From df9327a64e6e3065c99b122e11a7fc56459bd780 Mon Sep 17 00:00:00 2001
From: Paul Davis
+ This section of the manual collects together the collective wisdom
+ of the user community regarding details of using Ardour on various
+ specific platforms
+
+ 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.
+
+ 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:
+
+ Platform Specifics
+
+Ubuntu Linux
+
+
+
+
+ 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) +
+ If you plan to use Ardour on Ubuntu, you are strongly + recommended 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. +
++ 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 strongly recommended to download the + ready-to-run version from ardour.org. +
+ ++ 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. +
++ 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. +
++ 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. +
++ 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. +
+ ++ The specific issues known at this time (spring 2013) are: +
+
+ 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. +
+ ++ 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. +
+ +
+ Run the command sudo usermod -a -G
+ audio YOUR-LOGIN-NAME
. Then logout and login again.
+