1 files changed, 52 insertions, 0 deletions
diff --git a/src/vidutil.c b/src/vidutil.c
new file mode 100644
index 0000000..b55f216
--- /dev/null
+++ b/src/vidutil.c
@@ -0,0 +1,52 @@
+/**
+ * @file vidutil.c  Video utility functions
+ *
+ * Copyright (C) 2017 Creytiv.com
+ */
+
+#include <re.h>
+#include <rem.h>
+#include <baresip.h>
+#include "core.h"
+
+
+/**
+ * Calculate the RTP timestamp from Presentation Time Stamp (PTS)
+ * or Decoding Time Stamp (DTS) and framerate.
+ *
+ * @note The calculated RTP Timestamp may wrap around.
+ *
+ * @param pts Presentation Time Stamp (PTS)
+ * @param fps Framerate in [frames per second]
+ *
+ * @return RTP Timestamp
+ */
+uint32_t video_calc_rtp_timestamp(int64_t pts, unsigned fps)
+{
+       uint64_t rtp_ts;
+
+       if (!fps)
+	       return 0;
+
+       rtp_ts = ((uint64_t)VIDEO_SRATE * pts) / fps;
+
+       return (uint32_t)rtp_ts;
+}
+
+
+/**
+ * Calculate the timestamp in seconds from the RTP timestamp.
+ *
+ * @param rtp_ts RTP Timestamp
+ *
+ * @return Timestamp in seconds
+ */
+double video_calc_seconds(uint32_t rtp_ts)
+{
+	double timestamp;
+
+	/* convert from RTP clockrate to seconds */
+	timestamp = (double)rtp_ts / (double)VIDEO_SRATE;
+
+	return timestamp;
+}