clean_pitch_bend.py

import mido
import sys
import math

def clean_pitch_bend(input_path, output_path):
    mid = mido.MidiFile(input_path)

    # should make sure each track only manipulate one channel first
    # (if BENDY is used please color all relevant notes to color 1)
    # if a track manipulates multiple channels
    # 1) its most certainly incorrect behavior (for us)
    # 2) it will prevent domino from loading the file
    for tr_n, track in enumerate(mid.tracks):
        last_pb = {}
        new_events = []
        fucked_up_bends = "BENDY" in track.name
        channel = None
        delay_accum = 0
        for msg in track:
            if isinstance(msg, mido.Message) and msg.type != "sysex":
                if channel is None: channel = msg.channel
                elif channel != msg.channel:
                    raise Exception(f"track {tr_n} manipulates multiple channels")
                if fucked_up_bends and msg.is_cc(10):
                    # BENDY (the plugin I use to generate pitch bends in FL)
                    # sabotages panning like this for some reason
                    # TODO: dont do this to the init at measure 0 tick 0
                    msg.value += 1
                if msg.type == "pitchwheel":
                    # pitch is a signed int in mido
                    # i cant tell whether its just off by 1 or the math is completely incorrect
                    fixed_pitch = math.floor(msg.pitch / 8191.0 * 8192.0) if fucked_up_bends else msg.pitch
                    target_pb = last_pb.get(channel, None)
                    if target_pb is not None and target_pb.pitch == fixed_pitch:
                        delay_accum += msg.time
                        continue
                    msg.pitch = fixed_pitch
                    print(msg.pitch, str(target_pb))
                    last_pb[channel] = msg
                if delay_accum > 0:
                    msg.time += delay_accum
                    delay_accum = 0
            new_events.append(msg)
        track[:] = new_events

    mid.save(output_path)

clean_pitch_bend(sys.argv[1], sys.argv[2])