tests: videomixer: Add a testsuite for videomixer

This is mostly copy pasted from -base/tests/check/elements/adder.c

2 files changed, 1062 insertions, 0 deletions

diff --git a/tests/check/Makefile.am b/tests/check/Makefile.am
index a3a0ca0c4..c3bacc46c 100644
--- a/tests/check/Makefile.am
+++ b/tests/check/Makefile.am
@@ -155,6 +155,7 @@ check_PROGRAMS = \
 	elements/wavpackparse \
 	elements/wavparse \
 	elements/y4menc \
+	elements/videomixer \
 	pipelines/simple-launch-lines \
 	pipelines/effectv \
 	pipelines/tagschecking \
@@ -324,6 +325,8 @@ elements_gdkpixbufsink_CFLAGS = \
 elements_gdkpixbufsink_LDADD = \
 	$(LDADD) $(GDK_PIXBUF_LIBS)
 
+elements_videomixer_LDADD = $(LDADD)  $(GST_BASE_LIBS)
+elements_videomixer_CFLAGS = $(GST_BASE_CFLAGS) $(CFLAGS) $(AM_CFLAGS)
 
 pipelines_flacdec_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(CFLAGS) $(AM_CFLAGS)
 pipelines_flacdec_LDADD  = $(GST_PLUGINS_BASE_LIBS) -lgstaudio-$(GST_API_VERSION) $(LDADD)
diff --git a/tests/check/elements/videomixer.c b/tests/check/elements/videomixer.c
new file mode 100644
index 000000000..d2de07a72
--- /dev/null
+++ b/tests/check/elements/videomixer.c
@@ -0,0 +1,1059 @@
+/* GStreamer
+ *
+ * unit test for videmixer
+ *
+ * Copyright (C) <2005> Thomas Vander Stichele <thomas at apestaart dot org>
+ * Copyright (C) <2013> Thibault Saunier <thibault.saunier@collabora.com>
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifdef HAVE_VALGRIND
+# include <valgrind/valgrind.h>
+#endif
+
+#include <unistd.h>
+
+#include <gst/check/gstcheck.h>
+#include <gst/check/gstconsistencychecker.h>
+#include <gst/base/gstbasesrc.h>
+
+#define VIDEO_CAPS_STRING               \
+    "video/x-raw, "                 \
+    "width = (int) 320, "               \
+    "height = (int) 240, "              \
+    "framerate = (fraction) 25/1 , "    \
+    "format = (string) I420"
+
+static GMainLoop *main_loop;
+
+/* make sure downstream gets a CAPS event before buffers are sent */
+GST_START_TEST (test_caps)
+{
+  GstElement *pipeline, *src, *videomixer, *sink;
+  GstStateChangeReturn state_res;
+  GstCaps *caps;
+  GstPad *pad;
+
+  /* build pipeline */
+  pipeline = gst_pipeline_new ("pipeline");
+
+  src = gst_element_factory_make ("videotestsrc", "src1");
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (pipeline), src, videomixer, sink, NULL);
+
+  fail_unless (gst_element_link_many (src, videomixer, sink, NULL));
+
+  /* prepare playing */
+  state_res = gst_element_set_state (pipeline, GST_STATE_PAUSED);
+  fail_unless_equals_int (state_res, GST_STATE_CHANGE_ASYNC);
+
+  /* wait for preroll */
+  state_res = gst_element_get_state (pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+  fail_unless_equals_int (state_res, GST_STATE_CHANGE_SUCCESS);
+
+  /* check caps on fakesink */
+  pad = gst_element_get_static_pad (sink, "sink");
+  caps = gst_pad_get_current_caps (pad);
+  fail_unless (caps != NULL);
+  gst_caps_unref (caps);
+  gst_object_unref (pad);
+
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (pipeline);
+}
+
+GST_END_TEST;
+
+static void
+message_received (GstBus * bus, GstMessage * message, GstPipeline * bin)
+{
+  GST_INFO ("bus message from \"%" GST_PTR_FORMAT "\": %" GST_PTR_FORMAT,
+      GST_MESSAGE_SRC (message), message);
+
+  switch (message->type) {
+    case GST_MESSAGE_EOS:
+      g_main_loop_quit (main_loop);
+      break;
+    case GST_MESSAGE_WARNING:{
+      GError *gerror;
+      gchar *debug;
+
+      gst_message_parse_warning (message, &gerror, &debug);
+      gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
+      g_error_free (gerror);
+      g_free (debug);
+      break;
+    }
+    case GST_MESSAGE_ERROR:{
+      GError *gerror;
+      gchar *debug;
+
+      gst_message_parse_error (message, &gerror, &debug);
