Using a Qtractor MIDI track for both MIDI and audio

Basically Qtractor only does either MIDI or audio. The MIDI tracks are for processing MIDI and the audio tracks for processing audio. But a MIDI track in Qtractor can also post-process the audio coming out of a synth plug-in with FX plug-ins so it’s a bit more than just a MIDI track.

But what about plug-ins that do both audio and MIDI, like the LV2 version of the autotuner application zita-at1? If you put it in an audio track it will happily autotune all the audio but it won’t accept any incoming MIDI to pitch only to the MIDI notes it is being fed. And no way you can get MIDI into a Qtractor audio track. There’s no MIDI insert plug-in or the possibility to somehow expose MIDI IN ports of a plug-in in an audio track to Jack MIDI or ALSA.

But Qtractor does have a built-in Insert plug-in that can be fed audio from an audio bus and since a Qtractor MIDI track does know how to handle audio would it also know how to deal with such an insert? Well, yes it can which allows you to use a plug-in like the LV2 version of zita-at1 inside a MIDI track.

Setting up buses and tracks

You will need at least one bus and two tracks (of course you can use different bus and track names):

  • AutoTuneMix bus, input only and 2 channels
  • AutoTune MIDI track with dedicated audio outputs (this will create an audio bus called AutoTune)
  • AutoTuneMix audio track with the AutoTuneMix as input bus

Alternatively you could also skip the use of dedicated audio outputs and have the MIDI track output to the Master bus. This way you avoid the risk of introducing extra latency and the need to set up extra connections. You do lose the flexibility then to do basic stuff on the outcoming audio like panning or adjusting the gain. Which you can also workaround of course by using additional panning and/or gain plug-ins.

Once you’ve created the bus and the tracks insert the following plug-ins into the AutoTune MIDI track:

  • Insert
  • Any pre-processing effects plug-ins (like a compressor) – optional
  • LV2 version of zita-at1 autotuner
  • Any post-processing effects plug-ins (like a reverb) – optional

Insert them into this specific order. It is also possible to do the post-processing in the AutoTuneMix audio track. Now open the Properties window of the Insert plug-in and then open the Returns window. Connect the mic input of your audio device to the Insert/in ports as shown below.

Qtractor AutoTune Insert
Qtractor AutoTune Insert

Connect the AutoTune bus outputs to the AutoTuneMix inputs:

Qtractor Connections
Qtractor Connections

Create a MIDI clip with notes to autotune

Create a MIDI clip with the notes you would like to get autotuned in the AutoTune MIDI track, put the play-head on the right position and press play. Now incoming audio from the mic input of your audio device should get autotuned to the MIDI notes you entered in the MIDI clip:

Qtractor Mixer with LV2 version of zita-at1 autotuner
Qtractor Mixer with LV2 version of zita-at1 autotuner

As you can see both MIDI and audio goes through the AT1 autotuner plug-in and the outcoming audio is being fed into the AutoTuneMix track where you can do the rest of your post-processing if you wish.

Using a Qtractor MIDI track for both MIDI and audio

MOD sysadmin

A sysadmin is also jumping in to help with the infrastructure – mailing lists and wiki – so we can make sure there are usable tools available to us, after all, a brand new community is to be born!!!

From the MOD Kickstarter page, update #29.

So yes, I’m an official member of the MOD team now! I’m going to help out maintaining the current infrastructure and with the upcoming release of the MOD Duo some parts will have to be rebuilt or built up from scratch.

I will also be beta testing the MOD Duo, I’m eagerly awaiting for it to arrive in the mail. The MOD team has made some real good progress in getting the most out of the Allwinner A20 board they’re using. Also the amount of plugins that will be available for it will be staggering. This won’t be just an ordinary modelling FX unit but a complete all-in-one musical box that can also be used as a synthesizer or a loop station. And it’s going to be a rock-solid unit, the team working on making this possible contain some big names from the Linux audio community. The MOD Duo beta testing unit I will be receiving has been with Fons before for example, from what I understood he has done an in-depth analysis of the audio codec being used on the MOD Duo board.

