Confirmed the problem is the gstreamer-clutter plugin (which only totem seems to use by default). You can see the same problem here:
High CPU: gst-launch-1.0 filesrc location=bbb_sunflower_1080p_60fps_normal.mp4 ! qtdemux ! vaapidecodebin ! clutterautovideosink
Low CPU: gst-launch-1.0 filesrc location=bbb_sunflower_1080p_60fps_normal.mp4 ! qtdemux ! vaapidecodebin ! glimagesink
Confirmed the problem is the gstreamer-clutter plugin (which only totem seems to use by default). You can see the same problem here:
High CPU: bbb_sunflower_ 1080p_60fps_ normal. mp4 ! qtdemux ! vaapidecodebin ! clutterautovide osink
gst-launch-1.0 filesrc location=
Low CPU: bbb_sunflower_ 1080p_60fps_ normal. mp4 ! qtdemux ! vaapidecodebin ! glimagesink
gst-launch-1.0 filesrc location=