Add Torchscript sox effects (#760)

* Add sox_utils module

* Make init/shutdown thread safe

* Add sox effects implementation

* Add test for sox effects

* Update docstrings and add examples

docs/source/index.rst

@@ -13,6 +13,7 @@ The :mod:`torchaudio` package consists of I/O, popular datasets and common audio
    kaldi_io
    transforms
    functional
+   utils
 
 .. automodule:: torchaudio
    :members:

docs/source/sox_effects.rst

@@ -4,10 +4,16 @@
 torchaudio.sox_effects
 ======================
 
-Create SoX effects chain for preprocessing audio.
-
 .. currentmodule:: torchaudio.sox_effects
 
+Apply SoX effects chain on torch.Tensor or on file and load as torch.Tensor.
+
+.. autofunction:: apply_effects_tensor
+
+.. autofunction:: apply_effects_file
+
+Create SoX effects chain for preprocessing audio.
+
 :hidden:`SoxEffect`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/source/utils.rst

+.. role:: hidden
+    :class: hidden-section
+
+torchaudio.utils.sox_utils
+==========================
+
+Utility module to configure libsox. This affects functionalities in ``sox_io`` backend and ``torchaudio.sox_effects``.
+
+.. currentmodule:: torchaudio.utils.sox_utils
+
+.. autofunction:: set_seed
+
+.. autofunction:: set_verbosity
+
+.. autofunction:: set_buffer_size
+
+.. autofunction:: set_use_threads
+
+.. autofunction:: list_effects
+
+.. autofunction:: list_formats

test/assets/sox_effect_test_args.json

+{"effects": [["allpass", "300", "10"]]}
+{"effects": [["band", "300", "10"]]}
+{"effects": [["bandpass", "300", "10"]]}
+{"effects": [["bandreject", "300", "10"]]}
+{"effects": [["bass", "-10"]]}
+{"effects": [["bend", ".35,180,.25", ".15,740,.53", "0,-520,.3"]]}
+{"effects": [["biquad", "0.4", "0.2", "0.9", "0.7", "0.2", "0.6"]]}
+{"effects": [["chorus", "0.7", "0.9", "55", "0.4", "0.25", "2", "-t"]]}
+{"effects": [["chorus", "0.6", "0.9", "50", "0.4", "0.25", "2", "-t", "60", "0.32", "0.4", "1.3", "-s"]]}
+{"effects": [["chorus", "0.5", "0.9", "50", "0.4", "0.25", "2", "-t", "60", "0.32", "0.4", "2.3", "-t", "40", "0.3", "0.3", "1.3", "-s"]]}
+{"effects": [["channels", "1"]]}
+{"effects": [["channels", "2"]]}
+{"effects": [["channels", "3"]]}
+{"effects": [["compand", "0.3,1", "6:-70,-60,-20", "-5", "-90", "0.2"]]}
+{"effects": [["compand", ".1,.2", "-inf,-50.1,-inf,-50,-50", "0", "-90", ".1"]]}
+{"effects": [["compand", ".1,.1", "-45.1,-45,-inf,0,-inf", "45", "-90", ".1"]]}
+{"effects": [["contrast", "0"]]}
+{"effects": [["contrast", "25"]]}
+{"effects": [["contrast", "50"]]}
+{"effects": [["contrast", "75"]]}
+{"effects": [["contrast", "100"]]}
+{"effects": [["dcshift", "1.0"]]}
+{"effects": [["dcshift", "-1.0"]]}
+{"effects": [["deemph"]], "input_sample_rate": 44100}
+{"effects": [["delay", "1.5", "+1"]]}
+{"effects": [["dither", "-s"]]}
+{"effects": [["dither", "-S"]]}
+{"effects": [["divide"]]}
+{"effects": [["downsample", "2"]], "input_sample_rate": 8000, "output_sample_rate": 4000}
+{"effects": [["earwax"]], "input_sample_rate": 44100}
+{"effects": [["echo", "0.8", "0.88", "60", "0.4"]]}
+{"effects": [["echo", "0.8", "0.88", "6", "0.4"]]}
+{"effects": [["echo", "0.8", "0.9", "1000", "0.3"]]}
+{"effects": [["echo", "0.8", "0.9", "1000", "0.3", "1800", "0.25"]]}
+{"effects": [["echos", "0.8", "0.7", "700", "0.25", "700", "0.3"]]}
+{"effects": [["echos", "0.8", "0.7", "700", "0.25", "900", "0.3"]]}
+{"effects": [["echos", "0.8", "0.7", "40", "0.25", "63", "0.3"]]}
+{"effects": [["equalizer", "300", "10", "5"]]}
+{"effects": [["fade", "q", "3"]]}
+{"effects": [["fade", "h", "3"]]}
+{"effects": [["fade", "t", "3"]]}
+{"effects": [["fade", "l", "3"]]}
+{"effects": [["fade", "p", "3"]]}
+{"effects": [["fir", "0.0195", "-0.082", "0.234", "0.891", "-0.145", "0.043"]]}
+{"effects": [["fir", "test/assets/sox_effect_test_fir_coeffs.txt"]]}
+{"effects": [["flanger"]]}
+{"effects": [["gain", "-n"]]}
+{"effects": [["gain", "-n", "-3"]]}
+{"effects": [["gain", "-l", "-6"]]}
+{"effects": [["highpass", "-1", "300"]]}
+{"effects": [["highpass", "-2", "300"]]}
+{"effects": [["hilbert"]]}
+{"effects": [["loudness"]]}
+{"effects": [["lowpass", "-1", "300"]]}
+{"effects": [["lowpass", "-2", "300"]]}
+{"effects": [["mcompand", "0.005,0.1 -47,-40,-34,-34,-17,-33", "100", "0.003,0.05 -47,-40,-34,-34,-17,-33", "400", "0.000625,0.0125 -47,-40,-34,-34,-15,-33", "1600", "0.0001,0.025 -47,-40,-34,-34,-31,-31,-0,-30", "6400", "0,0.025 -38,-31,-28,-28,-0,-25"]], "input_sample_rate": 44100}
+{"effects": [["norm"]]}
+{"effects": [["oops"]]}
+{"effects": [["overdrive"]]}
+{"effects": [["pad"]]}
+{"effects": [["phaser"]]}
+{"effects": [["pitch", "6.48"], ["rate", "8030"]], "output_sample_rate": 8030}
+{"effects": [["pitch", "-6.50"], ["rate", "7970"]], "output_sample_rate": 7970}
+{"effects": [["rate", "4567"]], "output_sample_rate": 4567}
+{"effects": [["remix", "6", "7", "8", "0"]], "num_channels": 8}
+{"effects": [["remix", "1-3,7", "3"]], "num_channels": 8}
+{"effects": [["repeat"]]}
+{"effects": [["reverb"]]}
+{"effects": [["reverse"]]}
+{"effects": [["riaa"]], "input_sample_rate": 44100}
+{"effects": [["silence", "0"]]}
+{"effects": [["sinc", "3k"]]}
+{"effects": [["speed", "1.3"]], "input_sample_rate": 4000, "output_sample_rate": 5200}
+{"effects": [["speed", "0.7"]], "input_sample_rate": 4000, "output_sample_rate": 2800}
+{"effects": [["stat"]]}
+{"effects": [["stats"]]}
+{"effects": [["stretch"]]}
+{"effects": [["swap"]]}
+{"effects": [["synth"]]}
+{"effects": [["tempo", "0.9"]]}
+{"effects": [["tempo", "1.1"]]}
+{"effects": [["treble", "3"]]}
+{"effects": [["tremolo", "300", "40"]]}
+{"effects": [["tremolo", "300", "50"]]}
+{"effects": [["trim", "0", "0.1"]]}
+{"effects": [["upsample", "2"]], "input_sample_rate": 8000, "output_sample_rate": 16000}
+{"effects": [["vad"]]}
+{"effects": [["vol", "3"]]}

