librosa.core.get_duration

librosa.core.get_duration(y=None, sr=22050, S=None, n_fft=2048, hop_length=512, center=True, filename=None)[source]

Compute the duration (in seconds) of an audio time series, feature matrix, or filename.

Parameters:
y : np.ndarray [shape=(n,), (2, n)] or None

audio time series

sr : number > 0 [scalar]

audio sampling rate of y

S : np.ndarray [shape=(d, t)] or None

STFT matrix, or any STFT-derived matrix (e.g., chromagram or mel spectrogram). Durations calculated from spectrogram inputs are only accurate up to the frame resolution. If high precision is required, it is better to use the audio time series directly.

n_fft : int > 0 [scalar]

FFT window size for S

hop_length : int > 0 [ scalar]

number of audio samples between columns of S

center : boolean
  • If True, S[:, t] is centered at y[t * hop_length]
  • If False, then S[:, t] begins at y[t * hop_length]
filename : str

If provided, all other parameters are ignored, and the duration is calculated directly from the audio file. Note that this avoids loading the contents into memory, and is therefore useful for querying the duration of long files.

As in load(), this can also be an integer or open file-handle that can be processed by soundfile.

Returns:
d : float >= 0

Duration (in seconds) of the input time series or spectrogram.

Raises:
ParameterError

if none of y, S, or filename are provided.

Notes

get_duration can be applied to a file (filename), a spectrogram (S), or audio buffer (y, sr). Only one of these three options should be provided. If you do provide multiple options (e.g., filename and S), then filename takes precedence over S, and S takes precedence over (y, sr).

Examples

>>> # Load the example audio file
>>> y, sr = librosa.load(librosa.util.example_audio_file())
>>> librosa.get_duration(y=y, sr=sr)
61.45886621315193
>>> # Or directly from an audio file
>>> librosa.get_duration(filename=librosa.util.example_audio_file())
61.4
>>> # Or compute duration from an STFT matrix
>>> y, sr = librosa.load(librosa.util.example_audio_file())
>>> S = librosa.stft(y)
>>> librosa.get_duration(S=S, sr=sr)
61.44
>>> # Or a non-centered STFT matrix
>>> S_left = librosa.stft(y, center=False)
>>> librosa.get_duration(S=S_left, sr=sr)
61.3471201814059