medkit.core.audio.audio_buffer

Classes

AudioBuffer	Audio buffer base class. Gives access to raw audio samples.
FileAudioBuffer	Audio buffer giving access to audio files stored on the filesystem.
MemoryAudioBuffer	Audio buffer giving access to signals stored in memory.
PlaceholderAudioBuffer	Placeholder for a MemoryAudioBuffer for which we have lost the actual signal.

Module Contents

class medkit.core.audio.audio_buffer.AudioBuffer(sample_rate: int, nb_samples: int, nb_channels: int)

Bases: abc.ABC, medkit.core.dict_conv.SubclassMapping

Audio buffer base class. Gives access to raw audio samples.

Parameters:

sample_rate:

Sample rate of the signal, in samples per second.

nb_samples:

Duration of the signal in samples.

nb_channels:

Number of channels in the signal.

sample_rate

nb_samples

nb_channels

property duration: float

Duration of the signal in seconds.

abstract read(copy: bool = False) → numpy.ndarray

Return the signal in the audio buffer.

Parameters:

copy:

If True, the returned array will be a copy that can be safely mutated.

Returns:

np.ndarray:

Raw audio samples

abstract trim(start: int | None, end: int | None) → AudioBuffer

Return the signal from the original buffer trimmed by start and end indexes.

Parameters:

start: int, optional

Start sample of the new buffer (defaults to 0).

end: int, optional

End sample of the new buffer, excluded (default to full duration).

Returns:

AudioBuffer:

Trimmed audio buffer with new start and end samples, of same type as original audio buffer.

trim_duration(start_time: float | None = None, end_time: float | None = None) → AudioBuffer

Return the signal from the original buffer trimmed by start and end times.

Return a new audio buffer pointing to a portion of the signal in the original buffer, using boundaries in seconds. Since start_time and end_time are in seconds, the exact trim boundaries will be rounded to the nearest sample and will therefore depend on the sampling rate.

Parameters:

start_time: float, optional

Start time of the new buffer (defaults to 0.0).

end_time: float, optional

End time of thew new buffer, excluded (default to full duration).

Returns:

AudioBuffer:

Trimmed audio buffer with new start and end samples, of same type as original audio buffer.

classmethod __init_subclass__()

classmethod from_dict(data_dict: dict[str, Any]) → typing_extensions.Self

abstract to_dict() → dict[str, Any]

abstract __eq__(other: object) → bool

class medkit.core.audio.audio_buffer.FileAudioBuffer(path: str | pathlib.Path, trim_start: int | None = None, trim_end: int | None = None, sf_info: Any | None = None)

Bases: AudioBuffer

Audio buffer giving access to audio files stored on the filesystem.

To be used when manipulating unmodified raw audio.

Supports all file formats handled by libsndfile

Parameters:

path: str or Path

Path to the audio file.

trim_start: int, optional

First sample of audio file to consider.

trim_end: int, optional

First sample of audio file to exclude.

sf_info: Any, optional

Optional metadata dict returned by soundfile.

path

trim_start

trim_end

sample_rate

nb_samples

nb_channels

_trim_end

_trim_start

_sf_info

read(copy: bool = False) → numpy.ndarray

Return the signal in the audio buffer.

Parameters:

copy:

If True, the returned array will be a copy that can be safely mutated.

Returns:

np.ndarray:

Raw audio samples

trim(start: int | None = None, end: int | None = None) → AudioBuffer

Return the signal from the original buffer trimmed by start and end indexes.

Parameters:

start: int, optional

Start sample of the new buffer (defaults to 0).

end: int, optional

End sample of the new buffer, excluded (default to full duration).

Returns:

AudioBuffer:

Trimmed audio buffer with new start and end samples, of same type as original audio buffer.

to_dict() → dict[str, Any]

classmethod from_dict(data: dict[str, Any]) → typing_extensions.Self

__eq__(other: object) → bool

class medkit.core.audio.audio_buffer.MemoryAudioBuffer(signal: numpy.ndarray, sample_rate: int)

Bases: AudioBuffer

Audio buffer giving access to signals stored in memory.

To be used for reading or writing a modified audio signal.

Parameters:

signal: ndarray

Samples constituting the audio signal, with shape (nb_channel, nb_samples).

sample_rate: int

Sample rate of the signal, in samples per second.

_signal

read(copy: bool = False) → numpy.ndarray

Return the signal in the audio buffer.

Parameters:

copy:

If True, the returned array will be a copy that can be safely mutated.

Returns:

np.ndarray:

Raw audio samples

trim(start: int | None = None, end: int | None = None) → AudioBuffer

Return the signal from the original buffer trimmed by start and end indexes.

Parameters:

start: int, optional

Start sample of the new buffer (defaults to 0).

end: int, optional

End sample of the new buffer, excluded (default to full duration).

Returns:

AudioBuffer:

Trimmed audio buffer with new start and end samples, of same type as original audio buffer.

to_dict() → dict[str, Any]

classmethod from_dict(data: dict[str, Any]) → typing_extensions.Self

__eq__(other: object) → bool

class medkit.core.audio.audio_buffer.PlaceholderAudioBuffer(sample_rate: int, nb_samples: int, nb_channels: int)

Bases: AudioBuffer

Placeholder for a MemoryAudioBuffer for which we have lost the actual signal.

This class is only here so that MemoryAudioBuffer objects can be converted into json/yaml serializable dicts and then unserialized, but no further processing can be performed since the actual signal is not saved. Calling :meth`~read()` or :meth`~.trim()` will raise.

classmethod from_audio_buffer(audio_buffer: AudioBuffer) → PlaceholderAudioBuffer

read(copy: bool = False) → numpy.ndarray

Return the signal in the audio buffer.

Parameters:

copy:

If True, the returned array will be a copy that can be safely mutated.

Returns:

np.ndarray:

Raw audio samples

trim(start: int | None, end: int | None) → AudioBuffer

Return the signal from the original buffer trimmed by start and end indexes.

Parameters:

start: int, optional

Start sample of the new buffer (defaults to 0).

end: int, optional

End sample of the new buffer, excluded (default to full duration).

Returns:

AudioBuffer:

Trimmed audio buffer with new start and end samples, of same type as original audio buffer.

to_dict() → dict[str, Any]

classmethod from_dict(data: dict[str, Any]) → typing_extensions.Self

__eq__(other: object) → bool