wpe: Base wpe audio implementation on a web extension

This makes the implementation simpler and enable us to map
webviews and audio stream much more easily

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

12 files changed, 577 insertions, 100 deletions

diff --git a/ext/wpe/WPEThreadedView.cpp b/ext/wpe/WPEThreadedView.cpp
index 93f97e342..5dcb21603 100644
--- a/ext/wpe/WPEThreadedView.cpp
+++ b/ext/wpe/WPEThreadedView.cpp
@@ -22,6 +22,8 @@
 #endif
 
 #include "WPEThreadedView.h"
+#include "gstwpe.h"
+#include "gstwpesrcbin.h"
 
 #include <gst/gl/gl.h>
 #include <gst/gl/egl/gsteglimage.h>
@@ -165,6 +167,56 @@ gpointer WPEContextThread::s_viewThread(gpointer data)
     return nullptr;
 }
 
+#ifdef G_OS_UNIX
+static void
+initialize_web_extensions (WebKitWebContext *context)
+{
+    webkit_web_context_set_web_extensions_directory (context, gst_wpe_get_extension_path ());
+}
+
+static gboolean
+webkit_extension_msg_received (WebKitWebContext  *context,
+               WebKitUserMessage *message,
+               GstWpeSrc           *src)
+{
+    const gchar *name = webkit_user_message_get_name (message);
+    GVariant *params = webkit_user_message_get_parameters (message);
+    gboolean res = TRUE;
+
+    if (!g_strcmp0(name, "gstwpe.new_stream")) {
+        guint32 id = g_variant_get_uint32 (g_variant_get_child_value (params, 0));
+        const gchar *capsstr = g_variant_get_string (g_variant_get_child_value (params, 1), NULL);
+        GstCaps *caps = gst_caps_from_string (capsstr);
+        const gchar *stream_id = g_variant_get_string (g_variant_get_child_value (params, 2), NULL);
+        gst_wpe_src_new_audio_stream(src, id, caps, stream_id);
+        gst_caps_unref (caps);
+    } else if (!g_strcmp0(name, "gstwpe.set_shm")) {
+        auto fdlist = webkit_user_message_get_fd_list (message);
+        gint id = g_variant_get_uint32 (g_variant_get_child_value (params, 0));
+        gst_wpe_src_set_audio_shm (src, fdlist, id);
+    } else if (!g_strcmp0(name, "gstwpe.new_buffer")) {
+        guint32 id = g_variant_get_uint32 (g_variant_get_child_value (params, 0));
+        guint64 size = g_variant_get_uint64 (g_variant_get_child_value (params, 1));
+        gst_wpe_src_push_audio_buffer (src, id, size);
+
+        webkit_user_message_send_reply(message, webkit_user_message_new ("gstwpe.buffer_processed", NULL));
+    } else if (!g_strcmp0(name, "gstwpe.pause")) {
+        guint32 id = g_variant_get_uint32 (params);
+
+        gst_wpe_src_pause_audio_stream (src, id);
+    } else if (!g_strcmp0(name, "gstwpe.stop")) {
+        guint32 id = g_variant_get_uint32 (params);
+
+        gst_wpe_src_stop_audio_stream (src, id);
+    } else {
+        res = FALSE;
+        g_error("Unknown event: %s", name);
+    }
+
+    return res;
+}
+#endif
+
 WPEView* WPEContextThread::createWPEView(GstWpeVideoSrc* src, GstGLContext* context, GstGLDisplay* display, int width, int height)
 {
     GST_DEBUG("context %p display %p, size (%d,%d)", context, display, width, height);
@@ -179,13 +231,11 @@ WPEView* WPEContextThread::createWPEView(GstWpeVideoSrc* src, GstGLContext* cont
 
     WPEView* view = nullptr;
     dispatch([&]() mutable {
-        if (!glib.web_context) {
-            auto* manager = webkit_website_data_manager_new_ephemeral();
-            glib.web_context = webkit_web_context_new_with_website_data_manager(manager);
-            g_object_unref(manager);
-        }
+        auto* manager = webkit_website_data_manager_new_ephemeral();
+        auto web_context = webkit_web_context_new_with_website_data_manager(manager);
+        g_object_unref(manager);
 
-        view = new WPEView(glib.web_context, src, context, display, width, height);
+        view = new WPEView(web_context, src, context, display, width, height);
     });
 
     if (view && view->hasUri()) {
@@ -233,6 +283,26 @@ static void s_loadProgressChaned(GObject* object, GParamSpec*, gpointer data)
 
 WPEView::WPEView(WebKitWebContext* web_context, GstWpeVideoSrc* src, GstGLContext* context, GstGLDisplay* display, int width, int height)
 {
+#ifdef G_OS_UNIX
+{
+        GstObject *parent = gst_object_get_parent (GST_OBJECT (src));
+
+        if (parent && GST_IS_WPE_SRC (parent)) {
+            audio.init_ext_sigid = g_signal_connect (web_context,
+                              "initialize-web-extensions",
+                              G_CALLBACK (initialize_web_extensions),
+                              NULL);
+            audio.extension_msg_sigid = g_signal_connect (web_context,
+                                "user-message-received",
+                                G_CALLBACK (webkit_extension_msg_received),
+                                parent);
+            GST_INFO_OBJECT (parent, "Enabled audio");
+        }
+
+        gst_clear_object (&parent);
+}
+#endif // G_OS_UNIX
+
     g_mutex_init(&threading.ready_mutex);
     g_cond_init(&threading.ready_cond);
     threading.ready = FALSE;
@@ -353,6 +423,15 @@ WPEView::~WPEView()
     if (shm_committed)
         gst_buffer_unref (shm_committed);
 
