(In reply to Christoph Haag from comment #3)

> Also the decodebin element uses vaapi to decode =
the video, so I may have
> mischaracterized the bug in the first place that it's really an UVD pr=
oblem.

So does something like below work?

for X in $(seq 1 50); do gst-launch-1.0 -e filesrc
location=3Dbig_buck_bunny_720p_1mb.mp4 ! qtdemux ! avdec_h264 ! videoconver=
t !
omxh264enc ! fakesink; done

My Tonga used to have this issue and this post prompted me to look what fix=
ed
it =3D
it was a recent tonga firmware upgrade so not much use to you, also I think
power gating for uvd/vce is disabled for tonga - so maybe another differenc=
e.

While the issue existed I could work around by forcing my clocks to high wh=
en
testing vce =3D

echo high > /sys/class/drm/card0/device/power_dpm_force_performance_level
 then=20
echo auto > /sys/class/drm/card0/device/power_dpm_force_performance_level

after testing finished to keep thinks cooler :-) (note that if you change m=
odes
or your monitor goes into dpms this will happen anyway)