X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Ftiff.c;h=7ccda51404ad021deaca101a6c05323b8327d67e;hb=94eb600f354c486fd3a9b50e052e809452673fcf;hp=4721e9444912a0a1e3e25e4330d7972a5a130cd9;hpb=1f8e1c209db2ec098edd7880a4ac88864615d674;p=ffmpeg

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 4721e944491..7ccda51404a 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -772,9 +772,18 @@ static void set_sar(TiffContext *s, unsigned tag, unsigned num, unsigned den)
     int offset = tag == TIFF_YRES ? 2 : 0;
     s->res[offset++] = num;
     s->res[offset]   = den;
-    if (s->res[0] && s->res[1] && s->res[2] && s->res[3])
+    if (s->res[0] && s->res[1] && s->res[2] && s->res[3]) {
+        uint64_t num = s->res[2] * (uint64_t)s->res[1];
+        uint64_t den = s->res[0] * (uint64_t)s->res[3];
+        if (num > INT64_MAX || den > INT64_MAX) {
+            num = num >> 1;
+            den = den >> 1;
+        }
         av_reduce(&s->avctx->sample_aspect_ratio.num, &s->avctx->sample_aspect_ratio.den,
-                  s->res[2] * (uint64_t)s->res[1], s->res[0] * (uint64_t)s->res[3], INT32_MAX);
+                  num, den, INT32_MAX);
+        if (!s->avctx->sample_aspect_ratio.den)
+            s->avctx->sample_aspect_ratio = (AVRational) {0, 1};
+    }
 }
 
 static int tiff_decode_tag(TiffContext *s, AVFrame *frame)