[mythtv-users] black screen during playback

[Joey Morris]

Kenni Lund <kenni at kelu.dk> wrote on Sat, Jan 26, 2013 at 11:03:51AM +0100:
> 2013/1/25 Joey Morris <rjmorris.list at gmail.com>:
> > I tried everything I could think of to isolate the problem:
> > systematically swapping out every piece of hardware in the system,
> > reinstalling the OS, upgrading Myth to 0.26, and deleting the playback
> > profiles so Myth would regenerate the default ones. I still had the
> > problem of the black screen during video playback using VDPAU. Nothing
> > in the logs pointed to a problem.
> >
> > Finally it occurred to me that a common denominator between all these
> > configurations was the hostname, which Myth uses to pull in settings
> > from the database. I gave the system a new hostname, and my video with
> > VDPAU returned! I have no idea which setting in the database was
> > causing the problem.
> >
> > The lesson for me in this exercise was that to get a truly clean slate
> > with a Mythfrontend re-install, you have to use a new hostname.
> > Otherwise you'll pick up all the settings from your previous install.
> 
> I had that issue back in MythTV 0.24:
> http://www.mythtv.org/pipermail/mythtv-users/2011-July/318731.html

I was also on 0.24 when my problem started. I read your thread at the
time along with a few others mentioning the same problem, but none of
them included a solution. Or if they did, the solution didn't work in
my case.
 
> I came to the same conclusion as you - Changing the frontend hostname
> and hence getting a clean set of settings, fixed the issue. However,
> in my case the issue reoccurred some weeks after I reinstalled the
> system and changed the hostname. I did some further digging and I
> think I identified a VDPAU filter to be the cause of the issue or at
> least to be related to the issue. As far as I remember, my VDPAU
> filter were set to "vdpaucolorspace=auto". Once I deleted the string
> the issue got fixed (I didn't change the hostname / reset the
> settings, I only deleted that string) - and since I haven't seen the
> issue since, it seems like the issue somehow was related to that VDPAU
> filter.

I don't think the VDPAU filter was the culprit in my case. Both the
working config and non-working config have the VDPAU filter set to
"vdpaucolorspace=auto". In fact, I inspected the displayprofiles table
in the database, where all the playback profile settings are stored,
and all the settings are identical between the old hostname and the
new one.

Another database table, settings, does include many differences
between the old hostname and the new one. Maybe one of those was the
problem. While I'm curious to know which setting caused the problem, I
don't think I'm curious enough to go through and change those settings
one-by-one until I find it.