[mutter] tests: Add tests for virtual screen cast source

[Marge Bot <marge-bot src gnome org>]

commit 1940cd7fe9563c1f7ebc413adca08708630aeea6
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Feb 1 20:32:27 2021 +0100

    tests: Add tests for virtual screen cast source
    
    Tests that creating and starting a virtual screen cast monitor works,
    and that at least one one buffer is processed.
    
    Currently the content of the buffer isn't checked more than it can be
    mmap():ed. Only MemFd buffers are tested for for now, as DMA buffers
    would need a surfaceless EGL context to check properly.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>

 meson.build                    |   3 +
 src/tests/meson.build          |  17 ++
 src/tests/native-headless.c    |   2 +
 src/tests/native-screen-cast.c |  86 +++++++
 src/tests/native-screen-cast.h |  26 ++
 src/tests/screen-cast-client.c | 572 +++++++++++++++++++++++++++++++++++++++++
 6 files changed, 706 insertions(+)
---
diff --git a/meson.build b/meson.build
index c4bfdfe25c..9dd8c5e2af 100644
--- a/meson.build
+++ b/meson.build
@@ -277,6 +277,9 @@ if have_tests
     if not have_native_backend
       error('Native tests require the native backend')
     endif
+    if not have_remote_desktop
+      error('Native tests require remote desktop')
+    endif
   endif
 
   have_cogl_tests = get_option('cogl_tests')
diff --git a/src/tests/meson.build b/src/tests/meson.build
index e570db8c62..8ffe2f9e1f 100644
--- a/src/tests/meson.build
+++ b/src/tests/meson.build
@@ -166,6 +166,8 @@ if have_native_tests
   native_headless_tests = executable('mutter-native-headless-tests',
     sources: [
       'native-headless.c',
+      'native-screen-cast.c',
+      'native-screen-cast.h',
       'native-virtual-monitor.c',
       'native-virtual-monitor.h',
       'test-utils.c',
@@ -192,6 +194,21 @@ if have_native_tests
     install: have_installed_tests,
     install_dir: mutter_installed_tests_libexecdir,
   )
+
+  screen_cast_client = executable('mutter-screen-cast-client',
+    sources: [
+      'screen-cast-client.c',
+      dbus_screen_cast_built_sources,
+    ],
+    include_directories: tests_includepath,
+    c_args: tests_c_args,
+    dependencies: [
+      gio_dep,
+      libpipewire_dep,
+    ],
+    install: have_installed_tests,
+    install_dir: mutter_installed_tests_libexecdir,
+  )
 endif
 
 stacking_tests = [
diff --git a/src/tests/native-headless.c b/src/tests/native-headless.c
index 1b3d4a26c4..6b5da665c1 100644
--- a/src/tests/native-headless.c
+++ b/src/tests/native-headless.c
@@ -26,6 +26,7 @@
 #include "core/main-private.h"
 #include "meta/main.h"
 #include "meta/meta-backend.h"
+#include "tests/native-screen-cast.h"
 #include "tests/native-virtual-monitor.h"
 #include "tests/test-utils.h"
 
@@ -33,6 +34,7 @@ static void
 init_tests (void)
 {
   init_virtual_monitor_tests ();
+  init_screen_cast_tests ();
 }
 
 static gboolean
diff --git a/src/tests/native-screen-cast.c b/src/tests/native-screen-cast.c
new file mode 100644
index 0000000000..bcde15665d
--- /dev/null
+++ b/src/tests/native-screen-cast.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2021 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include "tests/native-screen-cast.h"
+
+#include <errno.h>
+#include <gio/gio.h>
+#include <unistd.h>
+
+static void
+test_client_exited (GObject      *source_object,
+                    GAsyncResult *result,
+                    gpointer      user_data)
+{
+  GError *error = NULL;
+
+  if (!g_subprocess_wait_finish (G_SUBPROCESS (source_object),
