Caution

You're reading an old version of this documentation. If you want up-to-date information, please have a look at 0.9.1.

librosa.output.annotation¶

librosa.output.annotation(path, intervals, annotations=None, delimiter=',', fmt='%0.3f')[source]¶

Save annotations in a 3-column format:

intervals[0, 0],intervals[0, 1],annotations[0]\n
intervals[1, 0],intervals[1, 1],annotations[1]\n
intervals[2, 0],intervals[2, 1],annotations[2]\n
...

This can be used for segment or chord annotations.

Warning

This function is deprecated in librosa 0.7.0. It will be removed in 0.8.

Parameters

pathstr

path to save the output CSV file

intervalsnp.ndarray [shape=(n, 2)]

array of interval start and end-times.

intervals[i, 0] marks the start time of interval i

intervals[i, 1] marks the end time of interval i

annotationsNone or list-like [shape=(n,)]

optional list of annotation strings. annotations[i] applies to the time range intervals[i, 0] to intervals[i, 1]

delimiterstr

character to separate fields

fmtstr

format-string for rendering time data

Raises

ParameterError: if annotations is not None and length does not match intervals

Examples

>>> y, sr = librosa.load(librosa.util.example_audio_file())
>>> data = librosa.feature.mfcc(y=y, sr=sr, hop_length=512)

Detect segment boundaries

>>> boundaries = librosa.segment.agglomerative(data, k=10)

Convert to time

>>> boundary_times = librosa.frames_to_time(boundaries, sr=sr,
...                                         hop_length=512)

Convert events boundaries to intervals

>>> intervals = np.hstack([boundary_times[:-1, np.newaxis],
...                        boundary_times[1:, np.newaxis]])

Make some fake annotations

>>> labels = ['Seg #{:03d}'.format(i) for i in range(len(intervals))]

Save the output

>>> librosa.output.annotation('segments.csv', intervals,
...                           annotations=labels)