[FFmpeg-cvslog] avcodec/jpeg2000dsp: Use unsigned to avoid overflow

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Tue Sep 27 01:20:27 2022 +0200| [3b09e8f5e9c0f419bd8cef7f4dd839cb4ed528d6] | committer: Andreas Rheinhardt

avcodec/jpeg2000dsp: Use unsigned to avoid overflow

Affected the jpeg2000dsp checkasm test.

Reviewed-by: Tomas Härdin <git at haerdin.se>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3b09e8f5e9c0f419bd8cef7f4dd839cb4ed528d6
---

 libavcodec/jpeg2000dsp.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/libavcodec/jpeg2000dsp.c b/libavcodec/jpeg2000dsp.c
index b61be3b72f..b1bff6d5b1 100644
--- a/libavcodec/jpeg2000dsp.c
+++ b/libavcodec/jpeg2000dsp.c
@@ -76,14 +76,13 @@ static void ict_int(void *_src0, void *_src1, void *_src2, int csize)
 
 static void rct_int(void *_src0, void *_src1, void *_src2, int csize)
 {
-    int32_t *src0 = _src0, *src1 = _src1, *src2 = _src2;
-    int32_t i0, i1, i2;
+    uint32_t *src0 = _src0, *src1 = _src1, *src2 = _src2;
     int i;
 
     for (i = 0; i < csize; i++) {
-        i1 = *src0 - (*src2 + *src1 >> 2);
-        i0 = i1 + *src2;
-        i2 = i1 + *src1;
+        uint32_t i1 = *src0 - ((int32_t)(*src2 + *src1) >> 2);
+        int32_t i0 = i1 + *src2;
+        int32_t i2 = i1 + *src1;
         *src0++ = i0;
         *src1++ = i1;
         *src2++ = i2;