philippe@philippe-desktop:~$ apt-cache depends libqt5multimedia5-plugins | grep gstreamer
  Depends: libgstreamer-plugins-base0.10-0
  Depends: libgstreamer0.10-0
philippe@philippe-desktop:~$ apt-cache depends libqt5webkit5 | grep gstreamer
  Depends: libgstreamer-plugins-base1.0-0
  Depends: libgstreamer1.0-0

------------

philippe@philippe-desktop:~/work/foo$ ./foo

(foo:18349): GLib-GObject-WARNING **: cannot register existing type 'GstObject'

(foo:18349): GLib-CRITICAL **: g_once_init_leave: assertion 'result != 0' failed

(foo:18349): GLib-GObject-CRITICAL **: g_type_register_static: assertion 'parent_type > 0' failed

(foo:18349): GLib-CRITICAL **: g_once_init_leave: assertion 'result != 0' failed

(foo:18349): GStreamer-CRITICAL **: gst_element_class_set_details_simple: assertion 'GST_IS_ELEMENT_CLASS (klass)' failed

(foo:18349): GStreamer-WARNING **: static caps 0x7f5b722e6c90 string is NULL

(foo:18349): GStreamer-CRITICAL **: gst_mini_object_unref: assertion 'mini_object != NULL' failed

(foo:18349): GStreamer-WARNING **: static caps 0x7f5b722e6c10 string is NULL

(foo:18349): GStreamer-CRITICAL **: gst_mini_object_unref: assertion 'mini_object != NULL' failed

(foo:18349): GStreamer-WARNING **: static caps 0x7f5b722e6c90 string is NULL

(foo:18349): GStreamer-CRITICAL **: gst_mini_object_unref: assertion 'mini_object != NULL' failed