+                                 result,
+                                 &error))
+    g_error ("Screen cast test client exited with an error: %s", error->message);
+
+  g_main_loop_quit (user_data);
+}
+
+static void
+meta_test_screen_cast_record_virtual (void)
+{
+  GSubprocessLauncher *launcher;
+  g_autofree char *test_client_path = NULL;
+  GError *error = NULL;
+  GSubprocess *subprocess;
+  GMainLoop *loop;
+
+  launcher =  g_subprocess_launcher_new ((G_SUBPROCESS_FLAGS_STDIN_PIPE |
+                                          G_SUBPROCESS_FLAGS_STDOUT_PIPE));
+
+  test_client_path = g_test_build_filename (G_TEST_BUILT,
+                                            "src",
+                                            "tests",
+                                            "mutter-screen-cast-client",
+                                            NULL);
+  g_subprocess_launcher_setenv (launcher,
+                                "XDG_RUNTIME_DIR", getenv ("XDG_RUNTIME_DIR"),
+                                TRUE);
+  subprocess = g_subprocess_launcher_spawn (launcher,
+                                            &error,
+                                            test_client_path,
+                                            NULL);
+  if (!subprocess)
+    g_error ("Failed to launch screen cast test client: %s", error->message);
+
+  loop = g_main_loop_new (NULL, FALSE);
+  g_subprocess_wait_check_async (subprocess,
+                                 NULL,
+                                 test_client_exited,
+                                 loop);
+  g_main_loop_run (loop);
+  g_assert_true (g_subprocess_get_successful (subprocess));
+  g_object_unref (subprocess);
+}
+
+void
+init_screen_cast_tests (void)
+{
+  g_test_add_func ("/backends/native/screen-cast/record-virtual",
+                   meta_test_screen_cast_record_virtual);
+}
diff --git a/src/tests/native-screen-cast.h b/src/tests/native-screen-cast.h
new file mode 100644
index 0000000000..3c79676c70
--- /dev/null
+++ b/src/tests/native-screen-cast.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2021 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#ifndef NATIVE_SCREEN_CAST_H
+#define NATIVE_SCREEN_CAST_H
+
+void init_screen_cast_tests (void);
+
+#endif /* NATIVE_SCREEN_CAST_H */
diff --git a/src/tests/screen-cast-client.c b/src/tests/screen-cast-client.c
new file mode 100644
index 0000000000..cc118f7aef
--- /dev/null
+++ b/src/tests/screen-cast-client.c
@@ -0,0 +1,572 @@
+/*
+ * Copyright (C) 2021 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include <pipewire/pipewire.h>
+#include <spa/param/format-utils.h>
+#include <spa/param/props.h>
+#include <spa/param/video/format-utils.h>
+#include <spa/utils/result.h>
+#include <stdint.h>
+#include <sys/mman.h>
+
+#include "meta-dbus-screen-cast.h"
+
+typedef struct _Stream
+{
+  MetaDBusScreenCastStream *proxy;
+  uint32_t pipewire_node_id;
+  struct spa_video_info_raw spa_format;
+  struct pw_stream *pipewire_stream;
+  struct spa_hook pipewire_stream_listener;
+  enum pw_stream_state state;
+  int buffer_count;
+} Stream;
+
+typedef struct _Session
+{
+  MetaDBusScreenCastSession *proxy;
+} Session;
+
+typedef struct _ScreenCast
+{
+  MetaDBusScreenCast *proxy;
+} ScreenCast;
+
+typedef struct _PipeWireSource
+{
+  GSource base;
+
+  struct pw_loop *pipewire_loop;
+} PipeWireSource;
+
+static PipeWireSource *_pipewire_source;
+static struct pw_context *_pipewire_context;
+static struct pw_core *_pipewire_core;
+static struct spa_hook _pipewire_core_listener;
+
+static gboolean
+pipewire_loop_source_prepare (GSource *base,
