[ Ref. https://www.mmdigest.com/Archives/Digests/202404/2024.04.23.02.html 

Success! MIDI to G-code finally working for laser piano roll!

After much pain and suffering -- mostly on Spencer Chase's end because
he wrote the program -- the conversion of MIDI files to G-code files
that can be cut by a modified laser engraver into piano rolls has been
finally accomplished!

Anyone who builds a machine to Spencer's specifications (ask him for
the instruction manual) can now cut, easily and quickly, a piano roll
from literally any MIDI file under the sun that is a solo piano piece
(and with some tweaking, even orchestral MIDIs) into a roll!

Spencer is still tweaking some things about the program; however,
I've already been able to convert the resulting G-code into images
and play them through the PlaySK piano roll reader like a real roll!
For those who want to code Duo-Art rolls by just drawing in the coding
on the image, you can do it!

I'm going to make a video on how to process MIDI files into images
as for now the perforator part of things is still being polished up.
However, even without a perforator, you could potentially print the
piano roll images and cut out the holes yourself (not recommended,
though).

As far as mastering goes, because the laser engraver isn't stepper based
(unlike the perforators used by Keystone, Julian Dyer at Laguna and
Tim Baxter at Meliora), the rolls can be mastered, in theory, to punch
100 rows per inch of paper which means that any timing discrepancies and
roll editing that used to be necessary are now pretty much redundant.

I currently have been mastering new files to 40 punches per inch if the
MIDI file is a standard one that is recorded to a metronome because that
gives even better timing precision than just slapping a file onto the
punch grid and rounding to the nearest row.

Also I'd like to mention that mastering rolls in general would be
extremely difficult if it weren't for Julian Dyer and his brilliantly
put together mastering program Perforation Editor. It's easy to use,
has a ton of functionality and for people who want to make their own
perforators, using the PunchMIDI format is your best bet at success!

In any case, as I mentioned, Spencer is still buttoning up a couple of
things but as it stands now, the process can be used to make rolls as
long as someone has the machine to do it!

Piotr Barcz
thepiotrcorporation@gmail.com.geentroep [delete ".geentroep" to reply]