test/assets/sox_effect_test_fir_coeffs.txt

+0.0195 -0.082 0.234 0.891 -0.145 0.043

test/common_utils/data_utils.py

@@ -72,6 +72,7 @@ def get_sinusoid(
     n_channels: int = 1,
     dtype: Union[str, torch.dtype] = "float32",
     device: Union[str, torch.device] = "cpu",
+    channels_first: bool = True,
 ):
     """Generate pseudo audio data with sine wave.
 
@@ -91,4 +92,7 @@ def get_sinusoid(
     pie2 = 2 * 3.141592653589793
     end = pie2 * frequency * duration
     theta = torch.linspace(0, end, sample_rate * duration, dtype=dtype, device=device)
-    return torch.sin(theta, out=None).repeat([n_channels, 1])
+    sin = torch.sin(theta, out=None).repeat([n_channels, 1])
+    if not channels_first:
+        sin = sin.t()
+    return sin

test/common_utils/test_case_utils.py

@@ -14,33 +14,28 @@ from .backend_utils import set_audio_backend
 class TempDirMixin:
     """Mixin to provide easy access to temp dir"""
     temp_dir_ = None
-    base_temp_dir = None
-    temp_dir = None
 
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
+    @property
+    def base_temp_dir(self):
         # If TORCHAUDIO_TEST_TEMP_DIR is set, use it instead of temporary directory.
         # this is handy for debugging.
         key = 'TORCHAUDIO_TEST_TEMP_DIR'
         if key in os.environ:
-            cls.base_temp_dir = os.environ[key]
-        else:
-            cls.temp_dir_ = tempfile.TemporaryDirectory()
-            cls.base_temp_dir = cls.temp_dir_.name
+            return os.environ[key]
+        if self.__class__.temp_dir_ is None:
+            self.__class__.temp_dir_ = tempfile.TemporaryDirectory()
+        return self.__class__.temp_dir_.name
 
     @classmethod
     def tearDownClass(cls):
         super().tearDownClass()
-        if isinstance(cls.temp_dir_, tempfile.TemporaryDirectory):
+        if cls.temp_dir_ is not None:
             cls.temp_dir_.cleanup()
-
-    def setUp(self):
-        super().setUp()
-        self.temp_dir = os.path.join(self.base_temp_dir, self.id())
+            cls.temp_dir_ = None
 
     def get_temp_path(self, *paths):
-        path = os.path.join(self.temp_dir, *paths)
+        temp_dir = os.path.join(self.base_temp_dir, self.id())
+        path = os.path.join(temp_dir, *paths)
         os.makedirs(os.path.dirname(path), exist_ok=True)
         return path
 

test/sox_effect/common.py

+def name_func(func, _, params):
+    if isinstance(params.args[0], str):
+        args = "_".join([str(arg) for arg in params.args])
+    else:
+        args = "_".join([str(arg) for arg in params.args[0]])
+    return f'{func.__name__}_{args}'

