rtpjitterbuffer: Fix lost duration when gap after lost timer

This patch fixes an issue with the estimated gap duration when there is
a gap immediately after a lost timer has been processed. Previously
there was a discrepancy beteen the gap in seqnum and gap in dts which
would cause wrong calculated duration. The issue would only be seen with
retranmission enabled since when it's disabled lost timers are only
created when a packet is received and the actual gap length and last dts
is known.

https://bugzilla.gnome.org/show_bug.cgi?id=769768

2 files changed, 25 insertions, 16 deletions

diff --git a/gst/rtpmanager/gstrtpjitterbuffer.c b/gst/rtpmanager/gstrtpjitterbuffer.c
index 931153056..c3ab683f5 100644
--- a/gst/rtpmanager/gstrtpjitterbuffer.c
+++ b/gst/rtpmanager/gstrtpjitterbuffer.c
@@ -3678,8 +3678,10 @@ do_lost_timeout (GstRtpJitterBuffer * jitterbuffer, TimerData * timer,
   next_in_seqnum = (seqnum + lost_packets) & 0xffff;
 
   /* we now only accept seqnum bigger than this */
-  if (gst_rtp_buffer_compare_seqnum (priv->next_in_seqnum, next_in_seqnum) > 0)
+  if (gst_rtp_buffer_compare_seqnum (priv->next_in_seqnum, next_in_seqnum) > 0) {
     priv->next_in_seqnum = next_in_seqnum;
+    priv->last_in_dts = apply_offset (jitterbuffer, timer->timeout);
+  }
 
   /* Avoid creating events if we don't need it. Note that we still need to create
    * the lost *ITEM* since it will be used to notify the outgoing thread of
diff --git a/tests/check/elements/rtpjitterbuffer.c b/tests/check/elements/rtpjitterbuffer.c
index b2a73ba45..5969d12a9 100644
--- a/tests/check/elements/rtpjitterbuffer.c
+++ b/tests/check/elements/rtpjitterbuffer.c
@@ -1875,8 +1875,6 @@ GST_START_TEST (test_gap_exceeds_latency)
   GstTestClock *testclock;
   const gint jb_latency_ms = 200;
 
-  guint32 timestamp_ms = 0;
-  guint32 rtp_ts = 0;
   gint i;
   GstEvent *out_event;
   GstBuffer *out_buf;
@@ -1893,10 +1891,7 @@ GST_START_TEST (test_gap_exceeds_latency)
   fail_unless_equals_int (GST_FLOW_OK,
       gst_harness_push (h, generate_test_buffer (0)));
 
-  timestamp_ms += 20;
-  rtp_ts += PCMU_RTP_TS_DURATION;
-  gst_harness_set_time (h, timestamp_ms * GST_MSECOND);
-
+  gst_harness_set_time (h, 1 * PCMU_BUF_DURATION);
   fail_unless_equals_int (GST_FLOW_OK,
       gst_harness_push (h, generate_test_buffer (1)));
 
@@ -1931,12 +1926,23 @@ GST_START_TEST (test_gap_exceeds_latency)
   fail_unless_equals_int (GST_FLOW_OK,
       gst_harness_push (h, generate_test_buffer (16)));
 
-  /* FIXME: something is up with the timestamp here!!?! */
+  /* Manually check the first rtx event */
   out_event = gst_harness_pull_upstream_event (h);
-  verify_rtx_event (out_event, 6, 119999994, 10, PCMU_BUF_DURATION);
-  /* lost more rtx with weird timestamps... */
+  verify_rtx_event (out_event, 6, 6 * PCMU_BUF_DURATION, 10, PCMU_BUF_DURATION);
+  /* Go throught the rest of rtx events. A bit more relaxed since order is
+   * partly an implentation detail. */
   for (i = 0; i < 12; i++) {
-    gst_event_unref (gst_harness_pull_upstream_event (h));
+    const GstStructure *s;
+    guint seqnum, retry;
+
+    fail_unless (out_event = gst_harness_pull_upstream_event (h));
+    fail_unless (s = gst_event_get_structure (out_event));
+    fail_unless (gst_structure_get_uint (s, "seqnum", &seqnum));
+    fail_unless (gst_structure_get_uint (s, "retry", &retry));
+    fail_unless (seqnum >= 6 && seqnum <= 12);
+
+    verify_rtx_event (out_event, seqnum, seqnum * PCMU_BUF_DURATION,
+        10 + retry * 40, PCMU_BUF_DURATION);
   }
 
   fail_unless_equals_int (0, gst_harness_upstream_events_in_queue (h));
@@ -1948,19 +1954,20 @@ GST_START_TEST (test_gap_exceeds_latency)
         gst_harness_push (h, generate_test_buffer (i)));
   }
 
-  /* FIXME: wtf is going on with timestamps and durations here??!? */
   gst_harness_crank_single_clock_wait (h);
   out_event = gst_harness_pull_event (h);
-  verify_lost_event (out_event, 3, 41428571, 78571423);
+  verify_lost_event (out_event, 3, 3 * PCMU_BUF_DURATION,
+      3 * PCMU_BUF_DURATION);
 
-  /* FIXME: and these rtx... */
   gst_harness_crank_single_clock_wait (h);
   out_event = gst_harness_pull_event (h);
-  verify_lost_event (out_event, 6, 119999994, 21428571);
+  verify_lost_event (out_event, 6, 6 * PCMU_BUF_DURATION,
+      1 * PCMU_BUF_DURATION);
 
   gst_harness_crank_single_clock_wait (h);
   out_event = gst_harness_pull_event (h);
-  verify_lost_event (out_event, 7, 141428565, 21428571);
+  verify_lost_event (out_event, 7, 7 * PCMU_BUF_DURATION,
+      1 * PCMU_BUF_DURATION);
 
   /* 8 */
   for (i = 8; i <= 16; i++) {