+                              int     *timeout)
+{
+  *timeout = -1;
+  return FALSE;
+}
+
+static gboolean
+pipewire_loop_source_dispatch (GSource     *source,
+                               GSourceFunc  callback,
+                               gpointer     user_data)
+{
+  PipeWireSource *pipewire_source = (PipeWireSource *) source;
+  int result;
+
+  result = pw_loop_iterate (pipewire_source->pipewire_loop, 0);
+  if (result < 0)
+    g_error ("pipewire_loop_iterate failed: %s", spa_strerror (result));
+
+  return TRUE;
+}
+
+static void
+pipewire_loop_source_finalize (GSource *source)
+{
+  PipeWireSource *pipewire_source = (PipeWireSource *) source;
+
+  pw_loop_leave (pipewire_source->pipewire_loop);
+  pw_loop_destroy (pipewire_source->pipewire_loop);
+}
+
+static GSourceFuncs pipewire_source_funcs =
+{
+  pipewire_loop_source_prepare,
+  NULL,
+  pipewire_loop_source_dispatch,
+  pipewire_loop_source_finalize
+};
+
+static PipeWireSource *
+create_pipewire_source (void)
+{
+  PipeWireSource *pipewire_source;
+
+  pipewire_source =
+    (PipeWireSource *) g_source_new (&pipewire_source_funcs,
+                                     sizeof (PipeWireSource));
+  pipewire_source->pipewire_loop = pw_loop_new (NULL);
+  g_assert_nonnull (pipewire_source->pipewire_loop);
+  g_source_add_unix_fd (&pipewire_source->base,
+                        pw_loop_get_fd (pipewire_source->pipewire_loop),
+                        G_IO_IN | G_IO_ERR);
+
+  pw_loop_enter (pipewire_source->pipewire_loop);
+  g_source_attach (&pipewire_source->base, NULL);
+
+  return pipewire_source;
+}
+
+static void
+on_core_error (void       *user_data,
+               uint32_t    id,
+               int         seq,
+               int         res,
+               const char *message)
+{
+  g_error ("PipeWire core error: id:%u %s", id, message);
+}
+
+static const struct pw_core_events core_events = {
+  PW_VERSION_CORE_EVENTS,
+  .error = on_core_error,
+};
+
+static void
+init_pipewire (void)
+{
+  pw_init (NULL, NULL);
+  _pipewire_source = create_pipewire_source ();
+  _pipewire_context = pw_context_new (_pipewire_source->pipewire_loop,
+                                      NULL, 0);
+  g_assert_nonnull (_pipewire_context);
+  _pipewire_core = pw_context_connect (_pipewire_context, NULL, 0);
+  g_assert_nonnull (_pipewire_core);
+
+  pw_core_add_listener (_pipewire_core,
+                        &_pipewire_core_listener,
+                        &core_events,
+                        NULL);
+}
+
+static void
+release_pipewire (void)
+{
+  g_clear_pointer (&_pipewire_core, pw_core_disconnect);
+  g_clear_pointer (&_pipewire_context, pw_context_destroy);
+  if (_pipewire_source)
+    {
+      g_source_destroy ((GSource *) _pipewire_source);
+      g_source_unref ((GSource *) _pipewire_source);
+      _pipewire_source = NULL;
+    }
+}
+
+static void
+on_stream_state_changed (void                 *user_data,
+                         enum pw_stream_state  old,
+                         enum pw_stream_state  state,
+                         const char           *error)
+{
+  Stream *stream = user_data;
+
+  switch (state)
+    {
+    case PW_STREAM_STATE_ERROR:
+      g_warning ("PipeWire stream error: %s", error);
+      break;
+    case PW_STREAM_STATE_PAUSED:
+    case PW_STREAM_STATE_STREAMING:
+    case PW_STREAM_STATE_UNCONNECTED:
+    case PW_STREAM_STATE_CONNECTING:
+      break;
+    }
+
+  stream->state = state;
+}
+
+static void
+on_stream_param_changed (void                 *user_data,
+                         uint32_t              id,
