Getting firewire audio work on Linux

My requirements for an audio interface where basically: low-latency, good pre-amps and DA/AD converters, and having more than two outputs. And well it had to be an external interface to use with my laptop (macbook), work with Linux, and below 400 eur.

I need low-latency for live gigs. I use to play bass and some synths with Guillamino, but I really want to incorporate soft synths, and live material processing with sooperlooper, supercollider and freewheeling.

For latency reasons I discarded buying a USB interface. Also it’s a plus that nowadays music shops have plenty of new firewire interfaces.

When recording music, monitoring or hearing an audio mix that is independent of what is being recorded is a must. Since I’m aiming to have a really portable recording station I don’t want to rely on external mixing desk. So I needed at least 4 outputs and flexible routing.

Firewire support for Linux is in its early stage but growing steadily. I knew about the freebob project when Pieter Palmers presented it at Linux Audio Conference 2005. Freebob is a Linux driver (by now only a JACK backend; alsa driver is planed) for devices based on the bebob chip. Fortunately many audio interfaces are based on this chip.

My choice: Focusrite Saffire (LE)

Edirol FA-101 and ESI QuataFire 610 also looked good and where options I also considered. But in comparison, Saffire bought more features (and hopefully sound quality) for its price. I’ve to say it is fantastic to have a huge two-story audio-gear supermarket (Alfasoni) near my flat in Barcelona. And their prices are generally lower than any other store in the city. Saffire (LE) was 323 eur plus taxes. Not bad.

Saffire (LE) audio interface have 6 ins and 8 outs (including digital spdif), and good quality audio (at least this is my first impression in a home-studio environment, and Focusrite have a reputation on its high-end gear).

In Linux, you don’t have an app for controlling the internal audio routing, but you can access all 6 ins and 8 outs with JACK, and with a ridiculous latency you can do all monitoring routing with JACK, so no big deal. Another happy surprise was to find that firewire provides enough power for the device. You only need to plug the power adapter for enabling phantom feed for condenser mics.

How to enable freebob driver in Ubuntu

That can be a little tricky. If your distribution doesn’t come with libfreebob package you’ll need to compile this library (and some dependencies) from the source and then rebuild libjack from subversion sources. But that’s not the end of the hassle. You’ll probably find (as I did) that the new compiled (svn) libjack is not compatible with already installed libjack and applications (I think they use different client/server protocols so the incompatibility have sense). Of course, I was not happy at all having to recompile all my jack applications so I looked at fixing the libjack .deb package from its source package.

Luckily, I found that enabling freebob in Ubuntu Feisty is really easy. Feisty is currently the testing/developing Ubuntu version, due for april 2007, so it’s not intended users who need a solid, reliable OS. However, since I have a macbook and the Feisty kernel supports macintel hardware much better than current Ubuntu Edgy, installing Feisty was a decision I already took. And I’ve had no crashes and had a good experience, so far.

So, the good news is that in Feisty you already have libfreebob0 in universe repository. The bad new is that, however, jackd comes with freebob driver disabled. Note that freebob is not a driver you can plug-in but is it built-in with jack. I believe it’s a packaging bug and very simple to resolve (though still in unconfirmed state).
Update: (January 25th) it seems that this problem has been resolved in new ubuntu-feisty libjack package (its already compiled against libfreebob). So ignore the next steps for compiling jackd from sources.

So here goes the how-to for enabling freebob in jackd maintaining all jack-apps compatible:

Enable universe binary and source repositories and install libfreebob-dev
$ sudo apt-get libfreebob0-dev
Download and compile libjack from source package. It can be done with a single instruction:
$ sudo sudo apt-get -b source libjack0.100.0-dev
Is very likely that you’ll need to install several -dev packages for compiling this source package. But don’t worry, the error message specify all those packages. After installing them, try again.
Then install all new created .deb packages:
$ sudo dpkg -i *.deb

Now if you do
$ jackd -d freebob
you’ll see that –though it still doesn’t work– at least it is using the freebob driver.

The rationale behind that is that the autoconfiguration of libjack enables freebob driver if it finds the the freebob library and headers installed. But libfreebob0 dependency is not enforced in its debian/rules, that’s why binary package have freebob disabled. And since Feisty already have libfreebob I think it should be enforced.

Fixing /dev/raw1304 permissions

Let’s fix the before-mentioned error. Doing jackd -d freebob I got:

Freebob using Firewire port 0, node -1
Ieee1394Service::initialize: Could not get 1394 handle: Permission denied
Is ieee1394 and raw1394 driver loaded?
Fatal (devicemanager.cpp)[68] initialize: Could not initialize Ieee1349Service object
Fatal (freebob.cpp)[69] freebob_new_handle: Could not initialize device manager
FreeBoB ERR: FREEBOB: Error creating virtual device

That’s because a normal user does not have access to raw1394
$ ls -l /dev/raw1394
crw-rw---- 1 root disk 171, 0 2006-12-17 16:10 /dev/raw1394

Changing permissions
$ sudo chmod o+rw /dev/raw1394
solves the problem. However after a new reboot the permissions have been reset. A permanent and easy way to solve this is adding your user into the disk group.
$ sudo gedit /etc/group
In my case, the username is parumi so I edited the group file like this: “disk:x:6:parumi”
Update: $ sudo adduser parumi disk is the right way instead of directly editing /etc/group. Thanks Maarten de Boer for this feedback.

Another solution is using udev rules like explained in this linux-audio-user thread

After that, login again and you should be able use jackd -d freebob and all installed jack-apps. Finally, this screenshot shows qjacktl connection window with the Focusrite Saffire (LE) 6 inputs and 8 outputs.