gstcefsrc.cc

#include <stdio.h>
#include <iostream>
#include <sstream>

#include <include/cef_app.h>
#include <include/cef_client.h>
#include <include/cef_render_handler.h>
#include <include/cef_life_span_handler.h>
#include <include/cef_load_handler.h>
#include <include/wrapper/cef_helpers.h>
#include <include/base/cef_bind.h>
#include <include/wrapper/cef_closure_task.h>

#include "gstcefsrc.h"
#include "gstcefaudiometa.h"

GST_DEBUG_CATEGORY_STATIC (cef_src_debug);
#define GST_CAT_DEFAULT cef_src_debug

#define DEFAULT_WIDTH 1920
#define DEFAULT_HEIGHT 1080
#define DEFAULT_FPS_N 30
#define DEFAULT_FPS_D 1
#define DEFAULT_URL "https://www.google.com"
#define DEFAULT_GPU FALSE
#define DEFAULT_CHROMIUM_DEBUG_PORT -1

static gboolean cef_inited = FALSE;
static gboolean init_result = FALSE;
static GMutex init_lock;
static GCond init_cond;

enum
{
  PROP_0,
  PROP_URL,
  PROP_GPU,
  PROP_CHROMIUM_DEBUG_PORT,
  PROP_CHROME_EXTRA_FLAGS
};

#define gst_cef_src_parent_class parent_class
G_DEFINE_TYPE (GstCefSrc, gst_cef_src, GST_TYPE_PUSH_SRC);

#define CEF_VIDEO_CAPS "video/x-raw, format=BGRA, width=[1, 2147483647], height=[1, 2147483647], framerate=[1/1, 60/1], pixel-aspect-ratio=1/1"
#define CEF_AUDIO_CAPS "audio/x-raw, format=F32LE, rate=[1, 2147483647], channels=[1, 2147483647], layout=interleaved"

static GstStaticPadTemplate gst_cef_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (CEF_VIDEO_CAPS)
    );

gchar* get_plugin_base_path () {
  GstPlugin *plugin = gst_registry_find_plugin(gst_registry_get(), "cef");
  gchar* base_path = g_path_get_dirname(gst_plugin_get_filename(plugin));
  gst_object_unref(plugin);
  return base_path;
}

class RenderHandler : public CefRenderHandler
{
  public:

    RenderHandler(GstCefSrc *element) :
        element (element)
    {
    }

    ~RenderHandler()
    {
    }

    void GetViewRect(CefRefPtr<CefBrowser> browser, CefRect &rect) override
    {
	  GST_LOG_OBJECT(element, "getting view rect");
      GST_OBJECT_LOCK (element);
      rect = CefRect(0, 0, element->vinfo.width ? element->vinfo.width : DEFAULT_WIDTH, element->vinfo.height ? element->vinfo.height : DEFAULT_HEIGHT);
      GST_OBJECT_UNLOCK (element);
    }

    void OnPaint(CefRefPtr<CefBrowser> browser, PaintElementType type, const RectList &dirtyRects, const void * buffer, int w, int h) override
    {
      GstBuffer *new_buffer;

      GST_LOG_OBJECT (element, "painting, width / height: %d %d", w, h);

      new_buffer = gst_buffer_new_allocate (NULL, element->vinfo.width * element->vinfo.height * 4, NULL);
      gst_buffer_fill (new_buffer, 0, buffer, w * h * 4);

      GST_OBJECT_LOCK (element);
      gst_buffer_replace (&(element->current_buffer), new_buffer);
      gst_buffer_unref (new_buffer);
      GST_OBJECT_UNLOCK (element);

      GST_LOG_OBJECT (element, "done painting");
    }

  private:

    GstCefSrc *element;

    IMPLEMENT_REFCOUNTING(RenderHandler);
};

class RequestHandler : public CefRequestHandler
{
  public:

    RequestHandler(GstCefSrc *element) :
        element (element)
    {
    }

    ~RequestHandler()
    {
    }

    virtual void OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser, TerminationStatus status) override
		{
			GST_WARNING_OBJECT (element, "Render subprocess terminated, reloading URL!");
      browser->Reload();
    }

  private:

    GstCefSrc *element;
    IMPLEMENT_REFCOUNTING(RequestHandler);
};


class AudioHandler : public CefAudioHandler
{
  public:

    AudioHandler(GstCefSrc *element) :
        mElement (element)
    {
    }

    ~AudioHandler()
    {
    }

  void OnAudioStreamStarted(CefRefPtr<CefBrowser> browser,
                            const CefAudioParameters& params,
                            int channels) override
  {
    GstStructure *s = gst_structure_new ("cef-audio-stream-start",
        "channels", G_TYPE_INT, channels,
        "rate", G_TYPE_INT, params.sample_rate,
        NULL);
    GstEvent *event = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM, s);

    mRate = params.sample_rate;
    mChannels = channels;
    mCurrentTime = GST_CLOCK_TIME_NONE;

    GST_OBJECT_LOCK (mElement);
    mElement->audio_events = g_list_append (mElement->audio_events, event);
    GST_OBJECT_UNLOCK (mElement);
  }

  void OnAudioStreamPacket(CefRefPtr<CefBrowser> browser,
                           const float** data,
                           int frames,
                           int64_t pts) override
  {
    GstBuffer *buf;
    GstMapInfo info;
    gint i, j;

    GST_LOG_OBJECT (mElement, "Handling audio stream packet with %d frames", frames);

    buf = gst_buffer_new_allocate (NULL, mChannels * frames * 4, NULL);

    gst_buffer_map (buf, &info, GST_MAP_WRITE);
    for (i = 0; i < mChannels; i++) {
      gfloat *cdata = (gfloat *) data[i];

      for (j = 0; j < frames; j++) {
        memcpy (info.data + j * 4 * mChannels + i * 4, &cdata[j], 4);
      }
    }
    gst_buffer_unmap (buf, &info);

    GST_OBJECT_LOCK (mElement);

    if (!GST_CLOCK_TIME_IS_VALID (mCurrentTime)) {
      mCurrentTime = gst_util_uint64_scale (mElement->n_frames,
          mElement->vinfo.fps_d * GST_SECOND, mElement->vinfo.fps_n);
    }

    GST_BUFFER_PTS (buf) = mCurrentTime;
    GST_BUFFER_DURATION (buf) = gst_util_uint64_scale (frames, GST_SECOND, mRate);
    mCurrentTime += GST_BUFFER_DURATION (buf);

    if (!mElement->audio_buffers) {
      mElement->audio_buffers = gst_buffer_list_new();
    }

    gst_buffer_list_add (mElement->audio_buffers, buf);
    GST_OBJECT_UNLOCK (mElement);

    GST_LOG_OBJECT (mElement, "Handled audio stream packet");
  }

  void OnAudioStreamStopped(CefRefPtr<CefBrowser> browser) override
  {
  }

  void OnAudioStreamError(CefRefPtr<CefBrowser> browser,
                          const CefString& message) override {
    GST_WARNING_OBJECT (mElement, "Audio stream error: %s", message.ToString().c_str());
  }

  private:

    GstCefSrc *mElement;
    GstClockTime mCurrentTime;
    gint mRate;
    gint mChannels;
    IMPLEMENT_REFCOUNTING(AudioHandler);
};

class BrowserClient :
  public CefClient,
  public CefLifeSpanHandler
{
  public:

    BrowserClient(CefRefPtr<CefRenderHandler> rptr, CefRefPtr<CefAudioHandler> aptr, CefRefPtr<CefRequestHandler> rqptr, GstCefSrc *element) :
        render_handler(rptr),
        audio_handler(aptr),
        request_handler(rqptr),
        mElement (element)
    {
    }

    virtual CefRefPtr<CefLifeSpanHandler> GetLifeSpanHandler() override {
        return this;
    }

    virtual CefRefPtr<CefRenderHandler> GetRenderHandler() override
    {
      return render_handler;
    }

    virtual CefRefPtr<CefAudioHandler> GetAudioHandler() override
    {
      return audio_handler;
    }

    virtual CefRefPtr<CefRequestHandler> GetRequestHandler() override
    {
      return request_handler;
    }

    virtual void OnBeforeClose(CefRefPtr<CefBrowser> browser) override;

    void MakeBrowser(int);
    void CloseBrowser(int);

  private:

    CefRefPtr<CefRenderHandler> render_handler;
    CefRefPtr<CefAudioHandler> audio_handler;
    CefRefPtr<CefRequestHandler> request_handler;

  public:
    GstCefSrc *mElement;

    IMPLEMENT_REFCOUNTING(BrowserClient);
};

void BrowserClient::OnBeforeClose(CefRefPtr<CefBrowser> browser) {
  mElement->browser = NULL;
  g_mutex_lock (&mElement->state_lock);
  mElement->started = FALSE;
  g_cond_signal (&mElement->state_cond);
  g_mutex_unlock(&mElement->state_lock);
}

void BrowserClient::MakeBrowser(int arg)
{
  CefWindowInfo window_info;
  CefRefPtr<CefBrowser> browser;
  CefBrowserSettings browser_settings;

  window_info.SetAsWindowless(0);
  browser = CefBrowserHost::CreateBrowserSync(window_info, this, std::string(mElement->url), browser_settings, nullptr, nullptr);

  browser->GetHost()->SetAudioMuted(true);

  mElement->browser = browser;

  g_mutex_lock (&mElement->state_lock);
  mElement->started = TRUE;
  g_cond_signal (&mElement->state_cond);
  g_mutex_unlock(&mElement->state_lock);
}

void BrowserClient::CloseBrowser(int arg)
{
  mElement->browser->GetHost()->CloseBrowser(true);
}

class App : public CefApp
{
  public:
    App(GstCefSrc *src) : src(src)
    {
    }

  virtual void OnBeforeCommandLineProcessing(const CefString &process_type,
                                             CefRefPtr<CefCommandLine> command_line) override
  {
    command_line->AppendSwitchWithValue("autoplay-policy", "no-user-gesture-required");
    command_line->AppendSwitch("enable-media-stream");
    command_line->AppendSwitch("disable-dev-shm-usage"); /* https://github.com/GoogleChrome/puppeteer/issues/1834 */
    command_line->AppendSwitch("enable-begin-frame-scheduling"); /* https://bitbucket.org/chromiumembedded/cef/issues/1368 */

    if (!src->gpu) {
      // Optimize for no gpu usage
      command_line->AppendSwitch("disable-gpu");
      command_line->AppendSwitch("disable-gpu-compositing");
    }

    if (src->chromium_debug_port >= 0) {
      command_line->AppendSwitchWithValue("remote-debugging-port", g_strdup_printf ("%i", src->chromium_debug_port));
    }

    if (src->chrome_extra_flags) {
      gchar **flags_list = g_strsplit ((const gchar *) src->chrome_extra_flags, ",", -1);
      guint i;

      for (i = 0; i < g_strv_length (flags_list); i++) {
        gchar **switch_value = g_strsplit ((const gchar *) flags_list[i], "=", -1);

        if (g_strv_length (switch_value) > 1) {
          GST_INFO_OBJECT (src, "Adding switch with value %s=%s", switch_value[0], switch_value[1]);
          command_line->AppendSwitchWithValue (switch_value[0], switch_value[1]);
        } else {
          GST_INFO_OBJECT (src, "Adding flag %s", flags_list[i]);
          command_line->AppendSwitch (flags_list[i]);
        }

        g_strfreev (switch_value);
      }

      g_strfreev (flags_list);
    }
  }

 private:
  IMPLEMENT_REFCOUNTING(App);
  GstCefSrc *src;
};

static GstFlowReturn gst_cef_src_create(GstPushSrc *push_src, GstBuffer **buf)
{
  GstCefSrc *src = GST_CEF_SRC (push_src);
  GList *tmp;