test/sox_effect/test_dataset.py

+from typing import List, Tuple
+
+import numpy as np
+import torch
+import torchaudio
+
+from ..common_utils import (
+    TempDirMixin,
+    PytorchTestCase,
+    skipIfNoExtension,
+    get_whitenoise,
+    load_wav,
+    save_wav,
+)
+
+
+class RandomPerturbationFile(torch.utils.data.Dataset):
+    """Given flist, apply random speed perturbation"""
+    def __init__(self, flist: List[str], sample_rate: int):
+        super().__init__()
+        self.flist = flist
+        self.sample_rate = sample_rate
+        self.rng = None
+
+    def __getitem__(self, index):
+        speed = self.rng.uniform(0.5, 2.0)
+        effects = [
+            ['gain', '-n', '-10'],
+            ['speed', f'{speed:.5f}'],  # duration of data is 0.5 ~ 2.0 seconds.
+            ['rate', f'{self.sample_rate}'],
+            ['pad', '0', '1.5'],  # add 1.5 seconds silence at the end
+            ['trim', '0', '2'],  # get the first 2 seconds
+        ]
+        data, _ = torchaudio.sox_effects.apply_effects_file(self.flist[index], effects)
+        return data
+
+    def __len__(self):
+        return len(self.flist)
+
+
+class RandomPerturbationTensor(torch.utils.data.Dataset):
+    """Apply speed purturbation to (synthetic) Tensor data"""
+    def __init__(self, signals: List[Tuple[torch.Tensor, int]], sample_rate: int):
+        super().__init__()
+        self.signals = signals
+        self.sample_rate = sample_rate
+        self.rng = None
+
+    def __getitem__(self, index):
+        speed = self.rng.uniform(0.5, 2.0)
+        effects = [
+            ['gain', '-n', '-10'],
+            ['speed', f'{speed:.5f}'],  # duration of data is 0.5 ~ 2.0 seconds.
+            ['rate', f'{self.sample_rate}'],
+            ['pad', '0', '1.5'],  # add 1.5 seconds silence at the end
+            ['trim', '0', '2'],  # get the first 2 seconds
+        ]
+        tensor, sample_rate = self.signals[index]
+        data, _ = torchaudio.sox_effects.apply_effects_tensor(tensor, sample_rate, effects)
+        return data
+
+    def __len__(self):
+        return len(self.signals)
+
+
+def init_random_seed(worker_id):
+    dataset = torch.utils.data.get_worker_info().dataset
+    dataset.rng = np.random.RandomState(worker_id)
+
+
+@skipIfNoExtension
+class TestSoxEffectsDataset(TempDirMixin, PytorchTestCase):
+    """Test `apply_effects_file` in multi-process dataloader setting"""
+
+    def _generate_dataset(self, num_samples=128):
+        flist = []
+        for i in range(num_samples):
+            sample_rate = np.random.choice([8000, 16000, 44100])
+            dtype = np.random.choice(['float32', 'int32', 'int16', 'uint8'])
+            data = get_whitenoise(n_channels=2, sample_rate=sample_rate, duration=1, dtype=dtype)
+            path = self.get_temp_path(f'{i:03d}_{dtype}_{sample_rate}.wav')
+            save_wav(path, data, sample_rate)
+            flist.append(path)
+        return flist
+
+    def test_apply_effects_file(self):
+        sample_rate = 12000
+        flist = self._generate_dataset()
+        dataset = RandomPerturbationFile(flist, sample_rate)
+        loader = torch.utils.data.DataLoader(
+            dataset, batch_size=32, num_workers=16,
+            worker_init_fn=init_random_seed,
+        )
+        for batch in loader:
+            assert batch.shape == (32, 2, 2 * sample_rate)
+
+    def _generate_signals(self, num_samples=128):
+        signals = []
+        for _ in range(num_samples):
+            sample_rate = np.random.choice([8000, 16000, 44100])
+            data = get_whitenoise(
+                n_channels=2, sample_rate=sample_rate, duration=1, dtype='float32')
+            signals.append((data, sample_rate))
+        return signals
+
+    def test_apply_effects_tensor(self):
+        sample_rate = 12000
+        signals = self._generate_signals()
+        dataset = RandomPerturbationTensor(signals, sample_rate)
+        loader = torch.utils.data.DataLoader(
+            dataset, batch_size=32, num_workers=16,
+            worker_init_fn=init_random_seed,
+        )
+        for batch in loader:
+            assert batch.shape == (32, 2, 2 * sample_rate)