+      gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
+      g_error_free (gerror);
+      g_free (debug);
+      g_main_loop_quit (main_loop);
+      break;
+    }
+    default:
+      break;
+  }
+}
+
+
+static GstFormat format = GST_FORMAT_UNDEFINED;
+static gint64 position = -1;
+
+static void
+test_event_message_received (GstBus * bus, GstMessage * message,
+    GstPipeline * bin)
+{
+  GST_INFO ("bus message from \"%" GST_PTR_FORMAT "\": %" GST_PTR_FORMAT,
+      GST_MESSAGE_SRC (message), message);
+
+  switch (message->type) {
+    case GST_MESSAGE_SEGMENT_DONE:
+      gst_message_parse_segment_done (message, &format, &position);
+      GST_INFO ("received segment_done : %" G_GINT64_FORMAT, position);
+      g_main_loop_quit (main_loop);
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+}
+
+
+GST_START_TEST (test_event)
+{
+  GstElement *bin, *src1, *src2, *videomixer, *sink;
+  GstBus *bus;
+  GstEvent *seek_event;
+  GstStateChangeReturn state_res;
+  gboolean res;
+  GstPad *srcpad, *sinkpad;
+  GstStreamConsistency *chk_1, *chk_2, *chk_3;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  src1 = gst_element_factory_make ("videotestsrc", "src1");
+  src2 = gst_element_factory_make ("videotestsrc", "src2");
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src1, src2, videomixer, sink, NULL);
+
+  res = gst_element_link (src1, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (src2, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  srcpad = gst_element_get_static_pad (videomixer, "src");
+  chk_3 = gst_consistency_checker_new (srcpad);
+  gst_object_unref (srcpad);
+
+  /* create consistency checkers for the pads */
+  srcpad = gst_element_get_static_pad (src1, "src");
+  chk_1 = gst_consistency_checker_new (srcpad);
+  sinkpad = gst_pad_get_peer (srcpad);
+  gst_consistency_checker_add_pad (chk_3, sinkpad);
+  gst_object_unref (sinkpad);
+  gst_object_unref (srcpad);
+
+  srcpad = gst_element_get_static_pad (src2, "src");
+  chk_2 = gst_consistency_checker_new (srcpad);
+  sinkpad = gst_pad_get_peer (srcpad);
+  gst_consistency_checker_add_pad (chk_3, sinkpad);
+  gst_object_unref (sinkpad);
+  gst_object_unref (srcpad);
+
+  seek_event = gst_event_new_seek (1.0, GST_FORMAT_TIME,
+      GST_SEEK_FLAG_SEGMENT | GST_SEEK_FLAG_FLUSH,
+      GST_SEEK_TYPE_SET, (GstClockTime) 0,
+      GST_SEEK_TYPE_SET, (GstClockTime) 2 * GST_SECOND);
+
+  format = GST_FORMAT_UNDEFINED;
+  position = -1;
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (bus, "message::segment-done",
+      (GCallback) test_event_message_received, bin);
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  GST_INFO ("starting test");
+
+  /* prepare playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* wait for completion */
+  state_res = gst_element_get_state (bin, NULL, NULL, GST_CLOCK_TIME_NONE);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  res = gst_element_send_event (bin, seek_event);
+  fail_unless (res == TRUE, NULL);
+
+  /* run pipeline */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  GST_INFO ("running main loop");
+  g_main_loop_run (main_loop);
+
+  state_res = gst_element_set_state (bin, GST_STATE_NULL);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  ck_assert_int_eq (position, 2 * GST_SECOND);
+
+  /* cleanup */
+  g_main_loop_unref (main_loop);
+  gst_consistency_checker_free (chk_1);
+  gst_consistency_checker_free (chk_2);
+  gst_consistency_checker_free (chk_3);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (bus);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+static guint play_count = 0;
+static GstEvent *play_seek_event = NULL;
+
+static void
+test_play_twice_message_received (GstBus * bus, GstMessage * message,
+    GstPipeline * bin)
+{
+  gboolean res;
+  GstStateChangeReturn state_res;
+
