midi.js

// a fucking piano

const TRANSPOSITION = 1         //how many pitches to shift down
const NOTES_DOWN = 0           //how many notes to shift down (stacks with transposition) (why? idk i dont speak music)
const IGNORE_BLACK_NOTES = false
const ROUND_BLACK_NOTES = false

const Midi = require('@tonejs/midi').Midi
const Tone = require('tone')
const fs = require('fs')
const owo = new Midi(fs.readFileSync('freedomdive.mid'))
const base = {"_":"piano -https://paderos-neko.store"}

let scales = [
    'C1',  'C#1', 'D1',  'D#1', 'E1',  'F1',  'F#1',
    'G1',  'G#1', 'A1',  'A#1', 'B1',  'C2',
    'C#2', 'D2',  'D#2', 'E2',  'F2',  'F#2', 'G2',
    'G#2', 'A2',  'A#2', 'B2', 'C3',  'C#3',
    'D3',  'D#3', 'E3',  'F3',  'F#3', 'G3',  'G#3',
    'A3',  'A#3', 'B3',   'C4',  'C#4', 'D4',
    'D#4', 'E4',  'F4',  'F#4', 'G4',  'G#4', 'A4',
    'A#4', 'B4',   'C5',  'C#5', 'D5',  'D#5',
    'E5',  'F5',  'F#5', 'G5',  'G#5', 'A5',  'A#5',
    'B5' /*extra,  'C6', 'C#6', 'D6',  'D#6', 'E6',  'F6',  'F#6',
    'G6',  'G#6', 'A6',  'A#6', 'B6'*/
]
if(IGNORE_BLACK_NOTES) scales = scales.filter(e=>!e.includes("#"))
console.log(scales,scales.length)

const detected = []

for(const ti in owo.tracks) {
    const track = owo.tracks[ti]
    const trackconv = []
    const noteticks = [...new Set(track.notes.map(m=>m.time))]
    for(const notetime of noteticks) {
        const timenoteson = []
        for(const note of track.notes){
            if(note.time == notetime) {
                const noted = new Tone.Midi(note.midi-(TRANSPOSITION*12)-NOTES_DOWN).toNote()
                if(!detected.includes(noted)) detected.push(noted)
                timenoteson.push(scales.indexOf(noted)+1+(noted.includes('%')&&ROUND_BLACK_NOTES? 1 : 0))
            }
        }
        trackconv.push([notetime,timenoteson])
    }
    const noteticks2 = [...new Set(track.notes.map(m=>m.time+m.duration))]
    const trackconv2 = []
    for(const notetime of noteticks2) {
        const timenotesoff = []
        for(const note of track.notes) {
            if(note.time+note.duration == notetime) {
                const noted = new Tone.Midi(note.midi-(TRANSPOSITION*12)-NOTES_DOWN).toNote()
                timenotesoff.push(scales.indexOf(noted)+1+(noted.includes('%')&&ROUND_BLACK_NOTES? 1 : 0))
            }
        }
        trackconv2.push([notetime,timenotesoff])
    }

    base['track'+ti] = [trackconv,trackconv2]
}
console.log('[note, index_in_range]',detected.filter((v,_,a)=>a.includes(v)),detected.map(m=>[m,scales.indexOf(m)]))
fs.writeFileSync('input.shitballspiano',JSON.stringify(base))
console.log('done')