Support file-like object in info (#1108)

test/torchaudio_unittest/soundfile_backend/info_test.py

 from unittest.mock import patch
 import warnings
+import tarfile
 
 import torch
 from torchaudio.backend import _soundfile_backend as soundfile_backend
@@ -125,3 +126,65 @@ class TestInfo(TempDirMixin, PytorchTestCase):
                 assert len(w) == 1
                 assert "UNSEEN_SUBTYPE subtype is unknown to TorchAudio" in str(w[-1].message)
                 assert info.bits_per_sample == 0
+
+
+@skipIfNoModule("soundfile")
+class TestFileObject(TempDirMixin, PytorchTestCase):
+    def _test_fileobj(self, ext, subtype, bits_per_sample):
+        """Query audio via file-like object works"""
+        duration = 2
+        sample_rate = 16000
+        num_channels = 2
+        num_frames = sample_rate * duration
+        path = self.get_temp_path(f'test.{ext}')
+
+        data = torch.randn(num_frames, num_channels).numpy()
+        soundfile.write(path, data, sample_rate, subtype=subtype)
+
+        with open(path, 'rb') as fileobj:
+            info = soundfile_backend.info(fileobj)
+        assert info.sample_rate == sample_rate
+        assert info.num_frames == num_frames
+        assert info.num_channels == num_channels
+        assert info.bits_per_sample == bits_per_sample
+
+    def test_fileobj_wav(self):
+        """Loading audio via file-like object works"""
+        self._test_fileobj('wav', 'PCM_16', 16)
+
+    @skipIfFormatNotSupported("FLAC")
+    def test_fileobj_flac(self):
+        """Loading audio via file-like object works"""
+        self._test_fileobj('flac', 'PCM_16', 16)
+
+    def _test_tarobj(self, ext, subtype, bits_per_sample):
+        """Query compressed audio via file-like object works"""
+        duration = 2
+        sample_rate = 16000
+        num_channels = 2
+        num_frames = sample_rate * duration
+        audio_file = f'test.{ext}'
+        audio_path = self.get_temp_path(audio_file)
+        archive_path = self.get_temp_path('archive.tar.gz')
+
+        data = torch.randn(num_frames, num_channels).numpy()
+        soundfile.write(audio_path, data, sample_rate, subtype=subtype)
+
+        with tarfile.TarFile(archive_path, 'w') as tarobj:
+            tarobj.add(audio_path, arcname=audio_file)
+        with tarfile.TarFile(archive_path, 'r') as tarobj:
+            fileobj = tarobj.extractfile(audio_file)
+            info = soundfile_backend.info(fileobj)
+        assert info.sample_rate == sample_rate
+        assert info.num_frames == num_frames
+        assert info.num_channels == num_channels
+        assert info.bits_per_sample == bits_per_sample
+
+    def test_tarobj_wav(self):
+        """Query compressed audio via file-like object works"""
+        self._test_tarobj('wav', 'PCM_16', 16)
+
+    @skipIfFormatNotSupported("FLAC")
+    def test_tarobj_flac(self):
+        """Query compressed audio via file-like object works"""
+        self._test_tarobj('flac', 'PCM_16', 16)

test/torchaudio_unittest/sox_io_backend/info_test.py

+import io
 import itertools
-from parameterized import parameterized
+import tarfile
 
+from parameterized import parameterized
 from torchaudio.backend import sox_io_backend
+from torchaudio._internal import module_utils as _mod_utils
 
 from torchaudio_unittest.common_utils import (
     TempDirMixin,
+    HttpServerMixin,
     PytorchTestCase,
     skipIfNoExec,
     skipIfNoExtension,
+    skipIfNoModule,
     get_asset_path,
     get_wav_data,
     save_wav,
@@ -18,6 +23,10 @@ from .common import (
 )
 
