Arch Linux

Ploppz

Member

Registered: 2013-09-14

Posts: 313

[Solved] PA + Jack: no sound

I did the KXStudio method here to make Jack + Pulseaudio work: https://wiki.archlinux.org/index.php/Pu … rough_JACK

When I pressed "Force Restart", sound ceased (which was previously going through PA only, in which case I heard the sound).

There is no sound from Firefox or mpd. "Output Devices" in pavucontrol looks like this:

and while sound should be playing, the bottom-most bar keeps changing as if reflecting that sound is playing. However, I do not hear anything.

Last edited by Ploppz (2018-07-30 11:07:56)

ooo

Member

Registered: 2013-04-10

Posts: 1,638

Re: [Solved] PA + Jack: no sound

Did you test that JACK is configured configured correctly and works by itself? i.e you can output audio directly trough JACK, and not via pulseaudio, from some application that has JACK output support.

Ploppz

Member

Registered: 2013-09-14

Posts: 313

Re: [Solved] PA + Jack: no sound

I have not had any luck making any sound using only Jack.
Having Pulseaudio running alone, I wrote `systemctl --user stop pulseaudio.socket`. Then I started Jack using Cadence, and made sure it's using the `ALSA -> Jack` bridge excluding Pulseaudio. Then I tried to make a test sound in Pure Data (making sure it was using Jack) - no luck.
I am not sure how I should configure it in Cadence. I tried: https://i.imgur.com/5eWr1s4.png knowing that the device 1 should be used, not 0.
By the way, I have `jack2-dbus` installed.

ooo

Member

Registered: 2013-04-10

Posts: 1,638

Re: [Solved] PA + Jack: no sound

Well, pulseaudio-jack sink simply outputs audio to the JACK server. If your JACK server isn't configured to output correctly, the audio coming from pulseaudio won't be audible either, even if the pulseaudio JACK sink itself was working correctly.

See the JACK documentation for how to configure it. The Arch wiki page is a decent source as well. If you're trying to output to HDMI or S/PDIF, the digital output may be correct, but you probably want more than 0 output channels for stereo output.

If you're not very familiar with PD, it may be better to use some simpler application for testing the JACK output, e.g. mpv or vlc.

Ploppz

Member

Registered: 2013-09-14

Posts: 313

Re: [Solved] PA + Jack: no sound

I read elsewhere that usually, channel 0 is HDMI. But I will try channel 0 then. So for testing with mpv I suppose I just have to run it like `mpv some/file.wav` and it should automatically use JACK is available.
I tried some more. I changed /etc/asound.conf to that mentioned on the JACK Arch wiki page.

/etc/asound.conf:

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

ctl.mixer0 {
    type hw
    card 1
}

# pcm type jack
pcm.jack {
    type jack
    playback_ports {
        0 system:playback_1
        1 system:playback_2
    }
    capture_ports {
        0 system:capture_1
        1 system:capture_2
    }
}

~/.asoundrc (not sure what to do with this, I found it like this)

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

pcm.jack {
    type jack
    playback_ports {
        0 system:playback_1
        1 system:playback_2
    }
    capture_ports {
        0 system:capture_1
        1 system:capture_2
    }
}

ctl.mixer0 {
    type hw
    card 0
}

In Cadence I chose `hw:Generic,0 [ALC892 Analog]`.

`mpv something.mp3` just malfunctions (no progress bar, takes a while before it cooperates to stop playing)
`mpc play` says: `ERROR: Failed to open "default detected output" [pulse]; pa_context_connect() has failed: Connection refused`
-- why is it trying to use Pulseaudio? Is that default?
And... oh! Pure Data test sound works now!
Not sure what's wrong with MPV though. If I don't force it to quit it just becomes a malfunctioning window (doesn't redraw etc), makes no sound.

Ploppz

Member

Registered: 2013-09-14

Posts: 313

Re: [Solved] PA + Jack: no sound

Actually I just realized that the tone I am hearing from Pure Data is not as it should be. It is switched on an off quickly (like 8 Hz). Now I also started Pulseaudio and I got the same result running JACK + Pulseaudio. (with the aforementioned ALSA configs).
Now that pulseaudio is also running, `mpd` is also outputting sound, but in the same way that Pure Data did: on-and-off quickly, as if multiplied by a square signal.

ooo

Member

Registered: 2013-04-10

Posts: 1,638

Re: [Solved] PA + Jack: no sound

I read elsewhere that usually, channel 0 is HDMI. But I will try channel 0 then.

You could actually check which device corresponds to which card and output. Try 'aplay -lL' for starters

So for testing with mpv I suppose I just have to run it like `mpv some/file.wav` and it should automatically use JACK is available.

No.. See mpv documentation regarding audio output.

I tried some more. I changed /etc/asound.conf to that mentioned on the JACK Arch wiki page.

It's not a good idea to copy/paste configs unless you actually know what they are doing. Both configs cause ALSA applications to output to ALSA's jack plug by default (assuming the jack plug is installed). If you're using pulseaudio with or without JACK, you'll most likely want ALSA outputting to pulseaudio, as the 'pulseaudio-alsa' package does.

In Cadence I chose `hw:Generic,0 [ALC892 Analog]`.

If you're trying to use the analog output of your sound card, that's probably correct. That's also most likely why PD started working for you. I'd imagine you'd hear all output to pulseaudio JACK sink as well.

`mpv something.mp3` just malfunctions (no progress bar, takes a while before it cooperates to stop playing)

Most likely some application, e.g. JACK is reserving the audio device you're trying to use with mpv.

EDIT.

Actually I just realized that the tone I am hearing from Pure Data is not as it should be. It is switched on an off quickly (like 8 Hz). Now I also started Pulseaudio and I got the same result running JACK + Pulseaudio. (with the aforementioned ALSA configs).
Now that pulseaudio is also running, `mpd` is also outputting sound, but in the same way that Pure Data did: on-and-off quickly, as if multiplied by a square signal.

Sounds like everything using pulseaudio is outputting to JACK as it should, but something is still wrong with your JACK configuration.

Last edited by ooo (2018-07-28 21:41:42)

Ploppz

Member

Registered: 2013-09-14

Posts: 313

Re: [Solved] PA + Jack: no sound

Indeed - when I doubled the buffer size in Jack my problems resolved! Thanks for your help.