peterf@2: #!/usr/bin/env python
peterf@2: '''
peterf@2: CREATED:2013-02-12 16:33:40 by Brian McFee <brm2132@columbia.edu>
peterf@2: 
peterf@2: Beat tracking with HPSS filtering
peterf@2: 
peterf@2: Usage: ./hpss_beats.py [-h] input_audio.mp3 output_beats.csv
peterf@2: '''
peterf@2: from __future__ import print_function
peterf@2: 
peterf@2: import argparse
peterf@2: import numpy as np
peterf@2: import sys
peterf@2: import librosa
peterf@2: 
peterf@2: # Some magic number defaults, FFT window and hop length
peterf@2: N_FFT = 2048
peterf@2: 
peterf@2: # We use a hop of 64 here so that the HPSS spectrogram input
peterf@2: # matches the default beat tracker parameters
peterf@2: HOP_LENGTH = 64
peterf@2: 
peterf@2: 
peterf@2: def hpss_beats(input_file, output_csv):
peterf@2:     '''HPSS beat tracking
peterf@2: 
peterf@2:     :parameters:
peterf@2:       - input_file : str
peterf@2:           Path to input audio file (wav, mp3, m4a, flac, etc.)
peterf@2: 
peterf@2:       - output_file : str
peterf@2:           Path to save beat event timestamps as a CSV file
peterf@2:     '''
peterf@2: 
peterf@2:     # Load the file
peterf@2:     print('Loading  ', input_file)
peterf@2:     y, sr = librosa.load(input_file)
peterf@2: 
peterf@2:     # Do HPSS
peterf@2:     print('Harmonic-percussive separation ... ')
peterf@2:     y = librosa.effects.percussive(y)
peterf@2: 
peterf@2:     # Construct onset envelope from percussive component
peterf@2:     print('Tracking beats on percussive component')
peterf@2:     onset_env = librosa.onset.onset_strength(y=y,
peterf@2:                                              sr=sr,
peterf@2:                                              hop_length=HOP_LENGTH,
peterf@2:                                              n_fft=N_FFT,
peterf@2:                                              aggregate=np.median)
peterf@2: 
peterf@2:     # Track the beats
peterf@2:     tempo, beats = librosa.beat.beat_track(onset_envelope=onset_env,
peterf@2:                                            sr=sr,
peterf@2:                                            hop_length=HOP_LENGTH)
peterf@2: 
peterf@2:     beat_times = librosa.frames_to_time(beats,
peterf@2:                                         sr=sr,
peterf@2:                                         hop_length=HOP_LENGTH)
peterf@2: 
peterf@2:     # Save the output
peterf@2:     print('Saving beats to ', output_csv)
peterf@2:     librosa.output.times_csv(output_csv, beat_times)
peterf@2: 
peterf@2: 
peterf@2: def process_arguments(args):
peterf@2:     '''Argparse function to get the program parameters'''
peterf@2: 
peterf@2:     parser = argparse.ArgumentParser(description='HPSS beat-tracking example')
peterf@2: 
peterf@2:     parser.add_argument('input_file',
peterf@2:                         action='store',
peterf@2:                         help='path to the input file (wav, mp3, etc)')
peterf@2: 
peterf@2:     parser.add_argument('output_file',
peterf@2:                         action='store',
peterf@2:                         help='path to the output file (csv of beat times)')
peterf@2: 
peterf@2:     return vars(parser.parse_args(args))
peterf@2: 
peterf@2: 
peterf@2: if __name__ == '__main__':
peterf@2:     # Get the parameters
peterf@2:     parameters = process_arguments(sys.argv[1:])
peterf@2: 
peterf@2:     # Run the beat tracker
peterf@2:     hpss_beats(parameters['input_file'], parameters['output_file'])