A brief python program to convert IQ's Pirates music to my Shadertoy tracker.

retrack.py

#!/usr/bin/env python3

from collections import defaultdict
import re

chan1 = '''
  // F2
  x = t; b = 0.0;
  D(36)D(2)D(2)D(20)D(2)D(16)D(6)D(2)D(226)
  y += instrument( 174.0, tint*(t-x) );

  // G2
  x = t; b = 0.0;
  D(53)D(208)
  y += instrument( 195.0, tint*(t-x) );

  // A2
  x = t; b = 0.0;
  D(34)D(2)D(2)D(2)D(1)D(7)D(2)D(2)D(2)D(1)D(3)D(8)D(2)D(8)D(2)D(4)D(2)D(2)D(2)D(1)
  D(31)D(2)D(4)D(138)D(46)D(2)
  y += instrument( 220.0, tint*(t-x) );

  // A#2
  x = t; b = 0.0;
  D(42)D(2)D(2)D(14)D(2)D(2)D(1)D(25)D(2)D(16)D(2)D(2)
  y += instrument( 233.0, tint*(t-x) );

  // B2
  x = t; b = 0.0;
  D(125)
  y += instrument( 246.0, tint*(t-x) );

  // C3
  x = t; b = 0.0;
  D(35)D(6)D(7)D(2)D(3)D(1)D(5)D(7)D(2)D(2)D(1)D(1)D(2)D(3)D(6)D(199)D(2)D(2)D(2)D(1)
  y += instrument( 261.0, tint*(t-x) );

  // C#3
  x = t; b = 0.0;
  D(120)D(2)D(4)D(132)D(1)D(5)D(42)D(2)
  y += instrument( 277.0, tint*(t-x) );

  // D3
  x = t; b = 0.0;
  D(0)D(2)D(1)D(2)D(1)D(2)D(1)D(1)D(1)D(1)D(2)D(1)D(2)D(1)D(2)D(1)D(1)D(1)D(1)D(2)
  D(1)D(2)D(1)D(2)D(1)D(3)D(2)D(2)D(2)D(2)D(2)D(1)D(5)D(3)D(5)D(2)D(2)D(12)D(2)D(6)
  D(2)D(2)D(2)D(2)D(2)D(1)D(1)D(2)D(5)D(3)D(2)D(2)D(2)D(3)D(3)D(6)D(1)D(136)D(9)D(2)
  D(2)D(2)D(1)D(17)D(2)D(2)D(2)D(1)D(11)
  y += instrument( 293.0, tint*(t-x) );

  // E3
  x = t; b = 0.0;
  D(41)D(7)D(2)D(15)D(7)D(2)D(27)D(6)D(13)D(2)D(4)D(132)D(1)D(23)D(2)D(2)D(2)D(18)D(4)
  y += instrument( 329.0, tint*(t-x) );

  // F3
  x = t; b = 0.0;
  D(42)D(2)D(2)D(20)D(2)D(2)D(19)D(11)D(2)D(6)D(2)D(4)D(5)D(5)D(8)D(2)D(2)D(20)D(2)D(16)
  D(6)D(2)D(82)D(4)D(2)D(2)D(2)D(2)D(1)D(12)D(5)D(2)D(2)D(2)D(1)D(7)
  y += instrument( 349.0, tint*(t-x) );

  // G3
  x = t; b = 0.0;
  D(47)D(24)D(19)D(2)D(2)D(2)D(2)D(3)D(11)D(37)D(120)D(13)D(2)D(2)D(2)D(18)
  y += instrument( 391.0, tint*(t-x) );

  // A3
  x = t; b = 0.0;
  D(95)D(5)D(2)D(12)D(16)D(2)D(2)D(2)D(1)D(7)D(2)D(2)D(2)D(1)D(3)D(8)D(2)D(8)D(2)D(4)
  D(2)D(2)D(2)D(1)D(31)D(2)D(4)D(2)D(2)D(12)D(1)D(1)D(30)D(2)D(2)D(3)D(12)D(5)D(2)D(2)
  D(3)
  y += instrument( 440.0, tint*(t-x) );

  // A#3
  x = t; b = 0.0;
  D(96)D(2)D(40)D(2)D(2)D(14)D(2)D(2)D(1)D(25)D(2)D(16)D(2)D(2)D(24)D(18)D(1)D(1)D(24)D(24)
  y += instrument( 466.0, tint*(t-x) );

