Stuttering audio in Linux: PulseAudio strikes again

I unmasked PulseAudio 10.0 back in January 2017 and installed it in my Gentoo Stable amd64 installation, and everything worked fine… until a couple of days ago, when the audio in streaming YouTube videos started to stutter every so often. It sounded rather like a scratched LP jumping. At first I thought the problem lay with Firefox, but the stuttering audio also occurred in Chrome. Then I wondered if my Internet connection was to blame; perhaps the ISP’s service had deteriorated. But a Windows 10 machine on my home network didn’t suffer from the problem, so that seemed to rule out the Internet connection. I tested the broadband throughput, and it was circa 32 Mbps, actually a little higher than the last time I tested it last year.

Now, Gentoo is a rolling distribution and I update my laptops regularly, but I couldn’t think what had been upgraded in the last couple of months that could be causing the problem. Although PulseAudio had not been upgraded since January, I began to wonder if PulseAudio could be involved, as my audio woes in the past have usually been due to PulseAudio.

I have always had PulseAudio installed with USE=”-realtime”:

user $ eix -I pulseaudio
[I] media-sound/pulseaudio
     Available versions:  10.0 {+X +alsa +alsa-plugin +asyncns bluetooth +caps dbus doc equalizer +gdbm +glib gnome gtk ipv6 jack libressl libsamplerate lirc native-headset neon ofono-headset +orc oss qt4 realtime selinux sox ssl system-wide systemd tcpd test +udev +webrtc-aec zeroconf ABI_MIPS="n32 n64 o32" ABI_PPC="32 64" ABI_S390="32 64" ABI_X86="32 64 x32"}
     Installed versions:  10.0(16:07:53 19/04/17)(X alsa alsa-plugin asyncns bluetooth caps dbus gdbm glib gnome gtk ipv6 jack orc qt4 ssl tcpd udev webrtc-aec zeroconf -doc -equalizer -libressl -libsamplerate -lirc -native-headset -neon -ofono-headset -oss -realtime -selinux -sox -system-wide -systemd -test ABI_MIPS="-n32 -n64 -o32" ABI_PPC="-32 -64" ABI_S390="-32 -64" ABI_X86="32 64 -x32")
     Homepage:            http://www.pulseaudio.org/
     Description:         A networked sound server with an advanced plugin system

but I wondered if PulseAudio’s real-time scheduling was somehow the cause of the problem, so I edited /etc/pulse/daemon.pa and added ‘realtime-scheduling = no‘ (I assume the default is ‘yes‘, as it was commented as such in the file):

; realtime-scheduling = yes
realtime-scheduling = no

Problem solved. PulseAudio is indeed a demon. 😡

About Fitzcarraldo
A Linux user with an interest in all things technical.

14 Responses to Stuttering audio in Linux: PulseAudio strikes again

  1. Thomas says:

    Thank you, this blogpost helped me a lot with playing YouTube videos on my laptop. 🙂 Maybe you should add info how to restart the demon (e.g. pulseaudio -k && sudo alsa force-reload) for n00bs like me.

  2. aturfer says:

    My Asus Z97 running KDE Neon has had choppy sound for a while now. Setting realtime-scheduling = no seems to have solved it for me! Thank you so much!!!

  3. Samir says:

    Thanks for this post. This solved the problem that I was having with my Bose QuietComfort 35 headphones. Just restarting the daemon didn’t work for me. I had to reboot the system. This was on Ubuntu 16.04.

  4. Darko says:

    Thanks It solved my problem too. Debian 9

  5. Stanley Joyce says:

    Thank you. This was very annoying. Turning realtime scheduling off solved my audio skipping issue as well. Linux Mint 18.3 (KDE edition)

  6. Pingback: A quest for bit-perfect audio in Linux – Chitpong's Note

  7. Jason says:

    I am having the same issue and I don’t know how to fix it

  8. hulloanson says:

    How did you figure it out? You’re a genius!

  9. Security says:

    Thanks! Worked like a charm

  10. daivd says:

    It worked for me on Linux Mint 19. Thanks!!!!

  11. mwrsa says:

    Same here. Some Videos on Mint 19.3 were simply impossible to watch, while others worked just fine. Anyway, this is the solution I was looking for. Ty so much!

  12. bobcov says:

    I had perfectly working 19.3 Mint Bluetooth audio until the laptop (Macbook 2006–no more OS X) died suddenly without shutting down due to a bad battery. After that, Bluetooth stuttered in an alternating pattern of several seconds fine, several seconds bad. Just in case this might be useful to anyone with a similar experience, the fix for me was to use Timeshift to rollback to the configuration from the day prior. Looking at resource monitor and processes didn’t yield any clue as to what the cause was, so I just rolled back.

  13. hab says:

    thanks man,

  14. hdspuser says:

    Worked in Debian 10.4 after adding realtime-scheduling = no to /etc/pulse/daemon.conf as root and reboot the system

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