diff --git a/libavcodec/videodsp_template.c b/libavcodec/videodsp_template.c
index 324d70f2cb..d653f4d524 100644
--- a/libavcodec/videodsp_template.c
+++ b/libavcodec/videodsp_template.c
@@ -64,7 +64,7 @@ void FUNC(ff_emulated_edge_mc)(uint8_t *buf, const uint8_t *src,
     av_assert2(start_x < end_x && block_w);
 
     w    = end_x - start_x;
-    src += start_y * src_linesize + start_x * sizeof(pixel);
+    src += start_y * src_linesize + start_x * (ptrdiff_t)sizeof(pixel);
     buf += start_x * sizeof(pixel);
 
     // top
@@ -87,7 +87,7 @@ void FUNC(ff_emulated_edge_mc)(uint8_t *buf, const uint8_t *src,
         buf += buf_linesize;
     }
 
-    buf -= block_h * buf_linesize + start_x * sizeof(pixel);
+    buf -= block_h * buf_linesize + start_x * (ptrdiff_t)sizeof(pixel);
     while (block_h--) {
         pixel *bufp = (pixel *) buf;