 
+if _mod_utils.is_module_available("requests"):
+    import requests
+
+
 @skipIfNoExec('sox')
 @skipIfNoExtension
 class TestInfo(TempDirMixin, PytorchTestCase):
@@ -197,3 +206,143 @@ class TestLoadWithoutExtension(PytorchTestCase):
         sinfo = sox_io_backend.info(path, format="mp3")
         assert sinfo.sample_rate == 16000
         assert sinfo.bits_per_sample == 0  # bit_per_sample is irrelevant for compressed formats
+
+
+@skipIfNoExtension
+@skipIfNoExec('sox')
+class TestFileObject(TempDirMixin, PytorchTestCase):
+    @parameterized.expand([
+        ('wav', 32),
+        ('mp3', 0),
+        ('flac', 24),
+        ('vorbis', 0),
+        ('amb', 32),
+    ])
+    def test_fileobj(self, ext, bits_per_sample):
+        """Querying audio via file object works"""
+        sample_rate = 16000
+        num_channels = 2
+        duration = 3
+        format_ = ext if ext in ['mp3'] else None
+        path = self.get_temp_path(f'test.{ext}')
+
+        sox_utils.gen_audio_file(
+            path, sample_rate, num_channels=2,
+            duration=duration)
+
+        with open(path, 'rb') as fileobj:
+            sinfo = sox_io_backend.info(fileobj, format_)
+
+        assert sinfo.sample_rate == sample_rate
+        assert sinfo.num_channels == num_channels
+        if ext not in ['mp3', 'vorbis']:  # these container formats do not have length info
+            assert sinfo.num_frames == sample_rate * duration
+        assert sinfo.bits_per_sample == bits_per_sample
+
+    def _test_bytesio(self, ext, bits_per_sample, duration):
+        sample_rate = 16000
+        num_channels = 2
+        format_ = ext if ext in ['mp3'] else None
+        path = self.get_temp_path(f'test.{ext}')
+
+        sox_utils.gen_audio_file(
+            path, sample_rate, num_channels=2,
+            duration=duration)
+
+        with open(path, 'rb') as file_:
+            fileobj = io.BytesIO(file_.read())
+        sinfo = sox_io_backend.info(fileobj, format_)
+
+        assert sinfo.sample_rate == sample_rate
+        assert sinfo.num_channels == num_channels
+        if ext not in ['mp3', 'vorbis']:  # these container formats do not have length info
+            assert sinfo.num_frames == sample_rate * duration
+        assert sinfo.bits_per_sample == bits_per_sample
+
+    @parameterized.expand([
+        ('wav', 32),
+        ('mp3', 0),
+        ('flac', 24),
+        ('vorbis', 0),
+        ('amb', 32),
+    ])
+    def test_bytesio(self, ext, bits_per_sample):
+        """Querying audio via ByteIO object works"""
+        self._test_bytesio(ext, bits_per_sample, duration=3)
+
+    @parameterized.expand([
+        ('wav', 32),
+        ('mp3', 0),
+        ('flac', 24),
+        ('vorbis', 0),
+        ('amb', 32),
+    ])
+    def test_bytesio_tiny(self, ext, bits_per_sample):
+        """Querying audio via ByteIO object works for small data"""
+        self._test_bytesio(ext, bits_per_sample, duration=1 / 1600)
+
+    @parameterized.expand([
+        ('wav', 32),
+        ('mp3', 0),
+        ('flac', 24),
+        ('vorbis', 0),
+        ('amb', 32),
+    ])
+    def test_tarfile(self, ext, bits_per_sample):
+        """Querying compressed audio via file-like object works"""
+        sample_rate = 16000
+        num_channels = 2
+        duration = 3
+        format_ = ext if ext in ['mp3'] else None
+        audio_file = f'test.{ext}'
+        audio_path = self.get_temp_path(audio_file)
+        archive_path = self.get_temp_path('archive.tar.gz')
+
+        sox_utils.gen_audio_file(
+            audio_path, sample_rate, num_channels=num_channels, duration=duration)
+
+        with tarfile.TarFile(archive_path, 'w') as tarobj:
+            tarobj.add(audio_path, arcname=audio_file)
+        with tarfile.TarFile(archive_path, 'r') as tarobj:
+            fileobj = tarobj.extractfile(audio_file)
+            sinfo = sox_io_backend.info(fileobj, format=format_)
+
+        assert sinfo.sample_rate == sample_rate
+        assert sinfo.num_channels == num_channels
+        if ext not in ['mp3', 'vorbis']:  # these container formats do not have length info
+            assert sinfo.num_frames == sample_rate * duration
+        assert sinfo.bits_per_sample == bits_per_sample
+
+
+@skipIfNoExtension
+@skipIfNoExec('sox')
+@skipIfNoModule("requests")
+class TestFileObjectHttp(HttpServerMixin, PytorchTestCase):
+    @parameterized.expand([
+        ('wav', 32),
+        ('mp3', 0),
+        ('flac', 24),
+        ('vorbis', 0),
+        ('amb', 32),
+    ])
+    def test_requests(self, ext, bits_per_sample):
+        """Querying compressed audio via requests works"""
+        sample_rate = 16000
+        num_channels = 2
+        duration = 3
+        format_ = ext if ext in ['mp3'] else None
+        audio_file = f'test.{ext}'
+        audio_path = self.get_temp_path(audio_file)
+
+        sox_utils.gen_audio_file(
+            audio_path, sample_rate, num_channels=num_channels, duration=duration)
+
+        url = self.get_url(audio_file)
+        with requests.get(url, stream=True) as resp:
+            sinfo = sox_io_backend.info(resp.raw, format=format_)
+
+        assert sinfo.sample_rate == sample_rate
+        assert sinfo.num_channels == num_channels
+        if ext not in ['mp3', 'vorbis']:  # these container formats do not have length info
+            assert sinfo.num_frames == sample_rate * duration
+        assert sinfo.bits_per_sample == bits_per_sample

