## Module as "Midi accurate driver"

Device/Module Wishlist

Original topic on PlanetZ: https://forums.scopeusers.com/viewtopic.php?t=28361

#### Module as "Midi accurate driver"

Posted: Sat Nov 21, 2009 4:03 pm
by lagoausente
First two links about what I refer to, midi timing jitter, unaccuray recording midi tracks;
http://openmuse.org/transport/fidelity.html
http://remixmag.com/mag/remix_question_time/
Audio have their own clock, moreover they have 16, 24 or 32 bits at 44.1khz of data buffered by the audio driver. In the worst case, you may have a little unaccuracy on the position of the whole track, but not between events, for example notes coming from a guitar you play captured through a mic.
Midi is diferent, the midi driver takes the timing based on the PC internal clock, there is no a continuous buffer of data coming, so the midi driver tells "when the event arrived". But since that´s controlled for the OS, and the OS makes lot´s of things at time, and have to Queue some processed, the events positions are not placed as accurate as audio.
My module idea is the follow;
A module like STS, with midi in, audio output, but also with audio input and midi output.
Intention is to record midi data inside an audio track, and back can play the audio track and can recover the midi data.
Note that something similar is done in Steinberg system link. Using one bit of the 24 bits to send through Spdif midi sync clock, aswell as midi tracks.
I´m not programmer so my idea is only by intuition.
Since Midi data is digital, the module should pack those bits in the audio track, filling the empty data as Zeros. That audio track should be recorded on the sequencer, of course coun´t be edited as the midi tracks are, or maybe yes, with a Vst plugin compatible to process offline and convert the audio track to a really midi track, but with exact accuracy. (something like a bounce, not-realtime).
In Scope, if you don´t need or don´t like to edit midi events, just playback that audio track to the "module", and conect the midi output to your favorite synth.
Disdvantages? More space required for recording.
Advantages? A perfect timing for your recordings. The main advantage of this theorical module unlike recording directly your synth audio output it that you could make changes on your synth knobs and settings, to re-record the same thing with diferent sound, but without the lack of midi timimg.
do you think would be posible? Very dificult to programm that?

#### Re: Module as "Midi accurate driver"

Posted: Mon Nov 23, 2009 9:20 am
by fra77x
Hello to all. I have found a way to achieve a lot better midi timing in xtc mode. It is very easy to be build in sdk maybe i'll upload a small device myself. The idea is to create an instrument for xtc mode that simply passes the midi right to the hardware midi out port (example: pulsar midi A dest.) You can also connect in there the audio in source so to appear in the same audio channel in your sequencer.
After that you load the "midi instrument" in XTC mode (the XTC project should NOT have the midi and audio that is included in the device).
Guess: far better midi timing than standard midi sequencer drivers. It's almost fine.
To my ears it is below what i like so guess: Currently i develop a midi sequencer for Scope that will also send midi out for your beloved external hardware synthesizers. In 4-5 months it will be available from S/C, Sur-audio lab.
All the best, John

#### Re: Module as "Midi accurate driver"

Posted: Mon Nov 23, 2009 11:40 am
by dawman
A MIDI Sequencer...?
I thought that wasn't possible, but I take your word on things so by all means, bring it on.
I have always wanted to have a native app.for MIDI sequencing. I can sync VDAT with the necessary audio if need be. We just need a MIDI Sequencer.
I look forward to this.

#### Re: Module as "Midi accurate driver"

Posted: Mon Nov 23, 2009 12:38 pm
by Tau
The sequencer sounds like a great idea! Aside from external MIDI output for notes, clock, sysex and CC, would be awesome if it could drive the automation inside scope in a higher resolution than 8-bit MIDI. If it could then sync to VDAT, we would be very close to having a full composition and production studio in Scope.
Good luck, John! Keep us posted!
T

#### Re: Module as "Midi accurate driver"

Posted: Mon Nov 23, 2009 9:32 pm
by lagoausente

> Hello to all. I have found a way to achieve a lot better midi timing in xtc mode. It is very easy to be build in sdk maybe i'll upload a small device myself. The idea is to create an instrument for xtc mode that simply passes the midi right to the hardware midi out port (example: pulsar midi A dest.) You can also connect in there the audio in source so to appear in the same audio channel in your sequencer.
> After that you load the "midi instrument" in XTC mode (the XTC project should NOT have the midi and audio that is included in the device).

Sorry but I didn´t understand ok that; "(the XTC project should NOT have the midi and audio that is included in the device)"?

> Guess: far better midi timing than standard midi sequencer drivers. It's almost fine.
> To my ears it is below what i like so guess: Currently i develop a midi sequencer for Scope that will also send midi out for your beloved external hardware synthesizers. In 4-5 months it will be available from S/C, Sur-audio lab.
> All the best, John

That sounds good, but how/where stores the midi track data? Manage their own sync/timing data and uses the hdd to store it? Sounds promising.