Working with multichannel audio files

The audio classes in OSEkit allow multichannel audio handling, e.g. the osekit.core.audio_data.AudioData.get_value() method returns a samples x channels matrix.

The osekit.core.audio_file.AudioFile.channels property depicts the number of channels of a given AudioFile:

from pathlib import Path
from osekit.core.audio_file import AudioFile

af = AudioFile(...)
print(af.channels)

>>> 3

The osekit.core.audio_data.AudioData.channels property relates to the list of channels concerned by this audio data:

from osekit.core.audio_data import AudioData

ad = AudioData.from_files(files=[af])
ad.channels = [0,2] # We want to keep only channels 0 and 2
print(ad.get_value().shape[1])

>>> 2 # One value array per channel

Finally, a SpectroData that has a linked AudioData targets a specific channel of this AudioData:

from osekit.core.spectro_data import SpectroData
from scipy.signal import ShortTimeFFT

sd = SpectroData.from_audio_data(data=ad, ...)
sd.audio_channel = 2 # The spectrum will be computed on the channel 2 of the file

Important

The osekit.core.spectro_data.SpectroData.audio_channel value refers to the index of the channel of the file.

If, as in the example above, the AudioFile has 3 channels [0,1,2], the AudioData targets channels [0,2] and the SpectroData targets the channel 2, the spectrum will be computed on the third channel of the file (with index 2).