peterf@2: #!/usr/bin/env python
peterf@2: '''
peterf@2: CREATED:2013-02-11 18:37:30 by Brian McFee <brm2132@columbia.edu>
peterf@2: 
peterf@2: Track beat events in an audio file
peterf@2: 
peterf@2: Usage:   ./beat_tracker.py [-h] input_file.mp3    output_beats.csv
peterf@2: '''
peterf@2: from __future__ import print_function
peterf@2: 
peterf@2: import argparse
peterf@2: import sys
peterf@2: import librosa
peterf@2: 
peterf@2: 
peterf@2: def beat_track(input_file, output_csv):
peterf@2:     '''Beat tracking function
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:     print('Loading ', input_file)
peterf@2:     y, sr = librosa.load(input_file, sr=22050)
peterf@2: 
peterf@2:     # Use a default hop size of 64 samples @ 22KHz ~= 3ms
peterf@2:     hop_length = 64
peterf@2: 
peterf@2:     # This is the window length used by default in stft
peterf@2:     print('Tracking beats')
peterf@2:     tempo, beats = librosa.beat.beat_track(y=y, sr=sr, hop_length=hop_length)
peterf@2: 
peterf@2:     print('Estimated tempo: {:0.2f} beats per minute'.format(tempo))
peterf@2: 
peterf@2:     # save output
peterf@2:     # 'beats' will contain the frame numbers of beat events.
peterf@2:     beat_times = librosa.frames_to_time(beats, sr=sr, hop_length=hop_length)
peterf@2: 
peterf@2:     print('Saving output to ', output_csv)
peterf@2:     librosa.output.times_csv(output_csv, beat_times)
peterf@2:     print('done!')
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='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:     beat_track(parameters['input_file'], parameters['output_file'])