+  GST_INFO ("bus message from \"%" GST_PTR_FORMAT "\": %" GST_PTR_FORMAT,
+      GST_MESSAGE_SRC (message), message);
+
+  switch (message->type) {
+    case GST_MESSAGE_SEGMENT_DONE:
+      play_count++;
+      if (play_count == 1) {
+        state_res = gst_element_set_state (GST_ELEMENT (bin), GST_STATE_READY);
+        ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+        /* prepare playing again */
+        state_res = gst_element_set_state (GST_ELEMENT (bin), GST_STATE_PAUSED);
+        ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+        /* wait for completion */
+        state_res =
+            gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+            GST_CLOCK_TIME_NONE);
+        ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+        res = gst_element_send_event (GST_ELEMENT (bin),
+            gst_event_ref (play_seek_event));
+        fail_unless (res == TRUE, NULL);
+
+        state_res =
+            gst_element_set_state (GST_ELEMENT (bin), GST_STATE_PLAYING);
+        ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+      } else {
+        g_main_loop_quit (main_loop);
+      }
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+}
+
+
+GST_START_TEST (test_play_twice)
+{
+  GstElement *bin, *src1, *src2, *videomixer, *sink;
+  GstBus *bus;
+  gboolean res;
+  GstStateChangeReturn state_res;
+  GstPad *srcpad;
+  GstStreamConsistency *consist;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  src1 = gst_element_factory_make ("videotestsrc", "src1");
+  src2 = gst_element_factory_make ("videotestsrc", "src2");
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src1, src2, videomixer, sink, NULL);
+
+  res = gst_element_link (src1, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (src2, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  srcpad = gst_element_get_static_pad (videomixer, "src");
+  consist = gst_consistency_checker_new (srcpad);
+  gst_object_unref (srcpad);
+
+  play_seek_event = gst_event_new_seek (1.0, GST_FORMAT_TIME,
+      GST_SEEK_FLAG_SEGMENT | GST_SEEK_FLAG_FLUSH,
+      GST_SEEK_TYPE_SET, (GstClockTime) 0,
+      GST_SEEK_TYPE_SET, (GstClockTime) 2 * GST_SECOND);
+
+  play_count = 0;
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (bus, "message::segment-done",
+      (GCallback) test_play_twice_message_received, bin);
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  GST_INFO ("starting test");
+
+  /* prepare playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* wait for completion */
+  state_res =
+      gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+      GST_CLOCK_TIME_NONE);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  res = gst_element_send_event (bin, gst_event_ref (play_seek_event));
+  fail_unless (res == TRUE, NULL);
+
+  GST_INFO ("seeked");
+
+  /* run pipeline */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  g_main_loop_run (main_loop);
+
+  state_res = gst_element_set_state (bin, GST_STATE_NULL);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  ck_assert_int_eq (play_count, 2);
+
+  /* cleanup */
+  g_main_loop_unref (main_loop);
+  gst_consistency_checker_free (consist);
+  gst_event_ref (play_seek_event);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (bus);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_play_twice_then_add_and_play_again)
+{
+  GstElement *bin, *src1, *src2, *src3, *videomixer, *sink;
+  GstBus *bus;
+  gboolean res;
+  GstStateChangeReturn state_res;
+  gint i;
+  GstPad *srcpad;
+  GstStreamConsistency *consist;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  src1 = gst_element_factory_make ("videotestsrc", "src1");
+  src2 = gst_element_factory_make ("videotestsrc", "src2");
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src1, src2, videomixer, sink, NULL);
