注意

点击此处下载完整示例代码

音频 I/O¶

本教程展示了如何使用 TorchAudio 的基本 I/O API 来检查音频数据，将它们加载到 PyTorch 张量中并保存 PyTorch 张量。

警告

从 2.8 版本开始，我们正在重构 TorchAudio，以使其进入维护阶段。因此：

本教程中描述的 API 在 2.8 版本中已被弃用，并将在 2.9 版本中移除。
PyTorch 用于音频和视频的解码和编码功能正在被整合到 TorchCodec 中。

请参阅 https://github.com/pytorch/audio/issues/3902 获取更多信息。

import torch
import torchaudio

print(torch.__version__)
print(torchaudio.__version__)

2.8.0+cu126
2.8.0

准备¶

首先，我们导入模块并下载本教程中使用的音频资产。

注意

在 Google Colab 中运行本教程时，请使用以下命令安装所需包

!pip install boto3

import io
import os
import tarfile
import tempfile

import boto3
import matplotlib.pyplot as plt
import requests
from botocore import UNSIGNED
from botocore.config import Config
from IPython.display import Audio
from torchaudio.utils import download_asset

SAMPLE_GSM = download_asset("tutorial-assets/steam-train-whistle-daniel_simon.gsm")
SAMPLE_WAV = download_asset("tutorial-assets/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042.wav")
SAMPLE_WAV_8000 = download_asset("tutorial-assets/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042-8000hz.wav")


def _hide_seek(obj):
    class _wrapper:
        def __init__(self, obj):
            self.obj = obj

        def read(self, n):
            return self.obj.read(n)

    return _wrapper(obj)

/pytorch/audio/examples/tutorials/audio_io_tutorial.py:56: UserWarning: torchaudio.utils.download.download_asset has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  SAMPLE_GSM = download_asset("tutorial-assets/steam-train-whistle-daniel_simon.gsm")

  0%|          | 0.00/7.99k [00:00<?, ?B/s]
100%|##########| 7.99k/7.99k [00:00<00:00, 11.3MB/s]
/pytorch/audio/examples/tutorials/audio_io_tutorial.py:57: UserWarning: torchaudio.utils.download.download_asset has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  SAMPLE_WAV = download_asset("tutorial-assets/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042.wav")
/pytorch/audio/examples/tutorials/audio_io_tutorial.py:58: UserWarning: torchaudio.utils.download.download_asset has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  SAMPLE_WAV_8000 = download_asset("tutorial-assets/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042-8000hz.wav")

  0%|          | 0.00/53.2k [00:00<?, ?B/s]
100%|##########| 53.2k/53.2k [00:00<00:00, 45.7MB/s]

查询音频元数据¶

函数 torchaudio.info() 获取音频元数据。您可以提供类似路径的对象或类似文件的对象。

metadata = torchaudio.info(SAMPLE_WAV)
print(metadata)

/pytorch/audio/examples/tutorials/audio_io_tutorial.py:80: UserWarning: torchaudio._backend.utils.info has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  metadata = torchaudio.info(SAMPLE_WAV)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:20: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:27: UserWarning: torchaudio._backend.common.AudioMetaData has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  return AudioMetaData(
AudioMetaData(sample_rate=16000, num_frames=54400, num_channels=1, bits_per_sample=16, encoding=PCM_S)

其中

sample_rate 是音频的采样率
num_channels 是通道数
num_frames 是每通道的帧数
bits_per_sample 是位深度
encoding 是样本编码格式

encoding 可以是以下值之一

"PCM_S"：带符号整数线性 PCM
"PCM_U"：无符号整数线性 PCM
"PCM_F"：浮点线性 PCM
"FLAC"：Flac，Free Lossless Audio Codec
"ULAW"：Mu-law，[维基百科]
"ALAW"：A-law [维基百科]
"MP3"：MP3，MPEG-1 音频层 III
"VORBIS"：OGG Vorbis [xiph.org]
"AMR_NB"：自适应多速率 [维基百科]
"AMR_WB"：自适应多速率宽带 [维基百科]
"OPUS"：Opus [opus-codec.org]
"GSM"：GSM-FR [维基百科]
"HTK"：单通道 16 位 PCM
"UNKNOWN" 以上都不是

注意

对于带有压缩和/或可变比特率（如 MP3）的格式，bits_per_sample 可以为 0。
对于 GSM-FR 格式，num_frames 可以为 0。

metadata = torchaudio.info(SAMPLE_GSM)
print(metadata)

