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This Page is under heavy construction. My plan is to get the guide basically done and improve on it. I'll remove this note once I think that the guide is of value. I have no idea how to make this page available once it is that far. Also, spelling and grammar correction is highly appreciated.

Introduction

This guide assumes that you don't know about Jack and associated topics but want to get it up and running quickly. The goal is to guide you step by step to a reliably running Jack server that allows you to input/output audio. Note that this guide won't provide you with an optimal solution but with a foundation. Some steps, although recommended, may not be necessary. Other steps, although not mentioned, may provide you with better results. Please consult further resources and help improve this wiki.

The Kernel

To get reliable, low-latency audio i/o with Jack we recommend to use the realtime kernel, provided by the ubuntu studio team. If you have installed ubuntu studio from the dvd, it is the only kernel you've got and you don't need to worry about that. You can check if you have the rt-kernel by typing:

uname -a

The result should look like this (note the -rt):

Linux [Computername] 2.6.24-16-rt #1 SMP PREEMPT RT Thu Apr 10 15:15:40 UTC 2008 i686 GNU/Linux

possibly <link> to 'HowToGetKernelAndStuffForRtAudio'

Ubuntu Studio Controls

Since Hardy Heron, Ubuntu Studio includes an application to make certain settings easier. Start Ubuntu Studio Controls from the System -> Administration Menu. Audio applications may need priority access to memory in order to work properly, therefor enable memlock and set it to 76%. This is just a rule of thumb and will keep Ardour from complaining.

Ubuntu Studio Controls also includes a checkbox to enable firewire audio devices, it's the checkbox labled 'Enable raw 1394'.

Basic jack settings using Jack Control

Next, we will try to get the jack server, also called jackd, running reliably, so that you don't experience dropouts or anything like that. To achieve that, you have to avoid so-called xruns (you can find more on that on UbuntuStudioPreparation).

Open Jack Control and press the button Setup.

<screenshotQjackctl>+label(this is how it should look like)

Make sure you pick the correct soundcard (Interface), tick the realtime checkbox, set the Frames/Period to 1024 and the Periods/Buffer to 3. These settings should work with most Interfaces; but if it doesn't, play with the sample rate, Frames/Period and Periods/Buffer controls. You should experiment later on if you need lower latencies. Please add your findings to our JackSettingsDatabase (currently found at QuickTips).

<link> to in-depth guide to jack and external resources

Make connections and record/play audio

Start Rosegarden, open connections using qjackctl <screenshot>; Attempt recording and set audiofilepath in rosegarden, Confirm that audio input/output works, without xruns, under load; <link> to in-depth documentation on Rosegarden and Jack Control;

Possible next steps

suggestions; <links> to in-depth documentation if not given already; <links> to external sources of information


UbuntuStudio/JackQuickStart (last edited 2011-02-21 17:06:39 by 94328)