+    if (audio.init_ext_sigid) {
+        WebKitWebContext* web_context = webkit_web_view_get_context (webkit.view);
+
+        g_signal_handler_disconnect(web_context, audio.init_ext_sigid);
+        g_signal_handler_disconnect(web_context, audio.extension_msg_sigid);
+        audio.init_ext_sigid = 0;
+        audio.extension_msg_sigid = 0;
+    }
+
     WPEContextThread::singleton().dispatch([&]() {
         if (webkit.view) {
             g_object_unref(webkit.view);
@@ -523,11 +602,6 @@ void WPEView::setDrawBackground(gboolean drawsBackground)
     webkit_web_view_set_background_color(webkit.view, &color);
 }
 
-void WPEView::registerAudioReceiver(const struct wpe_audio_receiver* audioReceiver, gpointer userData)
-{
-    wpe_audio_register_receiver(audioReceiver, userData);
-}
-
 void WPEView::releaseImage(gpointer imagePointer)
 {
     s_view->dispatch([&]() {
diff --git a/ext/wpe/WPEThreadedView.h b/ext/wpe/WPEThreadedView.h
index 31d564295..bb58b9372 100644
--- a/ext/wpe/WPEThreadedView.h
+++ b/ext/wpe/WPEThreadedView.h
@@ -23,7 +23,6 @@
 #include <glib.h>
 #include <gst/gl/gstglfuncs.h>
 #include <gst/gl/egl/gstgldisplay_egl.h>
-#include <wpe/extensions/audio.h>
 #include <wpe/fdo.h>
 #include <wpe/fdo-egl.h>
 #include <wpe/webkit.h>
@@ -52,8 +51,6 @@ public:
     void loadData(GBytes*);
     void setDrawBackground(gboolean);
 
-    void registerAudioReceiver(const struct wpe_audio_receiver*, gpointer);
-
     GstEGLImage* image();
     GstBuffer* buffer();
 
@@ -129,6 +126,11 @@ private:
         GstBuffer* committed;
     } shm { nullptr, nullptr };
 
+    struct {
+        gulong init_ext_sigid;
+        gulong extension_msg_sigid;
+    } audio {0, 0};
+
 };
 
 class WPEContextThread {
diff --git a/ext/wpe/gstwpe.cpp b/ext/wpe/gstwpe.cpp
index 30f90f3d9..80be4242b 100644
--- a/ext/wpe/gstwpe.cpp
+++ b/ext/wpe/gstwpe.cpp
@@ -65,19 +65,32 @@
 
 #include "gstwpevideosrc.h"
 #include "gstwpesrcbin.h"
+#include "gstwpe.h"
+
+static gchar *extension_path = NULL;
 
 GST_DEBUG_CATEGORY (wpe_video_src_debug);
 GST_DEBUG_CATEGORY (wpe_view_debug);
 GST_DEBUG_CATEGORY (wpe_src_debug);
 
+const gchar *gst_wpe_get_extension_path (void)
+{
+  return extension_path;
+}
+
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
+  gboolean result;
+  gchar *dirname = g_path_get_dirname (gst_plugin_get_filename (plugin));
+
   GST_DEBUG_CATEGORY_INIT (wpe_video_src_debug, "wpevideosrc", 0, "WPE Video Source");
   GST_DEBUG_CATEGORY_INIT (wpe_view_debug, "wpeview", 0, "WPE Threaded View");
   GST_DEBUG_CATEGORY_INIT (wpe_src_debug, "wpesrc", 0, "WPE Source");
 
-  gboolean result = gst_element_register (plugin, "wpevideosrc", GST_RANK_NONE,
+  extension_path = g_build_filename (dirname, "wpe-extension", NULL);
+  g_free (dirname);
+  result = gst_element_register (plugin, "wpevideosrc", GST_RANK_NONE,
       GST_TYPE_WPE_VIDEO_SRC);
   result &= gst_element_register(plugin, "wpesrc", GST_RANK_NONE, GST_TYPE_WPE_SRC);
   return result;
diff --git a/ext/wpe/gstwpe-private.h b/ext/wpe/gstwpe.h
index 8eed9914d..da0d2c9db 100644
--- a/ext/wpe/gstwpe-private.h
+++ b/ext/wpe/gstwpe.h
@@ -21,4 +21,4 @@
 
 #include <gst/gst.h>
 
-void gst_wpe_video_src_register_audio_receiver(GstElement*, const struct wpe_audio_receiver*, gpointer);
+const gchar *gst_wpe_get_extension_path (void);
diff --git a/ext/wpe/gstwpesrcbin.cpp b/ext/wpe/gstwpesrcbin.cpp
index 2a39a8112..2b50aaf9d 100644
--- a/ext/wpe/gstwpesrcbin.cpp
+++ b/ext/wpe/gstwpesrcbin.cpp
@@ -36,13 +36,16 @@
 
