ffplay: only update pts if not redisplaying a frame

Signed-off-by: Marton Balint <cus@passwd.hu>

ffplay.c

@@ -1382,7 +1382,7 @@ retry:
                 is->frame_timer += delay * FFMAX(1, floor((time-is->frame_timer) / delay));
 
             SDL_LockMutex(is->pictq_mutex);
-            if (!isnan(vp->pts))
+            if (!redisplay && !isnan(vp->pts))
                 update_video_pts(is, vp->pts, vp->pos, vp->serial);
             SDL_UnlockMutex(is->pictq_mutex);