+
+  srcpad = gst_element_get_static_pad (videomixer, "src");
+  consist = gst_consistency_checker_new (srcpad);
+  gst_object_unref (srcpad);
+
+  res = gst_element_link (src1, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (src2, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  play_seek_event = gst_event_new_seek (1.0, GST_FORMAT_TIME,
+      GST_SEEK_FLAG_SEGMENT | GST_SEEK_FLAG_FLUSH,
+      GST_SEEK_TYPE_SET, (GstClockTime) 0,
+      GST_SEEK_TYPE_SET, (GstClockTime) 2 * GST_SECOND);
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (bus, "message::segment-done",
+      (GCallback) test_play_twice_message_received, bin);
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  /* run it twice */
+  for (i = 0; i < 2; i++) {
+    play_count = 0;
+
+    GST_INFO ("starting test-loop %d", i);
+
+    /* prepare playing */
+    state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+    ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+    /* wait for completion */
+    state_res =
+        gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+        GST_CLOCK_TIME_NONE);
+    ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+    res = gst_element_send_event (bin, gst_event_ref (play_seek_event));
+    fail_unless (res == TRUE, NULL);
+
+    GST_INFO ("seeked");
+
+    /* run pipeline */
+    state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+    ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+    g_main_loop_run (main_loop);
+
+    state_res = gst_element_set_state (bin, GST_STATE_READY);
+    ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+    ck_assert_int_eq (play_count, 2);
+
+    /* plug another source */
+    if (i == 0) {
+      src3 = gst_element_factory_make ("videotestsrc", "src3");
+      gst_bin_add (GST_BIN (bin), src3);
+
+      res = gst_element_link (src3, videomixer);
+      fail_unless (res == TRUE, NULL);
+    }
+
+    gst_consistency_checker_reset (consist);
+  }
+
+  state_res = gst_element_set_state (bin, GST_STATE_NULL);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* cleanup */
+  g_main_loop_unref (main_loop);
+  gst_event_ref (play_seek_event);
+  gst_consistency_checker_free (consist);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (bus);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+/* check if adding pads work as expected */
+GST_START_TEST (test_add_pad)
+{
+  GstElement *bin, *src1, *src2, *videomixer, *sink;
+  GstBus *bus;
+  GstPad *srcpad;
+  gboolean res;
+  GstStateChangeReturn state_res;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  src1 = gst_element_factory_make ("videotestsrc", "src1");
+  g_object_set (src1, "num-buffers", 4, NULL);
+  src2 = gst_element_factory_make ("videotestsrc", "src2");
+  /* one buffer less, we connect with 1 buffer of delay */
+  g_object_set (src2, "num-buffers", 3, NULL);
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src1, videomixer, sink, NULL);
+
+  res = gst_element_link (src1, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  srcpad = gst_element_get_static_pad (videomixer, "src");
+  gst_object_unref (srcpad);
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (bus, "message::segment-done", (GCallback) message_received,
+      bin);
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  GST_INFO ("starting test");
+
+  /* prepare playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* wait for completion */
+  state_res =
+      gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+      GST_CLOCK_TIME_NONE);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* add other element */
+  gst_bin_add_many (GST_BIN (bin), src2, NULL);
+
+  /* now link the second element */
+  res = gst_element_link (src2, videomixer);
+  fail_unless (res == TRUE, NULL);
+
+  /* set to PAUSED as well */