/pytorch/audio/examples/tutorials/audio_io_tutorial.py:124: UserWarning: torchaudio._backend.utils.info has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  metadata = torchaudio.info(SAMPLE_GSM)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:20: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:27: UserWarning: torchaudio._backend.common.AudioMetaData has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  return AudioMetaData(
AudioMetaData(sample_rate=8000, num_frames=39680, num_channels=1, bits_per_sample=0, encoding=GSM)

查询文件类对象¶

torchaudio.info() 适用于文件类对象。

url = "https://download.pytorch.org/torchaudio/tutorial-assets/steam-train-whistle-daniel_simon.wav"
with requests.get(url, stream=True) as response:
    metadata = torchaudio.info(_hide_seek(response.raw))
print(metadata)

/pytorch/audio/examples/tutorials/audio_io_tutorial.py:137: UserWarning: torchaudio._backend.utils.info has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  metadata = torchaudio.info(_hide_seek(response.raw))
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:20: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:27: UserWarning: torchaudio._backend.common.AudioMetaData has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  return AudioMetaData(
AudioMetaData(sample_rate=44100, num_frames=109368, num_channels=2, bits_per_sample=16, encoding=PCM_S)

注意

当传递一个文件类对象时，info 不会读取所有底层数据；相反，它只从开头读取一部分数据。因此，对于给定的音频格式，它可能无法检索正确的元数据，包括格式本身。在这种情况下，您可以传递 format 参数来指定音频的格式。

加载音频数据¶

要加载音频数据，可以使用 torchaudio.load()。

此函数接受类似路径的对象或类似文件的对象作为输入。

返回值为波形 (Tensor) 和采样率 (int) 的元组。

默认情况下，生成的张量对象具有 dtype=torch.float32，其值范围为 [-1.0, 1.0]。

有关支持的格式列表，请参阅 torchaudio 文档。

waveform, sample_rate = torchaudio.load(SAMPLE_WAV)

/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)

def plot_waveform(waveform, sample_rate):
    waveform = waveform.numpy()

    num_channels, num_frames = waveform.shape
    time_axis = torch.arange(0, num_frames) / sample_rate

    figure, axes = plt.subplots(num_channels, 1)
    if num_channels == 1:
        axes = [axes]
    for c in range(num_channels):
        axes[c].plot(time_axis, waveform[c], linewidth=1)
        axes[c].grid(True)
        if num_channels > 1:
            axes[c].set_ylabel(f"Channel {c+1}")
    figure.suptitle("waveform")

plot_waveform(waveform, sample_rate)

def plot_specgram(waveform, sample_rate, title="Spectrogram"):
    waveform = waveform.numpy()

    num_channels, num_frames = waveform.shape

    figure, axes = plt.subplots(num_channels, 1)
    if num_channels == 1:
        axes = [axes]
    for c in range(num_channels):
        axes[c].specgram(waveform[c], Fs=sample_rate)
        if num_channels > 1:
            axes[c].set_ylabel(f"Channel {c+1}")
    figure.suptitle(title)

plot_specgram(waveform, sample_rate)

Audio(waveform.numpy()[0], rate=sample_rate)

从文件类对象加载¶

I/O 函数支持文件类对象。这允许从本地文件系统内部和外部的位置获取和解码音频数据。以下示例说明了这一点。

# Load audio data as HTTP request
url = "https://download.pytorch.org/torchaudio/tutorial-assets/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042.wav"
with requests.get(url, stream=True) as response:
    waveform, sample_rate = torchaudio.load(_hide_seek(response.raw))
plot_specgram(waveform, sample_rate, title="HTTP datasource")

/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)

# Load audio from tar file
tar_path = download_asset("tutorial-assets/VOiCES_devkit.tar.gz")
tar_item = "VOiCES_devkit/source-16k/train/sp0307/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042.wav"
with tarfile.open(tar_path, mode="r") as tarfile_:
    fileobj = tarfile_.extractfile(tar_item)
    waveform, sample_rate = torchaudio.load(fileobj)
plot_specgram(waveform, sample_rate, title="TAR file")

/pytorch/audio/examples/tutorials/audio_io_tutorial.py:244: UserWarning: torchaudio.utils.download.download_asset has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  tar_path = download_asset("tutorial-assets/VOiCES_devkit.tar.gz")

  0%|          | 0.00/110k [00:00<?, ?B/s]
100%|##########| 110k/110k [00:00<00:00, 92.7MB/s]
/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)

