gstreamer/tests/check/elements/rtpjitterbuffer.c

/* GStreamer
 *
 * Copyright (C) 2009 Nokia Corporation and its subsidary(-ies)
 *               contact: <stefan.kost@nokia.com>
 * Copyright (C) 2012 Cisco Systems, Inc
 *               Authors: Kelley Rogers <kelro@cisco.com>
 *               Havard Graff <hgraff@cisco.com>
 * Copyright (C) 2013-2016 Pexip AS
 *               Stian Selnes <stian@pexip>
 *               Havard Graff <havard@pexip>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include <gst/check/gstcheck.h>
#include <gst/check/gsttestclock.h>
#include <gst/check/gstharness.h>

#include <gst/rtp/gstrtpbuffer.h>

/* For ease of programming we use globals to keep refs for our floating
 * src and sink pads we create; otherwise we always have to do get_pad,
 * get_peer, and then remove references in every test function */
static GstPad *mysrcpad, *mysinkpad;
/* we also have a list of src buffers */
static GList *inbuffers = NULL;
static gint num_dropped = 0;

#define RTP_CAPS_STRING    \
    "application/x-rtp, "               \
    "media = (string)audio, "           \
    "payload = (int) 0, "               \
    "clock-rate = (int) 8000, "         \
    "encoding-name = (string)PCMU"

#define RTP_FRAME_SIZE 20

static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("application/x-rtp")
    );
static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("application/x-rtp, "
        "clock-rate = (int) [ 1, 2147483647 ]")
    );

static void
buffer_dropped (G_GNUC_UNUSED gpointer data, GstMiniObject * obj)
{
  GST_DEBUG ("dropping buffer %p", obj);
  num_dropped++;
}

static GstElement *
setup_jitterbuffer (gint num_buffers)
{
  GstElement *jitterbuffer;
  GstClock *clock;
  GstBuffer *buffer;
  GstCaps *caps;
  /* a 20 sample audio block (2,5 ms) generated with
   * gst-launch audiotestsrc wave=silence blocksize=40 num-buffers=3 !
   *    "audio/x-raw,channels=1,rate=8000" ! mulawenc ! rtppcmupay !
   *     fakesink dump=1
   */
  guint8 in[] = {
    /* first 4 bytes are rtp-header, next 4 bytes are timestamp */
    0x80, 0x80, 0x1c, 0x24, 0x46, 0xcd, 0xb7, 0x11, 0x3c, 0x3a, 0x7c, 0x5b,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  };
  GstClockTime ts = G_GUINT64_CONSTANT (0);
  GstClockTime tso = gst_util_uint64_scale (RTP_FRAME_SIZE, GST_SECOND, 8000);
  /*guint latency = GST_TIME_AS_MSECONDS (num_buffers * tso); */
  gint i;

  GST_DEBUG ("setup_jitterbuffer");
  jitterbuffer = gst_check_setup_element ("rtpjitterbuffer");
  /* we need a clock here */
  clock = gst_system_clock_obtain ();
  gst_element_set_clock (jitterbuffer, clock);
  gst_object_unref (clock);
  /* setup latency */
  /* latency would be 7 for 3 buffers here, default is 200
     g_object_set (G_OBJECT (jitterbuffer), "latency", latency, NULL);
     GST_INFO_OBJECT (jitterbuffer, "set latency to %u ms", latency);
   */

  mysrcpad = gst_check_setup_src_pad (jitterbuffer, &srctemplate);
  mysinkpad = gst_check_setup_sink_pad (jitterbuffer, &sinktemplate);
  gst_pad_set_active (mysrcpad, TRUE);
  gst_pad_set_active (mysinkpad, TRUE);

  /* create n buffers */
  caps = gst_caps_from_string (RTP_CAPS_STRING);
  gst_check_setup_events (mysrcpad, jitterbuffer, caps, GST_FORMAT_TIME);
  gst_caps_unref (caps);

  for (i = 0; i < num_buffers; i++) {
    buffer = gst_buffer_new_and_alloc (sizeof (in));
    gst_buffer_fill (buffer, 0, in, sizeof (in));
    GST_BUFFER_DTS (buffer) = ts;
    GST_BUFFER_PTS (buffer) = ts;
    GST_BUFFER_DURATION (buffer) = tso;
    gst_mini_object_weak_ref (GST_MINI_OBJECT (buffer), buffer_dropped, NULL);
    GST_DEBUG ("created buffer: %p", buffer);

    if (!i)
      GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);

    inbuffers = g_list_append (inbuffers, buffer);

    /* hackish way to update the rtp header */
    in[1] = 0x00;
    in[3]++;                    /* seqnumber */
    in[7] += RTP_FRAME_SIZE;    /* inc. timestamp with framesize */
    ts += tso;
  }
  num_dropped = 0;

  return jitterbuffer;
}

static GstStateChangeReturn
start_jitterbuffer (GstElement * jitterbuffer)
{
  GstStateChangeReturn ret;
  GstClockTime now;
  GstClock *clock;

  clock = gst_element_get_clock (jitterbuffer);
  now = gst_clock_get_time (clock);
  gst_object_unref (clock);

  gst_element_set_base_time (jitterbuffer, now);
  ret = gst_element_set_state (jitterbuffer, GST_STATE_PLAYING);

  return ret;
}

static void
cleanup_jitterbuffer (GstElement * jitterbuffer)
{
  GST_DEBUG ("cleanup_jitterbuffer");

  g_list_foreach (buffers, (GFunc) gst_mini_object_unref, NULL);
  g_list_free (buffers);
  buffers = NULL;

  g_list_free (inbuffers);
  inbuffers = NULL;

  gst_pad_set_active (mysrcpad, FALSE);
  gst_pad_set_active (mysinkpad, FALSE);
  gst_element_set_state (jitterbuffer, GST_STATE_NULL);
  gst_check_teardown_src_pad (jitterbuffer);
  gst_check_teardown_sink_pad (jitterbuffer);
  gst_check_teardown_element (jitterbuffer);
}

static void
check_jitterbuffer_results (gint num_buffers)
{
  GstBuffer *buffer;
  GList *node;
  GstClockTime ts = G_GUINT64_CONSTANT (0);
  GstClockTime tso = gst_util_uint64_scale (RTP_FRAME_SIZE, GST_SECOND, 8000);
  GstMapInfo map;
  guint16 prev_sn = 0, cur_sn;
  guint32 prev_ts = 0, cur_ts;

  /* sleep for twice the latency */
  g_usleep (400 * 1000);

  GST_INFO ("of %d buffer %d/%d received/dropped", num_buffers,
      g_list_length (buffers), num_dropped);
  /* if this fails, not all buffers have been processed */
  fail_unless_equals_int ((g_list_length (buffers) + num_dropped), num_buffers);

  /* check the buffer list */
  fail_unless_equals_int (g_list_length (buffers), num_buffers);
  for (node = buffers; node; node = g_list_next (node)) {
    fail_if ((buffer = (GstBuffer *) node->data) == NULL);
    fail_if (GST_BUFFER_PTS (buffer) != ts);
    gst_buffer_map (buffer, &map, GST_MAP_READ);
    cur_sn = ((guint16) map.data[2] << 8) | map.data[3];
    cur_ts = ((guint32) map.data[4] << 24) | ((guint32) map.data[5] << 16) |
        ((guint32) map.data[6] << 8) | map.data[7];
    gst_buffer_unmap (buffer, &map);

    if (node != buffers) {
      fail_unless (cur_sn > prev_sn);
      fail_unless (cur_ts > prev_ts);

      prev_sn = cur_sn;
      prev_ts = cur_ts;
    }
    ts += tso;
  }
}

GST_START_TEST (test_push_forward_seq)
{
  GstElement *jitterbuffer;
  const guint num_buffers = 3;
  GstBuffer *buffer;
  GList *node;

  jitterbuffer = setup_jitterbuffer (num_buffers);
  fail_unless (start_jitterbuffer (jitterbuffer)
      == GST_STATE_CHANGE_SUCCESS, "could not set to playing");

  /* push buffers: 0,1,2, */
  for (node = inbuffers; node; node = g_list_next (node)) {
    buffer = (GstBuffer *) node->data;
    fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  }

  /* check the buffer list */
  check_jitterbuffer_results (num_buffers);

  /* cleanup */
  cleanup_jitterbuffer (jitterbuffer);
}

GST_END_TEST;

GST_START_TEST (test_push_backward_seq)
{
  GstElement *jitterbuffer;
  const guint num_buffers = 4;
  GstBuffer *buffer;
  GList *node;

  jitterbuffer = setup_jitterbuffer (num_buffers);
  fail_unless (start_jitterbuffer (jitterbuffer)
      == GST_STATE_CHANGE_SUCCESS, "could not set to playing");

  /* push buffers: 0,3,2,1 */
  buffer = (GstBuffer *) inbuffers->data;
  fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  for (node = g_list_last (inbuffers); node != inbuffers;
      node = g_list_previous (node)) {
    buffer = (GstBuffer *) node->data;
    fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  }

  /* check the buffer list */
  check_jitterbuffer_results (num_buffers);

  /* cleanup */
  cleanup_jitterbuffer (jitterbuffer);
}

GST_END_TEST;

GST_START_TEST (test_push_unordered)
{
  GstElement *jitterbuffer;
  const guint num_buffers = 4;
  GstBuffer *buffer;

  jitterbuffer = setup_jitterbuffer (num_buffers);
  fail_unless (start_jitterbuffer (jitterbuffer)
      == GST_STATE_CHANGE_SUCCESS, "could not set to playing");

  /* push buffers; 0,2,1,3 */
  buffer = (GstBuffer *) inbuffers->data;
  fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  buffer = g_list_nth_data (inbuffers, 2);
  fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  buffer = g_list_nth_data (inbuffers, 1);
  fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  buffer = g_list_nth_data (inbuffers, 3);
  fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);

  /* check the buffer list */
  check_jitterbuffer_results (num_buffers);

  /* cleanup */
  cleanup_jitterbuffer (jitterbuffer);
}

GST_END_TEST;

gboolean is_eos;

static gboolean
eos_event_function (G_GNUC_UNUSED GstPad * pad,
    G_GNUC_UNUSED GstObject * parent, GstEvent * event)
{
  if (GST_EVENT_TYPE (event) == GST_EVENT_EOS) {
    g_mutex_lock (&check_mutex);
    is_eos = TRUE;
    g_cond_signal (&check_cond);
    g_mutex_unlock (&check_mutex);
  }
  gst_event_unref (event);
  return TRUE;
}

GST_START_TEST (test_push_eos)
{
  GstElement *jitterbuffer;
  const guint num_buffers = 5;
  GList *node;
  GstStructure *stats;
  guint64 pushed, lost, late, duplicates;
  int n = 0;

  is_eos = FALSE;

  jitterbuffer = setup_jitterbuffer (num_buffers);
  gst_pad_set_event_function (mysinkpad, eos_event_function);

  g_object_set (jitterbuffer, "latency", 1, NULL);

  fail_unless (start_jitterbuffer (jitterbuffer)
      == GST_STATE_CHANGE_SUCCESS, "could not set to playing");

  /* push buffers: 0,1,2, */
  for (node = inbuffers; node; node = g_list_next (node)) {
    GstBuffer *buffer;

    /* steal buffer from list */
    buffer = node->data;
    node->data = NULL;

    n++;
    /* Skip 1 */
    if (n == 2) {
      gst_buffer_unref (buffer);
      continue;
    }
    fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  }

  gst_pad_push_event (mysrcpad, gst_event_new_eos ());

  g_mutex_lock (&check_mutex);
  while (!is_eos)
    g_cond_wait (&check_cond, &check_mutex);
  g_mutex_unlock (&check_mutex);

  fail_unless_equals_int (g_list_length (buffers), num_buffers - 1);

