[mythtv-users] Video card update fail

[Stephen Worthington]

On Sun, 7 Oct 2018 16:16:44 -0700, you wrote:

>My system is using a Nvidia 6200.  DVI out to the TV and analog to a
>monitor. I am running Mythbuntu 16 on an old AMD 5400.  Sound is analog to
>the TV and SPDIF to a surround system we use for a few shows.
>
>After many hours I kind of got the new Nvidia 750ti card working.  I could
>not get the onboard audio to work no matter what my son and I tried and he
>is a Google software engineer so it stumped us both.  I had to cut down a
>HDMI connector to get the cable to fit but with that and several hours I
>got sound to the TV.  Not a permanent solution as no digital sound to the
>surround system.
>
>The final straw was that when I turned off the TV and turned it back on,
>Myth was on the monitor and not on the TV.  I tried both checkboxes on the
>find new devices and both acted the same.  The driver at that point was
>340.  The other choice was 361 which I used at first but switched at some
>point to get a picture to display.  Lots of trouble with the video card
>reading the TV EDIT wrong and sending out incorrect settings which would
>not display at all. Not sure if the driver was the issue but long story
>short, I ended up with the 340 driver.
>
>Finally I took out the 750ti and reinstalled my 6200 and sound works, myth
>doesn't switch when the TV is off.  Only issue is I got a little better
>picture quality with the 750 on VDPAU slim. Any higher level setting just
>crashed myth.
>
>I am 7 hours into getting nothing done.  Two of us working most of that
>time.  If anyone knows how to solve my problem I will put a few more hours
>into it.
>
>By the way, on the sound, we tried at least three audio managers, Alsa,
>Pulse, and one command line one to try and get audio out of the
>motherboard. Nothing worked.
>
>Allen

I think the 361 drivers are a better choice for a fairly modern card
like a 750ti.  Older drivers are likely to only have limited support
for it, and would likely be the reason for crashes when you tried to
use the higher VDPAU modes.  But the driver version recommended by
Nvidia for a 750ti is 390 - see if you can find packages for that. The
390 drivers will not run a 6200 now - I think the 304 drivers are what
is needed for that, and they are off support by Nvidia and hence are
no longer available in Ubuntu 18.04 and up.

If you have problems with things changing when you turn displays off,
the usual fix for that is to use the nvidia-settings software to
download the EDID data for the monitor and TV and set up the
/etc/X11/xorg.conf file to load the saved EDID data.  That way, when
the device is off, X can still get the data it needs to configure
things correctly.

MythTV uses alsa for the audio - I think it disables pulse when it
starts up.  If you run alsamixer, it should see two audio devices. The
default device will normally be the motherboard audio, and the second
device will be the HDMI audio device on the video card.  You need to
switch alsamixer to the HDMI audio device and enable (unmute) the
correct HDMI output (there may be more than one if the video card has
multiple connectors, or if the chipset used is capable of running
multiple connectors).  It is probably best just to unmute all the
available outputs.  Then use the audio test function in mythfrontend
to select the correct alsa output to send data out the HDMI.  That can
take a fair bit of trial and error as the names used by alsa are not
necessarily very informative.