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Source code for torchaudio.backend.sox_io_backend

import os
from typing import Tuple, Optional

import torch
from torchaudio._internal import (
    module_utils as _mod_utils,
)

import torchaudio
from .common import AudioMetaData


[docs]@_mod_utils.requires_sox() def info( filepath: str, format: Optional[str] = None, ) -> AudioMetaData: """Get signal information of an audio file. Args: filepath (path-like object or file-like object): Source of audio data. When the function is not compiled by TorchScript, (e.g. ``torch.jit.script``), the following types are accepted; * ``path-like``: file path * ``file-like``: Object with ``read(size: int) -> bytes`` method, which returns byte string of at most ``size`` length. When the function is compiled by TorchScript, only ``str`` type is allowed. Note: * When the input type is file-like object, this function cannot get the correct length (``num_samples``) for certain formats, such as ``mp3`` and ``vorbis``. In this case, the value of ``num_samples`` is ``0``. * This argument is intentionally annotated as ``str`` only due to TorchScript compiler compatibility. format (str or None, optional): Override the format detection with the given format. Providing the argument might help when libsox can not infer the format from header or extension. Returns: AudioMetaData: Metadata of the given audio. """ if not torch.jit.is_scripting(): if hasattr(filepath, 'read'): sinfo = torchaudio._torchaudio.get_info_fileobj(filepath, format) return AudioMetaData(*sinfo) filepath = os.fspath(filepath) sinfo = torch.ops.torchaudio.sox_io_get_info(filepath, format) return AudioMetaData(*sinfo)
[docs]@_mod_utils.requires_sox() def load( filepath: str, frame_offset: int = 0, num_frames: int = -1, normalize: bool = True, channels_first: bool = True, format: Optional[str] = None, ) -> Tuple[torch.Tensor, int]: """Load audio data from file. Note: This function can handle all the codecs that underlying libsox can handle, however it is tested on the following formats; * WAV, AMB * 32-bit floating-point * 32-bit signed integer * 24-bit signed integer * 16-bit signed integer * 8-bit unsigned integer (WAV only) * MP3 * FLAC * OGG/VORBIS * OPUS * SPHERE * AMR-NB To load ``MP3``, ``FLAC``, ``OGG/VORBIS``, ``OPUS`` and other codecs ``libsox`` does not handle natively, your installation of ``torchaudio`` has to be linked to ``libsox`` and corresponding codec libraries such as ``libmad`` or ``libmp3lame`` etc. By default (``normalize=True``, ``channels_first=True``), this function returns Tensor with ``float32`` dtype and the shape of `[channel, time]`. The samples are normalized to fit in the range of ``[-1.0, 1.0]``. When the input format is WAV with integer type, such as 32-bit signed integer, 16-bit signed integer, 24-bit signed integer, and 8-bit unsigned integer, by providing ``normalize=False``, this function can return integer Tensor, where the samples are expressed within the whole range of the corresponding dtype, that is, ``int32`` tensor for 32-bit signed PCM, ``int16`` for 16-bit signed PCM and ``uint8`` for 8-bit unsigned PCM. Since torch does not support ``int24`` dtype, 24-bit signed PCM are converted to ``int32`` tensors. ``normalize`` parameter has no effect on 32-bit floating-point WAV and other formats, such as ``flac`` and ``mp3``. For these formats, this function always returns ``float32`` Tensor with values normalized to ``[-1.0, 1.0]``. Args: filepath (path-like object or file-like object): Source of audio data. When the function is not compiled by TorchScript, (e.g. ``torch.jit.script``), the following types are accepted; * ``path-like``: file path * ``file-like``: Object with ``read(size: int) -> bytes`` method, which returns byte string of at most ``size`` length. When the function is compiled by TorchScript, only ``str`` type is allowed. Note: This argument is intentionally annotated as ``str`` only due to TorchScript compiler compatibility. frame_offset (int): Number of frames to skip before start reading data. num_frames (int, optional): Maximum number of frames to read. ``-1`` reads all the remaining samples, starting from ``frame_offset``. This function may return the less number of frames if there is not enough frames in the given file. normalize (bool, optional): When ``True``, this function always return ``float32``, and sample values are normalized to ``[-1.0, 1.0]``. If input file is integer WAV, giving ``False`` will change the resulting Tensor type to integer type. This argument has no effect for formats other than integer WAV type. channels_first (bool, optional): When True, the returned Tensor has dimension `[channel, time]`. Otherwise, the returned Tensor's dimension is `[time, channel]`. format (str or None, optional): Override the format detection with the given format. Providing the argument might help when libsox can not infer the format from header or extension. Returns: (torch.Tensor, int): Resulting Tensor and sample rate. If the input file has integer wav format and normalization is off, then it has integer type, else ``float32`` type. If ``channels_first=True``, it has `[channel, time]` else `[time, channel]`. """ if not torch.jit.is_scripting(): if hasattr(filepath, 'read'): return torchaudio._torchaudio.load_audio_fileobj( filepath, frame_offset, num_frames, normalize, channels_first, format) filepath = os.fspath(filepath) return torch.ops.torchaudio.sox_io_load_audio_file( filepath, frame_offset, num_frames, normalize, channels_first, format)