  GST_OBJECT_LOCK (src);

  if (src->audio_events) {
    for (tmp = src->audio_events; tmp; tmp = tmp->next) {
      gst_pad_push_event (GST_BASE_SRC_PAD (src), (GstEvent *) tmp->data);
    }

    g_list_free (src->audio_events);
    src->audio_events = NULL;
  }

  g_assert (src->current_buffer);
  *buf = gst_buffer_copy (src->current_buffer);

  if (src->audio_buffers) {
    gst_buffer_add_cef_audio_meta (*buf, src->audio_buffers);
    src->audio_buffers = NULL;
  }

  GST_BUFFER_PTS (*buf) = gst_util_uint64_scale (src->n_frames, src->vinfo.fps_d * GST_SECOND, src->vinfo.fps_n);
  GST_BUFFER_DURATION (*buf) = gst_util_uint64_scale (GST_SECOND, src->vinfo.fps_d, src->vinfo.fps_n);
  src->n_frames++;
  GST_OBJECT_UNLOCK (src);

  return GST_FLOW_OK;
}

/* Once we have started a first cefsrc for this process, we start
 * a UI thread and never shut it down. We could probably refine this
 * to stop and restart the thread as needed, but this updated approach
 * now no longer requires a main loop to be running, doesn't crash
 * when one is running either with CEF 86+, and allows for multiple
 * concurrent cefsrc instances.
 */
static gpointer
run_cef (GstCefSrc *src)
{
#ifdef G_OS_WIN32
  HINSTANCE hInstance = GetModuleHandle(NULL);
  CefMainArgs args(hInstance);
#else
  CefMainArgs args(0, NULL);
#endif

  CefSettings settings;
  CefRefPtr<App> app;
  CefWindowInfo window_info;
  CefBrowserSettings browserSettings;

  settings.no_sandbox = true;
  settings.windowless_rendering_enabled = true;
  settings.log_severity = LOGSEVERITY_DISABLE;

  GST_INFO  ("Initializing CEF");

  gchar* base_path = get_plugin_base_path();

  // If not absolute path append to current_dir
  if (!g_path_is_absolute(base_path)) {
    gchar* current_dir = g_get_current_dir();

    gchar* old_base_path = base_path;
    base_path = g_build_filename(current_dir, base_path, NULL);

    g_free(current_dir);
    g_free(old_base_path);
  }

  gchar* browser_subprocess_path = g_build_filename(base_path, "gstcefsubprocess", NULL);
  gchar* locales_dir_path = g_build_filename(base_path, "locales", NULL);

  CefString(&settings.browser_subprocess_path).FromASCII(browser_subprocess_path);
  CefString(&settings.locales_dir_path).FromASCII(locales_dir_path);

  g_free(base_path);
  g_free(browser_subprocess_path);
  g_free(locales_dir_path);

  app = new App(src);

  if (!CefInitialize(args, settings, app, nullptr)) {
    GST_ERROR ("Failed to initialize CEF");

    /* unblock start () */
    g_mutex_lock (&init_lock);
    cef_inited = TRUE;
    g_cond_signal(&init_cond);
    g_mutex_unlock (&init_lock);

    goto done;
  }

  g_mutex_lock (&init_lock);
  cef_inited = TRUE;
  init_result = TRUE;
  g_cond_signal(&init_cond);
  g_mutex_unlock (&init_lock);

  CefRunMessageLoop();

  CefShutdown();

  g_mutex_lock (&init_lock);
  cef_inited = FALSE;
  g_cond_signal(&init_cond);
  g_mutex_unlock (&init_lock);

done:
  return NULL;
}

void quit_message_loop (int arg)
{
  CefQuitMessageLoop();
}


class ShutdownEnforcer {
 public:
  ~ShutdownEnforcer() {
    if (!cef_inited)
      return;

