bernardo-torres / audio-resampling-in-python

Comparison of Python audio resampling implementations

Comparison of audio resampling libraries and some audio loaders.

View the two notebooks:

• Audio Resampling in Python.ipynb
• Audio Loading + Resampling.ipynb

Best by speed (resampling only)

Downsampling from 48 kHz to 44.1 kHz.

Library	Time on CPU
torchaudio_hann	0.87 ms
torchaudio_transform_hann	1.11 ms
torchaudio_transform_kaiser	1.38 ms
soxr	1.43 ms
torchaudio_kaiser	1.69 ms
scipy	2.40 ms
julius	9.21 ms
resampy_fast	13.63 ms
nnresample	18.33 ms
resampy_best	38.04 ms

Best by speed (loading + resampling)

Load Library	Resampling Library	Time on CPU
torchaudio-sox_io	torchaudio_hann	26.42 ms
torchaudio-soundfile	torchaudio_hann	27.05 ms
torchaudio-sox_io	torchaudio_kaiser	27.65 ms
torchaudio-soundfile	torchaudio_kaiser	27.15 ms
scipy	soxr	28.06 ms
torchaudio-sox_io	soxr	37.96 ms
torchaudio-soundfile	soxr	38.00 ms
torchaudio-soundfile	julius	39.17 ms
librosa	soxr	39.24 ms
soundfile	soxr	42.83 ms

Best by quality (resampling only)

• according to the original notebook Audio-resampling-in-python

1. Good:
   • scikit.samplerate/scikits-samplerate/samplerate/libsamplerate
   • librosa/resampy ("kaiser_best")
   • julius
2. Acceptable:
   • nnresample
   • lilfilter
   • torchaudio (transforms.Resample + resample_waveform)
   • librosa/resampy ("kaiser_fast")
3. Bad:
   • scipy.signal.resample

Please check plots in the Audio Resampling in Python.ipynb notebook. This version is an updated version of the original notebook but does not have all the libraries tested in the original notebook.