Comment # 2 on bug 101787 from Julien Isorce

Can you attach output of dmesg as suggested by the error message (and the dmesg
output just after boot) and also output when setting GST_DEBUG=6
Does it work with older fedora/mesa/kernel (i.e. regression) ?

You can try to compare with:

gst-launch-1.0 filesrc location=test.mp4 ! qtdemux ! h264parse ! vaapih264dec !
capsfilter caps="video/x-raw(memory:VASurface)" ! vaapih264enc ! qtmux !
filesink location=res.mp4