botched new section introduction
This commit is contained in:
parent
385c4554cc
commit
28f75f8ad5
@ -1,144 +0,0 @@
|
|||||||
---
|
|
||||||
layout: default
|
|
||||||
title: Ubuntu Linux
|
|
||||||
---
|
|
||||||
|
|
||||||
<h2>Ubuntu Linux</h2>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
Ubuntu Linux is the most popular variety of Linux in use on desktop
|
|
||||||
and laptop systems. It has the backing of a for-profit corporation
|
|
||||||
(Canonical Inc.) behind it, a defined philosophy and a huge and
|
|
||||||
worldwide user base.As a result, it is a common platform for people
|
|
||||||
who want to use Ardour and other tools for music creation and
|
|
||||||
pro-audio work.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
Unfortunately, Ubuntu has repeatedly caused major headaches for
|
|
||||||
people who want to use Ardour. These problems have arisen from a
|
|
||||||
combination of two basic issues:
|
|
||||||
|
|
||||||
<ul>
|
|
||||||
<li>Badly built packages of Ardour</li>
|
|
||||||
<li>Poor system configuration related to JACK, which Ardour (and
|
|
||||||
most other pro-audio tools on Linux) uses for audio and MIDI I/O.
|
|
||||||
</li>
|
|
||||||
</ul>
|
|
||||||
</p>
|
|
||||||
|
|
||||||
<h3>Problems with Ardour Packages</h3>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
It is not possible to know whether the current package of Ardour
|
|
||||||
released by Ubuntu has been correctly built or not. Ubuntu has a
|
|
||||||
history of making packaging errors that lead to crashes, missing
|
|
||||||
functionality and odd behaviour that is not present in the
|
|
||||||
ready-to-run version of the program that you can get from ardour.org
|
|
||||||
(or in the packages released by other distributions)
|
|
||||||
<p>
|
|
||||||
If you plan to use Ardour on Ubuntu, you are <strong>strongly
|
|
||||||
recommended</strong> to download the ready-to-run version from
|
|
||||||
ardour.org. Ardour's lead developer (and many of the most active
|
|
||||||
members of our user community) will not provide support for, and
|
|
||||||
will not investigate bugs reported for, Ubuntu's own packages of
|
|
||||||
Ardour.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
If have already installed the Ubuntu package of Ardour and find that
|
|
||||||
although the program starts up and basically runs, but you are
|
|
||||||
running into more subtle problems (for example, with plugin GUIs or
|
|
||||||
with export, or with the use of certain specific plugins), then you
|
|
||||||
are <strong>strongly recommended</strong> to download the
|
|
||||||
ready-to-run version from ardour.org.
|
|
||||||
</p>
|
|
||||||
|
|
||||||
<h3>Problems with PulseAudio and JACK Configuration</h3>
|
|
||||||
|
|
||||||
<h4>Problems with the interaction between PulseAudio and JACK</h4>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
Like many distributions, Ubuntu has decide to use PulseAudio as the
|
|
||||||
default audio system. PulseAudio is a rich and capable system that
|
|
||||||
provides excellent services for typical users of Linux on the
|
|
||||||
desktop. However, it is not capable of the type of performance that
|
|
||||||
tools like Ardour require and in particular does not offer the
|
|
||||||
possibility of sending audio between applications that can makes the
|
|
||||||
Linux audio environment a very interesting one.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
This would not a problem if it were not for the fact that JACK will
|
|
||||||
not run correctly (if at all) if it needs to use the same
|
|
||||||
soundcard/audio interface that PulseAudio is using. And since on
|
|
||||||
Ubuntu, PulseAudio is configured by default to always use the
|
|
||||||
(typically single) audio interface on your computer, this is a bit
|
|
||||||
of a problem.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
The developers of JACK and PulseAudio got together in 2009 and
|
|
||||||
agreed upon a mechanism by which PulseAudio and JACK could cooperate
|
|
||||||
in their use of a single soundcard. Whether or not PulseAudio is running by
|
|
||||||
default, when JACK starts up it sends out a request to use the
|
|
||||||
soundcard. If PulseAudio is running, it will give up its use of the
|
|
||||||
soundcard to allow JACK to take over (and can optionally be told to
|
|
||||||
route its own audio through JACK). When JACK finishes, it sends out
|
|
||||||
another message, and PulseAudio can once again use the soundcard
|
|
||||||
directly.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
This relatively simple system ought to be the basis for excellent
|
|
||||||
cooperation between PulseAudio and JACK. Unfortunately, it relies on
|
|
||||||
everything being correctly configured for it to work, and Ubuntu
|
|
||||||
have repeatedly failed to get this configuration correct.
|
|
||||||
</p>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
The specific issues known at this time (spring 2013) are:
|
|
||||||
<ul>
|
|
||||||
<li>a bug in PulseAudio that causes it not to give up the
|
|
||||||
soundcard when JACK asks</li>
|
|
||||||
<li>bad package dependency information that causes a critical
|
|
||||||
package to be missing even when JACK and PulseAudio are
|
|
||||||
installed</li>
|
|
||||||
<li>a bug that causes JACK to freeze up when told to stop,
|
|
||||||
causing issues with restarting</li>
|
|
||||||
</ul>
|
|
||||||
|
|
||||||
<h5>Symptoms</h5>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
<ul>
|
|
||||||
<li>Cannot start JACK (though see the next section for other
|
|
||||||
causes of this)</li>
|
|
||||||
<li>JACK starts but there is no sound coming from Ardour or other
|
|
||||||
applications that use JACK.</li>
|
|
||||||
</ul>
|
|
||||||
</p>
|
|
||||||
|
|
||||||
<h5>How to fix</h5>
|
|
||||||
|
|
||||||
<h2>Problems with JACK configuration<h2>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
To function as intended, JACK needs to run with access to two
|
|
||||||
operating system facilities called "realtime scheduling" and "memory
|
|
||||||
locking". This means that you, the user who starts JACK, must be
|
|
||||||
allowed access to these facilities. By default, Ubuntu does create a
|
|
||||||
user group that has this permission but ... it does not put new
|
|
||||||
users into this group by default. Consequently, you will not have
|
|
||||||
permission to run JACK in the way you should.
|
|
||||||
</p>
|
|
||||||
|
|
||||||
<h5>Symptoms</h5>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
A message like "Cannot lock down memory" in the output from JACK as
|
|
||||||
it starts up. This output may be "hidden" in the Messages window of
|
|
||||||
QJackctrl (aka JACK Control), so you should check there.
|
|
||||||
</p>
|
|
||||||
|
|
||||||
<h5>How to fix</h5>
|
|
||||||
|
|
||||||
<p>
|
|
||||||
Run the command <code>sudo usermod -a -G
|
|
||||||
audio <em>YOUR-LOGIN-NAME</em></code>. Then logout and login again.
|
|
||||||
</p>
|
|
||||||
Loading…
Reference in New Issue
Block a user