Posts Tagged 'linux'

m-audio transit on Ubuntu 12.04

I freshly installed Ubuntu 12.04 and the ubuntustudio meta package. To get the m-audio transit card working I followed my older post (m-audio transit and ubuntu linux), i.e. installing madfuload which comes in the repository and adjust the udev-rules. They do not work the way they come installed.

So I used the content from corrected-madfu-rules and saved it as /etc/udev/rules.d/41-madfuload.rules. The according file in /lib/udev/rules.d I left untouched. The “41” instead of “42” is there because it reads “…Pick a number higher than the rules you want to override, and yours will be used. …” in /etc/udev/rules.d/README.

Something hang on my machine when trying the outcome so I rebooted the machine, although this might not be necessary for everybody. After that the sound card works as it used to.

m-audio axiom 25 and linux

This is a short message  informing that I plugged a M-Audio Axiom 25 MIDI controller into the USB port and it was recognised immediately. Sooperlooper, Specimen, JackRack, Hydrogen… perfect. I didn’t yet figure out how the transport buttons work.  The manual is telling me weird stuff…

(as of Ubuntu 8.04, 2.6.24-23-rt)

Photo of the M-Audio Axiom 25 MIDI controller.

Photo of the M-Audio Axiom 25 MIDI controller.

compiling sooperlooper

I recently downloaded the newest sources of sooperlooper (1.6.13). Ubuntu 8.04 comes with a version from 2005 (1.0.8), which actually surprised me a bit. Compiling the sources is not a big deal, but ubuntu users will not find one of the packages from the build requirements in the standard repositories: Rubberband.

To compile rubberband you will need another package, fftw-3. This, in turn, requires vamp-sdk. Downloading and compiling from bottom to top you should be able to compile sooperlooper, all other packages (and their package-dev counterparts!) are found in the repositories.

sooperlooper segmentation fault

I wrote before, that I couldn’t get sooperlooper started. It turned out to be a problem which has nothing to do with sooperlooper. Because the sooperlooper server runs up fine but the GUI cannot connect to it. Filling in the right data for host name etc. and reconnecting, the GUI quits with a segmentatioin fault.

I found out that my hosts were not resolved correctly, apparently after changing my hostname the wrong way. So I changed the second line of file /etc/hosts so that it reads: myCorrectHostname
It was wrong before and after that sooperlooper works fine!

By the way: I could have known much earlier, since the GUI gives a message which ends in “…Also check that the system’s hostname resolves properly.”. But I only realised it when I was looking for how to get rid of a warning message that I got whenever running sudo anyCommand. It read
sudo: unable to resolve host myCorrectHostname
Both problems had the same cause. Solved!

a real-time kernel on a netbook

As I hoped it would be I can now give you some good news about using a real-time kernel on an ATOM platform. Basically: it works!

I bought an eeepc 1000h, one of those small laptops, which has an N270 chip from intel, 1GB of memory and a 160GB hard disc. I thought, this cannot have much less performance than my old laptop (see the About-page). I have an ubuntu 8.04 installed and usually run the linux-eeepc kernel.

To have good audio performance, I installed the real-time kernel from the 8.04  repositories and did what I wrote in the first post. Then I started the jack daemon with “/usr/bin/jackd -R -dalsa -dhw:0 -r48000 -p1024 -n2” and it worked quite well. I expected a lot of problems, but no. For some cutting, single track recording or trying bits and pieces it should be okay. I’ll give it a go and will try it out more. With an external audio card it could even be better…

So this is not bad. What the standard real-time installation still misses is a working  network. The camera and special keys do not do anything either. But I think, for the moment, this does not really matter.

Introduction to Sooperlooper

Sooperlooper is a live looping sampler. It’s a great program! The main idea is to record and loop different audio samples in parallel. Already saved audio files can be loaded and looped as well. Many different features for recording or synchronizing make it a toy for long hours of playing around with. It interfaces with the jack audio connection kit, comes with ubuntu linux and, obviously, is free to download, copy and alter (GPL V2.0). Compiling the source is not as easy on ubuntu platforms (due to some package problems), I might post on that later.

Running slgui (the user interface comes separated from the actual looping server) a window opens with one (empty) stereo loop device and the jack master output (which is the input plus all active loops) is opened.

sooperlooper main window

sooperlooper main window

The main functions to start with are the record button, trigger, overdub and mute.  When recording is started the input is piped to that loop and recorded. Pressing record again the loop is played back (and looped) from the beginning.  Overdub starts recording over what is played back, mixing both together with a ratio defined by the “feedback” bar. When muted “trig” starts looping the sample, whereas “once” stops playback (of that loop) after the first round.These few functions give already a lot of fun. Using “undo” and “redo” to the left one can play happily with the first loop.

All this is nicely done when using a MIDI keyboard. In the preferences  one can make sooperlooper to “learn” MIDI events for different commands. With vkeybd (post) I arranged the main functions on the keys from 1-5 for the first loop and the rows below for others.  A detailed description of all functions is found on the website.

More loops can be opened and synchronized, more on that in a later post.

live audio effects – creox

For real time audio effects I found creox (website) to be a stable solution. It consists of 5 different effects (Phaser, Flanger, Echo, Tremolo, Distortion) which can be dis- and enabled in different orders of connection. Presets can be saved, although not changed (as of version 0.2.2rc2). Instead one has to save a changed set under a new name. Unfortunately it doesn’t have MIDI control so one has to click or change focus – strike key, which is a bit awkward in live situations. But the presets window can be detached from the main window.

When creox is set into play mode (SPACE key) it opens up one stereo jack input and one output port. Via the jack control it can be connected to any other jack port.

Concerning stability: starting up is the critical phase to my experiences. After setting creox into play mode it sometimes dies. But if it survives, then it is usually stable. I tried jackrack (website) as well, which is a more professional effect station for LADSPA effects, but it seems to be less stable. Since jackrack includes MIDI control it should be worth fiddling around with it. Maybe compiling it on my system helps or my hardware (about) is just to weak…??? Any comments/experiences appreciated.