  /* Verify statistics */
  g_object_get (jitterbuffer, "stats", &stats, NULL);
  gst_structure_get (stats, "num-pushed", G_TYPE_UINT64, &pushed,
      "num-lost", G_TYPE_UINT64, &lost,
      "num-late", G_TYPE_UINT64, &late,
      "num-duplicates", G_TYPE_UINT64, &duplicates, NULL);
  fail_unless_equals_int (pushed, g_list_length (inbuffers) - 1);
  fail_unless_equals_int (lost, 1);
  fail_unless_equals_int (late, 0);
  fail_unless_equals_int (duplicates, 0);
  gst_structure_free (stats);

  /* cleanup */
  cleanup_jitterbuffer (jitterbuffer);
}

GST_END_TEST;

GST_START_TEST (test_basetime)
{
  GstElement *jitterbuffer;
  const guint num_buffers = 3;
  GstBuffer *buffer;
  GList *node;
  GstClockTime tso = gst_util_uint64_scale (RTP_FRAME_SIZE, GST_SECOND, 8000);

  jitterbuffer = setup_jitterbuffer (num_buffers);
  fail_unless (start_jitterbuffer (jitterbuffer)
      == GST_STATE_CHANGE_SUCCESS, "could not set to playing");

  /* push buffers: 2,1,0 */
  for (node = g_list_last (inbuffers); node; node = g_list_previous (node)) {
    buffer = (GstBuffer *) node->data;
    fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  }

  /* sleep for twice the latency */
  g_usleep (400 * 1000);

  /* if this fails, not all buffers have been processed */
  fail_unless_equals_int ((g_list_length (buffers) + num_dropped), num_buffers);

  buffer = (GstBuffer *) buffers->data;
  fail_unless (GST_BUFFER_DTS (buffer) != (num_buffers * tso));
  fail_unless (GST_BUFFER_PTS (buffer) != (num_buffers * tso));

  /* cleanup */
  cleanup_jitterbuffer (jitterbuffer);
}

GST_END_TEST;

static GstCaps *
request_pt_map (G_GNUC_UNUSED GstElement * jitterbuffer, guint pt)
{
  fail_unless (pt == 0);

  return gst_caps_from_string (RTP_CAPS_STRING);
}

GST_START_TEST (test_clear_pt_map)
{
  GstElement *jitterbuffer;
  const guint num_buffers = 10;
  gint i;
  GstBuffer *buffer;
  GList *node;

  jitterbuffer = setup_jitterbuffer (num_buffers);
  fail_unless (start_jitterbuffer (jitterbuffer)
      == GST_STATE_CHANGE_SUCCESS, "could not set to playing");

  g_signal_connect (jitterbuffer, "request-pt-map", (GCallback)
      request_pt_map, NULL);

  /* push buffers: 0,1,2, */
  for (node = inbuffers, i = 0; node && i < 3; node = g_list_next (node), i++) {
    buffer = (GstBuffer *) node->data;
    fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  }

  g_usleep (400 * 1000);

  g_signal_emit_by_name (jitterbuffer, "clear-pt-map", NULL);

  for (; node && i < 10; node = g_list_next (node), i++) {
    buffer = (GstBuffer *) node->data;
    fail_unless (gst_pad_push (mysrcpad, buffer) == GST_FLOW_OK);
  }

  /* check the buffer list */
  check_jitterbuffer_results (num_buffers);

  /* cleanup */
  cleanup_jitterbuffer (jitterbuffer);
}

GST_END_TEST;

#define TEST_BUF_CLOCK_RATE 8000
#define AS_TEST_BUF_RTP_TIME(gst_time) gst_util_uint64_scale_int (TEST_BUF_CLOCK_RATE, gst_time, GST_SECOND)
#define TEST_BUF_PT 0
#define TEST_BUF_SSRC 0x01BADBAD
#define TEST_BUF_MS  20
#define TEST_BUF_DURATION (TEST_BUF_MS * GST_MSECOND)
#define TEST_BUF_SIZE (64000 * TEST_BUF_MS / 1000)
#define TEST_RTP_TS_DURATION AS_TEST_BUF_RTP_TIME (TEST_BUF_DURATION)

static GstCaps *
generate_caps (void)
{
  return gst_caps_new_simple ("application/x-rtp",
      "media", G_TYPE_STRING, "audio",
      "clock-rate", G_TYPE_INT, TEST_BUF_CLOCK_RATE,
      "encoding-name", G_TYPE_STRING, "TEST",
      "payload", G_TYPE_INT, TEST_BUF_PT,
      "ssrc", G_TYPE_UINT, TEST_BUF_SSRC, NULL);
}

static GstBuffer *
generate_test_buffer_full (GstClockTime dts, guint seq_num, guint32 rtp_ts)
{
  GstBuffer *buf;
  guint8 *payload;
  guint i;
  GstRTPBuffer rtp = GST_RTP_BUFFER_INIT;

  buf = gst_rtp_buffer_new_allocate (TEST_BUF_SIZE, 0, 0);
  GST_BUFFER_DTS (buf) = dts;

  gst_rtp_buffer_map (buf, GST_MAP_READWRITE, &rtp);
  gst_rtp_buffer_set_payload_type (&rtp, TEST_BUF_PT);
  gst_rtp_buffer_set_seq (&rtp, seq_num);
  gst_rtp_buffer_set_timestamp (&rtp, rtp_ts);
  gst_rtp_buffer_set_ssrc (&rtp, TEST_BUF_SSRC);

  payload = gst_rtp_buffer_get_payload (&rtp);
  for (i = 0; i < TEST_BUF_SIZE; i++)
    payload[i] = 0xff;

  gst_rtp_buffer_unmap (&rtp);

  return buf;
}

static GstBuffer *
generate_test_buffer (guint seq_num)
{
  return generate_test_buffer_full (seq_num * TEST_BUF_DURATION,
      seq_num, seq_num * TEST_RTP_TS_DURATION);
}

static GstBuffer *
generate_test_buffer_rtx (GstClockTime dts, guint seq_num)
{
  GstBuffer *buffer = generate_test_buffer_full (dts, seq_num,
      seq_num * TEST_RTP_TS_DURATION);
  GST_BUFFER_FLAG_SET (buffer, GST_RTP_BUFFER_FLAG_RETRANSMISSION);
  return buffer;
}

static void
push_test_buffer (GstHarness * h, guint seq_num)
{
  gst_harness_set_time (h, seq_num * TEST_BUF_DURATION);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer (seq_num)));
}

static gint
get_rtp_seq_num (GstBuffer * buf)
{
  GstRTPBuffer rtp = GST_RTP_BUFFER_INIT;
  gint seq;
  gst_rtp_buffer_map (buf, GST_MAP_READ, &rtp);
  seq = gst_rtp_buffer_get_seq (&rtp);
  gst_rtp_buffer_unmap (&rtp);
  return seq;
}

#define verify_lost_event(h, exp_seq, exp_ts, exp_dur)                         \
  G_STMT_START {                                                               \
    GstEvent *_event;                                                          \
    const GstStructure *_s;                                                    \
    const GValue *_value;                                                      \
    guint _seq;                                                                \
    GstClockTime _ts;                                                          \
    GstClockTime _dur;                                                         \
    _event = gst_harness_pull_event (h);                                       \
    fail_unless (_event != NULL);                                              \
    _s = gst_event_get_structure (_event);                                     \
    fail_unless (_s != NULL);                                                  \
    fail_unless (gst_structure_get_uint (_s, "seqnum", &_seq));                \
    _value = gst_structure_get_value (_s, "timestamp");                        \
    fail_unless (_value && G_VALUE_HOLDS_UINT64 (_value));                     \
    _ts = g_value_get_uint64 (_value);                                         \
    _value = gst_structure_get_value (_s, "duration");                         \
    fail_unless (_value && G_VALUE_HOLDS_UINT64 (_value));                     \
    _dur = g_value_get_uint64 (_value);                                        \
    fail_unless_equals_int ((guint16)(exp_seq), _seq);                         \
    fail_unless_equals_uint64 (exp_ts, _ts);                                   \
    fail_unless_equals_uint64 (exp_dur, _dur);                                 \
    gst_event_unref (_event);                                                  \
  } G_STMT_END


#define verify_rtx_event(h, exp_seq, exp_ts, exp_delay, exp_spacing)           \
  G_STMT_START {                                                               \
    GstEvent *_event;                                                          \
    const GstStructure *_s;                                                    \
    const GValue *_value;                                                      \
    guint _seq;                                                                \
    GstClockTime _ts;                                                          \
    guint _delay;                                                              \
    GstClockTime _spacing;                                                     \
    _event = gst_harness_pull_upstream_event (h);                              \
    fail_unless (_event != NULL);                                              \
    _s = gst_event_get_structure (_event);                                     \
    fail_unless (_s != NULL);                                                  \
    fail_unless (gst_structure_get_uint (_s, "seqnum", &_seq));                \
    _value = gst_structure_get_value (_s, "running-time");                     \
    fail_unless (_value && G_VALUE_HOLDS_UINT64 (_value));                     \
    _ts = g_value_get_uint64 (_value);                                         \
    fail_unless (gst_structure_get_uint (_s, "delay", &_delay));               \
    _value = gst_structure_get_value (_s, "packet-spacing");                   \
    fail_unless (_value && G_VALUE_HOLDS_UINT64 (_value));                     \
    _spacing = g_value_get_uint64 (_value);                                    \
    fail_unless_equals_int ((guint16)(exp_seq), _seq);                         \
    fail_unless_equals_uint64 (exp_ts, _ts);                                   \
    fail_unless_equals_int (exp_delay, _delay);                                \
    fail_unless_equals_uint64 (exp_spacing, _spacing);                         \
    gst_event_unref (_event);                                                  \
  } G_STMT_END

static gboolean
verify_jb_stats (GstElement * jb, GstStructure * expected)
{
  gboolean ret;
  GstStructure *actual;
  g_object_get (jb, "stats", &actual, NULL);

  ret = gst_structure_is_subset (actual, expected);

  if (!ret) {
    gchar *e_str = gst_structure_to_string (expected);
    gchar *a_str = gst_structure_to_string (actual);
    fail_unless (ret, "%s is not a subset of %s", e_str, a_str);
    g_free (e_str);
    g_free (a_str);
  }

  gst_structure_free (expected);
  gst_structure_free (actual);

  return ret;
}

static guint
construct_deterministic_initial_state (GstHarness * h, gint latency_ms)
{
  guint next_seqnum = latency_ms / TEST_BUF_MS + 1;
  guint seqnum;
  gint i;

  g_assert (latency_ms % TEST_BUF_MS == 0);

  gst_harness_set_src_caps (h, generate_caps ());
  g_object_set (h->element, "latency", latency_ms, NULL);

  /* When the first packet arrives in the jitterbuffer, it will create a
   * timeout for this packet equal to the latency of the jitterbuffer.
   * This is known as DEADLINE internally, and is meant to allow the stream
   * to buffer a bit before starting to push it out, to get some ideas about
   * the nature of the stream. (packetspacing, jitter etc.)
   *
   * When writing tests using the test-clock, it it hence important to know
   * that by simply advancing the clock to this timeout, you are basically
   * describing a stream that had one initial packet, and then nothing at all
   * for the duration of the latency (100ms in this test), which is not a very
   * usual scenario.
   *
   * Instead, a pattern used throughout this test-suite, is to keep the buffers
   * arriving at their optimal time, until the DEADLINE is reached, and that
   * then becomes the "starting-point" for the test, because at this time
   * there should now be no waiting timers (unless using rtx) and we have
   * a "clean" state to craft the test from.
   */

  /* Packet 0 arrives at time 0ms, Packet 5 arrives at time 100ms */
  for (seqnum = 0; seqnum < next_seqnum; seqnum++) {
    push_test_buffer (h, seqnum);
    gst_harness_wait_for_clock_id_waits (h, 1, 60);
  }

