Re: dynamic and midi velocity

[Philippe Hezaine]

Brett McCoy a écrit :
> On Thu, Feb 18, 2010 at 7:27 PM, Peter Chubb
> <address@hidden> wrote:
>
> > I had a quick look at what it would take to generate notes with
> > different velocities instead of just CC 7 events.  It's harder than it
> > should be: dynamic events always come after the notes they affect, so
> > I couldn't see an obvious/easy way to get the current dynamics while
> > processing a note, ... 

Sorry for my bad English but may be this can help you.
When I was beginning the Drummer's "Gigsaw" I was using mididings which
is a Python app. It takes me a lot of time to understand why I always
get a few errors when I processed CC7-to-velocity.py (a script Dominic
Sacré especially wrote for this case). Finally I had to give up
mididings because it was unable to convert the midi output of Lilypond
which is not clean (an odd thing (bug?)). Dominic's answer was: Nothing
to do with mididings in this case. Fortunately I found midicomp.
 In the current Gigsaw's ugly hack I've found a solution. Here is the
excerpt in question:

" lancer midicomp pour obtenir le ascii
" Launch midicomp and get the ascii
:silent! !midicomp -vt MY-SONG.midi > MY-SONG.asc
:w!
"
" Ouvrir le .asc
" Open the .asc
:gvim MY-SONG.asc
"
" A cause d'une bizarrerie dans la sortie midi de Lilypond, rectifier
l'ordre d'apparition des Param
" Because of an odd thing (bug?) in the Lilypond's midi output, I
correct the range of Param
:silent! g/\(.*\)On.*\n\1Param/normal ddp
:w!
"
" Seulement maintenant copier les valeurs des Param vers les Note On
" Now i can paste the Param values to the Note On
"autre commande possible
"one another command
""""""""""":g/On/s/127/\=matchstr(getline(line('.')-1), 'val=\zs\d\+')
:silent! %s/val=\(\d\+\).*\n.*On.*vol=\zs\d\+/\1/
:w!
"
" Effacer toutes les lignes  Param
" Delete all the Param line
:silent! g/Param/d
:w!
"
" Retransformer le ascii en midi en l'envoyant dans MA-BASE
" Transform again the .asc to midi >  MY-BASE
:silent! !midicomp -c MY-SONG.asc > MY-SONG.midi


> > ...nor is it obvious to me how to get at notes in the
> > same voice as a dynamic indication at the same timestep.

In the Gigsaw each element of a chord burst out in its own variable,
hence a track for each drums instrument (or Voice, here I mean Voice in
a musical sense, ie. a fugue with 4 voices). It becomes a linear format.


> > Nor is it obvioous to me how to tell which voices dynamic indications
> > should be applied to.  Sometimes they should be for several (e.g.,
> > centered piano dynamics), sometimes just to the voice they are
> > attached to. And there's still the issue of handling what instruments
> > are capable of, and adjusting expression accordingly.
> >
> > There are three classes of instruments I can think of:
> >  1.  Instruments that play at a fixed volume no matter what you do:
> >      -- harpsichord, most organ stops, recorder, etc.
> >  2.  Instruments where the volume is determined at the start of a
> >      note, but you can't change it afterwards:
> >      -- piano, clavichord, most percussion, plucked strings, etc.
> >  3.  Instruments that can change volume anywhere -- most woodwinds and brass,
> >      swell stops on the organ, etc.
> >
> > So I'm leaving it in the `too hard' basket for now.
... [skip]
> -- Brett

Cheers.
--
  Phil.