     }
@@ -158,11 +158,9 @@ AVInteger av_int2i(int64_t a){
 }
 
 int64_t av_i2int(AVInteger a){
-    int i;
-    int64_t out=(int8_t)a.v[AV_INTEGER_SIZE-1];
+    uint64_t out = a.v[3];
 
-    for(i= AV_INTEGER_SIZE-2; i>=0; i--){
+    for (int i = 2; i >= 0; i--)
         out = (out<<16) + a.v[i];
-    }
     return out;
 }



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