  /* We release the DEADLINE timer for packet 0, verify the time is indeed
   * @latency_ms (100ms) and pull out all the buffers that have been released,
   * and verify their PTS and sequence numbers.
   */
  gst_harness_crank_single_clock_wait (h);
  fail_unless_equals_int64 (latency_ms * GST_MSECOND,
      gst_clock_get_time (GST_ELEMENT_CLOCK (h->element)));
  for (seqnum = 0; seqnum < next_seqnum; seqnum++) {
    GstBuffer *buf = gst_harness_pull (h);
    fail_unless_equals_uint64 (seqnum * TEST_BUF_DURATION,
        GST_BUFFER_PTS (buf));
    fail_unless_equals_int (seqnum, get_rtp_seq_num (buf));
    gst_buffer_unref (buf);
  }

  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));

  /* drop reconfigure event */
  gst_event_unref (gst_harness_pull_upstream_event (h));

  /* Verify that at this point our queues are empty */
  fail_unless_equals_int (0, gst_harness_buffers_in_queue (h));
  fail_unless_equals_int (0, gst_harness_events_in_queue (h));

  return next_seqnum;
}

GST_START_TEST (test_lost_event)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstBuffer *buf;
  gint latency_ms = 100;
  guint next_seqnum;
  guint missing_seqnum;

  g_object_set (h->element, "do-lost", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* We will now create a gap in the stream, by skipping one sequence-number,
   * and push the following packet.
   */
  missing_seqnum = next_seqnum;
  next_seqnum += 1;
  push_test_buffer (h, next_seqnum);

  /* This packet (@next_seqnum) will now be held back, awaiting the missing one,
   * verify that this is the case:
   */
  fail_unless_equals_int (0, gst_harness_buffers_in_queue (h));
  fail_unless_equals_int (0, gst_harness_events_in_queue (h));

  /* The lost-timeout for the missing packet will now be its pts + latency, so
   * now we will simply crank the clock to advance to this point in time, and
   * check that we get a lost-event, as well as the last packet we pushed in.
   */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, missing_seqnum,
      missing_seqnum * TEST_BUF_DURATION, TEST_BUF_DURATION);

  buf = gst_harness_pull (h);
  fail_unless_equals_uint64 (next_seqnum * TEST_BUF_DURATION,
      GST_BUFFER_PTS (buf));
  fail_unless_equals_int (next_seqnum, get_rtp_seq_num (buf));
  gst_buffer_unref (buf);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 1, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_only_one_lost_event_on_large_gaps)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstTestClock *testclock;
  GstBuffer *out_buf;
  guint next_seqnum;
  gint latency_ms = 200;
  gint num_lost_events = latency_ms / TEST_BUF_MS;
  gint i;

  testclock = gst_harness_get_testclock (h);
  /* Need to set max-misorder-time and max-dropout-time to 0 so the
   * jitterbuffer does not base them on packet rate calculations.
   * If it does, out gap is big enough to be considered a new stream and
   * we wait for a few consecutive packets just to be sure
   */
  g_object_set (h->element, "do-lost", TRUE,
      "max-misorder-time", 0, "max-dropout-time", 0, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* move time ahead to just before 10 seconds */
  gst_harness_set_time (h, 10 * GST_SECOND - 1);

  /* check that we have no pending waits */
  fail_unless_equals_int (0, gst_test_clock_peek_id_count (testclock));

  /* a buffer now arrives perfectly on time */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer (500)));

  /* release the wait, advancing the clock to 10 sec */
  fail_unless (gst_harness_crank_single_clock_wait (h));

  /* we should now receive a packet-lost-event for buffers 11 through 489 ... */
  verify_lost_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, TEST_BUF_DURATION * (490 - next_seqnum));

  /* ... as well as 490 (since at 10 sec 490 is too late) */
  verify_lost_event (h, 490, 490 * TEST_BUF_DURATION, TEST_BUF_DURATION);

  /* we get as many lost events as the the number of *
   * buffers the jitterbuffer is able to wait for */
  for (i = 1; i < num_lost_events; i++) {
    fail_unless (gst_harness_crank_single_clock_wait (h));
    verify_lost_event (h, 490 + i, (490 + i) * TEST_BUF_DURATION,
        TEST_BUF_DURATION);
  }

  /* and then the buffer is released */
  out_buf = gst_harness_pull (h);
  fail_unless (GST_BUFFER_FLAG_IS_SET (out_buf, GST_BUFFER_FLAG_DISCONT));
  fail_unless_equals_int (500, get_rtp_seq_num (out_buf));
  fail_unless_equals_uint64 (10 * GST_SECOND, GST_BUFFER_PTS (out_buf));
  gst_buffer_unref (out_buf);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-lost", G_TYPE_UINT64, (guint64) 489, NULL)));

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_two_lost_one_arrives_in_time)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstTestClock *testclock;
  GstClockID id;
  GstBuffer *buf;
  gint latency_ms = 100;
  guint next_seqnum;
  guint first_missing;
  guint second_missing;
  guint current_arrived;

  testclock = gst_harness_get_testclock (h);
  g_object_set (h->element, "do-lost", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* hop over 2 packets and make another one (gap of 2) */
  first_missing = next_seqnum;
  second_missing = next_seqnum + 1;
  current_arrived = next_seqnum + 2;
  push_test_buffer (h, current_arrived);

  /* verify that the jitterbuffer now wait for the latest moment it can push the
   * @first_missing packet out.
   */
  gst_test_clock_wait_for_next_pending_id (testclock, &id);
  fail_unless_equals_uint64 (first_missing * TEST_BUF_DURATION +
      latency_ms * GST_MSECOND, gst_clock_id_get_time (id));
  gst_clock_id_unref (id);

  /* let the time expire... */
  fail_unless (gst_harness_crank_single_clock_wait (h));

  /* we should now receive a packet-lost-event */
  verify_lost_event (h, first_missing,
      first_missing * TEST_BUF_DURATION, TEST_BUF_DURATION);

  /* @second_missing now arrives just in time */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer (second_missing)));

  /* verify that @second_missing made it through! */
  buf = gst_harness_pull (h);
  fail_unless (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
  fail_unless_equals_int (second_missing, get_rtp_seq_num (buf));
  gst_buffer_unref (buf);

  /* and see that @current_arrived now also is pushed */
  buf = gst_harness_pull (h);
  fail_unless (!GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
  fail_unless_equals_int (current_arrived, get_rtp_seq_num (buf));
  gst_buffer_unref (buf);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 2,
              "num-lost", G_TYPE_UINT64, (guint64) 1, NULL)));

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_late_packets_still_makes_lost_events)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstBuffer *out_buf;
  gint latency_ms = 100;
  guint next_seqnum;
  guint seqnum;
  GstClockTime now;

  g_object_set (h->element, "do-lost", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* jump 10 seconds forward in time */
  now = 10 * GST_SECOND;
  gst_harness_set_time (h, now);

  /* push a packet with a gap of 2, that now is very late */
  seqnum = next_seqnum + 2;
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_full (now,
              seqnum, seqnum * TEST_RTP_TS_DURATION)));

  /* we should now receive packet-lost-events for the gap 
   * FIXME: The timeout and duration here are a bit crap...
   */
  verify_lost_event (h, next_seqnum, 3400 * GST_MSECOND, 6500 * GST_MSECOND);
  verify_lost_event (h, next_seqnum + 1,
      9900 * GST_MSECOND, 3300 * GST_MSECOND);

  /* verify that packet @seqnum made it through! */
  out_buf = gst_harness_pull (h);
  fail_unless (GST_BUFFER_FLAG_IS_SET (out_buf, GST_BUFFER_FLAG_DISCONT));
  fail_unless_equals_int (seqnum, get_rtp_seq_num (out_buf));
  gst_buffer_unref (out_buf);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 1,
              "num-lost", G_TYPE_UINT64, (guint64) 2, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;


GST_START_TEST (test_num_late_when_considered_lost_arrives)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gboolean do_lost = __i__ != 0;
  gint latency_ms = 100;
  guint next_seqnum;

  g_object_set (h->element, "do-lost", do_lost, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* gap of 1 */
  push_test_buffer (h, next_seqnum + 1);

  /* crank to trigger lost-event */
  gst_harness_crank_single_clock_wait (h);

  if (do_lost) {
    /* we should now receive packet-lost-events for the missing packet */
    verify_lost_event (h, next_seqnum,
        next_seqnum * TEST_BUF_DURATION, TEST_BUF_DURATION);
  }

  /* pull out the pushed packet */
  gst_buffer_unref (gst_harness_pull (h));

  /* we have one lost packet in the stats */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 1,
              "num-lost", G_TYPE_UINT64, (guint64) 1,
              "num-late", G_TYPE_UINT64, (guint64) 0, NULL)));

  /* the missing packet now arrives (too late) */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer (next_seqnum)));

  /* and this increments num-late */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 1,
              "num-lost", G_TYPE_UINT64, (guint64) 1,
              "num-late", G_TYPE_UINT64, (guint64) 1, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_lost_event_uses_pts)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstClockTime now;
  gint latency_ms = 100;
  guint next_seqnum;
  guint lost_seqnum;

  g_object_set (h->element, "do-lost", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* hop over 1 packets and make another one (gap of 1), but due to
     network delays, this packets is also grossly late */
  lost_seqnum = next_seqnum;
  next_seqnum += 1;

  /* advance the clock to the latest time packet @next_seqnum could arrive */
  now = next_seqnum * TEST_BUF_DURATION + latency_ms * GST_MSECOND;
  gst_harness_set_time (h, now);
  gst_harness_push (h, generate_test_buffer_full (now, next_seqnum,
          next_seqnum * TEST_RTP_TS_DURATION));

  /* we should now have received a packet-lost-event for buffer 3 */
  verify_lost_event (h, lost_seqnum,
      lost_seqnum * TEST_BUF_DURATION, TEST_BUF_DURATION);

  /* and pull out packet 4 */
  gst_buffer_unref (gst_harness_pull (h));

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 1, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_lost_event_with_backwards_rtptime)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 40;

  g_object_set (h->element, "do-lost", TRUE, NULL);
  construct_deterministic_initial_state (h, latency_ms);

  /*
   * For video using B-frames, an expected sequence
   * could be like this:
   * (I = I-frame, P = P-frame, B = B-frame)
   *               ___   ___   ___   ___   ___
   *          ... | 3 | | 4 | | 5 | | 6 | | 7 |
   *               –––   –––   –––   –––   –––
   * rtptime:       3(I)  5(P)  5(P)  4(B)  6(P)
   * arrival(dts):  3     5     5     5     6
   *
   * Notice here that packet 6 (the B frame) make
   * the rtptime go backwards.
   *
   * But we get this:
   *               ___   ___   _ _   ___   ___
   *          ... | 3 | | 4 | |   | | 6 | | 7 |
   *               –––   –––   - -   –––   –––
   * rtptime:       3(I)  5(P)        4(B)  6(P)
   * arrival(dts):  3     5           5     6
   *
   */

  /* seqnum 3 */
  push_test_buffer (h, 3);
  gst_buffer_unref (gst_harness_pull (h));

  /* seqnum 4, arriving at time 5 with rtptime 5 */
  gst_harness_push (h,
      generate_test_buffer_full (5 * TEST_BUF_DURATION,
          4, 5 * TEST_RTP_TS_DURATION));
  gst_buffer_unref (gst_harness_pull (h));

  /* seqnum 6, arriving at time 5 with rtptime 4,
     making a gap for missing seqnum 5 */
  gst_harness_push (h,
      generate_test_buffer_full (5 * TEST_BUF_DURATION,
          6, 4 * TEST_RTP_TS_DURATION));

