disco.py

# /// script
# requires-python = ">=3.13"
# dependencies = [
#     "click~=8.4",
#     "librosa~=0.11.0",
#     "vamp~=1.1.0",
# ]
#
# [tool.uv.extra-build-dependencies]
# vamp = ["numpy~=2.5"]
# ///

import pathlib

import click
import librosa
import numpy
import scipy
import vamp


TOLERANCE = 0.003


def evaluate_beats(x, ts):
    offset, period = x
    diffs = (ts - offset) / period
    diffs %= 1.0
    diffs[diffs > 0.5] -= 1.0
    diffs = diffs * diffs
    return diffs.mean()


@click.command
@click.argument('path', type=pathlib.Path)
def main(path):
    data, rate = librosa.load(path)
    info = vamp.collect(data, rate, 'qm-vamp-plugins:qm-barbeattracker')
    info = info['list']

    ts = numpy.array([b['timestamp'].to_float() for b in info[2:]])
    ps = ts[1:] - ts[:-1]
    period = ps.mean()
    bpm = 60 / period

    offs = ((ts / period) % 1.0) * period
    offs[offs > period / 2] -= period
    beat_offset = offs.mean()

    opt = scipy.optimize.minimize(evaluate_beats, [beat_offset, period],
                                  method='powell', args=(ts,),
                                  options={
                                      'xtol': 1e-8,
                                      'ftol': 1e-8,
                                      'disp': True,
                                  })

    opt_offset, opt_period = opt.x
    opt_bpm = 60 / opt_period

    print(f'raw: {bpm} bpm + {beat_offset * 1000} ms')
    print(f'opt: {opt_bpm} bpm + {opt_offset * 1000} ms')


if __name__ == "__main__":
    main()

Meta.json

{
	"version": 1,
	"uniqueId": 3395510822,
	"songName": "RYTHM_OF_THE_NIGHT",
	"performedBy": [],
	"writtenBy": [],
	"seed": 1147525942,
	"tempo": 128.19999694824219,
	"customTempoSections": [],
	"beatOffset": 502,
	"startSongOffset": 0,
	"endSongOffset": 0,
	"uEAssetName": "RYTHM_OF_THE_NIGHT",
	"originalAudioFileHash": "a7e3160d51bff2fae56004a3fea7a8f0",
	"originalAudioFilePath": "Z:/home/agrif/local/sprunk/nonstoppop/RYTHM_OF_THE_NIGHT.ogg"
}