+  state_res = gst_element_set_state (src2, GST_STATE_PAUSED);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* now play all */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  g_main_loop_run (main_loop);
+
+  state_res = gst_element_set_state (bin, GST_STATE_NULL);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* cleanup */
+  g_main_loop_unref (main_loop);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (bus);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+/* check if removing pads work as expected */
+GST_START_TEST (test_remove_pad)
+{
+  GstElement *bin, *src, *videomixer, *sink;
+  GstBus *bus;
+  GstPad *pad, *srcpad;
+  gboolean res;
+  GstStateChangeReturn state_res;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  src = gst_element_factory_make ("videotestsrc", "src");
+  g_object_set (src, "num-buffers", 4, NULL);
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src, videomixer, sink, NULL);
+
+  res = gst_element_link (src, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  /* create an unconnected sinkpad in videomixer */
+  pad = gst_element_get_request_pad (videomixer, "sink_%u");
+  fail_if (pad == NULL, NULL);
+
+  srcpad = gst_element_get_static_pad (videomixer, "src");
+  gst_object_unref (srcpad);
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (bus, "message::segment-done", (GCallback) message_received,
+      bin);
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  GST_INFO ("starting test");
+
+  /* prepare playing, this will not preroll as videomixer is waiting
+   * on the unconnected sinkpad. */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* wait for completion for one second, will return ASYNC */
+  state_res = gst_element_get_state (GST_ELEMENT (bin), NULL, NULL, GST_SECOND);
+  ck_assert_int_eq (state_res, GST_STATE_CHANGE_ASYNC);
+
+  /* get rid of the pad now, videomixer should stop waiting on it and
+   * continue the preroll */
+  gst_element_release_request_pad (videomixer, pad);
+  gst_object_unref (pad);
+
+  /* wait for completion, should work now */
+  state_res =
+      gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+      GST_CLOCK_TIME_NONE);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* now play all */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  g_main_loop_run (main_loop);
+
+  state_res = gst_element_set_state (bin, GST_STATE_NULL);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* cleanup */
+  g_main_loop_unref (main_loop);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (G_OBJECT (bus));
+  gst_object_unref (G_OBJECT (bin));
+}
+
+GST_END_TEST;
+
+
+static GstBuffer *handoff_buffer = NULL;
+static void
+handoff_buffer_cb (GstElement * fakesink, GstBuffer * buffer, GstPad * pad,
+    gpointer user_data)
+{
+  GST_DEBUG ("got buffer %p", buffer);
+  gst_buffer_replace (&handoff_buffer, buffer);
+}
+
+/* check if clipping works as expected */
+GST_START_TEST (test_clip)
+{
+  GstSegment segment;
+  GstElement *bin, *videomixer, *sink;
+  GstBus *bus;
+  GstPad *sinkpad;
+  gboolean res;
+  GstStateChangeReturn state_res;
+  GstFlowReturn ret;
+  GstEvent *event;
+  GstBuffer *buffer;
+  GstCaps *caps;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  /* just an videomixer and a fakesink */
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  g_object_set (sink, "signal-handoffs", TRUE, NULL);
+  g_signal_connect (sink, "handoff", (GCallback) handoff_buffer_cb, NULL);
+  gst_bin_add_many (GST_BIN (bin), videomixer, sink, NULL);
+
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  /* set to playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* create an unconnected sinkpad in videomixer, should also automatically activate
+   * the pad */
+  sinkpad = gst_element_get_request_pad (videomixer, "sink_%u");