test/sox_effect/test_sox_effect.py

+import itertools
+
+from torchaudio import sox_effects
+from parameterized import parameterized
+
+from ..common_utils import (
+    TempDirMixin,
+    PytorchTestCase,
+    skipIfNoExtension,
+    get_sinusoid,
+    get_wav_data,
+    save_wav,
+    load_wav,
+    load_params,
+    sox_utils,
+)
+from .common import (
+    name_func,
+)
+
+
+@skipIfNoExtension
+class TestSoxEffects(PytorchTestCase):
+    def test_init(self):
+        """Calling init_sox_effects multiple times does not crush"""
+        for _ in range(3):
+            sox_effects.init_sox_effects()
+
+
+@skipIfNoExtension
+class TestSoxEffectsTensor(TempDirMixin, PytorchTestCase):
+    """Test suite for `apply_effects_tensor` function"""
+    @parameterized.expand(list(itertools.product(
+        ['float32', 'int32', 'int16', 'uint8'],
+        [8000, 16000],
+        [1, 2, 4, 8],
+        [True, False]
+    )), name_func=name_func)
+    def test_apply_no_effect(self, dtype, sample_rate, num_channels, channels_first):
+        """`apply_effects_tensor` without effects should return identical data as input"""
+        original = get_wav_data(dtype, num_channels, channels_first=channels_first)
+        expected = original.clone()
+        found, output_sample_rate = sox_effects.apply_effects_tensor(
+            expected, sample_rate, [], channels_first)
+
+        assert output_sample_rate == sample_rate
+        # SoxEffect should not alter the input Tensor object
+        self.assertEqual(original, expected)
+        # SoxEffect should not return the same Tensor object
+        assert expected is not found
+        # Returned Tensor should equal to the input Tensor
+        self.assertEqual(expected, found)
+
+    @parameterized.expand(
+        load_params("sox_effect_test_args.json"),
+        name_func=lambda f, i, p: f'{f.__name__}_{i}_{p.args[0]["effects"][0][0]}',
+    )
+    def test_apply_effects(self, args):
+        """`apply_effects_tensor` should return identical data as sox command"""
+        effects = args['effects']
+        num_channels = args.get("num_channels", 2)
+        input_sr = args.get("input_sample_rate", 8000)
+        output_sr = args.get("output_sample_rate")
+
+        input_path = self.get_temp_path('input.wav')
+        reference_path = self.get_temp_path('reference.wav')
+
+        original = get_sinusoid(
+            frequency=800, sample_rate=input_sr,
+            n_channels=num_channels, dtype='float32')
+        save_wav(input_path, original, input_sr)
+        sox_utils.run_sox_effect(
+            input_path, reference_path, effects, output_sample_rate=output_sr)
+
+        expected, expected_sr = load_wav(reference_path)
+        found, sr = sox_effects.apply_effects_tensor(original, input_sr, effects)
+
+        assert sr == expected_sr
+        self.assertEqual(expected, found)
+
+
+@skipIfNoExtension
+class TestSoxEffectsFile(TempDirMixin, PytorchTestCase):
+    """Test suite for `apply_effects_file` function"""
+    @parameterized.expand(list(itertools.product(
+        ['float32', 'int32', 'int16', 'uint8'],
+        [8000, 16000],
+        [1, 2, 4, 8],
+        [False, True],
+    )), name_func=name_func)
+    def test_apply_no_effect(self, dtype, sample_rate, num_channels, channels_first):
+        """`apply_effects_file` without effects should return identical data as input"""
+        path = self.get_temp_path('input.wav')
+        expected = get_wav_data(dtype, num_channels, channels_first=channels_first)
+        save_wav(path, expected, sample_rate, channels_first=channels_first)
+
+        found, output_sample_rate = sox_effects.apply_effects_file(
+            path, [], normalize=False, channels_first=channels_first)
+
+        assert output_sample_rate == sample_rate
+        self.assertEqual(expected, found)
+
+    @parameterized.expand(
+        load_params("sox_effect_test_args.json"),
+        name_func=lambda f, i, p: f'{f.__name__}_{i}_{p.args[0]["effects"][0][0]}',
+    )
+    def test_apply_effects(self, args):
+        """`apply_effects_file` should return identical data as sox command"""
+        dtype = 'int32'
+        channels_first = True
+        effects = args['effects']
+        num_channels = args.get("num_channels", 2)
+        input_sr = args.get("input_sample_rate", 8000)
+        output_sr = args.get("output_sample_rate")
+
+        input_path = self.get_temp_path('input.wav')
+        reference_path = self.get_temp_path('reference.wav')
+        data = get_wav_data(dtype, num_channels, channels_first=channels_first)
+        save_wav(input_path, data, input_sr, channels_first=channels_first)
+        sox_utils.run_sox_effect(
+            input_path, reference_path, effects, output_sample_rate=output_sr)
+
+        expected, expected_sr = load_wav(reference_path)
+        found, sr = sox_effects.apply_effects_file(
+            input_path, effects, normalize=False, channels_first=channels_first)
+
+        assert sr == expected_sr
+        self.assertEqual(found, expected)
+
+
+@skipIfNoExtension
+class TestFileFormats(TempDirMixin, PytorchTestCase):
+    """`apply_effects_file` gives the same result as sox on various file formats"""
+    @parameterized.expand(list(itertools.product(
+        ['float32', 'int32', 'int16', 'uint8'],
+        [8000, 16000],
+        [1, 2],
+    )), name_func=lambda f, _, p: f'{f.__name__}_{"_".join(str(arg) for arg in p.args)}')
+    def test_wav(self, dtype, sample_rate, num_channels):
+        """`apply_effects_file` works on various wav format"""
+        channels_first = True
+        effects = [['band', '300', '10']]
+
+        input_path = self.get_temp_path('input.wav')
+        reference_path = self.get_temp_path('reference.wav')
+        data = get_wav_data(dtype, num_channels, channels_first=channels_first)
+        save_wav(input_path, data, sample_rate, channels_first=channels_first)
+        sox_utils.run_sox_effect(input_path, reference_path, effects)
+
+        expected, expected_sr = load_wav(reference_path)
+        found, sr = sox_effects.apply_effects_file(
+            input_path, effects, normalize=False, channels_first=channels_first)
+
+        assert sr == expected_sr
+        self.assertEqual(found, expected)
+
+    @parameterized.expand(list(itertools.product(
+        [8000, 16000],
+        [1, 2],
+    )), name_func=lambda f, _, p: f'{f.__name__}_{"_".join(str(arg) for arg in p.args)}')
+    def test_mp3(self, sample_rate, num_channels):
+        """`apply_effects_file` works on various mp3 format"""
+        channels_first = True
+        effects = [['band', '300', '10']]
+
+        input_path = self.get_temp_path('input.mp3')
+        reference_path = self.get_temp_path('reference.wav')
+        sox_utils.gen_audio_file(input_path, sample_rate, num_channels)
+        sox_utils.run_sox_effect(input_path, reference_path, effects)
+
+        expected, expected_sr = load_wav(reference_path)
+        found, sr = sox_effects.apply_effects_file(
+            input_path, effects, channels_first=channels_first)
+        save_wav(self.get_temp_path('result.wav'), found, sr, channels_first=channels_first)
+
+        assert sr == expected_sr
+        self.assertEqual(found, expected, atol=1e-4, rtol=1e-8)
+
+    @parameterized.expand(list(itertools.product(
+        [8000, 16000],
+        [1, 2],
+    )), name_func=lambda f, _, p: f'{f.__name__}_{"_".join(str(arg) for arg in p.args)}')
+    def test_flac(self, sample_rate, num_channels):
+        """`apply_effects_file` works on various flac format"""
+        channels_first = True
+        effects = [['band', '300', '10']]
+
+        input_path = self.get_temp_path('input.flac')
+        reference_path = self.get_temp_path('reference.wav')
+        sox_utils.gen_audio_file(input_path, sample_rate, num_channels)
+        sox_utils.run_sox_effect(input_path, reference_path, effects, output_bitdepth=32)
+
+        expected, expected_sr = load_wav(reference_path)
+        found, sr = sox_effects.apply_effects_file(
+            input_path, effects, channels_first=channels_first)
+        save_wav(self.get_temp_path('result.wav'), found, sr, channels_first=channels_first)
+
+        assert sr == expected_sr
+        self.assertEqual(found, expected)
+
+    @parameterized.expand(list(itertools.product(
+        [8000, 16000],
+        [1, 2],
+    )), name_func=lambda f, _, p: f'{f.__name__}_{"_".join(str(arg) for arg in p.args)}')
+    def test_vorbis(self, sample_rate, num_channels):
+        """`apply_effects_file` works on various vorbis format"""
+        channels_first = True
+        effects = [['band', '300', '10']]
+
+        input_path = self.get_temp_path('input.vorbis')
+        reference_path = self.get_temp_path('reference.wav')
+        sox_utils.gen_audio_file(input_path, sample_rate, num_channels)
+        sox_utils.run_sox_effect(input_path, reference_path, effects, output_bitdepth=32)
+
+        expected, expected_sr = load_wav(reference_path)
+        found, sr = sox_effects.apply_effects_file(
+            input_path, effects, channels_first=channels_first)
+        save_wav(self.get_temp_path('result.wav'), found, sr, channels_first=channels_first)
+
+        assert sr == expected_sr
+        self.assertEqual(found, expected)

