jitterbuffer: reset skew when timestamps change

Refactor the jitterbuffer resync code.
Reset the skew correction when we detect a big timestamp discont.

See #593354

1 files changed, 20 insertions, 10 deletions

diff --git a/gst/rtpmanager/rtpjitterbuffer.c b/gst/rtpmanager/rtpjitterbuffer.c
index 18b7d07c6..55e084f37 100644
--- a/gst/rtpmanager/rtpjitterbuffer.c
+++ b/gst/rtpmanager/rtpjitterbuffer.c
@@ -117,6 +117,24 @@ rtp_jitter_buffer_reset_skew (RTPJitterBuffer * jbuf)
   GST_DEBUG ("reset skew correction");
 }
 
+static void
+rtp_jitter_buffer_resync (RTPJitterBuffer * jbuf, GstClockTime time,
+    GstClockTime gstrtptime, guint64 ext_rtptime, gboolean reset_skew)
+{
+  jbuf->base_time = time;
+  jbuf->base_rtptime = gstrtptime;
+  jbuf->base_extrtp = ext_rtptime;
+  jbuf->prev_out_time = -1;
+  jbuf->prev_send_diff = -1;
+  if (reset_skew) {
+    jbuf->window_filling = TRUE;
+    jbuf->window_pos = 0;
+    jbuf->window_min = 0;
+    jbuf->window_size = 0;
+    jbuf->skew = 0;
+  }
+}
+
 /* For the clock skew we use a windowed low point averaging algorithm as can be
  * found in http://www.grame.fr/pub/TR-050601.pdf. The idea is that the jitter is
  * composed of:
@@ -223,11 +241,7 @@ calculate_skew (RTPJitterBuffer * jbuf, guint32 rtptime, GstClockTime time,
     /* elapsed time at sender, timestamps can go backwards and thus be smaller
      * than our base time, take a new base time in that case. */
     GST_WARNING ("backward timestamps at server, taking new base time");
-    jbuf->base_time = time;
-    jbuf->base_rtptime = gstrtptime;
-    jbuf->base_extrtp = ext_rtptime;
-    jbuf->prev_out_time = -1;
-    jbuf->prev_send_diff = -1;
+    rtp_jitter_buffer_resync (jbuf, time, gstrtptime, ext_rtptime, FALSE);
     send_diff = 0;
   }
 
@@ -257,11 +271,7 @@ calculate_skew (RTPJitterBuffer * jbuf, guint32 rtptime, GstClockTime time,
   if (ABS (delta - jbuf->skew) > GST_SECOND) {
     GST_WARNING ("delta %" GST_TIME_FORMAT " too big, reset skew",
         GST_TIME_ARGS (delta - jbuf->skew));
-    jbuf->base_time = time;
-    jbuf->base_rtptime = gstrtptime;
-    jbuf->base_extrtp = ext_rtptime;
-    jbuf->prev_out_time = -1;
-    jbuf->prev_send_diff = -1;
+    rtp_jitter_buffer_resync (jbuf, time, gstrtptime, ext_rtptime, TRUE);
     send_diff = 0;
     delta = 0;
   }