# Load audio from S3
bucket = "pytorch-tutorial-assets"
key = "VOiCES_devkit/source-16k/train/sp0307/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042.wav"
client = boto3.client("s3", config=Config(signature_version=UNSIGNED))
response = client.get_object(Bucket=bucket, Key=key)
waveform, sample_rate = torchaudio.load(_hide_seek(response["Body"]))
plot_specgram(waveform, sample_rate, title="From S3")

/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)

切片技巧¶

提供 num_frames 和 frame_offset 参数会将解码限制为输入的相应片段。

使用普通的张量切片也可以达到同样的效果 (即 waveform[:, frame_offset:frame_offset+num_frames])。然而，提供 num_frames 和 frame_offset 参数效率更高。

这是因为一旦函数完成请求帧的解码，它就会停止数据采集和解码。当音频数据通过网络传输时，这很有利，因为一旦获取到所需的数据量，数据传输就会停止。

以下示例说明了这一点。

# Illustration of two different decoding methods.
# The first one will fetch all the data and decode them, while
# the second one will stop fetching data once it completes decoding.
# The resulting waveforms are identical.

frame_offset, num_frames = 16000, 16000  # Fetch and decode the 1 - 2 seconds

url = "https://download.pytorch.org/torchaudio/tutorial-assets/Lab41-SRI-VOiCES-src-sp0307-ch127535-sg0042.wav"
print("Fetching all the data...")
with requests.get(url, stream=True) as response:
    waveform1, sample_rate1 = torchaudio.load(_hide_seek(response.raw))
    waveform1 = waveform1[:, frame_offset : frame_offset + num_frames]
    print(f" - Fetched {response.raw.tell()} bytes")

print("Fetching until the requested frames are available...")
with requests.get(url, stream=True) as response:
    waveform2, sample_rate2 = torchaudio.load(
        _hide_seek(response.raw), frame_offset=frame_offset, num_frames=num_frames
    )
    print(f" - Fetched {response.raw.tell()} bytes")

print("Checking the resulting waveform ... ", end="")
assert (waveform1 == waveform2).all()
print("matched!")

Fetching all the data...
/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
 - Fetched 108844 bytes
Fetching until the requested frames are available...
 - Fetched 108844 bytes
Checking the resulting waveform ... matched!

将音频保存到文件¶

要以常用应用程序可解释的格式保存音频数据，可以使用 torchaudio.save()。

此函数接受类似路径的对象或类似文件的对象。

当传递一个文件类对象时，您还需要提供参数 format，以便函数知道应该使用哪种格式。如果是路径类对象，函数将从扩展名推断格式。如果您要保存到没有扩展名的文件，则需要提供参数 format。

保存 WAV 格式数据时，float32 张量的默认编码是 32 位浮点 PCM。您可以提供参数 encoding 和 bits_per_sample 来更改此行为。例如，要以 16 位有符号整数 PCM 格式保存数据，您可以执行以下操作。

注意

以较低位深度编码保存数据会减小生成文件的大小，但也会降低精度。

waveform, sample_rate = torchaudio.load(SAMPLE_WAV)

/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)

def inspect_file(path):
    print("-" * 10)
    print("Source:", path)
    print("-" * 10)
    print(f" - File size: {os.path.getsize(path)} bytes")
    print(f" - {torchaudio.info(path)}")
    print()

不带任何编码选项保存。函数将选择与所提供数据匹配的编码

with tempfile.TemporaryDirectory() as tempdir:
    path = f"{tempdir}/save_example_default.wav"
    torchaudio.save(path, waveform, sample_rate)
    inspect_file(path)

/pytorch/audio/src/torchaudio/_backend/utils.py:337: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.save_with_torchcodec` under the hood. Some parameters like format, encoding, bits_per_sample, buffer_size, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's encoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.encoders.AudioEncoder
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:247: UserWarning: torio.io._streaming_media_encoder.StreamingMediaEncoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamWriter(uri, format=muxer, buffer_size=buffer_size)
----------
Source: /tmp/tmp9pguk8sq/save_example_default.wav
----------
 - File size: 108878 bytes
/pytorch/audio/examples/tutorials/audio_io_tutorial.py:346: UserWarning: torchaudio._backend.utils.info has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  print(f" - {torchaudio.info(path)}")
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:20: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:27: UserWarning: torchaudio._backend.common.AudioMetaData has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  return AudioMetaData(
 - AudioMetaData(sample_rate=16000, num_frames=54400, num_channels=1, bits_per_sample=16, encoding=PCM_S)

保存为 16 位带符号整数线性 PCM 结果文件占用一半存储空间但损失精度

with tempfile.TemporaryDirectory() as tempdir:
    path = f"{tempdir}/save_example_PCM_S16.wav"
    torchaudio.save(path, waveform, sample_rate, encoding="PCM_S", bits_per_sample=16)
    inspect_file(path)