    CefPostTask(TID_UI, base::Bind(&quit_message_loop, 0));

    g_mutex_lock(&init_lock);
    while (cef_inited)
      g_cond_wait (&init_cond, &init_lock);
    g_mutex_unlock (&init_lock);
  }
} shutdown_enforcer;

static gpointer
init_cef (gpointer src)
{
  g_mutex_init (&init_lock);
  g_cond_init (&init_cond);

  g_thread_new("cef-ui-thread", (GThreadFunc) run_cef, src);

  return NULL;
}

static gboolean
gst_cef_src_start(GstBaseSrc *base_src)
{
  static GOnce init_once = G_ONCE_INIT;
  gboolean ret = FALSE;
  GstCefSrc *src = GST_CEF_SRC (base_src);
  CefRefPtr<BrowserClient> browserClient;
  CefRefPtr<RenderHandler> renderHandler = new RenderHandler(src);
  CefRefPtr<AudioHandler> audioHandler = new AudioHandler(src);
  CefRefPtr<RequestHandler> requestHandler = new RequestHandler(src);

  /* Initialize global variables */
  g_once (&init_once, init_cef, src);

  /* Make sure CEF is initialized before posting a task */
  g_mutex_lock (&init_lock);
  while (!cef_inited)
    g_cond_wait (&init_cond, &init_lock);
  g_mutex_unlock (&init_lock);

  if (!init_result)
    goto done;

  GST_OBJECT_LOCK (src);
  src->n_frames = 0;
  GST_OBJECT_UNLOCK (src);

  browserClient = new BrowserClient(renderHandler, audioHandler, requestHandler, src);
  CefPostTask(TID_UI, base::Bind(&BrowserClient::MakeBrowser, browserClient.get(), 0));

  /* And wait for this src's browser to have been created */
  g_mutex_lock(&src->state_lock);
  while (!src->started)
    g_cond_wait (&src->state_cond, &src->state_lock);
  g_mutex_unlock (&src->state_lock);

  ret = src->browser != NULL;

done:
  return ret;
}

static gboolean
gst_cef_src_stop (GstBaseSrc *base_src)
{
  GstCefSrc *src = GST_CEF_SRC (base_src);

  GST_INFO_OBJECT (src, "Stopping");

  if (src->browser) {
    src->browser->GetHost()->CloseBrowser(true);

    /* And wait for this src's browser to have been closed */
    g_mutex_lock(&src->state_lock);
    while (src->started)
      g_cond_wait (&src->state_cond, &src->state_lock);
    g_mutex_unlock (&src->state_lock);
  }

  return TRUE;
}

static void
gst_cef_src_get_times (GstBaseSrc * base_src, GstBuffer * buffer,
    GstClockTime * start, GstClockTime * end)
{
  GstClockTime timestamp = GST_BUFFER_PTS (buffer);
  GstClockTime duration = GST_BUFFER_DURATION (buffer);

  *end = timestamp + duration;
  *start = timestamp;

  GST_LOG_OBJECT (base_src, "Got times start: %" GST_TIME_FORMAT " end: %" GST_TIME_FORMAT, GST_TIME_ARGS (*start), GST_TIME_ARGS (*end));
}

static gboolean
gst_cef_src_query (GstBaseSrc * base_src, GstQuery * query)
{
  gboolean res = FALSE;
  GstCefSrc *src = GST_CEF_SRC (base_src);