  /* seqnum 7, arriving at time 6 with rtptime 6 */
  gst_harness_push (h,
      generate_test_buffer_full (6 * TEST_BUF_DURATION,
          7, 6 * TEST_RTP_TS_DURATION));

  /* we should now have received a packet-lost-event for seqnum 5,
     with time 5 and 0 duration */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, 5, 5 * TEST_BUF_DURATION, 0);

  /* and pull out 6 and 7 */
  gst_buffer_unref (gst_harness_pull (h));
  gst_buffer_unref (gst_harness_pull (h));

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) 7,
              "num-lost", G_TYPE_UINT64, (guint64) 1, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_all_packets_are_timestamped_zero)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstBuffer *out_buf;
  gint jb_latency_ms = 100;
  gint i, b;

  gst_harness_set_src_caps (h, generate_caps ());
  g_object_set (h->element, "do-lost", TRUE, "latency", jb_latency_ms, NULL);

  /* advance the clock with 10 seconds */
  gst_harness_set_time (h, 10 * GST_SECOND);

  /* push the first buffer through */
  gst_buffer_unref (gst_harness_push_and_pull (h, generate_test_buffer (0)));

  /* push some buffers in, all timestamped 0 */
  for (b = 1; b < 3; b++) {
    fail_unless_equals_int (GST_FLOW_OK,
        gst_harness_push (h,
            generate_test_buffer_full (0 * GST_MSECOND, b, 0)));

    /* check for the buffer coming out that was pushed in */
    out_buf = gst_harness_pull (h);
    fail_unless_equals_uint64 (0, GST_BUFFER_PTS (out_buf));
    gst_buffer_unref (out_buf);
  }

  /* hop over 2 packets and make another one (gap of 2) */
  b = 5;
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer_full (0 * GST_MSECOND, b, 0)));

  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));

  /* we should now receive packet-lost-events for buffer 3 and 4 */
  verify_lost_event (h, 3, 0, 0);
  verify_lost_event (h, 4, 0, 0);

  /* verify that buffer 5 made it through! */
  out_buf = gst_harness_pull (h);
  fail_unless (GST_BUFFER_FLAG_IS_SET (out_buf, GST_BUFFER_FLAG_DISCONT));
  fail_unless_equals_int (5, get_rtp_seq_num (out_buf));
  gst_buffer_unref (out_buf);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) 4,
              "num-lost", G_TYPE_UINT64, (guint64) 2, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_reorder_of_non_equidistant_packets)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstTestClock *testclock;
  gint latency_ms = 5;
  GstClockID pending_id;
  GstClockTime time;
  gint seq, frame;
  gint num_init_frames = 1;
  const GstClockTime frame_dur = TEST_BUF_DURATION;
  const guint32 frame_rtp_ts_dur = TEST_RTP_TS_DURATION;

  gst_harness_set_src_caps (h, generate_caps ());
  testclock = gst_harness_get_testclock (h);
  g_object_set (h->element, "do-lost", TRUE, "latency", latency_ms, NULL);

  for (frame = 0, seq = 0; frame < num_init_frames; frame++, seq += 2) {
    /* Push a couple of packets with identical timestamp, typical for a video
     * stream where one frame generates multiple packets. */
    gst_harness_set_time (h, frame * frame_dur);
    gst_harness_push (h, generate_test_buffer_full (frame * frame_dur,
            seq, frame * frame_rtp_ts_dur));
    gst_harness_push (h, generate_test_buffer_full (frame * frame_dur,
            seq + 1, frame * frame_rtp_ts_dur));

    if (frame == 0)
      /* deadline for buffer 0 expires */
      gst_harness_crank_single_clock_wait (h);

    gst_buffer_unref (gst_harness_pull (h));
    gst_buffer_unref (gst_harness_pull (h));
  }

  /* Finally push the last frame reordered */
  gst_harness_set_time (h, frame * frame_dur);
  gst_harness_push (h, generate_test_buffer_full (frame * frame_dur,
          seq + 1, frame * frame_rtp_ts_dur));

  /* Check the scheduled lost timer. The expected arrival of this packet
   * should be assumed to be the same as the last packet received since we
   * don't know wether the missing packet belonged to this or previous
   * frame. */
  gst_test_clock_wait_for_next_pending_id (testclock, &pending_id);
  time = gst_clock_id_get_time (pending_id);
  fail_unless_equals_int64 (time, frame * frame_dur + latency_ms * GST_MSECOND);
  gst_clock_id_unref (pending_id);

  /* And then missing packet arrives just in time */
  gst_harness_set_time (h, time - 1);
  gst_harness_push (h, generate_test_buffer_full (time - 1, seq,
          frame * frame_rtp_ts_dur));

  gst_buffer_unref (gst_harness_pull (h));
  gst_buffer_unref (gst_harness_pull (h));

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_loss_equidistant_spacing_with_parameter_packets)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 5;
  gint seq, frame;
  gint num_init_frames = 10;
  gint i;

  gst_harness_set_src_caps (h, generate_caps ());
  g_object_set (h->element, "do-lost", TRUE, "latency", latency_ms, NULL);

  /* drop stream-start, caps, segment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));

  for (frame = 0, seq = 0; frame < num_init_frames; frame++, seq++) {
    gst_harness_set_time (h, frame * TEST_BUF_DURATION);
    gst_harness_push (h, generate_test_buffer_full (frame * TEST_BUF_DURATION,
            seq, frame * TEST_RTP_TS_DURATION));

    if (frame == 0)
      /* deadline for buffer 0 expires */
      gst_harness_crank_single_clock_wait (h);

    gst_buffer_unref (gst_harness_pull (h));
  }

  /* Push three packets with same rtptime, simulating parameter packets +
   * frame. This should not disable equidistant mode as it is common for
   * certain audio codecs. */
  for (i = 0; i < 3; i++) {
    gst_harness_set_time (h, frame * TEST_BUF_DURATION);
    gst_harness_push (h, generate_test_buffer_full (frame * TEST_BUF_DURATION,
            seq++, frame * TEST_RTP_TS_DURATION));
    gst_buffer_unref (gst_harness_pull (h));
  }
  frame++;

  /* Finally push the last packet introducing a gap */
  gst_harness_set_time (h, frame * TEST_BUF_DURATION);
  gst_harness_push (h, generate_test_buffer_full (frame * TEST_BUF_DURATION,
          seq + 1, frame * TEST_RTP_TS_DURATION));

  /* Check that the lost event has been generated assuming equidistant
   * spacing. */
  verify_lost_event (h, seq,
      frame * TEST_BUF_DURATION - TEST_BUF_DURATION / 2, TEST_BUF_DURATION / 2);

  gst_buffer_unref (gst_harness_pull (h));

  gst_harness_teardown (h);
}

GST_END_TEST;


static void
gst_test_clock_set_time_and_process (GstTestClock * testclock,
    GstClockTime time)
{
  GstClockID id, tid;
  gst_test_clock_wait_for_next_pending_id (testclock, &id);
  gst_test_clock_set_time (testclock, time);
  tid = gst_test_clock_process_next_clock_id (testclock);
  g_assert (tid == id);
  gst_clock_id_unref (tid);
  gst_clock_id_unref (id);
}

GST_START_TEST (test_rtx_expected_next)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 200;
  guint next_seqnum;
  GstClockTime timeout;
  gint rtx_delay_ms;
  const GstClockTime rtx_retry_timeout_ms = 40;

  g_object_set (h->element, "do-lost", TRUE, NULL);
  g_object_set (h->element, "do-retransmission", TRUE, NULL);
  g_object_set (h->element, "rtx-retry-period", 120, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* At this point there is already existing a rtx-timer for @next_seqnum,
   * that will have a timeout of the expected arrival-time for that seqnum,
   * and a delay equal to 2*jitter==0 and 0.5*packet_spacing==10ms */
  timeout = next_seqnum * TEST_BUF_DURATION;
  rtx_delay_ms = 0.5 * TEST_BUF_MS;

  /* We crank the clock to time-out the next scheduled timer */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum, timeout, rtx_delay_ms, TEST_BUF_DURATION);

  /* now we wait for the next timeout, all following timeouts 40ms in the
   * future because this is rtx-retry-timeout */
  rtx_delay_ms += rtx_retry_timeout_ms;
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum, timeout, rtx_delay_ms, TEST_BUF_DURATION);

  /* And a third time... */
  rtx_delay_ms += rtx_retry_timeout_ms;
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum, timeout, rtx_delay_ms, TEST_BUF_DURATION);

  /* we should now receive a packet-lost-event for packet @next_seqnum */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, next_seqnum, timeout, TEST_BUF_DURATION);

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_next_seqnum_disabled)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 200;
  guint next_seqnum, missing_seqnum;
  GstTestClock *testclock;
  GstClockTime timeout, last_rtx_request;
  gint rtx_delay_ms;
  const GstClockTime rtx_retry_timeout_ms = 40;

  testclock = gst_harness_get_testclock (h);

  g_object_set (h->element, "do-lost", TRUE, NULL);
  g_object_set (h->element, "do-retransmission", TRUE, NULL);
  g_object_set (h->element, "rtx-retry-period", 120, NULL);
  g_object_set (h->element, "rtx-next-seqnum", FALSE, NULL);

  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* When rtx-next-seqnum is disabled there is no existing rtx-timer for
   * @next_seqnum until there is a gap and it's missing. */

  /* Check that we have no pending waits */
  fail_unless_equals_int (0, gst_test_clock_peek_id_count (testclock));

  /* Push next packet to create a gap and trigger rtx-timers */
  missing_seqnum = next_seqnum;
  next_seqnum += 1;
  push_test_buffer (h, next_seqnum);

  /* Now there should exist a rtx-timer for @next_seqnum, that will have a
   * timeout of the expected arrival-time for that seqnum, and a delay equal
   * to the elapsed time since the timeout and until now (which is the
   * duration of one buffer, 20 ms). */
  timeout = missing_seqnum * TEST_BUF_DURATION;
  rtx_delay_ms = TEST_BUF_MS;

  /* The first rtx-event is triggered immediately since the timeout + delay is
   * less than "now" */
  verify_rtx_event (h, missing_seqnum, timeout, rtx_delay_ms,
      TEST_BUF_DURATION);
  last_rtx_request = gst_clock_get_time (GST_CLOCK (testclock));
  fail_unless_equals_int64 (last_rtx_request,
      missing_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* now we wait for the next timeout, all following timers timeout in 40ms
   * increments because this is rtx-retry-timeout */
  rtx_delay_ms += rtx_retry_timeout_ms;
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, missing_seqnum, timeout, rtx_delay_ms,
      TEST_BUF_DURATION);
  last_rtx_request = gst_clock_get_time (GST_CLOCK (testclock));
  fail_unless_equals_int64 (last_rtx_request,
      missing_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* And a third time... */
  rtx_delay_ms += rtx_retry_timeout_ms;
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, missing_seqnum, timeout, rtx_delay_ms,
      TEST_BUF_DURATION);
  last_rtx_request = gst_clock_get_time (GST_CLOCK (testclock));
  fail_unless_equals_int64 (last_rtx_request,
      missing_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* we should now receive a packet-lost-event for packet @missing_seqnum */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, missing_seqnum, timeout, TEST_BUF_DURATION);

  /* Finally pull out the next packet */
  gst_buffer_unref (gst_harness_pull (h));

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_two_missing)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 200;
  guint next_seqnum;
  GstClockTime last_rtx_request, now;
  gint rtx_delay_ms_0 = 0.5 * TEST_BUF_MS;
  gint rtx_delay_ms_1 = 1.0 * TEST_BUF_MS;

  g_object_set (h->element, "do-retransmission", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);
  fail_unless_equals_int (11, next_seqnum);

