[mythtv-users] OpenGL render problems with radeon and 0.24.1

[Mark Kendall]

On 9 June 2011 05:47, Greg <dargllun at googlemail.com> wrote:
> Am Wed, 8 Jun 2011 11:44:25 -0500
> schrieb John King <jmking1 at gmail.com>:
>
>> I'm having problems with myth playback using the OpenGL renderer and
>> the radeon Xorg driver.  Basically it looks like the mythtv video
>
> This ticket maybe related (well, output isn't stuck anymore, but
> doesn't work either): http://code.mythtv.org/trac/ticket/9216
>
> FWIW, I'm also running MythTV with an RS780 using xv-blit, which works
> very well an reliable. Of course, working OpenGL would be a great
> thing, if only to fix the OSD scaling. Maybe we can help Mark Kendall
> finally solve out the issues, I should say the r600g should be running
> well enough by now to support this.

Coincidentally, I spent some time a couple of days ago on that ticket.

I slotted my HD4550 into a couple of boxes to test AMD/ATI OpenGL
issues. While I couldn't get the proprietary driver to install on
either box, the radeon driver worked perfectly on both machines.

One box is now quite old and the most up to date driver package I
could get still had a couple of issues with OpenGL 2.0 support (which
is not yet needed by default). On my master backend, using the very
latest radeon version, everything I could test with it MythTV wise
worked as expected. I then forced it to use the latest builds from the
xorg-edgers ppa and enabled Gallium - and again, no obvious issues.

So all told, while I was expecting a day of grief, I ended up being
pleasantly surprised:)

That said, there is still a significant performance issue with the
OpenGL video renderer. While the MythtTV code uses a different
approach to other players (and I would expect slightly higher CPU
usage), there is a difference of 20-30% cpu utilisation across
different platforms and using different GPU hardware. At this point I
still don't know what is causing it, though I'm fairly sure the key
factor is Qt; we rely quite heavily on the underlying Qt OpenGL
support and somewhere it is causing a problem.

regards

Mark