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_LATENCY:
    {
      GstClockTime latency;

      if (src->vinfo.fps_n) {
        latency = gst_util_uint64_scale (GST_SECOND, src->vinfo.fps_d, src->vinfo.fps_n);
        GST_DEBUG_OBJECT (src, "Reporting latency: %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
        gst_query_set_latency (query, TRUE, latency, GST_CLOCK_TIME_NONE);
      }
      res = TRUE;
      break;
    }
    default:
      res = GST_BASE_SRC_CLASS (parent_class)->query (base_src, query);
      break;
  }

  return res;
}

static GstCaps *
gst_cef_src_fixate (GstBaseSrc * base_src, GstCaps * caps)
{
  GstStructure *structure;

  caps = gst_caps_make_writable (caps);
  structure = gst_caps_get_structure (caps, 0);

  gst_structure_fixate_field_nearest_int (structure, "width", DEFAULT_WIDTH);
  gst_structure_fixate_field_nearest_int (structure, "height", DEFAULT_HEIGHT);

  if (gst_structure_has_field (structure, "framerate"))
    gst_structure_fixate_field_nearest_fraction (structure, "framerate", DEFAULT_FPS_N, DEFAULT_FPS_D);
  else
    gst_structure_set (structure, "framerate", GST_TYPE_FRACTION, DEFAULT_FPS_N, DEFAULT_FPS_D, NULL);


  caps = GST_BASE_SRC_CLASS (parent_class)->fixate (base_src, caps);

  GST_INFO_OBJECT (base_src, "Fixated caps to %" GST_PTR_FORMAT, caps);

  return caps;
}

static gboolean
gst_cef_src_set_caps (GstBaseSrc * base_src, GstCaps * caps)
{
  GstCefSrc *src = GST_CEF_SRC (base_src);
  gboolean ret = TRUE;
  GstBuffer *new_buffer;

  GST_INFO_OBJECT (base_src, "Caps set to %" GST_PTR_FORMAT, caps);

  GST_OBJECT_LOCK (src);
  gst_video_info_from_caps (&src->vinfo, caps);
  new_buffer = gst_buffer_new_allocate (NULL, src->vinfo.width * src->vinfo.height * 4, NULL);
  gst_buffer_replace (&(src->current_buffer), new_buffer);
  gst_buffer_unref (new_buffer);
  src->browser->GetHost()->SetWindowlessFrameRate(gst_util_uint64_scale (1, src->vinfo.fps_n, src->vinfo.fps_d));
  src->browser->GetHost()->WasResized();
  GST_OBJECT_UNLOCK (src);

  return ret;
}

static void
gst_cef_src_set_property (GObject * object, guint prop_id, const GValue * value,
    GParamSpec * pspec)
{
  GstCefSrc *src = GST_CEF_SRC (object);

  switch (prop_id) {
    case PROP_URL:
    {
      const gchar *url;

      url = g_value_get_string (value);
      g_free (src->url);
      src->url = g_strdup (url);

      g_mutex_lock(&src->state_lock);
      if (src->started) {
        src->browser->GetMainFrame()->LoadURL(src->url);
      }
      g_mutex_unlock(&src->state_lock);

      break;
    }
    case PROP_CHROME_EXTRA_FLAGS: {
      g_free (src->chrome_extra_flags);
      src->chrome_extra_flags = g_value_dup_string (value);
      break;
    }
    case PROP_GPU:
    {
      src->gpu = g_value_get_boolean (value);
      break;
    }
    case PROP_CHROMIUM_DEBUG_PORT:
    {
      src->chromium_debug_port = g_value_get_int (value);
      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_cef_src_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstCefSrc *src = GST_CEF_SRC (object);

  switch (prop_id) {
    case PROP_URL:
      g_value_set_string (value, src->url);
      break;
    case PROP_CHROME_EXTRA_FLAGS:
      g_value_set_string (value, src->chrome_extra_flags);
      break;
    case PROP_GPU:
      g_value_set_boolean (value, src->gpu);
      break;
    case PROP_CHROMIUM_DEBUG_PORT:
      g_value_set_int (value, src->chromium_debug_port);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_cef_src_finalize (GObject *object)
{
  GstCefSrc *src = GST_CEF_SRC (object);

