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chris65745

Member

Registered: 2021-05-13

Posts: 4

Zoom ignores alsa dmix

Hi,

I can't play audio from Zoom and other applications at the same time. Zoom will say the audio device is not working if there is another application already playing audio. Zoom also seems to lock down the sound card whenever it plays audio such that no other application can play audio at the same time. That said playing audio from multiple applications at the same time works fine as long as Zoom is not involved.

My Zoom version is 5.6.4

Here is my /etc/asound.conf:

pcm.!default {
    type plug
    slave.pcm "dmixer"
}

pcm.Uber {
    type hw
    card Uber
    device 0
}

pcm.dmixer {
    type dmix
    ipc_key 1024
    slave {
        pcm "Uber"
        period_time 0
        period_size 1024
        buffer_size 4096
        rate 44100
    }
    bindings {
        0 0
        1 1
    }
}

ctl.dmixer {
    type hw
    card Uber
}

Here is the fuser output while playing audio over brave and spotify and (unsuccessfully) trying a speaker test in Zoom:

chris@archie in ~ % doas fuser -v /dev/snd/*
                     USER        PID ACCESS COMMAND
/dev/snd/controlC0:  chris     23974 F.... zoom
/dev/snd/controlC2:  chris     23974 F.... zoom
/dev/snd/pcmC0D0c:   chris     23974 F...m zoom
/dev/snd/pcmC2D0p:   chris     17816 F...m brave
                     chris     23681 F...m spotify
/dev/snd/timer:      chris     17816 f.... brave
                     chris     23681 f.... spotify
                     chris     23974 f.... zoom

It seems like Zoom ignores dmix. I would like to avoid going back to pulseaudio if possible.
Any ideas how to fix this?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,991

Re: Zoom ignores alsa dmix

Check zooms audio settings, even on pulse it generally ignores system wide settings and you explicitly set which one it will use in the settings.  FWIW what you probably have to do so that the dmix/default device is actually listed granted they allow this with ALSA in the first place, is ammend your default definition so that it actually lists "default" in PCM listings (... check aplay -L it will be missing from there currently) with something like

pcm.!default {
    type plug
    slave.pcm "dmixer"
    hint {
        show on
        description "Default ALSA Output"
    }
}

chris65745

Member

Registered: 2021-05-13

Posts: 4

Re: Zoom ignores alsa dmix

Thanks for the reply. I added the hint to the default device but unfortunately the device still doesn't show up in Zoom's audio settings. It only lists my physical devices and another option called "Same as System" there. Maybe I can somehow make the default/dmix device the system default?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,991

Re: Zoom ignores alsa dmix

You could try to override the sysdefault in a similar vein so that it maps to the dmixer pcm instead of hw:0, that's a bit of the issue with plain ALSA there doesn't really exist a standardized and clearly defined way of how devices should be accessed and depending on how any given developer implements this they will either only show the PCMs (... which is what you'd want usually) or the physical devices which will lead to an exclusive lock.

chris65745

Member

Registered: 2021-05-13

Posts: 4

Re: Zoom ignores alsa dmix

I tried overwriting sysdefault in asound.conf but unfortunately that just leads to Zoom not being able to detect any devices (virtual or not). I think I will just bite the bullet and go back to pulseaudio because stuff just works there. Thanks for your help anyways.