MOD Duo final revision
MOD Duo final revision
MOD sysadmin

The Infinite Repeat – Cala Del Aceite

Finally got around finishing a new track. And it’s just 65BPM so no four to the floor this time. I posted the demo a while ago, this is more or less a definitive version (definitive is a fluid term in my dictionary).

http://theinfiniterepeat.com/music/the_ … aceite.ogg

This song is about one of the most beautiful places I know on this
planet, Cala Del Aceite in the most southern part of Spain:

http://www.conilplaya.com/fotos/playasd … eConil.htm

Tools used:

  • Qtractor for recording and mixing
  • seq24 for sequencing
  • The necessary plugins:
    • drumkv1 to hold the drum samples (drum samples are all from
    • http://samples.kb6.de/)
    • a lot of plugins that are part of Distrho or Carla: Noize Maker, Tal
    • Reverb III, ZynAddSubFX-LV2, Nekobi
    • MDA subsynth
    • FluidSynth DSSI for the Rhodes
    • linuxDSP plugins (EQ500, DYN500, MBC2B on the master bus)
    • Calf Vintage Delay
    • LADSPA comb filter, Fast Lookahead Limiter
    • GxZitaReverb

The background vocals for the choruses are sung by my wife. The ocean
sample is from Freesound:

http://www.freesound.org/people/dobroide/sounds/93653/

Cádiz is pretty close to Conil, hence the choice.

Thanks to everyone for making this possible. Especially falkTX and rncbc, couldn’t have done this without your valuable work.

Making promises that I can’t keep
It’s pushing me, pushing me into a deep
State of sadness, state of doubt
A state of awareness I can’t live without

Making mistakes, so hard to bear
It’s driving me, driving me to a point where
I can’t escape, I can’t shy away
From the daemons I refuse to obey

All is forgiven, all is well…

Awaiting the day that I’ll be relieved
From this burden, this burden that has grieved
So many loved ones, so many friends
All the people on which I depend

Stand up, act now, it’s time for a change
Lingering won’t help, help to rearrange
The current imbalance, the current state
Of things so rush now don’t hesitate

All is forgiven, all is well…

Creative Commons License
Cala Del Aceite by The Infinite Repeat is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

The Infinite Repeat – Cala Del Aceite

LV2 gaining momentum

The number of new LV2 plugins being released is steadily growing. The last couple of months at least the following LV2 plugins have been released:

  • Bitrot (a set of LV2 and LADSPA plugins for glitch effects)
  • beatslash-lv2 (a set of plugins for live beat repeating and beat slicing)
  • deteriorate-lv2 (a set of plugins to deteriorate the sound quality of live inputs)
  • midimsg-lv2 (a set of plugins to transform midi output into usable values to control other plugins)
  • QmidiArp (LV2 plugins of the three QMidiArp modules)
  • x42-plugins (collection of LV2 plugins: tuner, oscillator, x-fader, audio-level meters, midi filters etc.)
  • BLOP-LV2 (port of the LADSPA BLOP plugins)

Haven’t tried them all of them yet but the ones I did try (the QmidiArp modules as plugins and some of the x42 plugins) proved to be very promising. Besides new plugins being released work continues on a great number of plugins, the LV2 framework itself and on tools facilitating in the creation or building of LV2 plugins. Especially falkTX is in the vanguard with his current work on getting his Carla plugin host to work as a LV2 plugin. This would open up a lot of possibilities like using it in hosts that don’t support all plugin frameworks (think Ardour and DSSI support). In the meanwhile the guitarix team continues to add great LV2 plugins to their ever growing collection and Dave Robillard, the main author of LV2, doesn’t sit still either with releasing updated versions of the building blocks that form the LV2 framework.

LV2 gaining momentum

Bitwig Studio to be released

The 26th of March Bitwig Studio will be released. From the Bitwig Studio site:

Bitwig Studio is a multi-platform music-creation system for production, remixing and performance with a focus on flexible editing tools and a super-fast workflow.

It’s being developed by folks who have worked on Ableton Live and it will also be available for Linux. It’s a cross-platform DAW which means that for the GUI a platform agnostic framework has been used. In the case of Bitwig Studio the chosen framework is most probably Java which raised some eyebrows within the Linux Audio community. The price of the upcoming product met some scepticism too as it ends up higher than initially announced. Add to this that there’s barely any support for plugins (except native Linux VST) and you’ll understand that this upcoming release has fueled a discussion or two.

I haven’t seen anything yet of Bitwig Studio so I can’t judge the quality, workflow or usability of the product. I’ve registered for a beta testing account two years ago and didn’t hear anything from the Bitwig folks until recently so to be honest I completely lost interest in the product in the meanwhile.

Really, the people from Tracktion do it a lot better in that regard I think, it’s cheaper, they communicate more and it’s based on a cross-platform toolkit that has more credibility (Juce). But you never know, maybe I’ll get blown away when I get my hands on Bitwig Studio. You’ll be the first to hear.

Bitwig Studio to be released

Workshops Music Production with Open Source Software: Introduction and Basic Principles

This Saturday my series of workshops about music production with open source software will kick off. The first workshop will be an introduction to the open source ecosystem and attendees will get acquainted with some basic Linux audio principles; different work-flows (monolithic vs modular), ALSA/JACK/PulseAudio, most used and most useful applications and maybe a bit about plug-in frameworks (LADSPA/DSSI/LV2/VST). I will also outline the content of the following workshops and this workshop is a gauge to see if there is enough interest. So people should show up in considerate numbers because I’m not going to invest another 5 Saturday afternoons for just a few people. After all, I’m doing this for free (as in beer).