[docs]@_mod_utils.requires_sox() def save( filepath: str, src: torch.Tensor, sample_rate: int, channels_first: bool = True, compression: Optional[float] = None, format: Optional[str] = None, encoding: Optional[str] = None, bits_per_sample: Optional[int] = None, ): """Save audio data to file. Args: filepath (str or pathlib.Path): Path to save file. This function also handles ``pathlib.Path`` objects, but is annotated as ``str`` for TorchScript compiler compatibility. src (torch.Tensor): Audio data to save. must be 2D tensor. sample_rate (int): sampling rate channels_first (bool, optional): If ``True``, the given tensor is interpreted as `[channel, time]`, otherwise `[time, channel]`. compression (float or None, optional): Used for formats other than WAV. This corresponds to ``-C`` option of ``sox`` command. ``"mp3"`` Either bitrate (in ``kbps``) with quality factor, such as ``128.2``, or VBR encoding with quality factor such as ``-4.2``. Default: ``-4.5``. ``"flac"`` Whole number from ``0`` to ``8``. ``8`` is default and highest compression. ``"ogg"``, ``"vorbis"`` Number from ``-1`` to ``10``; ``-1`` is the highest compression and lowest quality. Default: ``3``. See the detail at http://sox.sourceforge.net/soxformat.html. format (str or None, optional): Override the audio format. When ``filepath`` argument is path-like object, audio format is infered from file extension. If file extension is missing or different, you can specify the correct format with this argument. When ``filepath`` argument is file-like object, this argument is required. Valid values are ``"wav"``, ``"mp3"``, ``"ogg"``, ``"vorbis"``, ``"amr-nb"``, ``"amb"``, ``"flac"``, ``"sph"``, ``"gsm"``, and ``"htk"``. encoding (str or None, optional): Changes the encoding for the supported formats. This argument is effective only for supported formats, such as ``"wav"``, ``""amb"`` and ``"sph"``. Valid values are; - ``"PCM_S"`` (signed integer Linear PCM) - ``"PCM_U"`` (unsigned integer Linear PCM) - ``"PCM_F"`` (floating point PCM) - ``"ULAW"`` (mu-law) - ``"ALAW"`` (a-law) Default values If not provided, the default value is picked based on ``format`` and ``bits_per_sample``. ``"wav"``, ``"amb"`` - | If both ``encoding`` and ``bits_per_sample`` are not provided, the ``dtype`` of the | Tensor is used to determine the default value. - ``"PCM_U"`` if dtype is ``uint8`` - ``"PCM_S"`` if dtype is ``int16`` or ``int32`` - ``"PCM_F"`` if dtype is ``float32`` - ``"PCM_U"`` if ``bits_per_sample=8`` - ``"PCM_S"`` otherwise ``"sph"`` format; - the default value is ``"PCM_S"`` bits_per_sample (int or None, optional): Changes the bit depth for the supported formats. When ``format`` is one of ``"wav"``, ``"flac"``, ``"sph"``, or ``"amb"``, you can change the bit depth. Valid values are ``8``, ``16``, ``32`` and ``64``. Default Value; If not provided, the default values are picked based on ``format`` and ``"encoding"``; ``"wav"``, ``"amb"``; - | If both ``encoding`` and ``bits_per_sample`` are not provided, the ``dtype`` of the | Tensor is used. - ``8`` if dtype is ``uint8`` - ``16`` if dtype is ``int16`` - ``32`` if dtype is ``int32`` or ``float32`` - ``8`` if ``encoding`` is ``"PCM_U"``, ``"ULAW"`` or ``"ALAW"`` - ``16`` if ``encoding`` is ``"PCM_S"`` - ``32`` if ``encoding`` is ``"PCM_F"`` ``"flac"`` format; - the default value is ``24`` ``"sph"`` format; - ``16`` if ``encoding`` is ``"PCM_U"``, ``"PCM_S"``, ``"PCM_F"`` or not provided. - ``8`` if ``encoding`` is ``"ULAW"`` or ``"ALAW"`` ``"amb"`` format; - ``8`` if ``encoding`` is ``"PCM_U"``, ``"ULAW"`` or ``"ALAW"`` - ``16`` if ``encoding`` is ``"PCM_S"`` or not provided. - ``32`` if ``encoding`` is ``"PCM_F"`` Supported formats/encodings/bit depth/compression are; ``"wav"``, ``"amb"`` - 32-bit floating-point PCM - 32-bit signed integer PCM - 24-bit signed integer PCM - 16-bit signed integer PCM - 8-bit unsigned integer PCM - 8-bit mu-law - 8-bit a-law Note: Default encoding/bit depth is determined by the dtype of the input Tensor. ``"mp3"`` Fixed bit rate (such as 128kHz) and variable bit rate compression. Default: VBR with high quality. ``"flac"`` - 8-bit - 16-bit - 24-bit (default) ``"ogg"``, ``"vorbis"`` - Different quality level. Default: approx. 112kbps ``"sph"`` - 8-bit signed integer PCM - 16-bit signed integer PCM - 24-bit signed integer PCM - 32-bit signed integer PCM (default) - 8-bit mu-law - 8-bit a-law - 16-bit a-law - 24-bit a-law - 32-bit a-law ``"amr-nb"`` Bitrate ranging from 4.75 kbit/s to 12.2 kbit/s. Default: 4.75 kbit/s ``"gsm"`` Lossy Speech Compression, CPU intensive. ``"htk"`` Uses a default single-channel 16-bit PCM format. Note: To save into formats that ``libsox`` does not handle natively, (such as ``"mp3"``, ``"flac"``, ``"ogg"`` and ``"vorbis"``), your installation of ``torchaudio`` has to be linked to ``libsox`` and corresponding codec libraries such as ``libmad`` or ``libmp3lame`` etc. """ if not torch.jit.is_scripting(): if hasattr(filepath, 'write'): torchaudio._torchaudio.save_audio_fileobj( filepath, src, sample_rate, channels_first, compression, format, encoding, bits_per_sample) return filepath = os.fspath(filepath) torch.ops.torchaudio.sox_io_save_audio_file( filepath, src, sample_rate, channels_first, compression, format, encoding, bits_per_sample)

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