Created attachment 91375 [details]
git bisect log
Simplest to illustrate the issue with a video taken on my phone:
www.youtube.com/watch?v=GvuNu1ZEgsw
In words, I would describe it as being stuck on looping a short sequence of
frames, then it skips forward in the stream to a later sequence of frames; I
think this is simply to keep it in range of the audio, which plays normally
throughout (but not through hdmi/displayport, audio is going out via usb
speakers)
This affects all h.264 playback; interlaced or progressive, SD or HD, though
the test clip shown above is a 23.976p movie. Unsure if it affects playback of
other codecs: I've been having system crashes attempting to play mpeg2 video
streams, but I believe that's an unrelated issue.
This behaviour seems to have been introduced in commit
91aca8c662faf0ec311968b2897a72a6d08b199d ("r600g,radeonsi: consolidate buffer
code, add handling of DISCARD_RANGE for SI") on Dec 12; discovered using git
bisect and a spare afternoon. :-) Before starting that process I had tested the
current ppa:wsnipex/mesa build (bad), the current master HEAD (bad), the
current 10.0 branch head (good)
On the previous commit, 12806449fa35aff47ad6f4615ede55776c9f66c8, playback is
fine.
Affected system is running Ubuntu 13.10 x86_64, running XBMC test builds from
https://launchpad.net/~wsnipex/+archive/xbmc-fernetmenta-master - afaik the
most developed vdpau-enabled *player*. Graphics card is an AMD Radeon HD 7750
(with four mini-displayports). lspci:
rachel@twilight:~/src/mesa$ lspci | grep Radeon
03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cape
Verde PRO [Radeon HD 7750]
03:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Cape
Verde/Pitcairn HDMI Audio [Radeon HD 7700/7800 Series]
Test builds of mesa directly from the read-only git repo; while for convenience
I borrowed the debian directory from the ppa builds to make .debs for
installation/deinstallation, I removed the patches (emptied
debian/patches/series) so it should all be vanilla builds.
Tried with stock current Ubuntu Saucy generic kernel and with 3.13-rc6 mainline
kernel build and with several other of the rc builds too until decided to
bisect mesa instead.