  // C4
  x = t; b = 0.0;
  D(131)D(6)D(7)D(2)D(3)D(1)D(5)D(7)D(2)D(2)D(1)D(1)D(2)D(3)D(6)D(47)D(2)
  y += instrument( 523.0, tint*(t-x) );

  // C#4
  x = t; b = 0.0;
  D(216)D(2)D(3)
  y += instrument( 554.0, tint*(t-x) );

  // D4
  x = t; b = 0.0;
  D(132)D(2)D(2)D(2)D(2)D(2)D(1)D(5)D(3)D(5)D(2)D(2)D(12)D(2)D(6)D(2)D(2)D(2)D(2)D(2)
  D(1)D(1)D(2)D(5)D(3)D(2)D(2)D(2)D(3)D(3)D(6)D(2)D(2)D(4)D(4)D(2)D(5)D(7)D(5)
  y += instrument( 587.0, tint*(t-x) );

  // E4
  x = t; b = 0.0;
  D(137)D(7)D(2)D(15)D(7)D(2)D(27)D(6)D(13)D(2)D(8)
  y += instrument( 659.0, tint*(t-x) );

  // F4
  x = t; b = 0.0;
  D(138)D(2)D(2)D(20)D(2)D(2)D(19)D(11)D(2)D(6)D(2)D(4)D(5)D(13)D(2)D(1)D(4)D(3)
  y += instrument( 698.0, tint*(t-x) );

  // G4
  x = t; b = 0.0;
  D(143)D(24)D(19)D(2)D(2)D(2)D(2)D(3)D(11)D(24)D(14)D(4)
  y += instrument( 783.0, tint*(t-x) );

  // A4
  x = t; b = 0.0;
  D(191)D(5)D(2)D(12)D(24)
  y += instrument( 880.0, tint*(t-x) );

  // A#4
  x = t; b = 0.0;
  D(192)D(2)D(52)
  y += instrument( 932.0, tint*(t-x) );

  // C5
  x = t; b = 0.0;
  y += instrument( 1046.0, tint*(t-x) );
'''

chan2 = '''
  // D0
  x = t; b = 0.0;
  D(24)D(6)D(3)
  y += instrument( 36.0, tint*(t-x) );

  // F0
  x = t; b = 0.0;
  D(66)D(2)D(1)D(2)D(91)D(2)D(1)D(2)
  y += instrument( 43.0, tint*(t-x) );

  // G0
  x = t; b = 0.0;
  D(96)D(2)D(1)D(2)D(91)D(2)D(1)D(2)D(49)D(2)D(1)D(2)D(1)D(2)D(1)D(2)
  y += instrument( 48.0, tint*(t-x) );

  // A0
  x = t; b = 0.0;
  D(48)D(2)D(1)D(2)D(22)D(2)D(43)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(22)D(2)
  D(43)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(1)D(2)D(1)D(2)
  D(37)D(2)D(1)D(2)
  y += instrument( 55.0, tint*(t-x) );

  // A#0
  x = t; b = 0.0;
  D(42)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(25)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(25)D(2)D(1)D(2)
  D(13)D(2)D(1)D(2)D(25)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(23)
  y += instrument( 58.0, tint*(t-x) );

  // C1
  x = t; b = 0.0;
  D(41)D(31)D(2)D(63)D(31)D(2)D(56)D(2)D(2)D(52)D(2)D(1)D(2)
  y += instrument( 65.0, tint*(t-x) );

  // D1
  x = t; b = 0.0;
  D(24)D(6)D(3)D(3)D(2)D(1)D(15)D(2)D(1)D(2)D(19)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)
  D(1)D(2)D(7)D(2)D(1)D(2)D(13)D(2)D(1)D(15)D(2)D(1)D(2)D(19)D(2)D(1)D(2)D(1)D(2)D(1)
  D(2)D(13)D(2)D(1)D(2)D(7)D(2)D(1)D(2)D(7)D(2)D(46)D(2)D(1)D(2)D(1)D(2)D(1)D(1)D(1)
  D(13)D(2)D(1)D(2)D(1)D(2)D(1)D(1)D(1)D(7)
  y += instrument( 73.0, tint*(t-x) );