test/sox_effect/test_torchscript.py

+from typing import List
+
+import torch
+from torchaudio import sox_effects
+from parameterized import parameterized
+
+from ..common_utils import (
+    TempDirMixin,
+    PytorchTestCase,
+    skipIfNoExtension,
+    get_sinusoid,
+    load_params,
+    save_wav,
+)
+
+
+class SoxEffectTensorTransform(torch.nn.Module):
+    effects: List[List[str]]
+
+    def __init__(self, effects: List[List[str]], sample_rate: int, channels_first: bool):
+        super().__init__()
+        self.effects = effects
+        self.sample_rate = sample_rate
+        self.channels_first = channels_first
+
+    def forward(self, tensor: torch.Tensor):
+        return sox_effects.apply_effects_tensor(
+            tensor, self.sample_rate, self.effects, self.channels_first)
+
+
+class SoxEffectFileTransform(torch.nn.Module):
+    effects: List[List[str]]
+    channels_first: bool
+
+    def __init__(self, effects: List[List[str]], channels_first: bool):
+        super().__init__()
+        self.effects = effects
+        self.channels_first = channels_first
+
+    def forward(self, path: str):
+        return sox_effects.apply_effects_file(path, self.effects, self.channels_first)
+
+
+@skipIfNoExtension
+class TestTorchScript(TempDirMixin, PytorchTestCase):
+    @parameterized.expand(
+        load_params("sox_effect_test_args.json"),
+        name_func=lambda f, i, p: f'{f.__name__}_{i}_{p.args[0]["effects"][0][0]}',
+    )
+    def test_apply_effects_tensor(self, args):
+        effects = args['effects']
+        channels_first = True
+        num_channels = args.get("num_channels", 2)
+        input_sr = args.get("input_sample_rate", 8000)
+
+        trans = SoxEffectTensorTransform(effects, input_sr, channels_first)
+
+        path = self.get_temp_path('sox_effect.zip')
+        torch.jit.script(trans).save(path)
+        trans = torch.jit.load(path)
+
+        wav = get_sinusoid(
+            frequency=800, sample_rate=input_sr,
+            n_channels=num_channels, dtype='float32', channels_first=channels_first)
+        found, sr_found = trans(wav)
+        expected, sr_expected = sox_effects.apply_effects_tensor(
+            wav, input_sr, effects, channels_first)
+
+        assert sr_found == sr_expected
+        self.assertEqual(expected, found)
+
+    @parameterized.expand(
+        load_params("sox_effect_test_args.json"),
+        name_func=lambda f, i, p: f'{f.__name__}_{i}_{p.args[0]["effects"][0][0]}',
+    )
+    def test_apply_effects_file(self, args):
+        effects = args['effects']
+        channels_first = True
+        num_channels = args.get("num_channels", 2)
+        input_sr = args.get("input_sample_rate", 8000)
+
+        trans = SoxEffectFileTransform(effects, channels_first)
+
+        path = self.get_temp_path('sox_effect.zip')
+        torch.jit.script(trans).save(path)
+        trans = torch.jit.load(path)
+
+        path = self.get_temp_path('input.wav')
+        wav = get_sinusoid(
+            frequency=800, sample_rate=input_sr,
+            n_channels=num_channels, dtype='float32', channels_first=channels_first)
+        save_wav(path, wav, sample_rate=input_sr, channels_first=channels_first)
+
+        found, sr_found = trans(path)
+        expected, sr_expected = sox_effects.apply_effects_file(path, effects, channels_first)
+
+        assert sr_found == sr_expected
+        self.assertEqual(expected, found)

test/utils/test_sox_utils.py

+from torchaudio.utils import sox_utils
+
+from ..common_utils import (
+    PytorchTestCase,
+    skipIfNoExtension,
+)
+
+
+@skipIfNoExtension
+class TestSoxUtils(PytorchTestCase):
+    """Smoke tests for sox_util module"""
+    def test_set_seed(self):
+        """`set_seed` does not crush"""
+        sox_utils.set_seed(0)
+
+    def test_set_verbosity(self):
+        """`set_verbosity` does not crush"""
+        for val in range(6, 0, -1):
+            sox_utils.set_verbosity(val)
+
+    def test_set_buffer_size(self):
+        """`set_buffer_size` does not crush"""
+        sox_utils.set_buffer_size(131072)
+        # back to default
+        sox_utils.set_buffer_size(8192)
+
+    def test_set_use_threads(self):
+        """`set_use_threads` does not crush"""
+        sox_utils.set_use_threads(True)
+        # back to default
+        sox_utils.set_use_threads(False)
+
+    def test_list_effects(self):
+        """`list_effects` returns the list of available effects"""
+        effects = sox_utils.list_effects()
+        # We cannot infer what effects are available, so only check some of them.
+        assert 'highpass' in effects
+        assert 'phaser' in effects
+        assert 'gain' in effects
+
+    def test_list_formats(self):
+        """`list_formats` returns the list of supported formats"""
+        formats = sox_utils.list_formats()
+        assert 'wav' in formats

torchaudio/__init__.py

@@ -4,6 +4,7 @@ from torchaudio import (
     compliance,
     datasets,
     kaldi_io,
+    utils,
     sox_effects,
     transforms
 )

torchaudio/csrc/register.cpp

@@ -18,6 +18,17 @@ static auto registerTensorSignal =
         .def("get_sample_rate", &sox_utils::TensorSignal::getSampleRate)
         .def("get_channels_first", &sox_utils::TensorSignal::getChannelsFirst);
 
+static auto registerSetSoxOptions =
+    torch::RegisterOperators()
+        .op("torchaudio::sox_utils_set_seed", &sox_utils::set_seed)
+        .op("torchaudio::sox_utils_set_verbosity", &sox_utils::set_verbosity)
+        .op("torchaudio::sox_utils_set_use_threads",
+            &sox_utils::set_use_threads)
+        .op("torchaudio::sox_utils_set_buffer_size",
+            &sox_utils::set_buffer_size)
+        .op("torchaudio::sox_utils_list_effects", &sox_utils::list_effects)
+        .op("torchaudio::sox_utils_list_formats", &sox_utils::list_formats);
+
 ////////////////////////////////////////////////////////////////////////////////
 // sox_io.h
 ////////////////////////////////////////////////////////////////////////////////
@@ -53,12 +64,23 @@ static auto registerSaveAudioFile = torch::RegisterOperators().op(
 // sox_effects.h
 ////////////////////////////////////////////////////////////////////////////////
 static auto registerSoxEffects =
-    torch::RegisterOperators(
-        "torchaudio::sox_effects_initialize_sox_effects",
-        &sox_effects::initialize_sox_effects)
+    torch::RegisterOperators()
+        .op("torchaudio::sox_effects_initialize_sox_effects",
+            &sox_effects::initialize_sox_effects)
         .op("torchaudio::sox_effects_shutdown_sox_effects",
             &sox_effects::shutdown_sox_effects)
-        .op("torchaudio::sox_effects_list_effects", &sox_effects::list_effects);
+        .op(torch::RegisterOperators::options()
+                .schema(
+                    "torchaudio::sox_effects_apply_effects_tensor(__torch__.torch.classes.torchaudio.TensorSignal input_signal, str[][] effects) -> __torch__.torch.classes.torchaudio.TensorSignal output_signal")
+                .catchAllKernel<
+                    decltype(sox_effects::apply_effects_tensor),
+                    &sox_effects::apply_effects_tensor>())
+        .op(torch::RegisterOperators::options()
+                .schema(
+                    "torchaudio::sox_effects_apply_effects_file(str path, str[][] effects, bool normalize, bool channels_first) -> __torch__.torch.classes.torchaudio.TensorSignal output_signal")
+                .catchAllKernel<
+                    decltype(sox_effects::apply_effects_file),
+                    &sox_effects::apply_effects_file>());
 