 #include "gstwpesrcbin.h"
 #include "gstwpevideosrc.h"
-#include "gstwpe-private.h"
+#include "gstwpe.h"
 #include "WPEThreadedView.h"
 
 #include <gst/allocators/allocators.h>
 #include <gst/base/gstflowcombiner.h>
 #include <wpe/extensions/audio.h>
 
+#include <sys/mman.h>
+#include <unistd.h>
+
 G_DEFINE_TYPE (GstWpeAudioPad, gst_wpe_audio_pad, GST_TYPE_GHOST_PAD);
 
 static void
@@ -106,6 +109,11 @@ GST_DEBUG_CATEGORY_EXTERN (wpe_src_debug);
 G_DEFINE_TYPE_WITH_CODE (GstWpeSrc, gst_wpe_src, GST_TYPE_BIN,
     G_IMPLEMENT_INTERFACE (GST_TYPE_URI_HANDLER, gst_wpe_src_uri_handler_init));
 
+/**
+ * GstWpeSrc!video
+ *
+ * Since: 1.20
+  */
 static GstStaticPadTemplate video_src_factory =
 GST_STATIC_PAD_TEMPLATE ("video", GST_PAD_SRC, GST_PAD_SOMETIMES,
     GST_STATIC_CAPS ("video/x-raw(memory:GLMemory), "
@@ -125,6 +133,14 @@ GST_STATIC_PAD_TEMPLATE ("video", GST_PAD_SRC, GST_PAD_SOMETIMES,
 #endif
                      ));
 
+/**
+ * GstWpeSrc!audio_%u
+ *
+ * Each audio stream in the renderer web page will expose the and `audio_%u`
+ * #GstPad.
+ *
+ * Since: 1.20
+  */
 static GstStaticPadTemplate audio_src_factory =
 GST_STATIC_PAD_TEMPLATE ("audio_%u", GST_PAD_SRC, GST_PAD_SOMETIMES,
     GST_STATIC_CAPS ( \
@@ -149,18 +165,15 @@ gst_wpe_src_chain_buffer (GstPad * pad, GstObject * parent, GstBuffer * buffer)
   return result;
 }
 
-static void
-on_audio_receiver_handle_start(void* data, uint32_t id, int32_t channels, const char* format, int32_t sampleRate)
+void
+gst_wpe_src_new_audio_stream(GstWpeSrc *src, guint32 id, GstCaps *caps, const gchar *stream_id)
 {
-  GstWpeSrc* src = GST_WPE_SRC (data);
   GstWpeAudioPad *audio_pad;
   GstPad *pad;
   gchar *name;
   GstEvent *stream_start;
   GstSegment segment;
-  GstCaps *caps;
 
-  GST_DEBUG_OBJECT (src, "Exposing audio pad for stream %u", id);
   name = g_strdup_printf ("audio_%u", id);
   audio_pad = gst_wpe_audio_pad_new (name);
   pad = GST_PAD_CAST (audio_pad);
@@ -170,19 +183,13 @@ on_audio_receiver_handle_start(void* data, uint32_t id, int32_t channels, const
   gst_element_add_pad (GST_ELEMENT_CAST (src), pad);
   gst_flow_combiner_add_pad (src->flow_combiner, pad);
 
-  name = gst_pad_create_stream_id_printf(pad, GST_ELEMENT_CAST (src), "%03u", id);
-  stream_start = gst_event_new_stream_start (name);
+  GST_DEBUG_OBJECT (src, "Adding pad: %" GST_PTR_FORMAT, pad);
+
+  stream_start = gst_event_new_stream_start (stream_id);
   gst_pad_push_event (pad, stream_start);
-  g_free (name);
 
-  caps = gst_caps_new_simple ("audio/x-raw", "format", G_TYPE_STRING, format,
-    "rate", G_TYPE_INT, sampleRate,
-    "channels", G_TYPE_INT, channels,
-    "channel-mask", GST_TYPE_BITMASK, gst_audio_channel_get_fallback_mask (channels),
-    "layout", G_TYPE_STRING, "interleaved", NULL);
   gst_audio_info_from_caps (&audio_pad->info, caps);
   gst_pad_push_event (pad, gst_event_new_caps (caps));
-  gst_caps_unref (caps);
 
   gst_segment_init (&segment, GST_FORMAT_TIME);
   gst_pad_push_event (pad, gst_event_new_segment (&segment));
@@ -190,23 +197,40 @@ on_audio_receiver_handle_start(void* data, uint32_t id, int32_t channels, const
   g_hash_table_insert (src->audio_src_pads, GUINT_TO_POINTER (id), audio_pad);
 }
 
-static void
-on_audio_receiver_handle_packet(void* data, struct wpe_audio_packet_export* packet_export, uint32_t id, int32_t fd, uint32_t size)
+void
+gst_wpe_src_set_audio_shm (GstWpeSrc* src, GUnixFDList *fds, guint32 id)
+{
+  gint fd;
+  GstWpeAudioPad *audio_pad = GST_WPE_AUDIO_PAD (g_hash_table_lookup (src->audio_src_pads, GUINT_TO_POINTER (id)));
+
+  g_return_if_fail (GST_IS_WPE_SRC (src));
+  g_return_if_fail (fds);
+  g_return_if_fail (g_unix_fd_list_get_length (fds) == 1);
+  g_return_if_fail (audio_pad->fd <= 0);
+
+  fd = g_unix_fd_list_get (fds, 0, NULL);
+  g_return_if_fail (fd >= 0);
+
+  if (audio_pad->fd > 0)
+    close(audio_pad->fd);
+
+  audio_pad->fd = dup(fd);
+}
+
+void
+gst_wpe_src_push_audio_buffer (GstWpeSrc* src, guint32 id, guint64 size)
 {
-  GstWpeSrc* src = GST_WPE_SRC (data);
   GstWpeAudioPad *audio_pad = GST_WPE_AUDIO_PAD (g_hash_table_lookup (src->audio_src_pads, GUINT_TO_POINTER (id)));
-  GstPad *pad = GST_PAD_CAST (audio_pad);
   GstBuffer *buffer;
   GstClock *clock;
 
