MIDI reverb remover

README.md

Usage

First, install python-midi:

pip3 install "https://github.com/mgedmin/python-midi/archive/refs/heads/python3.zip"

Then, run this script:

./noreverb.py path/to/midi/directory

The script will create a directory called "noreverb" inside the specified directory and copy the output MIDI files into that.

noreverb.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import midi, glob, os, sys, re, fnmatch, shutil, argparse

def nglob(which, where='.'):
	rule = re.compile(fnmatch.translate(which), re.IGNORECASE)
	return [name for name in os.listdir(where) if rule.match(name)]

set_to_zero_cc_events = [91, 93] # Reverb/Chorus
set_to_zero_evt_found = False
blacklisted_cc_events = [9, 38, 100, 101] # 
	
parser = argparse.ArgumentParser(description="Remove MIDI reverb")
parser.add_argument("mididirpath", type=str, help="The path to a folder containing MIDI files")
parser.add_argument("-s", "--soundfonts", action="store_true", help="Copy soundfonts to output dir")
args = parser.parse_args()
midi_path = os.path.abspath(args.mididirpath)

midi_files = nglob("*.mid", midi_path) + nglob("*.midi", midi_path)
soundfonts = nglob("*.sf2", midi_path) + nglob("*.dls", midi_path)

print(midi_files)

noreverb_path = os.path.join(midi_path, "noreverb")

os.makedirs(noreverb_path, exist_ok=True)

for file in midi_files:
	t = 0
	print("Processing: " + file)

	midi_pattern = midi.read_midifile(os.path.join(midi_path, file))
	new_pattern = midi.Pattern()
	new_pattern.resolution = midi_pattern.resolution
	
	for track in midi_pattern:
		print("Track " + str(t))
		
		set_to_zero_evt_found = False
		track_channel = 0
		
		for event in track:
			track_copy = track.copy()
			event_type = type(event)
			
			try:
				track_channel = event.channel
			except:
				pass
			
			if event_type is midi.events.ControlChangeEvent:
				if event.data[0] in blacklisted_cc_events:
					print("blacklisted: " + str(event))
					track_copy.remove(event)
				elif event.data[0] in set_to_zero_cc_events:
					set_to_zero_evt_found = True
					print("set to zero: " + str(event))
					new_event = midi.events.ControlChangeEvent(tick=event.tick, channel=event.channel, control=event.control, value=0)
					print(new_event)
					evt_index = track.index(event)
					track_copy.remove(event)
					track_copy.insert(evt_index, new_event)
			
		if not set_to_zero_evt_found:
			print("Manually setting reverb and chorus on track " + str(t) + " to zero")
			reverb = midi.events.ControlChangeEvent(tick=0, channel=track_channel, control=91, value=0)
			chorus = midi.events.ControlChangeEvent(tick=0, channel=track_channel, control=93, value=0)
			# reset = midi.events.ControlChangeEvent(tick=0, channel=track_channel, control=121, value=0)
			print(reverb)
			print(chorus)
			# print(reset)
			track_copy.insert(0, reverb)
			track_copy.insert(0, chorus)
			# track_copy.insert(0, reset)
			
		new_pattern.append(track_copy)
		t += 1

	midi.write_midifile(os.path.join(noreverb_path, os.path.basename(file)), new_pattern)

if args.soundfonts:
	print("Copying soundfonts…")
	for sf in soundfonts:
		print(sf)
		shutil.copy2(os.path.join(midi_path, sf), os.path.join(noreverb_path, os.path.basename(sf)))
	
print("Done!")