Comment # 9 on bug 101787 from Julien Isorce

(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)