-  g_return_if_fail (GST_IS_PAD (pad));
-  g_return_if_fail (fd >= 0);
+  g_return_if_fail (audio_pad->fd > 0);
 
-  GST_TRACE_OBJECT (pad, "Handling incoming audio packet");
-  buffer = gst_buffer_new ();
+  GST_TRACE_OBJECT (audio_pad, "Handling incoming audio packet");
 
-  GstMemory *mem = gst_fd_allocator_alloc (src->fd_allocator, dup (fd), size, GST_FD_MEMORY_FLAG_KEEP_MAPPED);
-  gst_buffer_append_memory (buffer, mem);
+  gpointer data = mmap (0, size, PROT_READ, MAP_PRIVATE, audio_pad->fd, 0);
+  buffer = gst_buffer_new_wrapped (g_memdup(data, size), size);
+  munmap (data, size);
   gst_buffer_add_audio_meta (buffer, &audio_pad->info, size, NULL);
 
   clock = gst_element_get_clock (GST_ELEMENT_CAST (src));
@@ -231,30 +255,33 @@ on_audio_receiver_handle_packet(void* data, struct wpe_audio_packet_export* pack
     audio_pad->discont_pending = FALSE;
   }
 
-  gst_flow_combiner_update_pad_flow (src->flow_combiner, pad, gst_pad_push (pad, buffer));
-  wpe_audio_packet_export_release (packet_export);
-  close (fd);
+  gst_flow_combiner_update_pad_flow (src->flow_combiner, GST_PAD (audio_pad),
+    gst_pad_push (GST_PAD_CAST (audio_pad), buffer));
 }
 
 static void
-on_audio_receiver_handle_stop(void* data, uint32_t id)
+gst_wpe_src_remove_audio_pad (GstWpeSrc *src, GstPad *pad)
 {
-  GstWpeSrc* src = GST_WPE_SRC (data);
-  GstWpeAudioPad *audio_pad = GST_WPE_AUDIO_PAD (g_hash_table_lookup (src->audio_src_pads, GUINT_TO_POINTER (id)));
-  GstPad *pad = GST_PAD_CAST (audio_pad);
+  GST_DEBUG_OBJECT (src, "Removing pad: %" GST_PTR_FORMAT, pad);
+  gst_element_remove_pad (GST_ELEMENT_CAST (src), pad);
+  gst_flow_combiner_remove_pad (src->flow_combiner, pad);
+}
+
+void
+gst_wpe_src_stop_audio_stream(GstWpeSrc* src, guint32 id)
+{
+  GstPad *pad = GST_PAD (g_hash_table_lookup (src->audio_src_pads, GUINT_TO_POINTER (id)));
   g_return_if_fail (GST_IS_PAD (pad));
 
   GST_INFO_OBJECT(pad, "Stopping");
   gst_pad_push_event (pad, gst_event_new_eos ());
-  gst_element_remove_pad (GST_ELEMENT_CAST (src), pad);
-  gst_flow_combiner_remove_pad (src->flow_combiner, pad);
+  gst_wpe_src_remove_audio_pad (src, pad);
   g_hash_table_remove (src->audio_src_pads, GUINT_TO_POINTER (id));
 }
 
-static void
-on_audio_receiver_handle_pause(void* data, uint32_t id)
+void
+gst_wpe_src_pause_audio_stream(GstWpeSrc* src, guint32 id)
 {
-  GstWpeSrc* src = GST_WPE_SRC (data);
   GstWpeAudioPad *audio_pad = GST_WPE_AUDIO_PAD (g_hash_table_lookup (src->audio_src_pads, GUINT_TO_POINTER (id)));
   GstPad *pad = GST_PAD_CAST (audio_pad);
   g_return_if_fail (GST_IS_PAD (pad));
@@ -266,26 +293,6 @@ on_audio_receiver_handle_pause(void* data, uint32_t id)
 }
 