+                         const struct spa_pod *format)
+{
+  Stream *stream = user_data;
+  uint8_t params_buffer[1024];
+  struct spa_pod_builder pod_builder;
+  const struct spa_pod *params[2];
+
+  if (!format || id != SPA_PARAM_Format)
+    return;
+
+  spa_format_video_raw_parse (format, &stream->spa_format);
+
+  pod_builder = SPA_POD_BUILDER_INIT (params_buffer, sizeof (params_buffer));
+
+  params[0] = spa_pod_builder_add_object (
+    &pod_builder,
+    SPA_TYPE_OBJECT_ParamBuffers, SPA_PARAM_Buffers,
+    SPA_PARAM_BUFFERS_buffers, SPA_POD_CHOICE_RANGE_Int (8, 1, 8),
+    SPA_PARAM_BUFFERS_dataType, SPA_POD_Int ((1 << SPA_DATA_MemPtr) |
+                                             (1 << SPA_DATA_MemFd)),
+    0);
+
+  params[1] = spa_pod_builder_add_object (
+    &pod_builder,
+    SPA_TYPE_OBJECT_ParamMeta, SPA_PARAM_Meta,
+    SPA_PARAM_META_type, SPA_POD_Id (SPA_META_Header),
+    SPA_PARAM_META_size, SPA_POD_Int (sizeof (struct spa_meta_header)),
+    0);
+
+  pw_stream_update_params (stream->pipewire_stream,
+                           params, G_N_ELEMENTS (params));
+}
+
+static void
+sanity_check_memfd (struct spa_buffer *buffer)
+{
+  size_t size;
+  uint8_t *map;
+
+  size = buffer->datas[0].maxsize + buffer->datas[0].mapoffset;
+  g_assert_cmpint (size, >, 0);
+  map = mmap (NULL, size, PROT_READ, MAP_PRIVATE, buffer->datas[0].fd, 0);
+  g_assert (map != MAP_FAILED);
+  munmap (map, size);
+}
+
+static void
+sanity_check_memptr (struct spa_buffer *buffer)
+{
+  size_t size;
+
+  size = buffer->datas[0].maxsize + buffer->datas[0].mapoffset;
+  g_assert_cmpint (size, >, 0);
+
+  g_assert_nonnull (buffer->datas[0].data);
+}
+
+static void
+process_buffer (Stream            *stream,
+                struct spa_buffer *buffer)
+{
+  if (buffer->datas[0].chunk->size == 0)
+    g_assert_not_reached ();
+  else if (buffer->datas[0].type == SPA_DATA_MemFd)
+    sanity_check_memfd (buffer);
+  else if (buffer->datas[0].type == SPA_DATA_DmaBuf)
+    g_assert_not_reached ();
+  else if (buffer->datas[0].type == SPA_DATA_MemPtr)
+    sanity_check_memptr (buffer);
+  else
+    g_assert_not_reached ();
+}
+
+static void
+on_stream_process (void *user_data)
+{
+  Stream *stream = user_data;
+  struct pw_buffer *next_buffer;
+  struct pw_buffer *buffer = NULL;
+
+  next_buffer = pw_stream_dequeue_buffer (stream->pipewire_stream);
+  while (next_buffer)
+    {
+      buffer = next_buffer;
+      next_buffer = pw_stream_dequeue_buffer (stream->pipewire_stream);
+
+      if (next_buffer)
+        pw_stream_queue_buffer (stream->pipewire_stream, buffer);
+    }
+  if (!buffer)
+    return;
+
+  process_buffer (stream, buffer->buffer);
+  pw_stream_queue_buffer (stream->pipewire_stream, buffer);
+
+  stream->buffer_count++;
+}
+
+static const struct pw_stream_events stream_events = {
+  PW_VERSION_STREAM_EVENTS,
+  .state_changed = on_stream_state_changed,
+  .param_changed = on_stream_param_changed,
+  .process = on_stream_process,
+};
+
+static void
+stream_connect (Stream *stream)
+{
+  struct pw_stream *pipewire_stream;
+  uint8_t params_buffer[1024];
+  struct spa_pod_builder pod_builder;
+  struct spa_rectangle min_rect;
+  struct spa_rectangle max_rect;
+  struct spa_fraction min_framerate;
+  struct spa_fraction max_framerate;
+  const struct spa_pod *params[2];
+  int ret;
+
+  pipewire_stream = pw_stream_new (_pipewire_core,
+                                   "mutter-test-pipewire-stream",
+                                   NULL);
+
+  min_rect = SPA_RECTANGLE (1, 1);
+  max_rect = SPA_RECTANGLE (50 , 50);
+  min_framerate = SPA_FRACTION (1, 1);
