144 lines
5.8 KiB
HTML
144 lines
5.8 KiB
HTML
---
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layout: default
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title: Ubuntu Linux
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---
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<p>
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Ubuntu Linux is the most popular variety of Linux in use on desktop
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and laptop systems. It has the backing of a for-profit corporation
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(Canonical Inc.), a defined philosophy and a huge and
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worldwide user base. As a result, it is a common platform for people
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who want to use Ardour and other tools for music creation and
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pro-audio work.
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</p>
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<h2>High Level Recommendations for Ubuntu Users</h2>
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<p>
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Currently, installing pro audio applications on vanilla Ubuntu requires
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some configuration, in order for the user to gain realtime privilege
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(read below).
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Ubuntu Studio, which is an official flavor of Ubuntu, and thus shares
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the repositories with Ubuntu, has this already configured.
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Other distributions, such as KXStudio, and Dreamstudio are largely based
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on Ubuntu, and like Ubuntu Studio, has these settings preconfigured, while
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also containing customized versions of Ubuntu packages, which often are
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more up to date.
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<p>
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<h2>Installing Ardour</h2>
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There may be unintended differences, and even bugs in Ubuntu native
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packages, as a result of a different building method. For this reason,
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Ardour developers highly recommend you to install the official
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ready-to-run version of the program that you can get from <a
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href="http://ardour.org/download">ardour.org</a>, as Ubuntu native
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packages are not supported in official Ardour forums or other
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support channels.
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<h2>Problems with the interaction between PulseAudio and JACK</h2>
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<dl>
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<dt>Background Info</dt>
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<dd>
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<p>
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Like many distributions, Ubuntu has decide to use PulseAudio as the
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default audio system. PulseAudio is a rich and capable system that
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provides excellent services for typical users of Linux on the
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desktop. However, it is not capable of the type of performance that
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tools like Ardour require and in particular does not offer the
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possibility of sending audio between applications that can makes the
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Linux audio environment a very interesting one.
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</p>
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<p>
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This would not a problem if it were not for the fact that JACK will
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not run correctly (if at all) if it needs to use the same
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soundcard/audio interface that PulseAudio is using. And since on
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Ubuntu, PulseAudio is configured by default to always use the
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(typically single) audio interface on your computer, this is a bit
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of a problem.
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</p>
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<p>
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The developers of JACK and PulseAudio got together in 2009 and
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agreed upon a mechanism by which PulseAudio and JACK could cooperate
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in their use of a single soundcard. Whether or not PulseAudio is running by
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default, when JACK starts up it sends out a request to use the
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soundcard. If PulseAudio is running, it will give up its use of the
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soundcard to allow JACK to take over (and can optionally be told to
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route its own audio through JACK). When JACK finishes, it sends out
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another message, and PulseAudio can once again use the soundcard
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directly.
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</p>
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</dd>
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<dt>What is the problem?</dt>
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<dd>
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<p>
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The specific issues known at this time for all flavors of Ubuntu
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12.04 and 12.10 are:
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<ul>
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<li>a bug in PulseAudio that causes it not to give up the
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soundcard when JACK asks (<a href="https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1163638">LP: #1163638</a>
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(fixed in Ubuntu 13.04).</li>
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</ul>
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</p>
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</dd>
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<dt>Symptoms</dt>
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<dd>
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<p>
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<ul>
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<li>Cannot start JACK (though see the next section for other
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causes of this)</li>
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</ul>
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</p>
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</dd>
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<dt>How to fix</dt>
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<p>
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These bugs do not affect the upcoming 13.04 release, and earlier
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releases (12.04 and 12.10) are in the process of being fixed.
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</p>
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<dd>
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</dd>
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</dl>
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<h2>Problems with JACK configuration</h2>
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<dl>
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<dt>What is the problem?</dt>
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<dd>
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<p>
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To function as intended, JACK needs to run with access to two
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operating system facilities called "realtime scheduling" and "memory
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locking". This means that you, the user who starts JACK, must be
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allowed access to these facilities. By default, Ubuntu does create a
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user group that has this permission but ... it does not put new
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users into this group by default. Read more about why <a href="https://wiki.ubuntu.com/Audio/TheAudioGroup">here</a>.
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Consequently, you will not have permission to run JACK in the way you should.
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</p>
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</dd>
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<dt>Symptoms</dt>
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<dd>
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<p>
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A message like "Cannot lock down memory" in the output from JACK as
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it starts up. This output may be "hidden" in the Messages window of
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QJackctrl (aka JACK Control), so you should check there.
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</p>
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</dd>
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<dt>How to fix</dt>
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<dd>
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<p>
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Make sure the file /etc/security/limits.d/audio.conf exists. If it is
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named /etc/security/limits.d/audio.conf.disabled, rename it to the former.
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Run the command <code>sudo usermod -a -G
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audio <em>YOUR-LOGIN-NAME</em></code>. Then logout and login again.
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On Ubuntu Studio the user is a member of audio group by default, but not
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on other official flavors.
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</p>
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</dd>
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</dl>
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<h2>Reporting Issues</h2>
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<p>Given the difficulties in supporting Ubuntu and the limited time/resources of the Ardour team, the <code>Ubuntu Studio Project</code> has requested that issues and bug reports related to Ubuntu, Ubuntu Studio and other derivitives be directed to them.</p>
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<h4>Contact Information for Ubuntu Studio</h4>
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<p><a href="http://ubuntustudio.org" target="_blank">The Ubuntu Studio Homepage</a></p>
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<p><a href="http://ubuntuforums.org/forumdisplay.php?f=335" target="_blank">The Ubuntu Studio Forums.</a></p>
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<p><a href="https://help.ubuntu.com/community/UbuntuStudio/MailLists" target="_blank">Information on the Ubuntu Studio Mailing Lists.</a></p>
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<p><a href="https://help.ubuntu.com/community/UbuntuStudio/IRC" target="_blank">Information on the Ubuntu Studio IRC channel.</a> #ubuntustudio on irc.freenode.net</p>
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