 static void
-on_audio_receiver_handle_resume(void* data, uint32_t id)
-{
-  GstWpeSrc* src = GST_WPE_SRC (data);
-  GstWpeAudioPad *audio_pad = GST_WPE_AUDIO_PAD (g_hash_table_lookup (src->audio_src_pads, GUINT_TO_POINTER (id)));
-  GstPad *pad = GST_PAD_CAST (audio_pad);
-  g_return_if_fail (GST_IS_PAD (pad));
-
-  GST_INFO_OBJECT(pad, "Resuming");
-}
-
-
-static const struct wpe_audio_receiver audio_receiver = {
-  .handle_start = on_audio_receiver_handle_start,
-  .handle_packet = on_audio_receiver_handle_packet,
-  .handle_stop = on_audio_receiver_handle_stop,
-  .handle_pause = on_audio_receiver_handle_pause,
-  .handle_resume = on_audio_receiver_handle_resume
-};
-
-static void
 gst_wpe_src_load_bytes (GstWpeVideoSrc * src, GBytes * bytes)
 {
   GstWpeSrc *self = GST_WPE_SRC (src);
@@ -366,9 +373,14 @@ static gchar *
 gst_wpe_src_get_uri (GstURIHandler * handler)
 {
   GstWpeSrc *src = GST_WPE_SRC (handler);
-  const gchar *location;
+  gchar *location;
+  gchar *res;
+
   g_object_get (src->video_src, "location", &location, NULL);
-  return g_strdup_printf ("wpe://%s", location);
+  res = g_strdup_printf ("wpe://%s", location);
+  g_free (location);
+
+  return res;
 }
 
 static gboolean
@@ -403,8 +415,14 @@ gst_wpe_src_init (GstWpeSrc * src)
   src->audio_src_pads = g_hash_table_new (g_direct_hash, g_direct_equal);
   src->flow_combiner = gst_flow_combiner_new ();
   src->video_src = gst_element_factory_make ("wpevideosrc", NULL);
+}
+
+static gboolean
+gst_wpe_audio_remove_audio_pad  (gint32  *id, GstPad *pad, GstWpeSrc  *self)
+{
+  gst_wpe_src_remove_audio_pad (self, pad);
 
-  gst_wpe_video_src_register_audio_receiver (src->video_src, &audio_receiver, src);
+  return TRUE;
 }
 
 static GstStateChangeReturn
@@ -418,6 +436,7 @@ gst_wpe_src_change_state (GstElement * element, GstStateChange transition)
 
   switch (transition) {
   case GST_STATE_CHANGE_PAUSED_TO_READY:{
+    g_hash_table_foreach_remove (src->audio_src_pads, (GHRFunc) gst_wpe_audio_remove_audio_pad, src);
     gst_flow_combiner_reset (src->flow_combiner);
     break;
   }
@@ -459,7 +478,8 @@ gst_wpe_src_class_init (GstWpeSrcClass * klass)
           (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
 
   gst_element_class_set_static_metadata (element_class, "WPE source",
-      "Source/Video/Audio", "Creates a video stream from a WPE browser",
+      "Source/Video/Audio", "Creates Audio/Video streams from a web"
+      " page using WPE web engine",
       "Philippe Normand <philn@igalia.com>, Žan Doberšek "
       "<zdobersek@igalia.com>");
 
diff --git a/ext/wpe/gstwpesrcbin.h b/ext/wpe/gstwpesrcbin.h
index c61505d61..4d09b6e40 100644
--- a/ext/wpe/gstwpesrcbin.h
+++ b/ext/wpe/gstwpesrcbin.h
@@ -23,6 +23,10 @@
 #include <gst/gst.h>
 #include <gst/audio/audio.h>
 
+#ifdef G_OS_UNIX
+#include <gio/gunixfdlist.h>
+#endif
+
 G_BEGIN_DECLS
 
 GType gst_wpe_audio_pad_get_type(void);
@@ -43,6 +47,7 @@ struct _GstWpeAudioPad
   GstAudioInfo     info;
   GstClockTime     buffer_time;
   gboolean         discont_pending;
+  gint fd;
 };
 
 struct _GstWpeAudioPadClass
@@ -67,4 +72,10 @@ struct _GstWpeSrcClass
 
 GType gst_wpe_src_get_type (void);
 
+void gst_wpe_src_new_audio_stream(GstWpeSrc *src, guint32 id, GstCaps *caps, const gchar *stream_id);
+void gst_wpe_src_set_audio_shm (GstWpeSrc* src, GUnixFDList *fds, guint32 id);
+void gst_wpe_src_push_audio_buffer (GstWpeSrc* src, guint32 id, guint64 size);
+void gst_wpe_src_pause_audio_stream (GstWpeSrc* src, guint32 id);
+void gst_wpe_src_stop_audio_stream (GstWpeSrc* src, guint32 id);
+
 G_END_DECLS
diff --git a/ext/wpe/gstwpevideosrc.cpp b/ext/wpe/gstwpevideosrc.cpp
index ca5fc59ec..6a7ffe3a1 100644
--- a/ext/wpe/gstwpevideosrc.cpp
+++ b/ext/wpe/gstwpevideosrc.cpp
@@ -75,7 +75,6 @@
 
 /*
  * TODO:
- * - Audio support (requires an AudioSession implementation in WebKit and a WPEBackend-fdo API for it)
  * - DMABuf support (requires changes in WPEBackend-fdo to expose DMABuf planes and fds)
  * - Custom EGLMemory allocator
  * - Better navigation events handling (would require a new GstNavigation API)
@@ -86,7 +85,6 @@
 #endif
 
 #include "gstwpevideosrc.h"
-#include "gstwpe-private.h"
 #include <gst/gl/gl.h>
 #include <gst/gl/egl/gstglmemoryegl.h>
 #include <gst/gl/wayland/gstgldisplay_wayland.h>
@@ -129,8 +127,6 @@ struct _GstWpeVideoSrc
   gint64 n_frames;              /* total frames sent */
 
