pulseaudio, analog sound output, and WHAT?

[Eric Oyen]

Oh joy!

I really wish the developers had not taken this route with pulse audio. Because of this, I have had no end of issues when trying to output screen reader audio to my headphones using a standard stereo audio output. My machine has SpDIF and HDMI outputs as well as analog, yet I have not been able to get analog working with any degree of functionality. I literally have to ssh into that machine and run console based programs because I can’t interact with that machine directly.

Thanks for the info on where to locate good example programs. Btw, the machine in question is my RaspberryPi 3 that I was trying to setup for the seeing with sound project.

-Eric
From the Central Offices of the Technomage Guild, Technical difficulties resolution Dept.


> On Nov 20, 2020, at 7:58 AM, Matt Graham via PLUG-discuss <plug-discuss at lists.phxlinux.org> wrote:
> 
> The firefox developers have basically said, "The microphone on your computer won't work at all unless you use pulseaudio."[0]  I've been trying to avoid pulseaudio for various reasons.[1]  But since Thanksgiving is canceled this year, I'll have to see the family virtually, and why not do that with bigbluebutton.org ?  This led me to a twisty maze of unwarranted assumptions and outright stupidity, which I will try to summarize below.  TL;DR: pulseaudio hates analog audio and making analog audio work properly requires editing config files by hand.
> 
> I first tried building pulseaudio and firefox with the pulseaudio USE flag on my laptop.  This worked almost perfectly.  I expected this to work basically identically on my desktop, because both machines use sound cards that are driven by the snd_hda_intel module.  Nope!
> 
> pulseaudio has a strong preference for digital audio.  Its autodetection will select the first digital device it finds as the default audio output.  For me, this was the HDMI output... which is hooked up to the TV, which is almost never on.  My actual sound card was also found, but it wasn't the default output, and it was set to output sound to the iec-958-stereo-output (S/PDIF jack).  I do not have anything plugged in to that.  Setting the default output to the analog sound card didn't work; pulseaudio refused to write any data to the analog card.
> 
> I found a solution at https://wiki.archlinux.org/index.php/PulseAudio/Examples , link "Simultaneous HDMI and analog output".  If a digital device exists, pulseaudio refuses to send data to analog devices unless it can *also* send data to a digital device.  This makes no sense.  I have no idea how ordinary users would deal with this problem.  The solution was to put the lines:
> 
> # make pulseaudio work with analog and digital things at
> # the same time.  Load analog device (NOTE: use aplay -l
> # to find the hw: numbers for the device you need, they
> # will be displayed as "card X: (name) device Y: and you
> # need to put those numbers in there.  X and Y for me
> # were both 0 because my analog card's first on the
> # PCI bus.  YMMV.)
> load-module module-alsa-sink device=hw:X,Y
> load-module module-combine-sink sink_name=combined
> set-default-sink combined
> 
> ...up at the top of the /etc/pulse/default.pa file.  I have no idea how Mint/Ubuntu et al would handle this for ordinary users.  There is no way to do any of this with the slightly more user-friendly pavucontrol[2].  I've had these speakers for 21 years, which may be a bit unusual, but are people really abandoning analog sound?  Regardless, I'm leaving this here in the hopes that some crawler will find it and some search engine will lead someone to a quicker fix than the multiple-hour @#%^ing around I had to do.
> 
> [0] "Select the audio input and output devices that exist and put them into 2 lists, have user choose speaker/mike from those 2 lists" is apparently much more difficult with ALSA than with pulseaudio or whatever OS X/Doze provides.  Or the firefox developers are lazy and clueless.
> 
> [1] Poettering, nuff said.
> 
> [2] Our UX experts have determined that the best way to deal is to pretend we're a phone!  So the menubar doesn't act like a menubar acts in real applications!  Isn't that edgy and disruptive?
> 
> -- 
> Crow202 Blog: http://crow202.org/wordpress
> There is no Darkness in Eternity
> But only Light too dim for us to see.
> ---------------------------------------------------
> PLUG-discuss mailing list - PLUG-discuss at lists.phxlinux.org
> To subscribe, unsubscribe, or to change your mail settings:
> https://lists.phxlinux.org/mailman/listinfo/plug-discuss