 } // namespace
 } // namespace torchaudio

torchaudio/csrc/sox_effects.cpp

 #include <sox.h>
 #include <torchaudio/csrc/sox_effects.h>
+#include <torchaudio/csrc/sox_effects_chain.h>
+#include <torchaudio/csrc/sox_utils.h>
 
-using namespace torch::indexing;
+using namespace torchaudio::sox_utils;
 
 namespace torchaudio {
 namespace sox_effects {
@@ -10,44 +12,125 @@ namespace {
 
 enum SoxEffectsResourceState { NotInitialized, Initialized, ShutDown };
 SoxEffectsResourceState SOX_RESOURCE_STATE = NotInitialized;
+std::mutex SOX_RESOUCE_STATE_MUTEX;
 
 } // namespace
 
 void initialize_sox_effects() {
-  if (SOX_RESOURCE_STATE == ShutDown) {
-    throw std::runtime_error(
-        "SoX Effects has been shut down. Cannot initialize again.");
-  }
-  if (SOX_RESOURCE_STATE == NotInitialized) {
-    if (sox_init() != SOX_SUCCESS) {
-      throw std::runtime_error("Failed to initialize sox effects.");
-    };
-    SOX_RESOURCE_STATE = Initialized;
+  const std::lock_guard<std::mutex> lock(SOX_RESOUCE_STATE_MUTEX);
+
+  switch (SOX_RESOURCE_STATE) {
+    case NotInitialized:
+      if (sox_init() != SOX_SUCCESS) {
+        throw std::runtime_error("Failed to initialize sox effects.");
+      };
+      SOX_RESOURCE_STATE = Initialized;
+    case Initialized:
+      break;
+    case ShutDown:
+      throw std::runtime_error(
+          "SoX Effects has been shut down. Cannot initialize again.");
   }
 };
 
 void shutdown_sox_effects() {
-  if (SOX_RESOURCE_STATE == NotInitialized) {
-    throw std::runtime_error(
-        "SoX Effects is not initialized. Cannot shutdown.");
+  const std::lock_guard<std::mutex> lock(SOX_RESOUCE_STATE_MUTEX);
+
+  switch (SOX_RESOURCE_STATE) {
+    case NotInitialized:
+      throw std::runtime_error(
+          "SoX Effects is not initialized. Cannot shutdown.");
+    case Initialized:
+      if (sox_quit() != SOX_SUCCESS) {
+        throw std::runtime_error("Failed to initialize sox effects.");
+      };
+      SOX_RESOURCE_STATE = ShutDown;
+    case ShutDown:
+      break;
   }
-  if (SOX_RESOURCE_STATE == Initialized) {
-    if (sox_quit() != SOX_SUCCESS) {
-      throw std::runtime_error("Failed to initialize sox effects.");
-    };
-    SOX_RESOURCE_STATE = ShutDown;
+}
+
+c10::intrusive_ptr<TensorSignal> apply_effects_tensor(
+    const c10::intrusive_ptr<TensorSignal>& input_signal,
+    std::vector<std::vector<std::string>> effects) {
+  auto in_tensor = input_signal->getTensor();
+  validate_input_tensor(in_tensor);
+
+  // Create SoxEffectsChain
+  const auto dtype = in_tensor.dtype();
+  torchaudio::sox_effects_chain::SoxEffectsChain chain(
+      /*input_encoding=*/get_encodinginfo("wav", dtype, 0.),
+      /*output_encoding=*/get_encodinginfo("wav", dtype, 0.));
+
+  // Prepare output buffer
+  std::vector<sox_sample_t> out_buffer;
+  out_buffer.reserve(in_tensor.numel());
+
+  // Build and run effects chain
+  chain.addInputTensor(input_signal.get());
+  for (const auto& effect : effects) {
+    chain.addEffect(effect);
   }
+  chain.addOutputBuffer(&out_buffer);
+  chain.run();
+
+  // Create tensor from buffer
+  const auto channels_first = input_signal->getChannelsFirst();
+  auto out_tensor = convert_to_tensor(
+      /*buffer=*/out_buffer.data(),
+      /*num_samples=*/out_buffer.size(),
+      /*num_channels=*/chain.getOutputNumChannels(),
+      dtype,
+      /*noramlize=*/false,
+      channels_first);
+
+  return c10::make_intrusive<TensorSignal>(
+      out_tensor, chain.getOutputSampleRate(), channels_first);
 }
 
-std::vector<std::string> list_effects() {
-  std::vector<std::string> names;
-  const sox_effect_fn_t* fns = sox_get_effect_fns();
-  for (int i = 0; fns[i]; ++i) {
-    const sox_effect_handler_t* handler = fns[i]();
-    if (handler && handler->name)
-      names.push_back(handler->name);
+c10::intrusive_ptr<TensorSignal> apply_effects_file(
+    const std::string path,
+    std::vector<std::vector<std::string>> effects,
+    const bool normalize,
+    const bool channels_first) {
+  // Open input file
+  SoxFormat sf(sox_open_read(
+      path.c_str(),
+      /*signal=*/nullptr,
+      /*encoding=*/nullptr,
+      /*filetype=*/nullptr));
+
+  validate_input_file(sf);
+
+  const auto dtype = get_dtype(sf->encoding.encoding, sf->signal.precision);
+
+  // Prepare output
+  std::vector<sox_sample_t> out_buffer;
+  out_buffer.reserve(sf->signal.length);
+
+  // Create and run SoxEffectsChain
+  torchaudio::sox_effects_chain::SoxEffectsChain chain(
+      /*input_encoding=*/sf->encoding,
+      /*output_encoding=*/get_encodinginfo("wav", dtype, 0.));
+
+  chain.addInputFile(sf);
+  for (const auto& effect : effects) {
+    chain.addEffect(effect);
   }
-  return names;
+  chain.addOutputBuffer(&out_buffer);
+  chain.run();
+
+  // Create tensor from buffer
+  auto tensor = convert_to_tensor(
+      /*buffer=*/out_buffer.data(),
+      /*num_samples=*/out_buffer.size(),
+      /*num_channels=*/chain.getOutputNumChannels(),
+      dtype,
+      normalize,
+      channels_first);
+
+  return c10::make_intrusive<TensorSignal>(
+      tensor, chain.getOutputSampleRate(), channels_first);
 }
 