  if (src->audio_buffers) {
    gst_buffer_list_unref (src->audio_buffers);
    src->audio_buffers = NULL;
  }

  g_list_free_full (src->audio_events, (GDestroyNotify) gst_event_unref);
  src->audio_events = NULL;

  g_cond_clear(&src->state_cond);
  g_mutex_clear(&src->state_lock);
}

static void
gst_cef_src_init (GstCefSrc * src)
{
  GstBaseSrc *base_src = GST_BASE_SRC (src);

  src->n_frames = 0;
  src->current_buffer = NULL;
  src->audio_buffers = NULL;
  src->audio_events = NULL;
  src->started = FALSE;
  src->chromium_debug_port = DEFAULT_CHROMIUM_DEBUG_PORT;

  gst_base_src_set_format (base_src, GST_FORMAT_TIME);
  gst_base_src_set_live (base_src, TRUE);

  g_cond_init (&src->state_cond);
  g_mutex_init (&src->state_lock);
}

static void
gst_cef_src_class_init (GstCefSrcClass * klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
  GstElementClass *gstelement_class = GST_ELEMENT_CLASS(klass);
  GstPushSrcClass *push_src_class = GST_PUSH_SRC_CLASS(klass);
  GstBaseSrcClass *base_src_class = GST_BASE_SRC_CLASS(klass);

  gobject_class->set_property = gst_cef_src_set_property;
  gobject_class->get_property = gst_cef_src_get_property;
  gobject_class->finalize = gst_cef_src_finalize;

  g_object_class_install_property (gobject_class, PROP_URL,
      g_param_spec_string ("url", "url",
          "The URL to display",
          DEFAULT_URL, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT)));

  g_object_class_install_property (gobject_class, PROP_GPU,
    g_param_spec_boolean ("gpu", "gpu",
          "Enable GPU usage in chromium (Improves performance if you have GPU)",
          DEFAULT_GPU, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | GST_PARAM_MUTABLE_READY)));

  g_object_class_install_property (gobject_class, PROP_CHROMIUM_DEBUG_PORT,
    g_param_spec_int ("chromium-debug-port", "chromium-debug-port",
          "Set chromium debug port (-1 = disabled) "
          "deprecated: use chrome-extra-flags instead", -1, G_MAXUINT16,
          DEFAULT_CHROMIUM_DEBUG_PORT, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | GST_PARAM_MUTABLE_READY)));

  g_object_class_install_property (gobject_class, PROP_CHROME_EXTRA_FLAGS,
    g_param_spec_string ("chrome-extra-flags", "chrome-extra-flags",
          "Comma delimiter flags to be passed into chrome "
          "(Example: show-fps-counter,remote-debugging-port=9222)",
          NULL, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | GST_PARAM_MUTABLE_READY)));

  gst_element_class_set_static_metadata (gstelement_class,
      "Chromium Embedded Framework source", "Source/Video",
      "Creates a video stream from an embedded Chromium browser", "Mathieu Duponchelle <mathieu@centricular.com>");

  gst_element_class_add_static_pad_template (gstelement_class,
      &gst_cef_src_template);

  base_src_class->fixate = GST_DEBUG_FUNCPTR(gst_cef_src_fixate);
  base_src_class->set_caps = GST_DEBUG_FUNCPTR(gst_cef_src_set_caps);
  base_src_class->start = GST_DEBUG_FUNCPTR(gst_cef_src_start);
  base_src_class->stop = GST_DEBUG_FUNCPTR(gst_cef_src_stop);
  base_src_class->get_times = GST_DEBUG_FUNCPTR(gst_cef_src_get_times);
  base_src_class->query = GST_DEBUG_FUNCPTR(gst_cef_src_query);

  push_src_class->create = GST_DEBUG_FUNCPTR(gst_cef_src_create);

  GST_DEBUG_CATEGORY_INIT (cef_src_debug, "cefsrc", 0,
      "Chromium Embedded Framework Source");
}