Corridor Nine

Open source acceleration on r600/r700

2009-03-15T08:55:00.000+06:00

Well, this is something that we, Radeon owners, have surely been waiting for. Thanks to the hard work of X.org and Ubuntu developers, an open source driver with 2D and XVideo acceleration support has recently hit the repositories (changelog). But, unfortunately, the driver still depends on kernel support, that has not been uploaded yet.

Anyway, if you don't want to wait for the kernel packages, the X.org wiki has cool instructions on building the latest DRM from source, and they just worked for me like a charm! For some extra confidence, I also did a "depmod -a" and "update-initramfs -u" after copying the modules in their places.

If everything goes well, here's what you'll get in your Xorg.0.log:

(==) RADEON(0): Using EXA acceleration architecture
(II) RADEON(0): Acceleration enabled

And of course, the difference is easily noticeable. Especially if you like moving and switching windows :) The video support is also outstanding. Even high resolution clips (like Big Buck Bunny or the Ruby videos) play VERY smoothly and are quickly switched into and out of fullscreen. Really cool! And they say, EXA acceleration should work with radeonhd as well by now, but I haven't tried this myself yet.

aoTuV Beta5.7

2009-03-09T14:00:00.010+06:00

Just in case, you'd like to try out the latest beta on Linux and need a static binary, here's mine - oggenc-aotuvb5d.bz2.

FLAC and Kate support included!

Python 3.0 / Hex On!

2009-01-31T19:11:00.044+06:00

This week, I've started playing with Python 3.0 (aka Py3k). The final 3.0 version had been released in December, so there is only a release candidate available in the Intrepid repositories, but I didn't care. In fact, it was dead easy to install - simply apt-get install python3 and you're all set!

Among the things, that amazed me the most, is a new fractions module (actually existing since Python 2.6), that provides support for rational numbers! What are rational numbers good for? Well, they're invaluable for pretty much anything, that involves just intonation, to say the least!

For example, here's how I've managed to code a simple Hexany generator in almost no time! Roughly speaking, a hexany is created from several prime (or not so prime) numbers, that are multiplied together in pairs to form a set. To get a scale out of it, the resulting numbers should be divided by a chosen "base note" and reduced to the octave range. So, first of all, we'll need a simple octave reduction function:

def octave_range(fr):
    if fr <= 0: raise ValueError("Invalid frequency ratio")
    elif fr > 2: return octave_range(fr / 2)
    elif fr < 1: return octave_range(fr * 2)
    else: return fr

Now, let's define a "base note" and use set comprehension (another Py3k feature) to fill the CPS with permutations of numbers from the Wikipedia example:

nums = [2, 3, 5, 7]
base = 5 * 7
cmps = {a * b for a in nums for b in nums if a != b}

And thanks to the fractions support, the final step is also going to be the easiest:

from fractions import Fraction
hexany = [octave_range(Fraction(note, base)) for note in cmps]
hexany.sort()

The code is also suitable for producing dekanies and other scales, based on Wilson's combination product sets. I still have to figure out the proper ways of using them in music though :P

Updates

2009-01-26T09:00:00.001+06:00

There's not much to write about, but here are several quick updates to keep this feed alive... First of all, Sced source code has been moved to the SuperCollider SVN tree, so any further development is going to continue out there... Another good news is that our favourite text editor - gedit is probably going to have some kind of D-Bus interface for the 2.26 release. So things like ScedDocument (and other means of feedback from sclang) could be finally made possible.

I have moved the few Russian posts in this blog into ratzez.blogspot.com, thanks to the Blogger import and export feature. It means, that from now on, I shall continue writing in English here and the secondary blog will be in Russian. Looks like it also makes the Blogger interface more convenient, 'cause the engine does not seem to respect the browser language anyway...

And yet one more thing, just in case you'd like to add a little Human look to your code... It can be done with a couple of Ubuntu-coloured themes for GtkSourceView. They're not quite polished yet, but already seem to nicely fit an all-human environment...

Back in Black

2008-11-23T12:37:00.013+06:00

There are several big changes in Sced expected in the near future, so today I'm releasing the latest stable 0.4 version, that does not introduce any new features, but has fixes for a couple of long-standing bugs.

It's worth mentioning however, that this version is a lot more compatible with stock and third-party style schemes for Gedit. That means, that your SuperCollider code is going to look cool and stylish, even with the darkest of them... Oh, and quite a number of themes is already available through this page at GNOME Live. Go and check them out!

One more thing. In order to make your Gedit even more great and powerful, make sure you also get the fullscreen plugin and the gedit-plugins package from your distro. The former enables the fullscreen mode for the distraction-free coding (or some live demos, perhaps), and the latter has some neat extensions like bracket completion and tabbar-disabler for an even cleaner workspace!

The Sced tarball itself is available through the usual location and the Debian/Ubuntu packages should be already in the PPA at the time of writing. Just in case you missed the installation instructions, check the following post for a short tutorial. And, of course, your feedback is much appreciated.

They did it!

2008-10-15T07:55:00.001+07:00

Yeah, I'm now running my Intrepid setup with a shiny new fglrx-8.543. It installs, it runs, it works with Jockey! Right in time, when I've started to lose my hope...

And I can even watch the video and play games - something I've been missing since I have installed Intrepid back in August :) My huge thanks to all the AMD/ATi and Ubuntu developers who have brought the driver back to us!

Time for some colliding under Ibex...

2008-10-03T12:44:00.003+07:00

Dang, it looks like I write in this blog, only when I publish the new SuperCollider binaries... Anyway, if you're interested in trying the latest (7803) SVN snapshot the easy way, it's now available (for Intrepid as well)!

