Re: [gentoo-user] Audio through second HDMI output on GPU?

[Mark Knecht]

On Sun, May 23, 2021 at 10:09 AM Dale <rdalek1967@×××××.com> wrote:
>
> Arve Barsnes wrote:
> > On Sun, 23 May 2021 at 18:22, Dale <rdalek1967@×××××.com> wrote:
> >> If you ever figure it out, please post what did it.  I watch TV from my
> >> puter too.  Right now, I tell Smplayer to send audio to the TV by
giving
> >> it the device name like you did.  Thing is, none of the entries in the
> >> drop down menu in settings works.  Odd but it is what it is.
> > Might be worth checking if the smplayer front-end is messing something
> > up, by going straight through mpv. My last steps for playing video
> > through the TV, with the audio going there as well:
> >
> > Get a list of all the audio devices on your system.
> > $ mpv --audio-device=help
> >
> > Use the correct device in your video command.
> > DISPLAY=:0.1 mpv --audio-device=alsa/hdmi:CARD=NVidia,DEV=0 -fs
video.mkv
> >
> > Also check what Mark mentioned about muted channels on the output card
> > through alsamixer.
> >
> > Regards,
> > Arve
> >
> >
>
>
> When I set mine up, I just set output driver to user defined and entered
> alsa:device=hw=1.7 in settings.  I only want Smplayer to output to the
> TV.  Everything else goes to the speakers hooked to the computer itself.
>
> The day may come when I use something other than Smplayer to watch TV
> tho.  If, or when, that day comes I'll have to figure out how to get the
> audio to work with it.  Right now, I'm still able to use the old gnome
> player still.  It's going to die one day tho since it is no longer
> maintained.
>
> I do find these audio topics interesting tho.  It seems it should be
> easy to send sound to any place it can go but it isn't easy to do for
> real.  It seems it is a problem for a lot of people doing what I think
> is at least somewhat common.
>
> Either way, glad you got it working.  It took me days to figure out mine
> too.
>
> Dale
>
> :-)  :-)

Dale and Arve,
   As I do home studio type recording using Linux I always find this topic
quite interesting but because of the more complicated setup of my audio
environment which makes use of a Hammerfall DSP card driving the speaker
but utilizes the internal Intel sound card for general audio, along with
cables outside to hook the two together, I'm just not sure what I see on my
system is very helpful to you two. Nonetheless I do have an older NVidia
GPU and would like to understand what's going on with all of this.

   A couple of requests:

1) instead of aplay -l please run aplay -L

2) Also provide the output of

cat /proc/asound/card2/codec#0

Note: Your card number may well be different than mine card0=Hammerfall,
card1=Internal Intel sound, card2=NVidia

   Also, there is an old (2014) document online from NVidia that provides a
lot of info on Alsa device naming and how NVidia GPUs handle audio. It's
one of the better ones I've found online making the dangerous assumption
that it hasn't all changed. There's lots of info in this document about
system config edits for non-pulseaudio users and things that might possibly
be of interest to Gentoo users with configuration more like Arve's, but
again, that's a guess on my part.

https://download.nvidia.com/XFree86/gpu-hdmi-audio-document/

   No rush on any of this.

Thanks,
Mark