diff --git a/file_input.c b/file_input.c
index 722deca7..03ba42d7 100644
--- a/file_input.c
+++ b/file_input.c
@@ -260,12 +260,12 @@ file_input_get_pkt(th_transport_t *t, file_input_t *fi, int64_t now)
   if(fi->fi_dts_offset == AV_NOPTS_VALUE)
     fi->fi_dts_offset = ffpkt.dts;
 
-  dts = ffpkt.dts - fi->fi_dts_offset;
+  dts = ffpkt.dts + fi->fi_dts_offset;
   fi->fi_last_dts = dts;
 
   pts = ffpkt.pts;
   if(pts != AV_NOPTS_VALUE)
-    pts -= fi->fi_dts_offset;
+    pts += fi->fi_dts_offset;
 
   pkt = pkt_alloc(ffpkt.data, ffpkt.size, pts, dts);
   pkt->pkt_duration = 0;