[mythtv-users] black screen during playback

[Kenni Lund]

2013/1/26 Joey Morris <rjmorris.list at gmail.com>:
> 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".

So did mine, that's *exactly* the same situation as I had. Two
frontends both with the default VDPAU filter enabled,
"vdpaucolorspace=auto". One of the frontends suddently stopped working
(black screen with audio under playback) with no changes to software
or hardware. Once I changed the hostname to reset the settings, the
frontend worked for at least some days up to a couple of weeks, after
which the issue appeared again and I could change the hostname once
again to temporarily "fix" the issue. After I had done this a number
of times over a period of 3-4 months with no luck in identifying the
real issue, I tried to pinpoint if I could avoid triggering the issue
by using some other playback settings in MythTV.

While being on a non-working frontend, I was able to recover VDPAU
playback functionality by removing "vdpaucolorspace=auto" *WITHOUT*
changing the hostname or by doing any other changes to settings. At
the same time, the black-screen issue did not reappear any more.

In other words, my conclusion was that removing "vdpaucolorspace=auto"
fixed the black screen issue immediately and also avoided that the
issue reappeared after some days/weeks.

If you experience the issue again in a couple of days/weeks, don't
reset the settings, just try to delete the VDPAU filter and see if it
doesn't fix the issue.

Best regards
Kenni