The instructions for installing the SuperCollider debs (and making some sounds) may be found in an earlier howto, but I also think of writing another introductory tutorial on Synths and SynthDefs in the next few days...

And most importantly, I'm probably going to perform a bit of live SC noise by the end of October. So any comments and tips, esp. from those of you, who have played live with SC/Linux are kindly welcome :)

Just couldn't resist...

2008-09-14T09:04:00.000+07:00

For the meme:

teaquetzl
roppongi
carthax

All of 'em are named after places (real and fictional) :)

SuperCollider for Human Beings

2008-05-21T18:50:00.009+07:00

This time with gedit support!!!

And here's a short hands-on tutorial, just in case anyone would like to try out this extremely efficient synthesis environment for the first time...

UPDATE: the binaries also work with the amd64/chroot configuration, that's commonly used for native execution of SC3 on 64-bit distributions. Thanks to Sornen for the instructions, which you can read here!

UPDATE: the PPA is now signed with a generated key, which can be added to your system with the following command:

gpg --keyserver keyserver.ubuntu.com --recv DD9300F1 && gpg --export --armor DD9300F1 | sudo apt-key add -

The i386 (and amd64 server-only) packages are available through my PPA. In order to install them on Hardy, add the following lines to your sources.list (replace hardy with intrepid or jaunty to suit your Ubuntu version):

deb http://ppa.launchpad.net/artfwo/ppa/ubuntu hardy main
deb-src http://ppa.launchpad.net/artfwo/ppa/ubuntu hardy main

And apt-get install supercollider and supercollider-gedit packages:

sudo apt-get update && sudo apt-get install supercollider supercollider-gedit

Then start gedit and open Edit->Preferences. Enable Sced plugin from the Plugins tab:

Okay, now we can try the interpreter. Select Tools->SuperCollider Mode from the gedit menu. The SuperCollider output panel will appear with a message that SuperCollider has started. Now type the following code just inside the currently open document:

"Hello, World!".postln;

Make sure that the cursor is on the same line and press CTRL+E. You should see "Hello, World" printed two times in the output window. The string is duplicated because "postln" returned the same string as a value, and the output also prints the results of the evaluated expressions.

If you'd like to get some sound, make sure that JACK is started. If not, start it with qjackctl or the following command:

jackd -d alsa

After JACK has started, select SuperCollider->Start Server from the gedit menu and execute the following code string, just like we did with the "Hello, World" example above:

{SinOsc.ar}.play;

You should hear an annoying beep from your left speaker. Not much, huh? Well, press ESC (Stop Sound) inside gedit for now. And append something like the following code to your document (yes, you can do all the work in the same document):

// This example is a modified patch
// from the SuperCollider book by David Cottle
// You can enable syntax highlighting
// by selecting View->Highlight Mode->Others->SuperCollider
( // press CTRL+E here
{
  RLPF.ar(
    Saw.ar(55),
    LFNoise1.kr([5, 5], mul: 440, add: 880),
    0.1,
    mul: 0.25
  )
}.play;
)

Note the brackets around the actual code. They're used to group code together into "blocks" and execute SuperCollider instructions simultaneously. In this example you will need to press CTRL+E where indicated to select and run our block. Remember, that you can shutdown the sound anytime with ESC! :)

As you can see, we have a Saw oscillator, connected to a resonant low-pass filter (RLPF) here and the cutoff frequency is controlled by an interpolated random value (LFNoise1). You can open reference pages for the respective modules (UGens) by positioning the cursor over them and pressing CTRL+U, but make sure that you install supercollider-doc package to get those.

Well, I hope this tutorial will help you get started with SuperCollider. Make sure you also stop by the SuperCollider website and the wiki for more tutorials and examples.

aoTuV beta5.5

2008-05-02T13:58:00.004+07:00

Decided to encode some recently purchased CDs at last, but due to a complete Hardy reinstall last week, I've had to go for some fresh aoTuV vorbis sources and to my suprise there has been a new beta available for quite some time already!

I don't think this version is substantially different from beta5 (aka 4.51), I can't hear any difference between the encoded file and the original at q6 (which is my default quality setting) and both versions produce seemingly identical output to me.

Nevertheless, I've decided to stick with beta5.5 just because it's the latest :) But I couldn't resist building a patched Ubuntu package besides a static oggenc binary, which I've always compiled for this purposes before (simply to keep the system libraries intact).

Just in case anyone's interested in trying beta5.5, the updated libvorbis binaries can be found in my PPA, but the statically linked oggenc 1.2.0 binary is available as well.

apturl in conversations

2008-04-14T18:40:00.005+07:00

I've just put together a little patch, that adds apturl support to Pidgin, allowing neat package installation by clicking apturls directly from conversation windows. Here's a screenshot, demonstrating the stuff:

The patch itself is here: https://bugs.launchpad.net/bugs/217611. Binaries are currently building in the PPA. Enjoy :)

SuperCollider for Hardy!

2008-04-11T15:36:00.009+07:00

Just a quick notice, that I've updated the SuperCollider binaries for Ubuntu 8.04 (Hardy Heron), that's going to be released later this month. This time, the packages are merged with the original 20060416 version as advised by #ubuntu-motu. Also, the supported architectures are extended to powerpc and lpia.

APT sources.list entries:

deb http://ppa.launchpad.net/artfwo/ppa/ubuntu hardy main
deb-src http://ppa.launchpad.net/artfwo/ppa/ubuntu hardy main

Enjoy!

Sced 0.3 released today!

2008-01-25T12:26:00.001+06:00

Okay, the blog is reset, and I have just uploaded the Sced 0.3 tarball to its usual location. This release includes awesome contributions by Eckard Riedenklau and requires gedit 2.20 and gtksourceview 2.0 to run. Enjoy!