Also put frame_average into util

Not yet needed by other tools than cuttime,
but its really just a utility function.

1 files changed, 20 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
index e642762..ddd46d3 100644
--- a/src/util.c
+++ b/src/util.c
@@ -103,6 +103,26 @@ frame_diff(struct video_frame *frame_a, struct video_frame *frame_b)
 	return average / (frame_a->width * frame_a->height);
 }
 
+double
+frame_average(struct video_frame *frame)
+{
+	double average = 0;
+	uint8_t *row = frame->data;
+	uint8_t *col = NULL;
+
+	for (int y = 0; y < frame->height; ++y) {
+		col = row;
+		for (int x = 0; x < frame->width; ++x) {
+			average += *col;
+			col++;
+		}
+		row += frame->stride;
+	}
+
+	return average / (frame->width * frame->height);
+}
+
+
 /* print time in format: "hh:mm:ss.xxx" */
 void
 print_time(int64_t msec) {