   WPEView *view;
-  const struct wpe_audio_receiver *audio_receiver;
-  gpointer audio_receiver_data;
 
   GMutex lock;
 };
@@ -299,11 +295,6 @@ gst_wpe_video_src_start (GstWpeVideoSrc * src)
 
   if (created_view) {
     src->n_frames = 0;
-    if (src->audio_receiver) {
-      src->view->registerAudioReceiver(src->audio_receiver, src->audio_receiver_data);
-      src->audio_receiver = NULL,
-      src->audio_receiver_data = NULL;
-    }
   }
   WPE_UNLOCK (src);
   return TRUE;
@@ -743,17 +734,4 @@ gst_wpe_video_src_class_init (GstWpeVideoSrcClass * klass)
       static_cast < GSignalFlags > (G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION),
       G_CALLBACK (gst_wpe_video_src_load_bytes), NULL, NULL, NULL,
       G_TYPE_NONE, 1, G_TYPE_BYTES);
-}
-
-void
-gst_wpe_video_src_register_audio_receiver(GstElement* video_src, const struct wpe_audio_receiver* receiver, gpointer user_data)
-{
-  GstWpeVideoSrc* src = GST_WPE_VIDEO_SOURCE(video_src);
-
-  if (!src->view) {
-    src->audio_receiver = receiver;
-    src->audio_receiver_data = user_data;
-    return;
-  }
-  src->view->registerAudioReceiver(receiver, user_data);
 }
\ No newline at end of file
diff --git a/ext/wpe/meson.build b/ext/wpe/meson.build
index 580d6649c..b46ae9567 100644
--- a/ext/wpe/meson.build
+++ b/ext/wpe/meson.build
@@ -16,12 +16,17 @@ if not wpe_dep.found() or not wpe_fdo_dep.found() or not egl_dep.found() or not
   subdir_done()
 endif
 