  // F1
  x = t; b = 0.0;
  D(66)D(2)D(1)D(2)D(91)D(2)D(1)D(2)D(121)D(2)D(1)D(1)D(1)
  y += instrument( 87.0, tint*(t-x) );

  // G1
  x = t; b = 0.0;
  D(96)D(2)D(1)D(2)D(91)D(2)D(1)D(2)D(49)D(2)D(1)D(2)D(1)D(2)D(1)D(2)
  y += instrument( 97.0, tint*(t-x) );

  // A1
  x = t; b = 0.0;
  D(48)D(2)D(1)D(2)D(22)D(2)D(43)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(22)D(2)
  D(43)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(1)D(2)D(1)D(2)
  D(37)D(2)D(1)D(2)
  y += instrument( 110.0, tint*(t-x) );

  // A#1
  x = t; b = 0.0;
  D(42)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(25)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(25)D(2)D(1)D(2)
  D(13)D(2)D(1)D(2)D(25)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(23)
  y += instrument( 116.0, tint*(t-x) );

  // C2
  x = t; b = 0.0;
  D(41)D(31)D(2)D(63)D(31)D(2)D(56)D(2)D(2)D(52)D(2)D(1)D(2)
  y += instrument( 130.0, tint*(t-x) );

  // D2
  x = t; b = 0.0;
  D(36)D(2)D(1)D(15)D(2)D(1)D(2)D(19)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)D(1)D(2)D(7)
  D(2)D(1)D(2)D(13)D(2)D(1)D(15)D(2)D(1)D(2)D(19)D(2)D(1)D(2)D(1)D(2)D(1)D(2)D(13)D(2)
  D(1)D(2)D(7)D(2)D(1)D(2)D(7)D(2)D(46)D(2)D(1)D(2)D(1)D(2)D(1)D(1)D(1)D(13)D(2)D(1)
  D(2)D(1)D(2)D(1)D(1)D(1)D(7)
  y += instrument( 146.0, tint*(t-x) );

  // F2
  x = t; b = 0.0;
  D(288)D(2)D(1)D(1)D(1)
'''

pitches = defaultdict(lambda: [[],[]])
channel_count = [0, 0]

for channel_id, channel in enumerate([chan1, chan2]):
  for line in channel.splitlines():
    match = re.search(r'// ([A-G]#?[0-9])', line)
    if match:
      pitch = re.sub('#', 's', match.groups()[0])
      position = 0

    match = re.search(r'D\(\d\)', line)
    if match:
      notes = re.split('[^0-9+]', line)
      for delta in notes:
        if delta:
          position += int(delta)
          pitches[position][channel_id].append(pitch)
          if len(pitches[position][channel_id]) > channel_count[channel_id]:
            channel_count[channel_id] = len(pitches[position][channel_id])

last_key = 0
for key in sorted(pitches.keys()):
  print(key, pitches[key])
  last_key = int(key)

print('channel_count:', channel_count)

num_measures = (last_key + 11) // 12
num_measures += 3
num_rows = num_measures * 12

print(f'code_rows: {last_key}, num_measures*12: {num_measures*12}')

print()
print(f'const int num_tracks = 6;')
print(f'const int beats_per_measure = 4;')
print(f'const int rows_per_beat = 3;')
print(f'const int num_measures = {num_measures};')
print(f'const int num_rows = num_tracks * beats_per_measure * rows_per_beat * num_measures;')
print(f'const uint instruments[] = uint[](IQ, IQ, IQ, IQ, IQ, IQ);')
print(f'const vec2 left = vec2(0.7, 0.3);')
print(f'const vec2 right = vec2(0.3, 0.7);')
print(f'const vec2 balances[] = vec2[](left, left, left, right, right, right);')

print(f'const uint tracks[] = uint[] (');
for row_id in range(num_rows):
  print('  ', end='')
  for channel_id in range(2):
    for pitch in pitches[row_id][channel_id]:
      print('%3s, ' % pitch, end='')
    for _ in range(3-len(pitches[row_id][channel_id])):
      print(' NO, ', end='')
  measure = row_id // 12
  beat = (row_id % 12) // 3
  row = (row_id % 12) % 3
  print(f'  // Row{row_id}, Measure{measure}, Beat{beat}.{row}')

print(');')