Created attachment 102577 [details]
dmesg output

Whenever I try playing a h264 encoded movie, the system/X11 locks up completely
with 3 different symptoms.
X freezes, I might be able to move the mousecursor (which doesn't change), was
able to log in to the machine remotely and reboot it.
X freezes first, full screen is garbled just a few seconds later.
Additionally I might be able to move some square, which is likely the
"cursor".. garbled as well. I must be honest I didn't try logging in remotely
there yet, if the machine itself is still alive.

Machie is running:
Linux 3.15.4 from the repo and tried on a 3.16rc4 today (Installed that to test
against a kernel bug)
Xorg is 1.15.2
mesa is 10.2.3
mplayer is SVN-r37224

I tried a mpeg2 video and played it just fine
( mplayer -vo vdpau -vc ffmpeg12vdpau <file> )
I also got two h264 files and it freezes/garbles every time there

http://samples.mplayerhq.hu/V-codecs/h264/PAFF/Grey.ts
http://samples.mplayerhq.hu/V-codecs/h264/nature_704x576_25Hz_1500kbits.h264
mplayer -vo vdpau -vc ffh264vdpau <file>

It reliably just freezes the screen, with the mouse working for a while or
completely garbles it.
I also had an occurrence of the screen going garbled and then black, back to
the garbled screen. Three times or something. Maybe he tried resetting the GPU
or something; I don't know. Not sure if I can find any logs from that one.

Also: Haven't tried any other codecs yet, that might be supported.