+giounix_dep = dependency('gio-unix-2.0', required: false)
 gstwpe = library('gstwpe',
   ['WPEThreadedView.cpp', 'gstwpe.cpp', 'gstwpevideosrc.cpp', 'gstwpesrcbin.cpp'],
-  dependencies : [egl_dep, wpe_dep, wpe_fdo_dep, gstallocators_dep, gstaudio_dep, gstvideo_dep, gstbase_dep, gstgl_dep, xkbcommon_dep, wl_server_dep],
+  dependencies : [egl_dep, wpe_dep, wpe_fdo_dep, gstallocators_dep, gstaudio_dep, gstvideo_dep, gstbase_dep, gstgl_dep, xkbcommon_dep, wl_server_dep, giounix_dep],
   cpp_args : gst_plugins_bad_args + ['-DHAVE_CONFIG_H=1'],
   include_directories : [configinc],
   install : true,
   install_dir : plugins_install_dir)
+
+if giounix_dep.found()
+  subdir('wpe-extension')
+endif
 pkgconfig.generate(gstwpe, install_dir : plugins_pkgconfig_install_dir)
 plugins += [gstwpe]
diff --git a/ext/wpe/wpe-extension/gstwpeaudiosink.c b/ext/wpe/wpe-extension/gstwpeaudiosink.c
new file mode 100644
index 000000000..28ded4260
--- /dev/null
+++ b/ext/wpe/wpe-extension/gstwpeaudiosink.c
@@ -0,0 +1,278 @@
+/* Copyright (C) <2020> Philippe Normand <philn@igalia.com>
+ * Copyright (C) <2021> Thibault Saunier <tsaunier@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.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include "gstwpeextension.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#define gst_wpe_audio_sink_parent_class parent_class
+GST_DEBUG_CATEGORY (wpe_audio_sink_debug);
+#define GST_CAT_DEFAULT wpe_audio_sink_debug
+
+struct _GstWpeAudioSink
+{
+  GstBaseSink parent;
+
+  guint32 id;
+  GCancellable *cancellable;;
+
+  gchar *caps;
+
+  GMutex buf_lock;
+  GCond buf_cond;
+  GUnixFDList *fdlist;
+};
+
+static guint id = -1;           /* atomic */
+
+G_DEFINE_TYPE_WITH_CODE (GstWpeAudioSink, gst_wpe_audio_sink,
+    GST_TYPE_BASE_SINK, GST_DEBUG_CATEGORY_INIT (wpe_audio_sink_debug,
+        "wpeaudio_sink", 0, "WPE Sink"););
+
+static GstStaticPadTemplate audio_sink_factory =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw"));
+
+static void
+message_consumed_cb (GObject * source_object, GAsyncResult * res,
+    GstWpeAudioSink * self)
+{
+  g_mutex_lock (&self->buf_lock);
+  g_cond_broadcast (&self->buf_cond);
+  g_mutex_unlock (&self->buf_lock);
+}
+
+static GstFlowReturn
+render (GstBaseSink * sink, GstBuffer * buf)
+{
+  gsize written_bytes;
+  static int init = 0;
+  char filename[1024];
+  const gint *fds;
+  WebKitUserMessage *msg;
+  GstMapInfo info;
+  GstWpeAudioSink *self = GST_WPE_AUDIO_SINK (sink);
+
+  if (!self->caps) {
+    GST_ELEMENT_ERROR (self, CORE, NEGOTIATION,
+        ("Trying to render buffer before caps were set"), (NULL));
+
+    return GST_FLOW_ERROR;
+  }
+
+  if (!gst_buffer_map (buf, &info, GST_MAP_READ)) {
+    GST_ELEMENT_ERROR (self, RESOURCE, READ, ("Failed to map input buffer"),
+        (NULL));
+
+    return GST_FLOW_ERROR;
+  }
+#ifdef HAVE_MEMFD_CREATE
+  if (!self->fdlist) {
+    gint fds[1] = { -1 };
+
+    fds[0] = memfd_create ("gstwpe-shm", MFD_CLOEXEC);
+#endif
+
+    if (fds[0] < 0) {
+      /* allocate shm pool */
+      snprintf (filename, 1024, "%s/%s-%d-%s", g_get_user_runtime_dir (),
+          "gstwpe-shm", init++, "XXXXXX");
+
+      fds[0] = g_mkstemp (filename);
+      if (fds[0] < 0) {
+        gst_buffer_unmap (buf, &info);
+        GST_ELEMENT_ERROR (self, RESOURCE, READ,
+            ("opening temp file %s failed: %s", filename, strerror (errno)),
+            (NULL));
+        return GST_FLOW_ERROR;
+      }
+
+      unlink (filename);
+    }
+
+    if (fds[0] <= 0)
+      goto write_error;
+
+    self->fdlist = g_unix_fd_list_new_from_array (fds, 1);
+    msg = webkit_user_message_new_with_fd_list ("gstwpe.set_shm",
+        g_variant_new ("(u)", self->id), self->fdlist);
+    gst_wpe_extension_send_message (msg, self->cancellable, NULL, NULL);
+  }
+
+  fds = g_unix_fd_list_peek_fds (self->fdlist, NULL);
+  if (ftruncate (fds[0], info.size) == -1)
+    goto write_error;
+
+  written_bytes = write (fds[0], info.data, info.size);
+  if (written_bytes < 0)
+    goto write_error;
+
+  if (written_bytes != info.size)
+    goto write_error;
+
+  if (lseek (fds[0], 0, SEEK_SET) == -1)
+    goto write_error;
+
+  msg = webkit_user_message_new ("gstwpe.new_buffer",
+      g_variant_new ("(ut)", self->id, info.size));
+
+  g_mutex_lock (&self->buf_lock);
+  gst_wpe_extension_send_message (msg, self->cancellable,
+      (GAsyncReadyCallback) message_consumed_cb, self);
+  g_cond_wait (&self->buf_cond, &self->buf_lock);
+  g_mutex_unlock (&self->buf_lock);
+
+  gst_buffer_unmap (buf, &info);
+
+  return GST_FLOW_OK;
+
+write_error:
+  gst_buffer_unmap (buf, &info);
+  GST_ELEMENT_ERROR (self, RESOURCE, WRITE, ("Couldn't write memfd: %s",
+          strerror (errno)), (NULL));
+
+  return GST_FLOW_ERROR;
+}
+
+static gboolean
+set_caps (GstBaseSink * sink, GstCaps * caps)
+{
+  GstWpeAudioSink *self = GST_WPE_AUDIO_SINK (sink);
+  gchar *stream_id;
+
+  if (self->caps) {
+    GST_ERROR_OBJECT (sink, "Renegotiation is not supported yet");
+
+    return FALSE;
+  }
+
+  self->caps = gst_caps_to_string (caps);
+  g_atomic_int_inc (&id);
+  self->id = g_atomic_int_get (&id);
+  stream_id = gst_pad_get_stream_id (GST_BASE_SINK_PAD (sink));
+  gst_wpe_extension_send_message (webkit_user_message_new ("gstwpe.new_stream",
+          g_variant_new ("(uss)", self->id, self->caps, stream_id)),
+      self->cancellable, NULL, NULL);
+  g_free (stream_id);
+
+  return TRUE;
+}
+
+static gboolean
+unlock (GstBaseSink * sink)
