The Mgt.

Ingen

themgt — Wed, 11 Mar 2009 20:17:25 +0000

Today i was curious and installed Ingen (formerly Om), a modular synthesizer which could be a replacement for AMS. Although the project looks quite promising I think the current status of the software is enough to use it productively. But I am very much looking forward to a proper release.

There is a short installation guide on the Ingen page. Basically, some additional packages, that the configuration script asks for, will have to be installed. On Ubuntu 8.10 there will be problems with the packages for redland and raptor because the versions in the repositories are not new enough for Ingen. My suggestion for this problem is to use the versions from the next Ubuntu release (Jaunty Jackalope) and install them in the following order: libraptor1 libraptor1-dev raptor-utils librasqal1 librasqal1-dev librdf0 librdf0-dev redland-utils

On Ubuntustudio

themgt — Mon, 09 Mar 2009 18:45:31 +0000

Here is a short note on the steps I had to take to make Ubuntustudio (You can either do a fresh install from the Ubuntustudio-DVD or by installing the relevant additional packages in a running Ubuntu installation)

First important thing was to add the following lines to /etc/security/limits.conf:

@audio - rtprio 90 @audio - nice -10 @audio - memlock unlimited

For that to work the local user has to be added to the group audio (if he/she isn’t already a member):

$sudo adduser [username] audio

Next thing was to get the external soundcard to work. I was lucky: I have a Maya 44 USB which runs out of the box (though I would not recommend this soundcard for other reasons). For other soundcards the ALSA compatibilty matrix or the FFADO device support list should be checked.
Then the automatic configuration script asoundconf has to be run. There is also a little GUI for System->Preferences for this task which can be installed with the package asoundconf-gtk.

Afterwards, in System->Preferences->Audio I switched everything to ALSA.

The volumes of the input and output channels of the soundcard can either be controlled with the tool alsamixer or by double-clicking on the loudspeaker-symbol (at least in Gnome).

There were also some problems with ALSA and Pulseaudio which resulted in no sound when using ALSA. I “solved” this by deinstalling every package that had to do with pulseaudio. Afterwards everything worked fine.

In the Jack Control tool you just have to make sure that you choose the right interface. At first, I didn’t get that it is also possible to click on the “>” to get some more information which device “hw:0″ actually is. The settings for Frames/Period and the Periods/Buffer have to be experimented with a bit to find a stable configuration with an acceptable latency.

compiler optimizations

themgt — Mon, 09 Mar 2009 18:05:09 +0000

Even in a package based distro it is sometimes neccessary to compile source code. In the configuration process it is usally possible to set additional options for the c(++) compiler with the variables CFLAGS and CXXFLAGS. By modifying them it is possible to optimize the compiled code to one’s individual system.

There is a nice guide on how to set appropriate optimization options from the gentoo documentation.

The allowed cpu-types for the march-parameter can be found in the man-page of gcc. Some important ones are pentium-m, pentium4, core2, pentium4m, athlon-4, athlon-xp, athlon64, athlon64-sse3.

Sometimes these variables are not specified explicitly and are read from the environment
To set the environment variables in such cases I use the following little shell-script I run before compiling (I didn’t set them globally on every start up because I don’t want to optimize per default).

CFLAGS="[options here]" CXXFLAGS="[options here]"

The settings are the same for CFLAGS and CXXFLAGS.

hydrogen went beta3

themgt — Thu, 05 Mar 2009 13:54:11 +0000

The drum machine hydrogen is now available in version 0.9.4 BETA3.

One very big advantage of this version is that mute groups now work (example: open hihat stops when pedal hihat is triggered). I also discovered that the version 0.9.3-5.1 in Ubuntu 8.10 wouldn’t want to start up anymore (segmentation fault), which might be due to the prior installation of LASH.

Anyway, the new version of hydrogen works fine and I am currently using it with the ns_kit7free drumkit which produces quite satisfying results. The only thing that bugs me at the moment is that I cannot decide upon a midi mapping of the samples yet.

For the time being, my recommendation for linux-audio is the following: Always install the newest versions you can get. It seems that the current development of the essential goes so rapidly at the moment that a lot of trouble can be prevented by using the newest versions.

Another note: ardour 2.8 (with improved VST-support) will be out soon and the midi support for the 3.0 branch looks very promising.

Opera: smooth fonts

themgt — Fri, 13 Feb 2009 11:53:24 +0000

I noticed that for some websites Opera did not render the fonts nicely. One example for this would be kiva.org.

However there is an easy solution to this problem that can be found here:

The following line has to be added to /usr/bin/opera under the #!/bin/bash line:

export QT_XFT=true

(Has to be added after every Opera upgrade)

And the following line needs to be added to /etc/opera6rc:

Enable Core X Fonts=0

I’m running Ubuntu 8.10 but it might well be applicable for other distros.

dia

themgt — Wed, 21 Jan 2009 15:07:41 +0000

dia is a program for creating diagrams very similar to Visio. This tool is very useful if you want to draw some boxes and arrows and give them names.
It can also do more sophisticated stuff like UML-diagrams, but there are of course better tools for specialized purposes in most cases. The program is very intuitive, so you can get what you want really fast with dia.

Books

themgt — Sun, 18 Jan 2009 12:21:03 +0000

Here are two free ebooks I stumbled upon quite recently:

Graph Theory

Logic for Computer Science

Both books seem to be suitable for studying and looking up things.

mdf2iso

themgt — Sat, 17 Jan 2009 14:33:38 +0000

Today I tried to burn an mdf image file (the file format of Alcohol 120%) with K3b which unfortunately didn’t work. But there’s a nice tool called mdf2iso that creates iso images out of mdf files and works just perfectly.

Is it fall yet?

themgt — Fri, 16 Jan 2009 18:45:50 +0000

So, I’m gonna start a blawg here… First, I hope that this site here is a good choice. In particular, I hope that commenting on the articles will be possible without problems. I did consider a homebrew solutions but that just wouldn’t be worth the effort. But hopefully, I can migrate this stuff here if I ever consider to do so. I will use the default layout now for a while to make clear to everybody that this is a blog.

Why this blog? Everybody knows this situation when we’re trying to fix a problem and search for a solution on the webs. And then after a long time we can either find the solution somewhere or have thought of something clever ourselves. One of the main purposes of this site is to write down these solutions to make them available for search engines. And if such a solution can’t be found one might theoretize about why it can’t be found…

I will mostly write about Ubuntu, linux audio and the impossibility of finding suitable hardware. To give it a more personal touch i will maybe also write a little about music and the making of such and my reflections on life. And i’ll eventually add some fancy tags.