+  max_framerate = SPA_FRACTION (30, 1);
+
+  pod_builder = SPA_POD_BUILDER_INIT (params_buffer, sizeof (params_buffer));
+  params[0] = spa_pod_builder_add_object (
+    &pod_builder,
+    SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
+    SPA_FORMAT_mediaType, SPA_POD_Id (SPA_MEDIA_TYPE_video),
+    SPA_FORMAT_mediaSubtype, SPA_POD_Id (SPA_MEDIA_SUBTYPE_raw),
+    SPA_FORMAT_VIDEO_format, SPA_POD_Id (SPA_VIDEO_FORMAT_BGRx),
+    SPA_FORMAT_VIDEO_size, SPA_POD_CHOICE_RANGE_Rectangle (&min_rect,
+                                                           &min_rect,
+                                                           &max_rect),
+    SPA_FORMAT_VIDEO_framerate, SPA_POD_Fraction (&SPA_FRACTION(0, 1)),
+    SPA_FORMAT_VIDEO_maxFramerate, SPA_POD_CHOICE_RANGE_Fraction (&min_framerate,
+                                                                  &min_framerate,
+                                                                  &max_framerate),
+    0);
+
+  stream->pipewire_stream = pipewire_stream;
+
+  pw_stream_add_listener (pipewire_stream,
+                          &stream->pipewire_stream_listener,
+                          &stream_events,
+                          stream);
+
+  ret = pw_stream_connect (stream->pipewire_stream,
+                           PW_DIRECTION_INPUT,
+                           stream->pipewire_node_id,
+                           PW_STREAM_FLAG_AUTOCONNECT,
+                           params, 1);
+  if (ret < 0)
+    g_error ("Failed to connect PipeWire stream: %s", g_strerror (-ret));
+}
+
+static void
+stream_wait_for_node (Stream *stream)
+{
+  while (!stream->pipewire_node_id)
+    g_main_context_iteration (NULL, TRUE);
+}
+
+static G_GNUC_UNUSED void
+stream_wait_for_streaming (Stream *stream)
+{
+  while (stream->state != PW_STREAM_STATE_STREAMING)
+    g_main_context_iteration (NULL, TRUE);
+}
+
+static G_GNUC_UNUSED void
+stream_wait_for_render (Stream *stream)
+{
+  while (stream->buffer_count == 0)
+    g_main_context_iteration (NULL, TRUE);
+}
+
+static void
+on_pipewire_stream_added (MetaDBusScreenCastStream *proxy,
+                          unsigned int              node_id,
+                          Stream                   *stream)
+{
+  stream->pipewire_node_id = (uint32_t) node_id;
+  stream_connect (stream);
+}
+
+static Stream *
+stream_new (const char *path)
+{
+  Stream *stream;
+  GError *error = NULL;
+
+  stream = g_new0 (Stream, 1);
+  stream->proxy = meta_dbus_screen_cast_stream_proxy_new_for_bus_sync (
+    G_BUS_TYPE_SESSION,
+    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+    "org.gnome.Mutter.ScreenCast",
+    path,
+    NULL,
+    &error);
+  if (!stream->proxy)
+    g_error ("Failed to acquire proxy: %s", error->message);
+
+  g_signal_connect (stream->proxy, "pipewire-stream-added",
+                    G_CALLBACK (on_pipewire_stream_added),
+                    stream);
+
+  return stream;
+}
+
+static void
+stream_free (Stream *stream)
+{
+  g_clear_pointer (&stream->pipewire_stream, pw_stream_destroy);
+  g_clear_object (&stream->proxy);
+  g_free (stream);
+}
+
+static void
+session_start (Session *session)
+{
+  GError *error = NULL;
+
+  if (!meta_dbus_screen_cast_session_call_start_sync (session->proxy,
+                                                      NULL,
+                                                      &error))
+    g_error ("Failed to start session: %s", error->message);
+}
+
+static void
+session_stop (Session *session)
+{
+  GError *error = NULL;
+
+  if (!meta_dbus_screen_cast_session_call_stop_sync (session->proxy,
