State of Jack as a full pulsaudio replacement

Luke Kuhn lukekuhn at
Fri May 4 20:30:51 UTC 2012

All these bugs and "no sound output" complaints with Pulseaudio bring back the idea of finding a way to make Jack replace Pulseaudio altogether. Removing pulseaudio is not always enough, in many but not all cases a replacement is needed. I remember the old days of Dapper and applications grabbing the sound card and having to reboot just to get audacity to connect to alsa, and as late as Hardy using sound cards that would only connect to one program at a time. This while all those Windows clunkers made that one program a sound server that seemed to work fine. We have  a good sound server too, jack, and a good front end for it, qjackctl, which I discovered in ubuntustudio hardy.

 My big desktops do fine with straight ALSA for my video editing(kdenlive) , audio editing(audacity) and general uses. Their onboard sound cards include mixer functions enough to play sound from multiple sources with alsa by itself. This is apparently a hardware support capability.  My intel Atom netbook, containing a copy of the same OS, is another story entirely. No output from any mono soundtrack in alsa, as the soundcard does not support a mono output at all. On the other hand, pulseaudio is just too heavy for it, killing sync in video playback, even for 360p h264 video.

I ended up using jack as a pulseaudio replacement in that netbook. Anything other than flash or audacity, I fire up jack from qjackctl.

Using no sound server, only Flash, Xine, kdenlive and audacity can connect to alsa directly on that sound card. With jack, all the video players and audacious work fine, Mplayer and Audacious needing to be told in preferences to use jack.   Using either jack for sound or straight alsa(xine only) with a stereo soundtrack, that same netbook will only fall 1 or 2 seconds behind the sound and sometimes keep up entirely on a 720p HD video at 25 fps in H264 codec. A full 30fps still defeats it. This shows that Jack is much lighter and more efficient code than pulseaudio. In fact, it shows that Jack is imposing very little load on the CPU compared to no sound server at all. I learned about Pulsaudio's resource use playing with old Pentium 3's, when Lucid could not play video files that Jaunty played just fine. Removing pulseaudio restored the playback sync.

Thanks to whoever put on onto using Volti to control volume with alsa direct or via jack! That takes care of the "no volume control applet without pulseaudio" issue and works in most DE's. You need the classic-systray extension to put it where you can see it in gnome-shell, comes up fine in both Icewm(traditional system tray) and in Unity if you add it to the whitelist for systray applets. 

Audacity works fine with Jack running, the only showstoppers for running jack full-time by itself are kdenlive (no Jack support yet!) and that old binary blob nasty, Adobe Flash. I am using 64 bit flash direct from Adobe, I do  know if the "pulseaudio-extrasound" package aimed at making Pulseaudio work would work with jack instead. With adobe deciding to throw Firefox under the bus and push proprietary browsers, I have a feeling open-source replacements for flash are about to hit the big time anyway.

Three ways of making Flash work with Jack  via alsa, gstreamer, or pulseaudio,  plus a library for direct Jack support for Flash was being described at

This page dates back to 2012. All these methods are said to create some added latency in audio from Flash, opposite the audio ahead of video effect that a too-heavy CPU load or slow graphics will create. Have yet to test them, I control jack from qjackctl on the netbook-and rarely use Flash to actually watch videos, as I download and keep anything worth watching anyway due to limited bandwidth and a preference for local copies of everything.

None of that matters on a big, high-powered A/V worstation, though a direct jack/no pulseaudio solution might help with other kinds of latency issues. What does matter is getting sound to work on a sound editing system without forcing users to learn a lot of new programming that might send them to another distro.

Having to start qjackctl or configure an application in its preferences to use Jack is one thing, having to root around on Google for what text file to exit, commands to run, etc is quite another.

With Precise now out, this question can again be considered for future reference. Thankfully, in Linux distros nobody has to wait, if Pulseaudio doesn't work for a user it can be removed and Ubuntu has been careful to keep too much from depending on it.  

Maybe a debian package that conflicts with pulseaudio, depends on jack and qjackctl, pulls in one of the solutions for flash and anto-configures other applications to use Jack by default would make this something an end user could actually work with?  That would be something that could be used as an advanced option at install or a recommended fix for situations where Pulseaudio acts up.

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