+  fail_if (sinkpad == NULL, NULL);
+
+  gst_pad_send_event (sinkpad, gst_event_new_stream_start ("test"));
+
+  caps = gst_caps_from_string (VIDEO_CAPS_STRING);
+
+  gst_pad_set_caps (sinkpad, caps);
+  gst_caps_unref (caps);
+
+  /* send segment to videomixer */
+  gst_segment_init (&segment, GST_FORMAT_TIME);
+  segment.start = GST_SECOND;
+  segment.stop = 2 * GST_SECOND;
+  segment.time = 0;
+  event = gst_event_new_segment (&segment);
+  gst_pad_send_event (sinkpad, event);
+
+  /* should be clipped and ok */
+  buffer = gst_buffer_new_and_alloc (115200);
+  GST_BUFFER_TIMESTAMP (buffer) = 0;
+  GST_BUFFER_DURATION (buffer) = 250 * GST_MSECOND;
+  GST_DEBUG ("pushing buffer %p", buffer);
+  ret = gst_pad_chain (sinkpad, buffer);
+  ck_assert_int_eq (ret, GST_FLOW_OK);
+  fail_unless (handoff_buffer == NULL);
+
+  /* should be partially clipped */
+  buffer = gst_buffer_new_and_alloc (115200);
+  GST_BUFFER_TIMESTAMP (buffer) = 900 * GST_MSECOND;
+  GST_BUFFER_DURATION (buffer) = 250 * GST_MSECOND;
+  GST_DEBUG ("pushing buffer %p", buffer);
+  ret = gst_pad_chain (sinkpad, buffer);
+  ck_assert_int_eq (ret, GST_FLOW_OK);
+  fail_unless (handoff_buffer != NULL);
+  gst_buffer_replace (&handoff_buffer, NULL);
+
+  /* should not be clipped */
+  buffer = gst_buffer_new_and_alloc (115200);
+  GST_BUFFER_TIMESTAMP (buffer) = 1 * GST_SECOND;
+  GST_BUFFER_DURATION (buffer) = 250 * GST_MSECOND;
+  GST_DEBUG ("pushing buffer %p", buffer);
+  ret = gst_pad_chain (sinkpad, buffer);
+  ck_assert_int_eq (ret, GST_FLOW_OK);
+  fail_unless (handoff_buffer != NULL);
+  gst_buffer_replace (&handoff_buffer, NULL);
+
+  /* should be clipped and ok */
+  buffer = gst_buffer_new_and_alloc (115200);
+  GST_BUFFER_TIMESTAMP (buffer) = 2 * GST_SECOND;
+  GST_BUFFER_DURATION (buffer) = 250 * GST_MSECOND;
+  GST_DEBUG ("pushing buffer %p", buffer);
+  ret = gst_pad_chain (sinkpad, buffer);
+  ck_assert_int_eq (ret, GST_FLOW_OK);
+  fail_unless (handoff_buffer == NULL);
+
+  gst_object_unref (sinkpad);
+  gst_element_set_state (bin, GST_STATE_NULL);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (bus);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_duration_is_max)
+{
+  GstElement *bin, *src[3], *videomixer, *sink;
+  GstStateChangeReturn state_res;
+  GstFormat format = GST_FORMAT_TIME;
+  gboolean res;
+  gint64 duration;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+
+  /* 3 sources, an videomixer and a fakesink */
+  src[0] = gst_element_factory_make ("videotestsrc", NULL);
+  src[1] = gst_element_factory_make ("videotestsrc", NULL);
+  src[2] = gst_element_factory_make ("videotestsrc", NULL);
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src[0], src[1], src[2], videomixer, sink,
+      NULL);
+
+  gst_element_link (src[0], videomixer);
+  gst_element_link (src[1], videomixer);
+  gst_element_link (src[2], videomixer);
+  gst_element_link (videomixer, sink);
+
+  /* irks, duration is reset on basesrc */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  fail_unless (state_res != GST_STATE_CHANGE_FAILURE, NULL);
+
+  /* set durations on src */
+  GST_BASE_SRC (src[0])->segment.duration = 1000;
+  GST_BASE_SRC (src[1])->segment.duration = 3000;
+  GST_BASE_SRC (src[2])->segment.duration = 2000;
+
+  /* set to playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  fail_unless (state_res != GST_STATE_CHANGE_FAILURE, NULL);
+
+  /* wait for completion */
+  state_res =
+      gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+      GST_CLOCK_TIME_NONE);
+  fail_unless (state_res != GST_STATE_CHANGE_FAILURE, NULL);
+
+  res = gst_element_query_duration (GST_ELEMENT (bin), format, &duration);
+  fail_unless (res, NULL);
+
+  ck_assert_int_eq (duration, 3000);
+
+  gst_element_set_state (bin, GST_STATE_NULL);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_duration_unknown_overrides)