+{
+  GstWpeAudioSink *self = GST_WPE_AUDIO_SINK (sink);
+
+  g_cancellable_cancel (self->cancellable);
+  g_mutex_lock (&self->buf_lock);
+  g_cond_broadcast (&self->buf_cond);
+  g_mutex_unlock (&self->buf_lock);
+
+  return TRUE;
+}
+
+static gboolean
+stop (GstBaseSink * sink)
+{
+  GstWpeAudioSink *self = GST_WPE_AUDIO_SINK (sink);
+
+  if (!self->caps) {
+    GST_DEBUG_OBJECT (sink, "Stopped before started");
+
+    return TRUE;
+  }
+
+  /* Stop processing and claim buffers back */
+  unlock (sink);
+
+  GST_DEBUG_OBJECT (sink, "Stopping %d", self->id);
+  gst_wpe_extension_send_message (webkit_user_message_new ("gstwpe.stop",
+          g_variant_new_uint32 (self->id)), self->cancellable, NULL, NULL);
+
+  return TRUE;
+}
+
+static GstStateChangeReturn
+change_state (GstElement * element, GstStateChange transition)
+{
+  GstWpeAudioSink *self = GST_WPE_AUDIO_SINK (element);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+      gst_wpe_extension_send_message (webkit_user_message_new ("gstwpe.pause",
+              g_variant_new_uint32 (self->id)), self->cancellable, NULL, NULL);
+      break;
+    default:
+      break;
+  }
+
+  return GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS,
+      change_state, (element, transition), GST_STATE_CHANGE_SUCCESS);
+}
+
+static void
+dispose (GObject * object)
+{
+  GstWpeAudioSink *self = GST_WPE_AUDIO_SINK (object);
+
+  g_clear_object (&self->cancellable);
+  g_clear_pointer (&self->caps, g_free);
+}
+
+static void
+gst_wpe_audio_sink_init (GstWpeAudioSink * self)
+{
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (self);
+  GstPadTemplate *pad_template =
+      gst_element_class_get_pad_template (GST_ELEMENT_CLASS (klass), "sink");
+  g_return_if_fail (pad_template != NULL);
+
+  self->cancellable = g_cancellable_new ();
+}
+
+static void
+gst_wpe_audio_sink_class_init (GstWpeAudioSinkClass * klass)
+{
+  GstPadTemplate *tmpl;
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GstBaseSinkClass *gstbasesink_class = (GstBaseSinkClass *) klass;
+
+  object_class->dispose = dispose;
+
+  gst_element_class_set_static_metadata (gstelement_class,
+      "WPE internal audio sink", "Sink/Audio",
+      "Internal sink to be used in wpe when running inside gstwpe",
+      "Thibault Saunier <tsaunier@igalia.com>");
+
+  tmpl = gst_static_pad_template_get (&audio_sink_factory);
+  gst_element_class_add_pad_template (gstelement_class, tmpl);
+
+  gstelement_class->change_state = GST_DEBUG_FUNCPTR (change_state);
+  gstbasesink_class->stop = GST_DEBUG_FUNCPTR (stop);
+  gstbasesink_class->unlock = GST_DEBUG_FUNCPTR (unlock);
+  gstbasesink_class->render = GST_DEBUG_FUNCPTR (render);
+  gstbasesink_class->set_caps = GST_DEBUG_FUNCPTR (set_caps);
+}
diff --git a/ext/wpe/wpe-extension/gstwpeextension.c b/ext/wpe/wpe-extension/gstwpeextension.c
new file mode 100644
index 000000000..f73a7e54e
--- /dev/null
+++ b/ext/wpe/wpe-extension/gstwpeextension.c
@@ -0,0 +1,63 @@
+/* Copyright (C) <2021> Thibault Saunier <tsaunier@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.
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "gstwpeextension.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+#include <gst/gst.h>
+#include <gmodule.h>
+#include <gio/gunixfdlist.h>
+#include <wpe/webkit-web-extension.h>
+
+G_MODULE_EXPORT void webkit_web_extension_initialize (WebKitWebExtension *
+    extension);
+
+static WebKitWebExtension *global_extension = NULL;
+
+void
+webkit_web_extension_initialize (WebKitWebExtension * extension)
+{
+  g_return_if_fail (!global_extension);
+
+  gst_init (NULL, NULL);
+
+  /* Register our own audio sink to */
+  gst_element_register (NULL, "gstwpeaudiosink", GST_RANK_PRIMARY + 500,
+      gst_wpe_audio_sink_get_type ());
+
+  GST_INFO ("Mark processus as WebProcess");
+  if (!g_setenv ("GST_WPE_ID", "1", TRUE))
+    g_error ("Could not set GST_WPE_ID envvar\n");
+
+  global_extension = extension;
+  GST_INFO_OBJECT (global_extension, "Setting as global extension.");
+}
+
+void
+gst_wpe_extension_send_message (WebKitUserMessage * msg,
+    GCancellable * cancellable, GAsyncReadyCallback cb, gpointer udata)
+{
+  webkit_web_extension_send_message_to_context (global_extension, msg,
+      cancellable, cb, udata);
+}
diff --git a/ext/wpe/wpe-extension/gstwpeextension.h b/ext/wpe/wpe-extension/gstwpeextension.h
new file mode 100644
index 000000000..9f3ec57c6
--- /dev/null
+++ b/ext/wpe/wpe-extension/gstwpeextension.h
@@ -0,0 +1,25 @@
+/* Copyright (C) <2021> Thibault Saunier <tsaunier@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.
+ */
+
+#pragma once
+
+#include <wpe/webkit-web-extension.h>
+#include <gio/gunixfdlist.h>
+#include <gst/gst.h>
+#include <gst/base/gstbasesink.h>
+
+void gst_wpe_extension_send_message (WebKitUserMessage *msg, GCancellable *cancellable, GAsyncReadyCallback cb, gpointer udata);
+
+G_DECLARE_FINAL_TYPE (GstWpeAudioSink, gst_wpe_audio_sink, GST, WPE_AUDIO_SINK, GstBaseSink);
\ No newline at end of file
diff --git a/ext/wpe/wpe-extension/meson.build b/ext/wpe/wpe-extension/meson.build
new file mode 100644
index 000000000..9e159c730
--- /dev/null
+++ b/ext/wpe/wpe-extension/meson.build
@@ -0,0 +1,8 @@
+library('gstwpeextension',
+  ['gstwpeextension.c', 'gstwpeaudiosink.c'],
+  dependencies : [wpe_dep, gst_dep, gstbase_dep, giounix_dep],
+  c_args : ['-DHAVE_CONFIG_H=1'],
+  include_directories : [configinc],
+  install : true,
+  install_dir : plugins_install_dir / 'wpe-extension')
+