  /*
   * The expected sequence of buffers is this:
   *      ____   ____   ____   ____
   * ... | 10 | | 11 | | 12 | | 13 |
   *      ––––   ––––   ––––   ––––
   *      200ms  220ms  240ms  260ms
   *
   * But instead we get this:
   *      ____    _ _    _ _   ____
   * ... | 10 |  |   |  |   | | 13 |
   *      ––––    - -    - -   ––––
   *      200ms                260ms
   *
   * Now it is important to note that the next thing that happens is that
   * the RTX timeout for packet 11 will happen at time 230ms, so we crank
   * the timer thread to advance the time to this:
   */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, 11, 11 * TEST_BUF_DURATION,
      rtx_delay_ms_0, TEST_BUF_DURATION);
  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      11 * TEST_BUF_DURATION + rtx_delay_ms_0 * GST_MSECOND);
  gst_harness_wait_for_clock_id_waits (h, 1, 60);

  /* The next scheduled RTX for packet 11 is now at 230 + 40 = 270ms,
     so the next thing that happens is that buffer 13 arrives in perfect time: */
  now = 13 * TEST_BUF_DURATION;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h,
          generate_test_buffer_full (now, 13, 13 * TEST_RTP_TS_DURATION)));

  /*
   *
   * This will estimate the dts on the two missing packets to:
   *      ____   ____
   * ... | 11 | | 12 | ...
   *      ––––   ––––
   *      220ms  240ms
   *
   * And given their regular interspacing of 20ms, it will schedule two RTX
   * timers for them like so:
   *
   *      ____   ____
   * ... | 11 | | 12 | ...
   *      ––––   ––––
   *      230ms  250ms
   *
   * There are however two problems, packet 11 we have already sent one RTX for
   * and its timeout is currently at 270ms, so we should not tamper with that,
   * and as for packet 12, 250ms has already expired, so we now expect to see
   * an rtx-event being sent for packet 12 immediately.
   *
   * Since the current time is 260 ms and packet 12 was expected at 240 ms,
   * the delay of the rtx-event is 20 ms.
   */
  verify_rtx_event (h, 12, 12 * TEST_BUF_DURATION,
      rtx_delay_ms_1, TEST_BUF_DURATION);
  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      12 * TEST_BUF_DURATION + rtx_delay_ms_1 * GST_MSECOND);

  /* and another crank will see the second RTX event being sent for packet 11 */
  gst_harness_crank_single_clock_wait (h);
  rtx_delay_ms_0 += 40;
  verify_rtx_event (h, 11, 11 * TEST_BUF_DURATION,
      rtx_delay_ms_0, TEST_BUF_DURATION);
  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      11 * TEST_BUF_DURATION + rtx_delay_ms_0 * GST_MSECOND);

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_buffer_arrives_just_in_time)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 5 * TEST_BUF_MS;
  gint next_seqnum;
  GstBuffer *buffer;
  GstClockTime now, last_rtx_request;
  gint rtx_delay_ms = 0.5 * TEST_BUF_MS;

  g_object_set (h->element, "do-retransmission", TRUE,
      "rtx-max-retries", 1, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* Crank clock to send retransmission events requesting seqnum 6 which has
   * not arrived yet. */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* seqnum 6 arrives just before it times out and is considered lost */
  now = 200 * GST_MSECOND;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, next_seqnum)));
  buffer = gst_harness_pull (h);
  fail_unless_equals_int (next_seqnum, get_rtp_seq_num (buffer));
  gst_buffer_unref (buffer);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 1,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-per-packet", G_TYPE_DOUBLE, 1.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) (now - last_rtx_request),
              NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_buffer_arrives_too_late)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 5 * TEST_BUF_MS;
  gint next_seqnum;
  GstClockTime now, last_rtx_request;
  gint rtx_delay_ms = 0.5 * TEST_BUF_MS;

  g_object_set (h->element, "do-retransmission", TRUE,
      "do-lost", TRUE, "rtx-max-retries", 1, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* Crank clock to send retransmission events requesting seqnum 6 which has
   * not arrived yet. */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* packet @next_seqnum is considered lost */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, TEST_BUF_DURATION);

  /* packet @next_seqnum arrives too late */
  now = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, next_seqnum)));

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 1,
              "num-late", G_TYPE_UINT64, (guint64) 1,
              "num-duplicates", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 0,
              "rtx-per-packet", G_TYPE_DOUBLE, 1.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) (now - last_rtx_request),
              NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_original_buffer_does_not_update_rtx_stats)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 100;
  gint next_seqnum;
  GstBuffer *buffer;
  GstClockTime now, last_rtx_request;
  gint rtx_delay_ms = 0.5 * TEST_BUF_MS;

  g_object_set (h->element, "do-retransmission", TRUE,
      "rtx-max-retries", 1, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);
  fail_unless_equals_int (6, next_seqnum);

  /* Crank clock to send retransmission events requesting @next_seqnum which has
   * not arrived yet. */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* ORIGINAL seqnum 6 arrives just before it times out and is considered
   * lost. */
  now = 200 * GST_MSECOND;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_full (now,
              next_seqnum, next_seqnum * TEST_RTP_TS_DURATION)));
  buffer = gst_harness_pull (h);
  fail_unless_equals_int (next_seqnum, get_rtp_seq_num (buffer));
  gst_buffer_unref (buffer);

  /* due to the advance in time, we will now also have sent
     an rtx-request for 7 */
  next_seqnum++;
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  /* The original buffer does not count in the RTX stats. */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 0,
              "rtx-per-packet", G_TYPE_DOUBLE, 0.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) 0, NULL)));

  /* Now the retransmitted packet arrives and stats should be updated. Note
   * that the buffer arrives in time and should not be considered late, but
   * a duplicate. */
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, 6)));

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 1,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 0,
              "rtx-per-packet", G_TYPE_DOUBLE, 1.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) (now - last_rtx_request),
              NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_duplicate_packet_updates_rtx_stats)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 100;
  gint next_seqnum;
  GstClockTime now, rtx_request_6, rtx_request_7;
  gint rtx_delay_ms_0 = 0.5 * TEST_BUF_MS;
  gint rtx_delay_ms_1 = 1.0 * TEST_BUF_MS;
  gint i;

  g_object_set (h->element, "do-retransmission", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);
  fail_unless_equals_int (6, next_seqnum);

  /* Push packet 8 so that 6 and 7 is missing */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer (8)));

  /* Wait for NACKs on 6 and 7 */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, 6, 6 * TEST_BUF_DURATION,
      rtx_delay_ms_0, TEST_BUF_DURATION);
  rtx_request_6 = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (rtx_request_6,
      6 * TEST_BUF_DURATION + rtx_delay_ms_0 * GST_MSECOND);

  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h,
      7, 7 * TEST_BUF_DURATION, rtx_delay_ms_1, TEST_BUF_DURATION);
  rtx_request_7 = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (rtx_request_7,
      7 * TEST_BUF_DURATION + rtx_delay_ms_1 * GST_MSECOND);

  /* Original packet 7 arrives */
  now = 161 * GST_MSECOND;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_full (now, 7, 7 * TEST_RTP_TS_DURATION)));

  /* We're still waiting for packet 6, so 7 should not be pushed */
  gst_harness_wait_for_clock_id_waits (h, 1, 60);
  fail_unless_equals_int (gst_harness_buffers_in_queue (h), 0);

  /* The original buffer does not count in the RTX stats. */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 0,
              "rtx-per-packet", G_TYPE_DOUBLE, 0.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) 0, NULL)));

  /* Push RTX packet 7. Should be dropped as duplicate but update RTX stats. */
  now = 162 * GST_MSECOND;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, 7)));
  gst_harness_wait_for_clock_id_waits (h, 1, 60);
  fail_unless_equals_int (gst_harness_buffers_in_queue (h), 0);

  /* Check RTX stats with updated num-duplicates and rtx-rtt fields */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 1,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 0,
              "rtx-per-packet", G_TYPE_DOUBLE, 1.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) (now - rtx_request_7),
              NULL)));

  /* RTX packet 6 arrives, both 6, 7 and 8 is ready to be pulled */
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, 6)));

  for (i = 6; i <= 8; i++) {
    GstBuffer *buf = gst_harness_pull (h);
    fail_unless_equals_int (i, get_rtp_seq_num (buf));
    gst_buffer_unref (buf);
  }

  /* RTX stats is updated with success count increased. */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 3,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 1,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-per-packet", G_TYPE_DOUBLE, 1.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64)
              /* Use the rtx-rtt formula. Can be subject to change though. */
              ((now - rtx_request_6) + 47 * (now - rtx_request_7)) / 48,
              NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_buffer_arrives_after_lost_updates_rtx_stats)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 100;
  gint next_seqnum;
  GstClockTime now, last_rtx_request;
  gint rtx_delay_ms = 0.5 * TEST_BUF_MS;

  g_object_set (h->element, "do-retransmission", TRUE,
      "do-lost", TRUE, "rtx-max-retries", 1, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* Crank clock to send retransmission events requesting seqnum 6 which has
   * not arrived yet. */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* seqnum 6 is considered lost */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, TEST_BUF_DURATION);

  /* seqnum 6 arrives too late */
  now = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, next_seqnum)));

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 1,
              "num-late", G_TYPE_UINT64, (guint64) 1,
              "num-duplicates", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 0,
              "rtx-per-packet", G_TYPE_DOUBLE, 1.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) (now - last_rtx_request),
              NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_rtt_larger_than_retry_timeout)
{
  /* When RTT is larger than retry period we will send two or more requests
   * before receiving any retransmission packets */
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 100;
  gint next_seqnum;
  gint rtx_retry_timeout_ms = 20;
  gint rtx_delay_ms = 0.5 * TEST_BUF_MS;
  gint rtt = rtx_retry_timeout_ms * GST_MSECOND + 1;
  GstClockTime now, first_request, second_request;

  g_object_set (h->element, "do-retransmission", TRUE,
      "rtx-retry-timeout", rtx_retry_timeout_ms, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* Wait for first NACK on 6 */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);
  first_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (first_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* Packet @next_seqnum + 1 arrives in time (so that we avoid its EXPECTED
   * timers to interfer with our test) */
  push_test_buffer (h, next_seqnum + 1);

  /* Simulating RTT > rtx-retry-timeout, we send a new NACK before receiving
   * the RTX packet. Wait for second NACK on @next_seqnum */
  gst_harness_crank_single_clock_wait (h);
  rtx_delay_ms += rtx_retry_timeout_ms;
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);
  second_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (second_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* The first retransmitted packet arrives */
  now = first_request + rtt;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, next_seqnum)));

  /* Pull packets @next_seqnum and @next_seqnum + 1 */
  gst_buffer_unref (gst_harness_pull (h));
  gst_buffer_unref (gst_harness_pull (h));

  /* Stats should be updated. Note that RTT is not updated since we cannot be
   * sure whether the RTX packet is in response to the first or second NACK. */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 2,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-per-packet", G_TYPE_DOUBLE, 2.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) 0, NULL)));

  /* Packet @next_seqnum + 2 arrives in time */
  push_test_buffer (h, next_seqnum + 2);
  gst_buffer_unref (gst_harness_pull (h));

  /* Now the second retransmitted packet arrives */
  now = second_request + rtt;
  gst_harness_set_time (h, now);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
          generate_test_buffer_rtx (now, next_seqnum)));

  /* The stats is updated with the correct RTT. */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum + 3,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "num-late", G_TYPE_UINT64, (guint64) 0,
              "num-duplicates", G_TYPE_UINT64, (guint64) 1,
              "rtx-count", G_TYPE_UINT64, (guint64) 2,
              "rtx-success-count", G_TYPE_UINT64, (guint64) 1,
              "rtx-per-packet", G_TYPE_DOUBLE, 2.0,
              "rtx-rtt", G_TYPE_UINT64, (guint64) rtt, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_no_request_if_time_past_retry_period)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  const gint latency_ms = 200;
  const gint retry_period_ms = 120;
  GstTestClock *testclock;
  GstClockID pending_id;
  GstClockTime time;
  gint i;

  gst_harness_set_src_caps (h, generate_caps ());
  testclock = gst_harness_get_testclock (h);

  g_object_set (h->element, "do-lost", TRUE, NULL);
  g_object_set (h->element, "do-retransmission", TRUE, NULL);
  g_object_set (h->element, "latency", latency_ms, NULL);
  g_object_set (h->element, "rtx-retry-period", retry_period_ms, NULL);