+{
+  GstElement *bin, *src[3], *videomixer, *sink;
+  GstStateChangeReturn state_res;
+  GstFormat format = GST_FORMAT_TIME;
+  gboolean res;
+  gint64 duration;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+
+  /* 3 sources, an videomixer and a fakesink */
+  src[0] = gst_element_factory_make ("videotestsrc", NULL);
+  src[1] = gst_element_factory_make ("videotestsrc", NULL);
+  src[2] = gst_element_factory_make ("videotestsrc", NULL);
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src[0], src[1], src[2], videomixer, sink,
+      NULL);
+
+  gst_element_link (src[0], videomixer);
+  gst_element_link (src[1], videomixer);
+  gst_element_link (src[2], videomixer);
+  gst_element_link (videomixer, sink);
+
+  /* irks, duration is reset on basesrc */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  fail_unless (state_res != GST_STATE_CHANGE_FAILURE, NULL);
+
+  /* set durations on src */
+  GST_BASE_SRC (src[0])->segment.duration = GST_CLOCK_TIME_NONE;
+  GST_BASE_SRC (src[1])->segment.duration = 3000;
+  GST_BASE_SRC (src[2])->segment.duration = 2000;
+
+  /* set to playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  fail_unless (state_res != GST_STATE_CHANGE_FAILURE, NULL);
+
+  /* wait for completion */
+  state_res =
+      gst_element_get_state (GST_ELEMENT (bin), NULL, NULL,
+      GST_CLOCK_TIME_NONE);
+  fail_unless (state_res != GST_STATE_CHANGE_FAILURE, NULL);
+
+  res = gst_element_query_duration (GST_ELEMENT (bin), format, &duration);
+  fail_unless (res, NULL);
+
+  ck_assert_int_eq (duration, GST_CLOCK_TIME_NONE);
+
+  gst_element_set_state (bin, GST_STATE_NULL);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+
+static gboolean looped = FALSE;
+
+static void
+loop_segment_done (GstBus * bus, GstMessage * message, GstElement * bin)
+{
+  GST_INFO ("bus message from \"%" GST_PTR_FORMAT "\": %" GST_PTR_FORMAT,
+      GST_MESSAGE_SRC (message), message);
+
+  if (looped) {
+    g_main_loop_quit (main_loop);
+  } else {
+    GstEvent *seek_event;
+    gboolean res;
+
+    seek_event = gst_event_new_seek (1.0, GST_FORMAT_TIME,
+        GST_SEEK_FLAG_SEGMENT,
+        GST_SEEK_TYPE_SET, (GstClockTime) 0,
+        GST_SEEK_TYPE_SET, (GstClockTime) 1 * GST_SECOND);
+
+    res = gst_element_send_event (bin, seek_event);
+    fail_unless (res == TRUE, NULL);
+    looped = TRUE;
+  }
+}
+
+GST_START_TEST (test_loop)
+{
+  GstElement *bin, *src1, *src2, *videomixer, *sink;
+  GstBus *bus;
+  GstEvent *seek_event;
+  GstStateChangeReturn state_res;
+  gboolean res;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  bin = gst_pipeline_new ("pipeline");
+  bus = gst_element_get_bus (bin);
+  gst_bus_add_signal_watch_full (bus, G_PRIORITY_HIGH);
+
+  src1 = gst_element_factory_make ("videotestsrc", "src1");
+  src2 = gst_element_factory_make ("videotestsrc", "src2");
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (bin), src1, src2, videomixer, sink, NULL);
+
+  res = gst_element_link (src1, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (src2, videomixer);
+  fail_unless (res == TRUE, NULL);
+  res = gst_element_link (videomixer, sink);
+  fail_unless (res == TRUE, NULL);
+
+  seek_event = gst_event_new_seek (1.0, GST_FORMAT_TIME,
+      GST_SEEK_FLAG_SEGMENT | GST_SEEK_FLAG_FLUSH,
+      GST_SEEK_TYPE_SET, (GstClockTime) 0,
+      GST_SEEK_TYPE_SET, (GstClockTime) 1 * GST_SECOND);
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (bus, "message::segment-done",
+      (GCallback) loop_segment_done, bin);
+  g_signal_connect (bus, "message::error", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::warning", (GCallback) message_received, bin);
+  g_signal_connect (bus, "message::eos", (GCallback) message_received, bin);
+
+  GST_INFO ("starting test");
