avcodec/dss_sp: Fix runtime error: signed integer overflow: 2147481189 + 4096 cannot...

Fixes: 1441/clusterfuzz-testcase-minimized-6223152357048320

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/dss_sp.c b/libavcodec/dss_sp.c
index 2100936..14025fc 100644 (file)
--- a/libavcodec/dss_sp.c
+++ b/libavcodec/dss_sp.c
@@ -529,7 +529,7 @@ static void dss_sp_shift_sq_sub(const int32_t *filter_buf,
         for (i = 14; i > 0; i--)
             error_buf[i] = error_buf[i - 1];
 
-        tmp = (tmp + 4096) >> 13;
+        tmp = (int)(tmp + 4096U) >> 13;
 
         error_buf[1] = tmp;