  /* push the first couple of buffers */
  push_test_buffer (h, 0);
  push_test_buffer (h, 1);

  /* drop reconfigure event */
  gst_event_unref (gst_harness_pull_upstream_event (h));
  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));

  /* Wait for the first EXPECTED timer to be scheduled */
  gst_test_clock_wait_for_next_pending_id (testclock, &pending_id);
  time = gst_clock_id_get_time (pending_id);
  gst_clock_id_unref (pending_id);
  fail_unless_equals_int64 (time, 2 * TEST_BUF_DURATION + 10 * GST_MSECOND);

  /* Let the first EXPECTED timer time out and be sent. However, set the 'now'
   * time to be past the retry-period simulating that the jitterbuffer has too
   * much to do and is not able to process all timers in real-time. In this
   * case the jitterbuffer should not schedule a new EXPECTED timer as that
   * would just make matters worse (more unnecessary processing of a request
   * that is already too late to be valuable). In practice this typically
   * happens for high loss networks with low RTT. */
  gst_test_clock_set_time_and_process (testclock,
      2 * TEST_BUF_DURATION + retry_period_ms * GST_MSECOND + 1);

  /* Verify the event. It could be argued that this request is already too
   * late and unnecessary. However, in order to keep things simple (for now)
   * we just keep the already scehduled EXPECTED timer, but refrain from
   * scheduled another EXPECTED timer */
  verify_rtx_event (h, 2, 2 * TEST_BUF_DURATION, 10, TEST_BUF_DURATION);

  /* "crank" to reach the DEADLINE for packet 0 */
  gst_harness_crank_single_clock_wait (h);
  gst_buffer_unref (gst_harness_pull (h));
  gst_buffer_unref (gst_harness_pull (h));

  fail_unless_equals_int (0, gst_harness_upstream_events_in_queue (h));
  fail_unless_equals_int (0, gst_harness_events_in_queue (h));

  /* "crank" to time out the LOST event */
  gst_harness_crank_single_clock_wait (h);
  verify_lost_event (h, 2, 2 * TEST_BUF_DURATION, TEST_BUF_DURATION);

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_same_delay_and_retry_timeout)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 5 * TEST_BUF_MS;
  gint next_seqnum;
  gint rtx_delay_ms = 20;
  GstClockTime last_rtx_request;

  g_object_set (h->element, "do-retransmission", TRUE,
      "rtx-max-retries", 3, "rtx-delay", rtx_delay_ms,
      "rtx-retry-timeout", rtx_delay_ms, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* Crank clock to send retransmission events requesting seqnum 6 which has
   * not arrived yet. */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);
  /* first rtx for packet @next_seqnum should arrive at the right time */
  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * GST_MSECOND);

  /* verify we have pulled out all rtx-events */
  fail_unless_equals_int (0, gst_harness_upstream_events_in_queue (h));

  /* now crank to get the second attempt at packet @next_seqnum */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms * 2, TEST_BUF_DURATION);

  /* second rtx for seqnum 6 should arrive at 140 + 20ms */
  last_rtx_request = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  fail_unless_equals_int64 (last_rtx_request,
      next_seqnum * TEST_BUF_DURATION + rtx_delay_ms * 2 * GST_MSECOND);

  /* verify we have pulled out all rtx-events */
  fail_unless_equals_int (0, gst_harness_upstream_events_in_queue (h));

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) next_seqnum,
              "num-lost", G_TYPE_UINT64, (guint64) 0,
              "rtx-count", G_TYPE_UINT64, (guint64) 2, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_with_backwards_rtptime)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 40;

  g_object_set (h->element, "do-retransmission", TRUE, NULL);
  construct_deterministic_initial_state (h, latency_ms);

  /*
   * For video using B-frames, an expected sequence
   * could be like this:
   * (I = I-frame, P = P-frame, B = B-frame)
   *               ___   ___   ___
   *          ... | 3 | | 4 | | 5 |
   *               –––   –––   –––
   * rtptime:       3(I)  5(P)  4(B)
   * arrival(dts):  3     5     5
   *
   * Notice here that packet 5 (the B frame) make
   * the rtptime go backwards.
   */

  /* seqnum 3, arriving at time 3 with rtptime 3 */
  push_test_buffer (h, 3);
  gst_buffer_unref (gst_harness_pull (h));

  /* seqnum 4, arriving at time 5 with rtptime 5 */
  gst_harness_push (h, generate_test_buffer_full (5 * TEST_BUF_DURATION,
          4, 5 * TEST_RTP_TS_DURATION));
  gst_buffer_unref (gst_harness_pull (h));

  /* seqnum 5, arriving at time 5 with rtptime 4 */
  gst_harness_push (h, generate_test_buffer_full (5 * TEST_BUF_DURATION,
          5, 4 * TEST_RTP_TS_DURATION));
  gst_buffer_unref (gst_harness_pull (h));

  /* crank to time-out the rtx-request for seqnum 6, the point here
     being that the backwards rtptime did not mess up the timeout for
     the rtx event */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, 6, 5 * TEST_BUF_DURATION + 15 * GST_MSECOND,
      17, 35 * GST_MSECOND);

  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) 6,
              "rtx-count", G_TYPE_UINT64, (guint64) 1,
              "num-lost", G_TYPE_UINT64, (guint64) 0, NULL)));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_timer_reuse)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  gint latency_ms = 5 * TEST_BUF_MS;
  gint rtx_delay_ms = 0.5 * TEST_BUF_MS;
  guint next_seqnum;

  g_object_set (h->element, "do-retransmission", TRUE,
      "do-lost", TRUE, "rtx-max-retries", 1, NULL);
  next_seqnum = construct_deterministic_initial_state (h, latency_ms);

  /* crank to timeout the only rtx-request, and the timer will
   * now reschedule as a lost-timer internally */
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  /* but now buffer 6 arrives, and this should now reuse the lost-timer
   * for 6, as an expected-timer for 7 */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer (next_seqnum)));

  /* now crank to timeout the expected-timer for 7 and verify */
  next_seqnum++;
  gst_harness_crank_single_clock_wait (h);
  verify_rtx_event (h, next_seqnum,
      next_seqnum * TEST_BUF_DURATION, rtx_delay_ms, TEST_BUF_DURATION);

  gst_harness_teardown (h);
}

GST_END_TEST;


static void
start_test_rtx_large_packet_spacing (GstHarness * h,
    gint latency_ms, gint frame_dur_ms, gint rtx_rtt_ms,
    guint16 * dst_lost_seq, GstClockTime * dst_now)
{
  gint i, seq, frame;
  GstBuffer *buffer;
  GstClockTime now, lost_packet_time;
  GstClockTime frame_dur = frame_dur_ms * GST_MSECOND;

  gst_harness_set_src_caps (h, generate_caps ());
  g_object_set (h->element,
      "do-lost", TRUE, "latency", latency_ms, "do-retransmission", TRUE, NULL);

  /* Pushing 2 frames @frame_dur_ms ms apart from each other to initialize
   * packet_spacing and avg jitter */
  for (frame = 0, seq = 0, now = 0; frame < 2;
      frame++, seq += 2, now += frame_dur) {
    gst_harness_set_time (h, now);
    gst_harness_push (h, generate_test_buffer_full (now, seq,
            AS_TEST_BUF_RTP_TIME (now)));
    gst_harness_push (h, generate_test_buffer_full (now, seq + 1,
            AS_TEST_BUF_RTP_TIME (now)));

    if (frame == 0)
      /* deadline for buffer 0 expires */
      gst_harness_crank_single_clock_wait (h);

    gst_buffer_unref (gst_harness_pull (h));
    gst_buffer_unref (gst_harness_pull (h));
  }

  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));
  /* drop reconfigure event */
  gst_event_unref (gst_harness_pull_upstream_event (h));

  /* The first packet (#@seq) of the 3rd frame is lost */
  lost_packet_time = now;
  gst_harness_set_time (h, now);
  gst_harness_push (h, generate_test_buffer_full (now, seq + 1,
          AS_TEST_BUF_RTP_TIME (now)));

  /* RTX delay calculated as:
   *     MIN(rtx_delay_max, MAX(2*avg_jitter, 0.5 * packet_spacing)).
   * Where rtx_delay_max:
   *     rtx_delay_max = latency - rtx_rtt.
   * We have not used RTX yet, so rtx_rtt = 0, rtx_delay_max = latency.
   * Thus we expect the first RTX event to be sent in @latency_ms ms */
  gst_harness_crank_single_clock_wait (h);
  fail_unless_equals_int64 (now + latency_ms * GST_MSECOND,
      gst_clock_get_time (GST_ELEMENT_CLOCK (h->element)));
  verify_rtx_event (h, seq, now, latency_ms, frame_dur);
  verify_lost_event (h, seq, now, 0);
  gst_buffer_unref (gst_harness_pull (h));
  now += latency_ms * GST_MSECOND;

  /* Sending lost packet as RTX to initialize rtx_rtt */
  now += rtx_rtt_ms * GST_MSECOND;
  gst_harness_set_time (h, now);
  buffer =
      generate_test_buffer_full (now, seq,
      AS_TEST_BUF_RTP_TIME (lost_packet_time));
  GST_BUFFER_FLAG_SET (buffer, GST_RTP_BUFFER_FLAG_RETRANSMISSION);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h, buffer));

  /* No buffers should be pushed through, as lost packet arrived too late */
  fail_unless_equals_int (0, gst_harness_buffers_in_queue (h));

  seq += 2;
  frame += 1;
  now = frame * frame_dur;
  gst_harness_set_time (h, now);

  /* The first packet (#@seq) of the 4th frame is lost */
  gst_harness_push (h, generate_test_buffer_full (now, seq + 1,
          AS_TEST_BUF_RTP_TIME (now)));
  *dst_lost_seq = seq;
  *dst_now = now;
}

GST_START_TEST (test_rtx_large_packet_spacing_and_small_rtt)
{
  GstClockTime now;
  guint16 lost_seq;
  gint latency_ms = 20;
  gint frame_dur_ms = 50;
  gint rtx_rtt_ms = 5;
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");

  start_test_rtx_large_packet_spacing (h, latency_ms, frame_dur_ms, rtx_rtt_ms,
      &lost_seq, &now);

  /* With small rtx_rtt, RTX event expected to be sent in
     (@latency_ms - @rtx_rtt_ms) ms */
  gst_harness_crank_single_clock_wait (h);
  fail_unless_equals_int64 (now + (latency_ms - rtx_rtt_ms) * GST_MSECOND,
      gst_clock_get_time (GST_ELEMENT_CLOCK (h->element)));
  verify_rtx_event (h, lost_seq, now, (latency_ms - rtx_rtt_ms),
      frame_dur_ms * GST_MSECOND);

  /* After @latency ms the packet should be considered lost */
  gst_harness_crank_single_clock_wait (h);
  fail_unless_equals_int64 (now + latency_ms * GST_MSECOND,
      gst_clock_get_time (GST_ELEMENT_CLOCK (h->element)));
  verify_lost_event (h, lost_seq, now, 0);
  gst_buffer_unref (gst_harness_pull (h));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_large_packet_spacing_and_large_rtt)
{
  GstClockTime now;
  guint16 lost_seq;
  gint latency_ms = 20;
  gint frame_dur_ms = 50;
  gint rtx_rtt_ms = 30;
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");

  start_test_rtx_large_packet_spacing (h, latency_ms, frame_dur_ms, rtx_rtt_ms,
      &lost_seq, &now);