 } // namespace sox_effects

torchaudio/csrc/sox_effects.h

@@ -2,6 +2,7 @@
 #define TORCHAUDIO_SOX_EFFECTS_H
 
 #include <torch/script.h>
+#include <torchaudio/csrc/sox_utils.h>
 
 namespace torchaudio {
 namespace sox_effects {
@@ -10,7 +11,15 @@ void initialize_sox_effects();
 
 void shutdown_sox_effects();
 
-std::vector<std::string> list_effects();
+c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal> apply_effects_tensor(
+    const c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal>& input_signal,
+    std::vector<std::vector<std::string>> effects);
+
+c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal> apply_effects_file(
+    const std::string path,
+    std::vector<std::vector<std::string>> effects,
+    const bool normalize = true,
+    const bool channels_first = true);
 
 } // namespace sox_effects
 } // namespace torchaudio

torchaudio/csrc/sox_effects_chain.cpp

+#include <torchaudio/csrc/sox_effects_chain.h>
+#include <torchaudio/csrc/sox_utils.h>
+
+using namespace torch::indexing;
+using namespace torchaudio::sox_utils;
+
+namespace torchaudio {
+namespace sox_effects_chain {
+
+namespace {
+
+// Helper struct to safely close sox_effect_t* pointer returned by
+// sox_create_effect
+struct SoxEffect {
+  explicit SoxEffect(sox_effect_t* se) noexcept : se_(se){};
+  SoxEffect(const SoxEffect& other) = delete;
+  SoxEffect(const SoxEffect&& other) = delete;
+  SoxEffect& operator=(const SoxEffect& other) = delete;
+  SoxEffect& operator=(SoxEffect&& other) = delete;
+  ~SoxEffect() {
+    if (se_ != nullptr) {
+      free(se_);
+    }
+  }
+  operator sox_effect_t*() const {
+    return se_;
+  };
+  sox_effect_t* operator->() noexcept {
+    return se_;
+  }
+
+ private:
+  sox_effect_t* se_;
+};
+
+/// helper classes for passing the location of input tensor and output buffer
+///
+/// drain/flow callback functions require plaing C style function signature and
+/// the way to pass extra data is to attach data to sox_fffect_t::priv pointer.
+/// The following structs will be assigned to sox_fffect_t::priv pointer which
+/// gives sox_effect_t an access to input Tensor and output buffer object.
+struct TensorInputPriv {
+  size_t index;
+  TensorSignal* signal;
+};
+struct TensorOutputPriv {
+  std::vector<sox_sample_t>* buffer;
+};
+
+/// Callback function to feed Tensor data to SoxEffectChain.
+int tensor_input_drain(sox_effect_t* effp, sox_sample_t* obuf, size_t* osamp) {
+  // Retrieve the input Tensor and current index
+  auto priv = static_cast<TensorInputPriv*>(effp->priv);
+  auto index = priv->index;
+  auto signal = priv->signal;
+  auto tensor = signal->getTensor();
+  auto num_channels = effp->out_signal.channels;
+
+  // Adjust the number of samples to read
+  const size_t num_samples = tensor.numel();
+  if (index + *osamp > num_samples) {
+    *osamp = num_samples - index;
+  }
+  // Ensure that it's a multiple of the number of channels
+  *osamp -= *osamp % num_channels;
+
+  // Slice the input Tensor and unnormalize the values
+  const auto tensor_ = [&]() {
+    auto i_frame = index / num_channels;
+    auto num_frames = *osamp / num_channels;
+    auto t = (signal->getChannelsFirst())
+        ? tensor.index({Slice(), Slice(i_frame, i_frame + num_frames)}).t()
+        : tensor.index({Slice(i_frame, i_frame + num_frames), Slice()});
+    return unnormalize_wav(t.reshape({-1})).contiguous();
+  }();
+  priv->index += *osamp;
+
+  // Write data to SoxEffectsChain buffer.
+  auto ptr = tensor_.data_ptr<int32_t>();
+  std::copy(ptr, ptr + *osamp, obuf);
+
+  return (priv->index == num_samples) ? SOX_EOF : SOX_SUCCESS;
+}
+
+/// Callback function to fetch data from SoxEffectChain.
+int tensor_output_flow(
+    sox_effect_t* effp LSX_UNUSED,
+    sox_sample_t const* ibuf,
+    sox_sample_t* obuf LSX_UNUSED,
+    size_t* isamp,
+    size_t* osamp) {
+  *osamp = 0;
+  // Get output buffer
+  auto out_buffer = static_cast<TensorOutputPriv*>(effp->priv)->buffer;
+  // Append at the end
+  out_buffer->insert(out_buffer->end(), ibuf, ibuf + *isamp);
+  return SOX_SUCCESS;
+}
+
+sox_effect_handler_t* get_tensor_input_handler() {
+  static sox_effect_handler_t handler{/*name=*/"input_tensor",
+                                      /*usage=*/NULL,
+                                      /*flags=*/SOX_EFF_MCHAN,
+                                      /*getopts=*/NULL,
+                                      /*start=*/NULL,
+                                      /*flow=*/NULL,
+                                      /*drain=*/tensor_input_drain,
+                                      /*stop=*/NULL,
+                                      /*kill=*/NULL,
+                                      /*priv_size=*/sizeof(TensorInputPriv)};
+  return &handler;
+}
+
+sox_effect_handler_t* get_tensor_output_handler() {
+  static sox_effect_handler_t handler{/*name=*/"output_tensor",
+                                      /*usage=*/NULL,
+                                      /*flags=*/SOX_EFF_MCHAN,
+                                      /*getopts=*/NULL,
+                                      /*start=*/NULL,
+                                      /*flow=*/tensor_output_flow,
+                                      /*drain=*/NULL,
+                                      /*stop=*/NULL,
+                                      /*kill=*/NULL,
+                                      /*priv_size=*/sizeof(TensorOutputPriv)};
+  return &handler;
+}
+
+} // namespace
+
+SoxEffectsChain::SoxEffectsChain(
+    sox_encodinginfo_t input_encoding,
+    sox_encodinginfo_t output_encoding)
+    : in_enc_(input_encoding),
+      out_enc_(output_encoding),
+      in_sig_(),
+      interm_sig_(),
+      sec_(sox_create_effects_chain(&in_enc_, &out_enc_)) {
+  if (!sec_) {
+    throw std::runtime_error("Failed to create effect chain.");
+  }
+}
+
+SoxEffectsChain::~SoxEffectsChain() {
+  if (sec_ != nullptr) {
+    sox_delete_effects_chain(sec_);
+  }
+}
+
+void SoxEffectsChain::run() {
+  sox_flow_effects(sec_, NULL, NULL);
+}
+
+void SoxEffectsChain::addInputTensor(TensorSignal* signal) {
+  in_sig_ = get_signalinfo(signal, "wav");
+  interm_sig_ = in_sig_;
+  SoxEffect e(sox_create_effect(get_tensor_input_handler()));
+  auto priv = static_cast<TensorInputPriv*>(e->priv);
+  priv->signal = signal;
+  priv->index = 0;
+  if (sox_add_effect(sec_, e, &interm_sig_, &in_sig_) != SOX_SUCCESS) {
+    throw std::runtime_error("Failed to add effect: input_tensor");
+  }
+}
+
+void SoxEffectsChain::addOutputBuffer(
+    std::vector<sox_sample_t>* output_buffer) {
+  SoxEffect e(sox_create_effect(get_tensor_output_handler()));
+  static_cast<TensorOutputPriv*>(e->priv)->buffer = output_buffer;
+  if (sox_add_effect(sec_, e, &interm_sig_, &in_sig_) != SOX_SUCCESS) {
+    throw std::runtime_error("Failed to add effect: output_tensor");
+  }
+}
+
+void SoxEffectsChain::addInputFile(sox_format_t* sf) {
+  in_sig_ = sf->signal;
+  interm_sig_ = in_sig_;
+  SoxEffect e(sox_create_effect(sox_find_effect("input")));
+  char* opts[] = {(char*)sf};
+  sox_effect_options(e, 1, opts);
+  if (sox_add_effect(sec_, e, &interm_sig_, &in_sig_) != SOX_SUCCESS) {
+    std::ostringstream stream;
+    stream << "Failed to add effect: input " << sf->filename;
+    throw std::runtime_error(stream.str());
+  }
+}
+
+void SoxEffectsChain::addEffect(const std::vector<std::string> effect) {
+  const auto num_args = effect.size();
+  if (num_args == 0) {
+    throw std::runtime_error("Invalid argument: empty effect.");
+  }
+  const auto name = effect[0];
+  if (UNSUPPORTED_EFFECTS.find(name) != UNSUPPORTED_EFFECTS.end()) {
+    std::ostringstream stream;
+    stream << "Unsupported effect: " << name;
+    throw std::runtime_error(stream.str());
+  }
+
+  SoxEffect e(sox_create_effect(sox_find_effect(name.c_str())));
+  const auto num_options = num_args - 1;
+
+  std::vector<char*> opts;
+  for (size_t i = 1; i < num_args; ++i) {
+    opts.push_back((char*)effect[i].c_str());
+  }
+  if (sox_effect_options(e, num_options, num_options ? opts.data() : nullptr) !=
+      SOX_SUCCESS) {
+    std::ostringstream stream;
+    stream << "Invalid effect option:";
+    for (const auto& v : effect) {
+      stream << " " << v;
+    }
+    throw std::runtime_error(stream.str());
+  }
+
+  if (sox_add_effect(sec_, e, &interm_sig_, &in_sig_) != SOX_SUCCESS) {
+    std::ostringstream stream;
+    stream << "Failed to add effect: \"" << name;
+    for (size_t i = 1; i < num_args; ++i) {
+      stream << " " << effect[i];
+    }
+    stream << "\"";
+    throw std::runtime_error(stream.str());
+  }
+}
+
+int64_t SoxEffectsChain::getOutputNumChannels() {
+  return interm_sig_.channels;
+}
+
+int64_t SoxEffectsChain::getOutputSampleRate() {
+  return interm_sig_.rate;
+}
+
+} // namespace sox_effects_chain
+} // namespace torchaudio

