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

Flux

  • Aanbieding geaccepteerd voor een nieuwe baan. Oftewel, word een Linux beheerder. Dat wil ik al sinds ik in de automatisering zit dus lijkt me een goeie stap.
  • Meissie is weer zwanger. Tweede kiddo wordt verwacht rond 19 februari.
  • Eerste kiddo kan inmiddels lopen en breekt de boel af, zichzelf niet ontziend.
  • Ben druk bezig met een nieuwe remix en ben erachter gekomen dat ondanks de bugs Hydrogen echt een vette sampler is. Pitchen, stretchen, werkt als een speer. Voor deze track gebruik ik ook voor het eerst Zita AT1 en heb bij het maken heb ik de Calf Saturator ontdekt. Heb ook een goeie drums samplepack gevonden. Wordt hopelijk een vette track. Prehear onderaan.
  • Na een korte flirt met Jack2 gebruik ik weer good ol’ Jack1. Ook heb ik de upgrades van libraw1394 en libffado2 teruggedraaid. Systeem is weer stabieler nu.

Flux

ZIta Resampler, AutoTuner en Reverb

Drie nieuwe pakketten in mijn PPA, Zita-Resampler, Zita-AT1 en Zita-REV1:


  • Zita-Resampler: Libzita-resampler is a C++ library for resampling audio signals. It is designed to be used within a real-time processing context, to be fast, and to provide high-quality sample rate conversion.
  • Zita-AT1: AT1 is an ‘autotuner’, normally used to correct the pitch of a voice singing (slightly) out of tune. Compared to ‘Autotalent’ it provides an improved pitch estimation algorithm, and much cleaner resampling. AT1 does not include formant correction, so it should be used to correct small errors only and not to really transpose a song. The ‘expected’ pitch can be controlled by Midi (via Jack only), or be a fixed set of notes. AT1 can probably be used on some instruments as well, but is primarily designed to cover the vocal range. It’s also usable as a quick and dirty guitar tuner.
  • Zita-REV1: REV1 is a reworked version of the reverb originally developed for Aeolus. Its character is more ‘hall’ than ‘plate’, but it can be used on a wide variety of instruments or voices. It is not a spatialiser – the early reflections are different for the L and R inputs, but do not correspond to any real room. They have been tuned to match left and right sources to some extent.




ZIta Resampler, AutoTuner en Reverb