Announcement on the site of De Bakkerij

Facebook event

Workshops Music Production with Open Source Software: Introduction and Basic Principles

The wait is almost over

For years users have been asking for a ZynAddSubFX or Yoshimi plug-in with a GUI for Linux. It seems the wait is almost over thanks to the great work of Filipe Coelho aka falkTX.

ZynAddSubFX-LV2 Test #1 (Qtractor)

According to falkTX work on the plug-in is almost 90% done. Parameters can be restored too as the following video shows.

ZynAddSubFX-LV2 Test #2 (Ardour)

Apparently the developer of ZynAddSubFX is working on exposing all parameters so in the future it should also be possible to automate Zyn’s most relevant parameters. Needless to say this stuff is still highly experimental so use at your own risk. I’ve done quite some tests and the plug-in keeps up well, also if you use many of them within a project (I’ve tested with a project with about 15 ZynAddSubFX-LV2 instances). But this doesn’t mean the plug-in doesn’t have any flaws, closing its GUI could crash your DAW for instance. Further tests should reveal all the obvious bugs so everyone, get that code and test it! Build instructions can be found in the aforementioned forum thread.

Many, many thanks to falkTX for making this possible!

The wait is almost over

Carla on the Raspberry Pi

Last week I managed to get Carla running on my RPi. Carla is a really nice plugin host that supports the most important plugin frameworks available for Linux (LV2, DSSI, LADSPA and VST) with some awesome extra features like a built-in ZynAddSubFX synth and support for SF2, SFZ and GIG files. The latter didn’t work until yesterday but I managed to compile LinuxSampler (which is needed by Carla in order to be able to load SFZ and GIG files) for the RPi with the help of Paul Brossier aka piem from the Aubio project.

I just wrote him a mail:

Hello Paul,

I’m trying to package LinuxSampler for Raspberry Pi but I’m running into an issue when compiling which fails with a message related to RTMath.h. After some googling I ended up here:
http://bb.linuxsampler.org/viewtopic.php?f=2&t=514#p3156
So I started scouring the interwebs and found this:
http://packages.qa.debian.org/l/linuxsampler/news/20050806T210205Z.html
Where there is a reference to a possible fix. But the diff.gz that contains the patch is untraceable. I know this announcement is almost 8 years old but do you think you still have the diff or maybe an idea what changes you made to the code?

Thanks in advance and keep up the good work with Aubio!

Best regards,

Jeremy Jongepier

And guess what, he replied almost instantly! He gave me some pointers where to add some extra code and even though I’m not a coder I started trying things out. But then I stumbled upon actual patches to resolve this issue. I needed both the ARM and atomic patch and after applying those LinuxSampler compiled flawlessly in my Raspbian ARM chroot. The few lines of code I cooked up myself were almost identical so I got quite far actually. I should really pick up learning how to code, I think I’d learn fast.

So after compiling LinuxSampler I could rebuild Carla against the freshly created LinuxSampler libs. Installed the deb on my RPi and loaded some SFZ’s. It all worked like a charm. Carla is like a Swiss Army Knife, I’m really starting to appreciate this piece of software. Kudos to falkTX! And thanks to Paul Brossier for responding so quickly and helping me to get on the right track.


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Carla running on the Raspberry Pi

Carla on the Raspberry Pi

Open AV Productions: Fabla

Who recalls the times when Linux audio users were craving for a sampler LV2 plugin? Soon we will have even more choice besides drumkv1 and samplv1, enter Fabla! No idea what Fabla stands for but it sure looks fablalous.


Fabla by Open AV Productions uses the same release model as used with Sorcer recently. Instead of a year it took 9 days to push back the release date of Sorcer and hopefully the same thing will happen with Fabla. I’d love to get my hands on this plugin so I’ve done my part to speed up the release date.

Edit: Fabla has been released within 8 days!

Open AV Productions: Fabla

Ardour with video and LV2 MIDI plugins chaining support

Got so absorbed hacking my UG802 that I completely missed this: https://community.ardour.org/node/7219

So not only can you add video to your Ardour project but now it’s also possible to chain multiple LV2 plugins that accept MIDI. The video support is the great work of Robin Gareus and it was actually a presentation on this functionality that got me acquainted with the Linux Audio meetings at the HKU almost 3 years ago. So yes, he’s been working on it quite a while so I assume it works well.

I have actually never worked with Ardour, I’ve always used Qtractor. But maybe it’s getting time to check out Ardour too, especially now that the MIDI part is stabilizing.

Ardour with video and LV2 MIDI plugins chaining support