C++ (Cpp) gst_vulkan_local_context_query示例

示例#1

文件： vkdevice.c 项目： Haifen/gst-plugins-bad

gboolean
gst_vulkan_device_run_context_query (GstElement * element,
    GstVulkanDevice ** device)
{
  GstQuery *query;

  g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
  g_return_val_if_fail (device != NULL, FALSE);

  if (*device && GST_IS_VULKAN_DEVICE (*device))
    return TRUE;

  if ((query =
          gst_vulkan_local_context_query (element,
              GST_VULKAN_DEVICE_CONTEXT_TYPE_STR, FALSE))) {
    GstContext *context;

    gst_query_parse_context (query, &context);
    if (context)
      gst_context_get_vulkan_device (context, device);
  }

  GST_DEBUG_OBJECT (element, "found device %p", *device);

  gst_query_unref (query);

  if (*device)
    return TRUE;

  return FALSE;
}

示例#2

文件： vkutils.c 项目： jhgorse/gst-plugins-bad

void
gst_vulkan_global_context_query (GstElement * element,
    const gchar * context_type)
{
  GstQuery *query;
  GstMessage *msg;

  if ((query = gst_vulkan_local_context_query (element, context_type, TRUE))) {
    gst_query_unref (query);
    return;
  }

  /* 3) Post a GST_MESSAGE_NEED_CONTEXT message on the bus with
   *    the required context type and afterwards check if a
   *    usable context was set now as in 1). The message could
   *    be handled by the parent bins of the element and the
   *    application.
   */
  GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
      "posting need context message");
  msg = gst_message_new_need_context (GST_OBJECT_CAST (element), context_type);
  gst_element_post_message (element, msg);

  /*
   * Whomever responds to the need-context message performs a
   * GstElement::set_context() with the required context in which the element
   * is required to update the display_ptr or call gst_vulkan_handle_set_context().
   */
}