Source code for torchaudio.backend.utils
"""Defines utilities for switching audio backends"""
import warnings
from typing import Optional, List
import torchaudio
from torchaudio._internal import module_utils as _mod_utils
from . import (
no_backend,
sox_io_backend,
soundfile_backend,
)
__all__ = [
'list_audio_backends',
'get_audio_backend',
'set_audio_backend',
]
[docs]def list_audio_backends() -> List[str]:
"""List available backends
Returns:
List[str]: The list of available backends.
"""
backends = []
if _mod_utils.is_module_available('soundfile'):
backends.append('soundfile')
if _mod_utils.is_sox_available():
backends.append('sox_io')
return backends
[docs]def set_audio_backend(backend: Optional[str]):
"""Set the backend for I/O operation
Args:
backend (str or None): Name of the backend.
One of ``"sox_io"`` or ``"soundfile"`` based on availability
of the system. If ``None`` is provided the current backend is unassigned.
"""
if backend is not None and backend not in list_audio_backends():
raise RuntimeError(
f'Backend "{backend}" is not one of '
f'available backends: {list_audio_backends()}.')
if backend is None:
module = no_backend
elif backend == 'sox_io':
module = sox_io_backend
elif backend == 'soundfile':
module = soundfile_backend
else:
raise NotImplementedError(f'Unexpected backend "{backend}"')
for func in ['save', 'load', 'info']:
setattr(torchaudio, func, getattr(module, func))
def _init_audio_backend():
backends = list_audio_backends()
if 'sox_io' in backends:
set_audio_backend('sox_io')
elif 'soundfile' in backends:
set_audio_backend('soundfile')
else:
warnings.warn('No audio backend is available.')
set_audio_backend(None)
[docs]def get_audio_backend() -> Optional[str]:
"""Get the name of the current backend
Returns:
Optional[str]: The name of the current backend or ``None`` if no backend is assigned.
"""
if torchaudio.load == no_backend.load:
return None
if torchaudio.load == sox_io_backend.load:
return 'sox_io'
if torchaudio.load == soundfile_backend.load:
return 'soundfile'
raise ValueError('Unknown backend.')