wpe: Implement audio support

The wpesrc bin now exposes "sometimes" audio src pads, one for every PCM audio
stream created by WPEWebKit.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2252>

3 files changed, 177 insertions, 0 deletions

diff --git a/tests/examples/meson.build b/tests/examples/meson.build
index 2eba1d47e..802d2b628 100644
--- a/tests/examples/meson.build
+++ b/tests/examples/meson.build
@@ -14,6 +14,7 @@ subdir('uvch264')
 subdir('va')
 subdir('waylandsink')
 subdir('webrtc')
+subdir('wpe')
 
 executable('playout',
   'playout.c',
diff --git a/tests/examples/wpe/meson.build b/tests/examples/wpe/meson.build
new file mode 100644
index 000000000..3e7f66495
--- /dev/null
+++ b/tests/examples/wpe/meson.build
@@ -0,0 +1,14 @@
+examples = ['wpe']
+
+foreach example : examples
+  exe_name = example
+  src_file = '@0@.c'.format(example)
+
+  executable(exe_name,
+    src_file,
+    install: false,
+    include_directories : [configinc],
+    dependencies : [glib_dep, gst_dep],
+    c_args : ['-DHAVE_CONFIG_H=1'],
+  )
+endforeach
diff --git a/tests/examples/wpe/wpe.c b/tests/examples/wpe/wpe.c
new file mode 100644
index 000000000..27470e95c
--- /dev/null
+++ b/tests/examples/wpe/wpe.c
@@ -0,0 +1,162 @@
+/* Copyright (C) <2018, 2019> Philippe Normand <philn@igalia.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.
+ */
+
+#include <gst/gst.h>
+
+static GMainLoop *loop;
+static GstElement *pipe1;
+static GstBus *bus1;
+
+static gboolean
+_bus_watch (GstBus * bus, GstMessage * msg, GstElement * pipe)
+{
+  switch (GST_MESSAGE_TYPE (msg)) {
+    case GST_MESSAGE_STATE_CHANGED:
+      if (GST_ELEMENT (msg->src) == pipe) {
+        GstState old, new, pending;
+
+        gst_message_parse_state_changed (msg, &old, &new, &pending);
+
+        {
+          gchar *dump_name = g_strconcat ("state_changed-",
+              gst_element_state_get_name (old), "_",
+              gst_element_state_get_name (new), NULL);
+          GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (msg->src),
+              GST_DEBUG_GRAPH_SHOW_ALL, dump_name);
+          g_free (dump_name);
+        }
+      }
+      break;
+    case GST_MESSAGE_ERROR:{
+      GError *err = NULL;
+      gchar *dbg_info = NULL;
+
+      GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipe),
+          GST_DEBUG_GRAPH_SHOW_ALL, "error");
+
+      gst_message_parse_error (msg, &err, &dbg_info);
+      g_printerr ("ERROR from element %s: %s\n",
+          GST_OBJECT_NAME (msg->src), err->message);
+      g_printerr ("Debugging info: %s\n", (dbg_info) ? dbg_info : "none");
+      g_error_free (err);
+      g_free (dbg_info);
+      g_main_loop_quit (loop);
+      break;
+    }
+    case GST_MESSAGE_EOS:{
+      GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipe),
+          GST_DEBUG_GRAPH_SHOW_ALL, "eos");
+      g_print ("EOS received\n");
+      g_main_loop_quit (loop);
+      break;
+    }
+    default:
+      break;
+  }
+
+  return TRUE;
+}
+
+static void
+_wpe_pad_added (GstElement * src, GstPad * new_pad, GstElement * pipe)
+{
+  GstElement *out;
+  GstPad *sink;
+  gchar *name = gst_pad_get_name (new_pad);
+  gchar *bin_name;
+
+  if (g_str_has_prefix (name, "audio")) {
+    out =
+        gst_parse_bin_from_description
+        ("audioresample ! audioconvert ! autoaudiosink", TRUE, NULL);
+  } else {
+    out =
+        gst_parse_bin_from_description
+        ("queue ! glcolorconvert ! gtkglsink enable-last-sample=0", TRUE, NULL);
+  }
+
+  bin_name = g_strdup_printf ("%s-bin", name);
+  g_free (name);
+
+  gst_object_set_name (GST_OBJECT_CAST (out), bin_name);
+  g_free (bin_name);
+
+  gst_bin_add (GST_BIN (pipe), out);
+  sink = out->sinkpads->data;
+  gst_pad_link (new_pad, sink);
+  gst_element_sync_state_with_parent (out);
+}
+
+static void
+_wpe_pad_removed (GstElement * src, GstPad * pad, GstElement * pipe)
+{
+  gchar *name = gst_pad_get_name (pad);
+  gchar *bin_name = g_strdup_printf ("%s-bin", name);
+  GstElement *bin = gst_bin_get_by_name (GST_BIN_CAST (pipe), bin_name);
+
+  if (GST_IS_ELEMENT (bin)) {
+    gst_bin_remove (GST_BIN_CAST (pipe), bin);
+    gst_element_set_state (bin, GST_STATE_NULL);
+  }
+  g_free (name);
+  g_free (bin_name);
+}
+
+int
+main (int argc, char *argv[])
+{
+  GstElement *src;
+
+  if (argc < 2) {
+    g_printerr ("Usage: %s <website url>\n", argv[0]);
+    return 1;
+  }
+
+  gst_init (&argc, &argv);
+
+  loop = g_main_loop_new (NULL, FALSE);
+  pipe1 = gst_pipeline_new (NULL);
+  bus1 = gst_pipeline_get_bus (GST_PIPELINE (pipe1));
+  gst_bus_add_watch (bus1, (GstBusFunc) _bus_watch, pipe1);
+
+  src = gst_element_factory_make ("wpesrc", NULL);
+
+  gst_bin_add (GST_BIN_CAST (pipe1), src);
+  gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_READY);
+
+  g_signal_connect (src, "pad-added", G_CALLBACK (_wpe_pad_added), pipe1);
+  g_signal_connect (src, "pad-removed", G_CALLBACK (_wpe_pad_removed), pipe1);
+
+  g_object_set (src, "location", argv[1], NULL);
+
+  g_print ("Starting pipeline\n");
+  gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_PLAYING);
+
+  g_main_loop_run (loop);
+
+  gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_NULL);
+  g_print ("Pipeline stopped\n");
+
+  gst_bus_remove_watch (bus1);
+  gst_object_unref (bus1);
+  gst_object_unref (pipe1);
+
+  gst_deinit ();
+
+  return 0;
+}