[PD] "musical" timing, something like Max´s "metrical timing Transport" and [metro 16n]

[Ingo]

I don't have an exact plan on how to do this without spending a lot of time
finding the most effective way for getting the accurate sample positions.
Maybe someone else has done that before.

However, in your particular case I would simply use midi clock from Ableton
to sync the two. That looks much easier.

If your timing resolution is a maximum of 24 clocks per quarter note you
don't have to do anything. Just trigger the Pd sequencer steps from the
incoming midi clock.

If you need a higer resolution you could simply use a [timer], [cputime] or
[realtime] to check the time from one clock to another and use that for
subdividing for higher resolutions.

As in the example below with 120 BPM and 500 ms per beat each midi clock
would have a resolution of 20.83333... ms (500 / 24). Using a resolution of
96 / quarter note you would have to divide this by 4 which comes out to
5.208333... ms.

(BTW, you can see already from the 5.2083333333... ms that the time you
would have to enter for the metro would render a tempo that is slightly
off!)

Syncing to midi clock would allow you to follow the tempo that is programmed
in Ableton without having to worry about calculating the duration of each
clock.

In Pd use [midiin] and [route] or [select] to get F8 (hex) = 248 (decimal).
This is how to get the clock time of 96 clocks / quarter note:

[midiin]
    |
[sel 248]
    |
 [t b b]
  |   |
 [timer]
    |
  [/ 4]

Don't start interpolation until the second incoming clock (or provide a
usable value before the first clock is coming in). I.e. when starting jump
from 0 to 4 and then increase by 1.

Check out the midi specs for additional features like song pointer or midi
timecode (which has nothing to do with midi clock), etc.


Ingo



> Thanks Ingo, I must do the testing. In fact Im recordind de midiout to 
> Ableton Live.
>  "recalculating the position from time to time and resyncing to the 
> absolute sample position might be necessary" how can I do this?
> did you see my patch? im working with something lika a "master" metro 
> and a couple of "slave" metro objetcs that control a particular 
> sequence.
> 
>
> 2013/3/21 Ingo <ingo at miamiwave.com>:
> > I would assume that the rounding errors of metro would make the 
> > tempo
> drift
> > after a while - depending on the speed.
> >
> > Using the sample rate would be more accurate.
> >
> > In order to insure that the rounding errors are not influencing the 
> > the position after a long time recalculating the position from time 
> > to time
> and
> > resyncing to the absolute sample position might be necessary.
> >
> > However, such an accuracy would only be needed if the music is to be
> synced
> > to anything external like a DAW, I guess.
> >
> > Ingo
> >
> >> If you mean milliseconds to bpm and vice versa:
> >>
> >> minute = 60,000 ms;
> >>
> >> bpm * ms = 60,000;
> >>
> >> bpm = 60,000 / ms;
> >>
> >> ms = 60,000 / bpm;
> >>
> >> [120 \
> >> |
> >> [t b f]
> >> |     /
> >> [60000(
> >> |   /
> >> [/ ]
> >> |
> >> [500 \
> >>
> >> Send this to the right inlet of [metro]. Then connect a counter 
> >> [int ]/[+ 1]/[% 16] (outlet of the modulo to right inlet of [int]) 
> >> to the outlet of [metro]. That then counts from 0 to 15 with an 
> >> interval of 500 ms.
> >>
> >> --Funs