/pytorch/audio/src/torchaudio/_backend/utils.py:337: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.save_with_torchcodec` under the hood. Some parameters like format, encoding, bits_per_sample, buffer_size, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's encoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.encoders.AudioEncoder
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:247: UserWarning: torio.io._streaming_media_encoder.StreamingMediaEncoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamWriter(uri, format=muxer, buffer_size=buffer_size)
----------
Source: /tmp/tmpjkq8v6mk/save_example_PCM_S16.wav
----------
 - File size: 108878 bytes
/pytorch/audio/examples/tutorials/audio_io_tutorial.py:346: UserWarning: torchaudio._backend.utils.info has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  print(f" - {torchaudio.info(path)}")
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:20: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:27: UserWarning: torchaudio._backend.common.AudioMetaData has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  return AudioMetaData(
 - AudioMetaData(sample_rate=16000, num_frames=54400, num_channels=1, bits_per_sample=16, encoding=PCM_S)

torchaudio.save() 也可以处理其他格式。举几个例子

formats = [
    "flac",
    # "vorbis",
    # "sph",
    # "amb",
    # "amr-nb",
    # "gsm",
]

waveform, sample_rate = torchaudio.load(SAMPLE_WAV_8000)
with tempfile.TemporaryDirectory() as tempdir:
    for format in formats:
        path = f"{tempdir}/save_example.{format}"
        torchaudio.save(path, waveform, sample_rate, format=format)
        inspect_file(path)

/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/utils.py:337: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.save_with_torchcodec` under the hood. Some parameters like format, encoding, bits_per_sample, buffer_size, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's encoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.encoders.AudioEncoder
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:247: UserWarning: torio.io._streaming_media_encoder.StreamingMediaEncoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamWriter(uri, format=muxer, buffer_size=buffer_size)
----------
Source: /tmp/tmpelk2y9va/save_example.flac
----------
 - File size: 45262 bytes
/pytorch/audio/examples/tutorials/audio_io_tutorial.py:346: UserWarning: torchaudio._backend.utils.info has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  print(f" - {torchaudio.info(path)}")
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:20: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:27: UserWarning: torchaudio._backend.common.AudioMetaData has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  return AudioMetaData(
 - AudioMetaData(sample_rate=8000, num_frames=27200, num_channels=1, bits_per_sample=16, encoding=FLAC)

保存到文件类对象¶

与其他 I/O 函数类似，您可以将音频保存到文件类对象。保存到文件类对象时，参数 format 是必需的。

waveform, sample_rate = torchaudio.load(SAMPLE_WAV)

# Saving to bytes buffer
buffer_ = io.BytesIO()
torchaudio.save(buffer_, waveform, sample_rate, format="wav")

buffer_.seek(0)
print(buffer_.read(16))

/pytorch/audio/src/torchaudio/_backend/utils.py:213: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.load_with_torchcodec` under the hood. Some parameters like ``normalize``, ``format``, ``buffer_size``, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's decoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.decoders.AudioDecoder.html#torchcodec.decoders.AudioDecoder.
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:88: UserWarning: torio.io._streaming_media_decoder.StreamingMediaDecoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamReader(src, format, None, buffer_size)
/pytorch/audio/src/torchaudio/_backend/utils.py:337: UserWarning: In 2.9, this function's implementation will be changed to use torchaudio.save_with_torchcodec` under the hood. Some parameters like format, encoding, bits_per_sample, buffer_size, and ``backend`` will be ignored. We recommend that you port your code to rely directly on TorchCodec's encoder instead: https://docs.pytorch.ac.cn/torchcodec/stable/generated/torchcodec.encoders.AudioEncoder
  warnings.warn(
/pytorch/audio/src/torchaudio/_backend/ffmpeg.py:247: UserWarning: torio.io._streaming_media_encoder.StreamingMediaEncoder has been deprecated. This deprecation is part of a large refactoring effort to transition TorchAudio into a maintenance phase. The decoding and encoding capabilities of PyTorch for both audio and video are being consolidated into TorchCodec. Please see https://github.com/pytorch/audio/issues/3902 for more information. It will be removed from the 2.9 release.
  s = torchaudio.io.StreamWriter(uri, format=muxer, buffer_size=buffer_size)
b'RIFFF\xa9\x01\x00WAVEfmt '

脚本总运行时间： ( 0 分钟 1.561 秒)

由 Sphinx-Gallery 生成的画廊