torchaudio/backend/_soundfile_backend.py

@@ -55,10 +55,12 @@ def info(filepath: str, format: Optional[str] = None) -> AudioMetaData:
     """Get signal information of an audio file.
 
     Args:
-        filepath (str or pathlib.Path): Path to audio file.
-            This functionalso handles ``pathlib.Path`` objects, but is annotated as ``str``
-            for the consistency with "sox_io" backend, which has a restriction on type annotation
-            for TorchScript compiler compatiblity.
+        filepath (path-like object or file-like object):
+            Source of audio data.
+            Note:
+                  * This argument is intentionally annotated as ``str`` only,
+                    for the consistency with "sox_io" backend, which has a restriction
+                    on type annotation due to TorchScript compiler compatiblity.
         format (str, optional):
             Not used. PySoundFile does not accept format hint.
 

torchaudio/backend/sox_io_backend.py

@@ -10,6 +10,26 @@ import torchaudio
 from .common import AudioMetaData
 
 
+@torch.jit.unused
+def _info(
+        filepath: str,
+        format: Optional[str] = None,
+) -> AudioMetaData:
+    if hasattr(filepath, 'read'):
+        sinfo = torchaudio._torchaudio.get_info_fileobj(
+            filepath, format)
+        sample_rate, num_channels, num_frames, bits_per_sample = sinfo
+        return AudioMetaData(
+            sample_rate, num_frames, num_channels, bits_per_sample)
+    sinfo = torch.ops.torchaudio.sox_io_get_info(os.fspath(filepath), format)
+    return AudioMetaData(
+        sinfo.get_sample_rate(),
+        sinfo.get_num_frames(),
+        sinfo.get_num_channels(),
+        sinfo.get_bits_per_sample(),
+    )
+
+
 @_mod_utils.requires_module('torchaudio._torchaudio')
 def info(
         filepath: str,
@@ -18,9 +38,21 @@ def info(
     """Get signal information of an audio file.
 