+                                                     NULL,
+                                                     &error))
+    g_error ("Failed to stop session: %s", error->message);
+}
+
+static Stream *
+session_record_virtual (Session *session)
+{
+  GVariantBuilder properties_builder;
+  GVariant *properties_variant;
+  GError *error = NULL;
+  g_autofree char *stream_path = NULL;
+  Stream *stream;
+
+  g_variant_builder_init (&properties_builder, G_VARIANT_TYPE ("a{sv}"));
+  properties_variant = g_variant_builder_end (&properties_builder);
+
+  if (!meta_dbus_screen_cast_session_call_record_virtual_sync (
+        session->proxy,
+        properties_variant,
+        &stream_path,
+        NULL,
+        &error))
+    g_error ("Failed to create session: %s", error->message);
+
+  stream = stream_new (stream_path);
+  g_assert_nonnull (stream);
+  return stream;
+}
+
+static Session *
+session_new (const char *path)
+{
+  Session *session;
+  GError *error = NULL;
+
+  session = g_new0 (Session, 1);
+  session->proxy = meta_dbus_screen_cast_session_proxy_new_for_bus_sync (
+    G_BUS_TYPE_SESSION,
+    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+    "org.gnome.Mutter.ScreenCast",
+    path,
+    NULL,
+    &error);
+  if (!session->proxy)
+    g_error ("Failed to acquire proxy: %s", error->message);
+
+  return session;
+}
+
+static void
+session_free (Session *session)
+{
+  g_clear_object (&session->proxy);
+  g_free (session);
+}
+
+static Session *
+screen_cast_create_session (ScreenCast *screen_cast)
+{
+  GVariantBuilder properties_builder;
+  GVariant *properties_variant;
+  GError *error = NULL;
+  g_autofree char *session_path = NULL;
+  Session *session;
+
+  g_variant_builder_init (&properties_builder, G_VARIANT_TYPE ("a{sv}"));
+  properties_variant = g_variant_builder_end (&properties_builder);
+
+  if (!meta_dbus_screen_cast_call_create_session_sync (screen_cast->proxy,
+                                                       properties_variant,
+                                                       &session_path,
+                                                       NULL,
+                                                       &error))
+    g_error ("Failed to create session: %s", error->message);
+
+  session = session_new (session_path);
+  g_assert_nonnull (session);
+  return session;
+}
+
+static ScreenCast *
+screen_cast_new (void)
+{
+  ScreenCast *screen_cast;
+  GError *error = NULL;
+
+  screen_cast = g_new0 (ScreenCast, 1);
+  screen_cast->proxy = meta_dbus_screen_cast_proxy_new_for_bus_sync (
+    G_BUS_TYPE_SESSION,
+    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+    "org.gnome.Mutter.ScreenCast",
+    "/org/gnome/Mutter/ScreenCast",
+    NULL,
+    &error);
+  if (!screen_cast->proxy)
+    g_error ("Failed to acquire proxy: %s", error->message);
+
+  return screen_cast;
+}
+
+static void
+screen_cast_free (ScreenCast *screen_cast)
+{
+  g_clear_object (&screen_cast->proxy);
+  g_free (screen_cast);
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  ScreenCast *screen_cast;
+  Session *session;
+  Stream *stream;
+
+  init_pipewire ();
+
+  screen_cast = screen_cast_new ();
+  session = screen_cast_create_session (screen_cast);
+  stream = session_record_virtual (session);
+
+  session_start (session);
+
+  stream_wait_for_node (stream);
+  stream_wait_for_streaming (stream);
+  stream_wait_for_render (stream);
+
+  session_stop (session);
+
+  stream_free (stream);
+  session_free (session);
+  screen_cast_free (screen_cast);
+
+  release_pipewire ();
+
+  return EXIT_SUCCESS;
+}