[SOLVED] audio problems with zoom Linux client, slackware64 -current

bennyt · 12-08-2022, 04:52 PM

Hi, I've trawled for help on this issue but without a specific answer:

With a fresh -current install, sound on browsers and mplayer is working fine out of the box. I typically use pavucontrol to switch devices etc.

So I then tried the Zoom client (used to work on my old -current). It works fine until getting to the audio.

Maybe it doesn't like pulseaudio or something. I get several of these:

Code:

ALSA lib pcm_dmix.c:999:(snd_pcm_dmix_open) unable to open slave

Followed by several of these:

Code:

ALSA lib pcm_dsnoop.c:566:(snd_pcm_dsnoop_open) unable to open slave

It seems to have a problem accessing the "sysdefault" device. Maybe it is trying to access alsa directly in some way?

I can replicate this error with:

Code:

aplay -D sysdefault <sound_file>

Following a suggestion somewhere I edited /etc/asound.conf:

Code:

#pcm.default pulse
#ctl.default pulse
pcm.!default {
    type hw
    card 1
}

ctl.!default {
    type hw
    card 1
}

I assume this bypasses pulseaudio in some way. Regardless, with this change, it appears that provided no other apps are using the sound, Zoom can access the sound hardware successfully. However, if youtube is open (but not playing) or I open pavucontrol, and *then* run Zoom, I again get the above errors and no sound. The same behavior is seen with aplay -D sysdefault <sound_file>. It works ok provided nothing else is using the sound, but fails with "unable to open slave" as above as soon as I open pavucontrol.

So I'm kind of lost here. Too many parameters and config files. Does anyone know why Zoom does not talk to pulse, and have a better solution?

Thanks

marav · 12-08-2022, 06:00 PM

Hi,

Maybe you can try switching to pipewire ?

Code:

# pipewire-enable.sh

and logout/login

bennyt · 12-08-2022, 06:15 PM

Thanks, that's new to me!

I'll take a look.

Also, I have a clarification and update. It appears the edit to /etc/asound.conf is not necessary. The problem is basically that Zoom *will* work if nothing else is using the audio but it does not work if, e.g. pavucontrol is running (huh?). *However*, I recovered an old version of Zoom (from Jan 2022) that was working, and ... it works just fine!

This sounds like a problem with Zoom rather than Slackware audio, but I will investigate further (and look at pipewire).

bennyt · 12-08-2022, 06:30 PM

OK, I also just realised that there is an up-to-date slackbuilds Zoom package. I built that, and it also works just fine. Might have to put this down to user error :/ I'll mark as solved.