     Args:
-        filepath (str or pathlib.Path):
-            Path to audio file. This function also handles ``pathlib.Path`` objects,
-            but is annotated as ``str`` for TorchScript compatibility.
+        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, optional):
             Override the format detection with the given format.
             Providing the argument might help when libsox can not infer the format
@@ -29,10 +61,13 @@ def info(
     Returns:
         AudioMetaData: Metadata of the given audio.
     """
-    # Cast to str in case type is `pathlib.Path`
-    filepath = str(filepath)
+    if not torch.jit.is_scripting():
+        return _info(filepath, format)
     sinfo = torch.ops.torchaudio.sox_io_get_info(filepath, format)
-    return AudioMetaData(sinfo.get_sample_rate(), sinfo.get_num_frames(), sinfo.get_num_channels(),
+    return AudioMetaData(
+        sinfo.get_sample_rate(),
+        sinfo.get_num_frames(),
+        sinfo.get_num_channels(),
         sinfo.get_bits_per_sample())
 
 

torchaudio/csrc/pybind.cpp

@@ -100,6 +100,10 @@ PYBIND11_MODULE(_torchaudio, m) {
       "get_info",
       &torch::audio::get_info,
       "Gets information about an audio file");
+  m.def(
+      "get_info_fileobj",
+      &torchaudio::sox_io::get_info_fileobj,
+      "Get metadata of audio in file object.");
   m.def(
       "load_audio_fileobj",
       &torchaudio::sox_io::load_audio_fileobj,

torchaudio/csrc/sox/io.cpp

@@ -36,7 +36,7 @@ int64_t SignalInfo::getBitsPerSample() const {
   return bits_per_sample;
 }
 
-c10::intrusive_ptr<SignalInfo> get_info(
+c10::intrusive_ptr<SignalInfo> get_info_file(
     const std::string& path,
     c10::optional<std::string>& format) {
   SoxFormat sf(sox_open_read(
@@ -149,6 +149,56 @@ void save_audio_file(
 
 #ifdef TORCH_API_INCLUDE_EXTENSION_H
 
+std::tuple<int64_t, int64_t, int64_t, int64_t> get_info_fileobj(
+    py::object fileobj,
+    c10::optional<std::string>& format) {
+  // Prepare in-memory file object
+  // When libsox opens a file, it also reads the header.
+  // When opening a file there are two functions that might touch FILE* (and the
+  // underlying buffer).
+  // * `auto_detect_format`
+  //   https://github.com/dmkrepo/libsox/blob/b9dd1a86e71bbd62221904e3e59dfaa9e5e72046/src/formats.c#L43
+  // * `startread` handler of detected format.
+  //   https://github.com/dmkrepo/libsox/blob/b9dd1a86e71bbd62221904e3e59dfaa9e5e72046/src/formats.c#L574
+  // To see the handler of a particular format, go to
+  //   https://github.com/dmkrepo/libsox/blob/b9dd1a86e71bbd62221904e3e59dfaa9e5e72046/src/<FORMAT>.c
+  // For example, voribs can be found
+  //   https://github.com/dmkrepo/libsox/blob/b9dd1a86e71bbd62221904e3e59dfaa9e5e72046/src/vorbis.c#L97-L158
+  //
+  // `auto_detect_format` function only requires 256 bytes, but format-dependant
+  // `startread` handler might require more data. In case of vorbis, the size of
+  // header is unbounded, but typically 4kB maximum.
+  //
+  // "The header size is unbounded, although for streaming a rule-of-thumb of
+  // 4kB or less is recommended (and Xiph.Org's Vorbis encoder follows this
+  // suggestion)."
+  //
+  // See:
+  // https://xiph.org/vorbis/doc/Vorbis_I_spec.html
+  auto capacity = 4096;
+  std::string buffer(capacity, '\0');
+  auto* buf = const_cast<char*>(buffer.data());
+  auto num_read = read_fileobj(&fileobj, capacity, buf);
+  // If the file is shorter than 256, then libsox cannot read the header.
+  auto buf_size = (num_read > 256) ? num_read : 256;
+
+  SoxFormat sf(sox_open_mem_read(
+      buf,
+      buf_size,
+      /*signal=*/nullptr,
+      /*encoding=*/nullptr,
+      /*filetype=*/format.has_value() ? format.value().c_str() : nullptr));
+
+  // In case of streamed data, length can be 0
+  validate_input_file(sf, /*check_length=*/false);
+
+  return std::make_tuple(
+      static_cast<int64_t>(sf->signal.rate),
+      static_cast<int64_t>(sf->signal.channels),
+      static_cast<int64_t>(sf->signal.length / sf->signal.channels),
+      static_cast<int64_t>(sf->encoding.bits_per_sample));
+}
+
 std::tuple<torch::Tensor, int64_t> load_audio_fileobj(
     py::object fileobj,
     c10::optional<int64_t>& frame_offset,