  /* With large rtx_rtt, RTX event expected to be sent in @latency_ms ms.
     The buffer considered lost. */
  gst_harness_crank_single_clock_wait (h);
  fail_unless_equals_int64 (now + latency_ms * GST_MSECOND,
      gst_clock_get_time (GST_ELEMENT_CLOCK (h->element)));
  verify_rtx_event (h, lost_seq, now, latency_ms, frame_dur_ms * GST_MSECOND);
  verify_lost_event (h, lost_seq, now, 0);
  gst_buffer_unref (gst_harness_pull (h));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_rtx_large_packet_spacing_does_not_reset_jitterbuffer)
{
  gint latency_ms = 20;
  gint frame_dur_ms = 50;
  gint rtx_rtt_ms = 5;
  gint i, seq;
  GstBuffer *buffer;
  GstClockTime now, lost_packet_time;
  GstClockTime frame_dur = frame_dur_ms * GST_MSECOND;
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");

  gst_harness_set_src_caps (h, generate_caps ());
  g_object_set (h->element,
      "do-lost", TRUE, "latency", latency_ms, "do-retransmission", TRUE, NULL);

  /* Pushing 2 frames @frame_dur_ms ms apart from each other to initialize
   * packet_spacing and avg jitter */
  for (seq = 0, now = 0; seq < 2; ++seq, now += frame_dur) {
    gst_harness_set_time (h, now);
    gst_harness_push (h, generate_test_buffer_full (now, seq,
            AS_TEST_BUF_RTP_TIME (now)));
    if (seq == 0)
      gst_harness_crank_single_clock_wait (h);
    buffer = gst_harness_pull (h);
    fail_unless_equals_int64 (now, GST_BUFFER_PTS (buffer));
    gst_buffer_unref (buffer);
  }

  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));
  /* drop reconfigure event */
  gst_event_unref (gst_harness_pull_upstream_event (h));

  /* Waiting for the RTX timer of packet #2 to timeout */
  lost_packet_time = now;
  gst_harness_crank_single_clock_wait (h);
  fail_unless_equals_int64 (now + latency_ms * GST_MSECOND,
      gst_clock_get_time (GST_ELEMENT_CLOCK (h->element)));
  verify_rtx_event (h, seq, now, latency_ms, frame_dur);
  verify_lost_event (h, seq, now, frame_dur);
  now += latency_ms * GST_MSECOND;

  /* Pushing packet #2 as RTX */
  now += rtx_rtt_ms * GST_MSECOND;
  gst_harness_set_time (h, now);
  buffer =
      generate_test_buffer_full (now, seq,
      AS_TEST_BUF_RTP_TIME (lost_packet_time));
  GST_BUFFER_FLAG_SET (buffer, GST_RTP_BUFFER_FLAG_RETRANSMISSION);
  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h, buffer));
  fail_unless_equals_int (0, gst_harness_buffers_in_queue (h));

  /* Packet #3 should have PTS not affected by clock skew logic */
  seq += 1;
  now = seq * frame_dur;
  gst_harness_set_time (h, now);
  gst_harness_push (h, generate_test_buffer_full (now, seq,
          AS_TEST_BUF_RTP_TIME (now)));
  buffer = gst_harness_pull (h);
  fail_unless_equals_int64 (now, GST_BUFFER_PTS (buffer));
  gst_buffer_unref (buffer);

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_minor_reorder_does_not_skew)
{
  gint latency_ms = 20;
  gint frame_dur_ms = 50;
  guint rtx_min_delay_ms = 110;
  gint hickup_ms = 2;
  gint i, seq;
  GstBuffer *buffer;
  GstClockTime now;
  GstClockTime frame_dur = frame_dur_ms * GST_MSECOND;
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");

  gst_harness_set_src_caps (h, generate_caps ());
  g_object_set (h->element,
      "do-lost", TRUE, "latency", latency_ms, "do-retransmission", TRUE,
      "rtx-min-delay", rtx_min_delay_ms, NULL);

  /* Pushing 2 frames @frame_dur_ms ms apart from each other to initialize
   * packet_spacing and avg jitter */
  for (seq = 0, now = 0; seq < 2; ++seq, now += frame_dur) {
    gst_harness_set_time (h, now);
    gst_harness_push (h, generate_test_buffer_full (now, seq,
            AS_TEST_BUF_RTP_TIME (now)));
    if (seq == 0)
      gst_harness_crank_single_clock_wait (h);
    buffer = gst_harness_pull (h);
    fail_unless_equals_int64 (now, GST_BUFFER_PTS (buffer));
    gst_buffer_unref (buffer);
  }

  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));
  /* drop reconfigure event */
  gst_event_unref (gst_harness_pull_upstream_event (h));

  /* Pushing packet #4 before #3, shortly after #3 would have arrived normally */
  gst_harness_set_time (h, now + hickup_ms * GST_MSECOND);
  gst_harness_push (h, generate_test_buffer_full (now + hickup_ms * GST_MSECOND,
          seq + 1, AS_TEST_BUF_RTP_TIME (now + frame_dur)));

  /* Pushing packet #3 after #4 when #4 would have normally arrived */
  gst_harness_set_time (h, now + frame_dur);
  gst_harness_push (h, generate_test_buffer_full (now + frame_dur, seq,
          AS_TEST_BUF_RTP_TIME (now)));

  /* Pulling should be retrieving #3 first */
  buffer = gst_harness_pull (h);
  fail_unless_equals_int64 (now, GST_BUFFER_PTS (buffer));
  gst_buffer_unref (buffer);

  /* Pulling should be retrieving #4 second */
  buffer = gst_harness_pull (h);
  fail_unless_equals_int64 (now + frame_dur, GST_BUFFER_PTS (buffer));
  gst_buffer_unref (buffer);

  now += 2 * frame_dur;
  seq += 2;

  /* Pushing packet #5 normal again */
  gst_harness_set_time (h, now);
  gst_harness_push (h, generate_test_buffer_full (now, seq,
          AS_TEST_BUF_RTP_TIME (now)));
  buffer = gst_harness_pull (h);
  fail_unless_equals_int64 (now, GST_BUFFER_PTS (buffer));
  gst_buffer_unref (buffer);

  seq++;
  now += frame_dur;

  /* Pushing packet #6 half a frame early to trigger clock skew */
  gst_harness_set_time (h, now);
  gst_harness_push (h, generate_test_buffer_full (now, seq,
          AS_TEST_BUF_RTP_TIME (now + frame_dur / 2)));
  buffer = gst_harness_pull (h);
  fail_unless (now + frame_dur / 2 > GST_BUFFER_PTS (buffer),
      "pts should have been adjusted due to clock skew");
  gst_buffer_unref (buffer);

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_deadline_ts_offset)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstTestClock *testclock;
  GstClockID id;
  const gint jb_latency_ms = 10;

  gst_harness_set_src_caps (h, generate_caps ());
  testclock = gst_harness_get_testclock (h);

  g_object_set (h->element, "latency", jb_latency_ms, NULL);

  /* push the first buffer in */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer (0)));

  /* wait_next_timeout() syncs on the deadline timer */
  gst_test_clock_wait_for_next_pending_id (testclock, &id);
  fail_unless_equals_uint64 (jb_latency_ms * GST_MSECOND,
      gst_clock_id_get_time (id));
  gst_clock_id_unref (id);

  /* add ts-offset while waiting */
  g_object_set (h->element, "ts-offset", 20 * GST_MSECOND, NULL);

  gst_test_clock_set_time_and_process (testclock, jb_latency_ms * GST_MSECOND);

  /* wait_next_timeout() syncs on the new deadline timer */
  gst_test_clock_wait_for_next_pending_id (testclock, &id);
  fail_unless_equals_uint64 ((20 + jb_latency_ms) * GST_MSECOND,
      gst_clock_id_get_time (id));
  gst_clock_id_unref (id);

  /* now make deadline timer timeout */
  gst_test_clock_set_time_and_process (testclock,
      (20 + jb_latency_ms) * GST_MSECOND);

  gst_buffer_unref (gst_harness_pull (h));

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_big_gap_seqnum)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  const gint num_consecutive = 5;
  const guint gap = 20000;
  gint i;
  guint seqnum_org;
  GstClockTime dts_base;
  guint seqnum_base;
  guint32 rtpts_base;
  GstClockTime expected_ts;

  g_object_set (h->element, "do-lost", TRUE, "do-retransmission", TRUE, NULL);
  seqnum_org = construct_deterministic_initial_state (h, 100);

  /* a sudden jump in sequence-numbers (and rtptime), but packets keep arriving
     at the same pace */
  dts_base = seqnum_org * TEST_BUF_DURATION;
  seqnum_base = seqnum_org + gap;
  rtpts_base = seqnum_base * TEST_RTP_TS_DURATION;

  for (i = 0; i < num_consecutive; i++) {
    fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
            generate_test_buffer_full (dts_base + i * TEST_BUF_DURATION,
                seqnum_base + i, rtpts_base + i * TEST_RTP_TS_DURATION)));
  }

  for (i = 0; i < num_consecutive; i++) {
    GstBuffer *buf = gst_harness_pull (h);
    guint expected_seqnum = seqnum_base + i;
    fail_unless_equals_int (expected_seqnum, get_rtp_seq_num (buf));

    expected_ts = dts_base + i * TEST_BUF_DURATION;
    fail_unless_equals_int (expected_ts, GST_BUFFER_PTS (buf));
    gst_buffer_unref (buf);
  }

  fail_unless_equals_int (0, gst_harness_events_in_queue (h));

  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_big_gap_arrival_time)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  const gint num_consecutive = 5;
  const guint gap = 20000;
  gint i;
  guint seqnum_org;
  GstClockTime dts_base;
  guint seqnum_base;
  guint32 rtpts_base;
  GstClockTime expected_ts;

  g_object_set (h->element, "do-lost", TRUE, "do-retransmission", TRUE, NULL);
  seqnum_org = construct_deterministic_initial_state (h, 100);

  /* packets are being held back on the wire, then continues */
  dts_base = (seqnum_org + gap) * TEST_BUF_DURATION;
  seqnum_base = seqnum_org;
  rtpts_base = seqnum_base * TEST_RTP_TS_DURATION;

  for (i = 0; i < num_consecutive; i++) {
    fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h,
            generate_test_buffer_full (dts_base + i * TEST_BUF_DURATION,
                seqnum_base + i, rtpts_base + i * TEST_RTP_TS_DURATION)));
  }

  for (i = 0; i < num_consecutive; i++) {
    GstBuffer *buf = gst_harness_pull (h);
    guint expected_seqnum = seqnum_base + i;
    fail_unless_equals_int (expected_seqnum, get_rtp_seq_num (buf));

    expected_ts = dts_base + i * TEST_BUF_DURATION;
    fail_unless_equals_int (expected_ts, GST_BUFFER_PTS (buf));
    gst_buffer_unref (buf);
  }

  fail_unless_equals_int (0, gst_harness_events_in_queue (h));

  gst_harness_teardown (h);
}

GST_END_TEST;

typedef struct
{
  guint seqnum_offset;
  guint late_buffer;
} TestLateArrivalInput;

static const TestLateArrivalInput
    test_considered_lost_packet_in_large_gap_arrives_input[] = {
  {0, 1}, {0, 2}, {65535, 1}, {65535, 2}, {65534, 1}, {65534, 2}
};

