1 files changed, 13 insertions, 0 deletions
diff --git a/src/util.h b/src/util.h
index 5921a86..bc926b6 100644
--- a/src/util.h
+++ b/src/util.h
@@ -3,6 +3,16 @@
 
 #include <stdint.h>
 
+static inline void
+pswap(void **p1, void **p2)
+{
+	void *tmp;
+
+	tmp = *p1;
+	*p1 = *p2;
+	*p2 = tmp;
+}
+
 int
 pgm_read(char *filename, unsigned char **buf, int *xsize, int *ysize);
 
@@ -13,6 +23,9 @@ pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, char *filename);
 void
 frame_mix(struct video_frame *frame_a, struct video_frame *frame_b);
 
+double
+frame_diff(struct video_frame *frame_a, struct video_frame *frame_b);
+
 void
 print_time(int64_t msec);