This web application mirrors a MIDI keyboard so that low-pitch keys are on the right hand side of the keyboard and high-pitch keys are on the left hand side.
It is based on WebMIDI which is, as of today (2019-06), only supported by Chrome.
This project is written in TypeScript. It thus needs to be compilated.
With the current directory at the root of the repository, run:
npm install: Install the TypeScript dependencies.make: Runs the TypeScript compiler and copies the static files.
This will create the output/ folder that contains the compiled
JavaScript files from the TypeScript files in src/ and copies other
input files.
You need a web-server to be able to use WebMidi. The simplest one is the one included in Python. Simply run:
python3 -m http.server --directory output/
This will run an HTTP server on port 8000 of all IP addresses of the machine. You can then visit http://127.0.0.1:8000 to access it.
In input combobox select the input port corresponding to your MIDI keyboard.
In output combobox select the MIDI output port corresponding to the MIDI instrument used to generate sounds.
If you are using a digital piano then input and output may point to the same instrument.
To prevent the instrument from generating two notes for each key, the usual note and the mirrored note, you need to disable the instrument's Local Control. Usually this is available in the instrument's menu.
On some instruments the local control can be disabled by sending a MIDI event. If this is the case then pressing the Disable button in this application will disable it.
For other instruments you will have to use the instruments' buttons to disable the local control.
Copyright (C) 2019 Stéphane SOPPERA.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.