GST_START_TEST (test_considered_lost_packet_in_large_gap_arrives)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstTestClock *testclock;
  GstClockID id;
  GstBuffer *buffer;
  gint jb_latency_ms = 20;
  const TestLateArrivalInput *test_input =
      &test_considered_lost_packet_in_large_gap_arrives_input[__i__];
  guint seq_offset = test_input->seqnum_offset;
  guint late_buffer = test_input->late_buffer;
  gint i;

  gst_harness_set_src_caps (h, generate_caps ());
  testclock = gst_harness_get_testclock (h);
  g_object_set (h->element, "do-lost", TRUE, "latency", jb_latency_ms, NULL);

  /* first push buffer 0 */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer_full (0 * TEST_BUF_DURATION,
              0 + seq_offset, 0 * TEST_RTP_TS_DURATION)));
  fail_unless (gst_harness_crank_single_clock_wait (h));
  gst_buffer_unref (gst_harness_pull (h));

  /* drop GstEventStreamStart & GstEventCaps & GstEventSegment */
  for (i = 0; i < 3; i++)
    gst_event_unref (gst_harness_pull_event (h));

  /* hop over 3 packets, and push buffer 4 (gap of 3) */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h, generate_test_buffer_full (4 * TEST_BUF_DURATION,
              4 + seq_offset, 4 * TEST_RTP_TS_DURATION)));

  /* the jitterbuffer should be waiting for the timeout of a "large gap timer"
   * for buffer 1 and 2 */
  gst_test_clock_wait_for_next_pending_id (testclock, &id);
  fail_unless_equals_uint64 (1 * TEST_BUF_DURATION +
      jb_latency_ms * GST_MSECOND, gst_clock_id_get_time (id));
  gst_clock_id_unref (id);

  /* now buffer 1 sneaks in before the lost event for buffer 1 and 2 is
   * processed */
  fail_unless_equals_int (GST_FLOW_OK,
      gst_harness_push (h,
          generate_test_buffer_full (late_buffer * TEST_BUF_DURATION,
              late_buffer + seq_offset, late_buffer * TEST_RTP_TS_DURATION)));

  /* time out for lost packets 1 and 2 (one event, double duration) */
  fail_unless (gst_harness_crank_single_clock_wait (h));
  verify_lost_event (h, 1 + seq_offset, 1 * TEST_BUF_DURATION,
      2 * TEST_BUF_DURATION);

  /* time out for lost packets 3 */
  fail_unless (gst_harness_crank_single_clock_wait (h));
  verify_lost_event (h, 3 + seq_offset, 3 * TEST_BUF_DURATION,
      1 * TEST_BUF_DURATION);

  /* buffer 4 is pushed as normal */
  buffer = gst_harness_pull (h);
  fail_unless_equals_int ((4 + seq_offset) & 0xffff, get_rtp_seq_num (buffer));
  gst_buffer_unref (buffer);

  /* we have lost 3, and one of them arrived eventually, but too late */
  fail_unless (verify_jb_stats (h->element,
          gst_structure_new ("application/x-rtp-jitterbuffer-stats",
              "num-pushed", G_TYPE_UINT64, (guint64) 2,
              "num-lost", G_TYPE_UINT64, (guint64) 3,
              "num-late", G_TYPE_UINT64, (guint64) 1, NULL)));

  gst_object_unref (testclock);
  gst_harness_teardown (h);
}

GST_END_TEST;

GST_START_TEST (test_performance)
{
  GstHarness *h =
      gst_harness_new_parse
      ("rtpjitterbuffer do-lost=1 do-retransmission=1 latency=1000");
  GTimer *timer = g_timer_new ();
  const gdouble test_duration = 2.0;
  guint buffers_pushed = 0;
  guint buffers_received;

  gst_harness_set_src_caps (h, generate_caps ());
  gst_harness_use_systemclock (h);

  while (g_timer_elapsed (timer, NULL) < test_duration) {
    /* Simulate 1ms packets */
    guint n = buffers_pushed * 2;       // every packet also produces a gap
    guint16 seqnum = n & 0xffff;
    guint32 rtp_ts = n * 8;
    GstClockTime dts = n * GST_MSECOND;
    gst_harness_push (h, generate_test_buffer_full (dts, seqnum, rtp_ts));
    buffers_pushed++;
    g_usleep (G_USEC_PER_SEC / 10000);
  }
  g_timer_destroy (timer);

  buffers_received = gst_harness_buffers_received (h);
  GST_INFO ("Pushed %d, received %d (%.1f%%)", buffers_pushed, buffers_received,
      100.0 * buffers_received / buffers_pushed);

  gst_harness_teardown (h);
}

GST_END_TEST;

static gpointer
generate_harness_buffer (gpointer data)
{
  GstHarness *h = data;
  guint i;

  for (i = 32766; i < 41000; i++)
    gst_harness_push (h, generate_test_buffer (1000 + i));

  return NULL;
}


GST_START_TEST (test_fill_queue)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  const gint num_consecutive = 40000;
  gint i;
  GstSegment segment;
  GThread *t;
  GstBuffer *buf;

  gst_segment_init (&segment, GST_FORMAT_TIME);
  gst_harness_set_src_caps (h, generate_caps ());

  gst_harness_play (h);

  gst_harness_push (h, generate_test_buffer (1000));
  gst_harness_push (h, generate_test_buffer (1002));

  for (i = 3; i < 32766; i++)
    gst_harness_push (h, generate_test_buffer (1000 + i));

  t = g_thread_new ("fill-queue-test-push", generate_harness_buffer, h);

  /* Just give a chance to the thread to start and to try to push one packet */
  g_usleep (100 * 1000);

  fail_unless (gst_harness_crank_single_clock_wait (h));

  buf = gst_harness_pull (h);
  fail_unless_equals_int (1000, get_rtp_seq_num (buf));
  gst_buffer_unref (buf);

  /* Gap at 1001 here */
  fail_unless (gst_harness_crank_single_clock_wait (h));

  buf = gst_harness_pull (h);
  fail_unless_equals_int (1002, get_rtp_seq_num (buf));
  gst_buffer_unref (buf);

  for (i = 3; i < num_consecutive; i++) {
    GstBuffer *buf = gst_harness_pull (h);
    fail_unless_equals_int (1000 + i, get_rtp_seq_num (buf));
    gst_buffer_unref (buf);
  }

  g_thread_join (t);

  gst_harness_teardown (h);
}

GST_END_TEST;

typedef struct
{
  gint64 dts_skew;
  gint16 seqnum_skew;
} RtxSkewCtx;

static const RtxSkewCtx rtx_does_not_affect_pts_calculation_input[] = {
  {0, 0},
  {20 * GST_MSECOND, -100},
  {20 * GST_MSECOND, 100},
  {-10 * GST_MSECOND, 1},
  {100 * GST_MSECOND, 0},
};

GST_START_TEST (test_rtx_does_not_affect_pts_calculation)
{
  GstHarness *h = gst_harness_new ("rtpjitterbuffer");
  GstBuffer *buffer;
  guint next_seqnum;
  guint rtx_seqnum;
  GstClockTime now;
  const RtxSkewCtx *ctx = &rtx_does_not_affect_pts_calculation_input[__i__];

  /* set up a deterministic state and take the time on the clock */
  g_object_set (h->element, "do-retransmission", TRUE, "do-lost", TRUE, NULL);
  next_seqnum = construct_deterministic_initial_state (h, 3000);
  now = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));

  /* push in a "bad" RTX buffer, arriving at various times / seqnums */
  rtx_seqnum = next_seqnum + ctx->seqnum_skew;
  buffer = generate_test_buffer_full (now + ctx->dts_skew, rtx_seqnum,
      rtx_seqnum * TEST_RTP_TS_DURATION);
  GST_BUFFER_FLAG_SET (buffer, GST_RTP_BUFFER_FLAG_RETRANSMISSION);
  gst_harness_push (h, buffer);

  /* now push in the next regular buffer at its ideal time, and verify the
     rouge RTX-buffer did not mess things up */
  push_test_buffer (h, next_seqnum);
  now = gst_clock_get_time (GST_ELEMENT_CLOCK (h->element));
  buffer = gst_harness_pull (h);
  fail_unless_equals_int64 (now, GST_BUFFER_PTS (buffer));

  gst_buffer_unref (buffer);

  gst_harness_teardown (h);
}

GST_END_TEST;

static Suite *
rtpjitterbuffer_suite (void)
{
  Suite *s = suite_create ("rtpjitterbuffer");
  TCase *tc_chain = tcase_create ("general");

  suite_add_tcase (s, tc_chain);
  tcase_add_test (tc_chain, test_push_forward_seq);
  tcase_add_test (tc_chain, test_push_backward_seq);
  tcase_add_test (tc_chain, test_push_unordered);
  tcase_add_test (tc_chain, test_push_eos);
  tcase_add_test (tc_chain, test_basetime);
  tcase_add_test (tc_chain, test_clear_pt_map);

  tcase_add_test (tc_chain, test_lost_event);
  tcase_add_test (tc_chain, test_only_one_lost_event_on_large_gaps);
  tcase_add_test (tc_chain, test_two_lost_one_arrives_in_time);
  tcase_add_test (tc_chain, test_late_packets_still_makes_lost_events);
  tcase_add_test (tc_chain, test_lost_event_uses_pts);
  tcase_add_test (tc_chain, test_lost_event_with_backwards_rtptime);

  tcase_add_test (tc_chain, test_all_packets_are_timestamped_zero);
  tcase_add_loop_test (tc_chain, test_num_late_when_considered_lost_arrives, 0,
      2);
  tcase_add_test (tc_chain, test_reorder_of_non_equidistant_packets);
  tcase_add_test (tc_chain,
      test_loss_equidistant_spacing_with_parameter_packets);

  tcase_add_test (tc_chain, test_rtx_expected_next);
  tcase_add_test (tc_chain, test_rtx_next_seqnum_disabled);
  tcase_add_test (tc_chain, test_rtx_two_missing);
  tcase_add_test (tc_chain, test_rtx_buffer_arrives_just_in_time);
  tcase_add_test (tc_chain, test_rtx_buffer_arrives_too_late);
  tcase_add_test (tc_chain, test_rtx_original_buffer_does_not_update_rtx_stats);
  tcase_add_test (tc_chain, test_rtx_duplicate_packet_updates_rtx_stats);
  tcase_add_test (tc_chain,
      test_rtx_buffer_arrives_after_lost_updates_rtx_stats);
  tcase_add_test (tc_chain, test_rtx_rtt_larger_than_retry_timeout);
  tcase_add_test (tc_chain, test_rtx_no_request_if_time_past_retry_period);
  tcase_add_test (tc_chain, test_rtx_same_delay_and_retry_timeout);
  tcase_add_test (tc_chain, test_rtx_with_backwards_rtptime);
  tcase_add_test (tc_chain, test_rtx_timer_reuse);
  tcase_add_test (tc_chain, test_rtx_large_packet_spacing_and_small_rtt);
  tcase_add_test (tc_chain, test_rtx_large_packet_spacing_and_large_rtt);
  tcase_add_test (tc_chain,
      test_rtx_large_packet_spacing_does_not_reset_jitterbuffer);
  tcase_add_test (tc_chain, test_minor_reorder_does_not_skew);
  tcase_add_loop_test (tc_chain, test_rtx_does_not_affect_pts_calculation, 0,
      G_N_ELEMENTS (rtx_does_not_affect_pts_calculation_input));

  tcase_add_test (tc_chain, test_deadline_ts_offset);
  tcase_add_test (tc_chain, test_big_gap_seqnum);
  tcase_add_test (tc_chain, test_big_gap_arrival_time);
  tcase_add_test (tc_chain, test_fill_queue);

  tcase_add_loop_test (tc_chain,
      test_considered_lost_packet_in_large_gap_arrives, 0,
      G_N_ELEMENTS (test_considered_lost_packet_in_large_gap_arrives_input));

  tcase_add_test (tc_chain, test_performance);

  return s;
}

GST_CHECK_MAIN (rtpjitterbuffer);