+
+  /* prepare playing */
+  state_res = gst_element_set_state (bin, GST_STATE_PAUSED);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  /* wait for completion */
+  state_res = gst_element_get_state (bin, NULL, NULL, GST_CLOCK_TIME_NONE);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  res = gst_element_send_event (bin, seek_event);
+  fail_unless (res == TRUE, NULL);
+
+  /* run pipeline */
+  state_res = gst_element_set_state (bin, GST_STATE_PLAYING);
+  ck_assert_int_ne (state_res, GST_STATE_CHANGE_FAILURE);
+
+  GST_INFO ("running main loop");
+  g_main_loop_run (main_loop);
+
+  state_res = gst_element_set_state (bin, GST_STATE_NULL);
+
+  /* cleanup */
+  g_main_loop_unref (main_loop);
+  gst_bus_remove_signal_watch (bus);
+  gst_object_unref (bus);
+  gst_object_unref (bin);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_flush_start_flush_stop)
+{
+  GstPadTemplate *sink_template;
+  GstPad *tmppad, *sinkpad1, *sinkpad2, *videomixer_src;
+  GstElement *pipeline, *src1, *src2, *videomixer, *sink;
+
+  GST_INFO ("preparing test");
+
+  /* build pipeline */
+  pipeline = gst_pipeline_new ("pipeline");
+  src1 = gst_element_factory_make ("videotestsrc", "src1");
+  src2 = gst_element_factory_make ("videotestsrc", "src2");
+  videomixer = gst_element_factory_make ("videomixer", "videomixer");
+  sink = gst_element_factory_make ("fakesink", "sink");
+  gst_bin_add_many (GST_BIN (pipeline), src1, src2, videomixer, sink, NULL);
+
+  sink_template =
+      gst_element_class_get_pad_template (GST_ELEMENT_GET_CLASS (videomixer),
+      "sink_%u");
+  fail_unless (GST_IS_PAD_TEMPLATE (sink_template));
+  sinkpad1 = gst_element_request_pad (videomixer, sink_template, NULL, NULL);
+  tmppad = gst_element_get_static_pad (src1, "src");
+  gst_pad_link (tmppad, sinkpad1);
+  gst_object_unref (tmppad);
+
+  sinkpad2 = gst_element_request_pad (videomixer, sink_template, NULL, NULL);
+  tmppad = gst_element_get_static_pad (src2, "src");
+  gst_pad_link (tmppad, sinkpad2);
+  gst_object_unref (tmppad);
+
+  gst_element_link (videomixer, sink);
+
+  gst_element_set_state (pipeline, GST_STATE_PLAYING);
+  fail_unless (gst_element_get_state (pipeline, NULL, NULL,
+          GST_CLOCK_TIME_NONE) == GST_STATE_CHANGE_SUCCESS);
+
+  videomixer_src = gst_element_get_static_pad (videomixer, "src");
+  fail_if (GST_PAD_IS_FLUSHING (videomixer_src));
+  gst_pad_send_event (sinkpad1, gst_event_new_flush_start ());
+  fail_unless (GST_PAD_IS_FLUSHING (videomixer_src));
+  gst_pad_send_event (sinkpad1, gst_event_new_flush_stop (TRUE));
+  fail_if (GST_PAD_IS_FLUSHING (videomixer_src));
+  gst_object_unref (videomixer_src);
+
+  /* cleanup */
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (pipeline);
+}
+
+GST_END_TEST;
+
+
+static Suite *
+videomixer_suite (void)
+{
+  Suite *s = suite_create ("videomixer");
+  TCase *tc_chain = tcase_create ("general");
+
+  suite_add_tcase (s, tc_chain);
+  tcase_add_test (tc_chain, test_caps);
+  tcase_add_test (tc_chain, test_event);
+  tcase_add_test (tc_chain, test_play_twice);
+  tcase_add_test (tc_chain, test_play_twice_then_add_and_play_again);
+  tcase_add_test (tc_chain, test_add_pad);
+  tcase_add_test (tc_chain, test_remove_pad);
+  tcase_add_test (tc_chain, test_clip);
+  tcase_add_test (tc_chain, test_duration_is_max);
+  tcase_add_test (tc_chain, test_duration_unknown_overrides);
+  tcase_add_test (tc_chain, test_loop);
+  tcase_add_test (tc_chain, test_flush_start_flush_stop);
+
+  /* Use a longer timeout */
+#ifdef HAVE_VALGRIND
+  if (RUNNING_ON_VALGRIND) {
+    tcase_set_timeout (tc_chain, 5 * 60);
+  } else
+#endif
+  {
+    /* this is shorter than the default 60 seconds?! (tpm) */
+    /* tcase_set_timeout (tc_chain, 6); */
+  }
+
+  return s;
+}
+
+GST_CHECK_MAIN (videomixer);