torchaudio/csrc/sox_effects_chain.h

+#ifndef TORCHAUDIO_SOX_EFFECTS_CHAIN_H
+#define TORCHAUDIO_SOX_EFFECTS_CHAIN_H
+
+#include <sox.h>
+#include <torch/script.h>
+#include <torchaudio/csrc/sox_utils.h>
+
+namespace torchaudio {
+namespace sox_effects_chain {
+
+// Helper struct to safely close sox_effects_chain_t with handy methods
+class SoxEffectsChain {
+  const sox_encodinginfo_t in_enc_;
+  const sox_encodinginfo_t out_enc_;
+  sox_signalinfo_t in_sig_;
+  sox_signalinfo_t interm_sig_;
+  sox_effects_chain_t* sec_;
+
+ public:
+  explicit SoxEffectsChain(
+      sox_encodinginfo_t input_encoding,
+      sox_encodinginfo_t output_encoding);
+  SoxEffectsChain(const SoxEffectsChain& other) = delete;
+  SoxEffectsChain(const SoxEffectsChain&& other) = delete;
+  SoxEffectsChain& operator=(const SoxEffectsChain& other) = delete;
+  SoxEffectsChain& operator=(SoxEffectsChain&& other) = delete;
+  ~SoxEffectsChain();
+  void run();
+  void addInputTensor(torchaudio::sox_utils::TensorSignal* signal);
+  void addInputFile(sox_format_t* sf);
+  void addOutputBuffer(std::vector<sox_sample_t>* output_buffer);
+  void addEffect(const std::vector<std::string> effect);
+  int64_t getOutputNumChannels();
+  int64_t getOutputSampleRate();
+};
+
+} // namespace sox_effects_chain
+} // namespace torchaudio
+
+#endif