https://bugs.freedesktop.org/show_bug.cgi?id=101787
--- Comment #9 from Julien Isorce julien.isorce@gmail.com --- (In reply to 247 from comment #3)
and to answer your question, yes it was perfectly working in fedora 25...
You can try to bisect mesa.
From the logs you attached I could not see anything abivous. Do you really want
hardware decoding btw ?
Also does gst-launch-1.0 filesrc location=test.mp4 ! qtdemux ! h264parse ! vaapih264dec ! videoconvert ! xvimagesink
And what is the output of vainfo ? (just install vainfo package)