torchaudio/csrc/sox/io.h

@@ -28,7 +28,7 @@ struct SignalInfo : torch::CustomClassHolder {
   int64_t getBitsPerSample() const;
 };
 
-c10::intrusive_ptr<SignalInfo> get_info(
+c10::intrusive_ptr<SignalInfo> get_info_file(
     const std::string& path,
     c10::optional<std::string>& format);
 
@@ -50,6 +50,10 @@ void save_audio_file(
 
 #ifdef TORCH_API_INCLUDE_EXTENSION_H
 
+std::tuple<int64_t, int64_t, int64_t, int64_t> get_info_fileobj(
+    py::object fileobj,
+    c10::optional<std::string>& format);
+
 std::tuple<torch::Tensor, int64_t> load_audio_fileobj(
     py::object fileobj,
     c10::optional<int64_t>& frame_offset,

torchaudio/csrc/sox/register.cpp

@@ -47,7 +47,7 @@ TORCH_LIBRARY_FRAGMENT(torchaudio, m) {
           "get_bits_per_sample",
           &torchaudio::sox_io::SignalInfo::getBitsPerSample);
 
-  m.def("torchaudio::sox_io_get_info", &torchaudio::sox_io::get_info);
+  m.def("torchaudio::sox_io_get_info", &torchaudio::sox_io::get_info_file);
   m.def(
       "torchaudio::sox_io_load_audio_file("
       "str path,"

torchaudio/csrc/sox/utils.cpp

@@ -317,5 +317,37 @@ sox_encodinginfo_t get_encodinginfo(
       /*opposite_endian=*/sox_false};
 }
 
+#ifdef TORCH_API_INCLUDE_EXTENSION_H
+
+uint64_t read_fileobj(py::object* fileobj, const uint64_t size, char* buffer) {
+  uint64_t num_read = 0;
+  while (num_read < size) {
+    auto request = size - num_read;
+    auto chunk = static_cast<std::string>(
+        static_cast<py::bytes>(fileobj->attr("read")(request)));
+    auto chunk_len = chunk.length();
+    if (chunk_len == 0) {
+      break;
+    }
+    if (chunk_len > request) {
+      std::ostringstream message;
+      message
+          << "Requested up to " << request << " bytes but, "
+          << "received " << chunk_len << " bytes. "
+          << "The given object does not confirm to read protocol of file object.";
+      throw std::runtime_error(message.str());
+    }
+
+    std::cerr << "req: " << request << ", fetched: " << chunk_len << std::endl;
+    std::cerr << "buffer: " << (void*)buffer << std::endl;
+    memcpy(buffer, chunk.data(), chunk_len);
+    buffer += chunk_len;
+    num_read += chunk_len;
+  }
+  return num_read;
+}
+
+#endif // TORCH_API_INCLUDE_EXTENSION_H
+
 } // namespace sox_utils
 } // namespace torchaudio

torchaudio/csrc/sox/utils.h

@@ -4,6 +4,10 @@
 #include <sox.h>
 #include <torch/script.h>
 
+#ifdef TORCH_API_INCLUDE_EXTENSION_H
+#include <torch/extension.h>
+#endif // TORCH_API_INCLUDE_EXTENSION_H
+
 namespace torchaudio {
 namespace sox_utils {
 
@@ -127,6 +131,12 @@ sox_encodinginfo_t get_encodinginfo(
     const caffe2::TypeMeta dtype,
     c10::optional<double>& compression);
 
+#ifdef TORCH_API_INCLUDE_EXTENSION_H
+
+uint64_t read_fileobj(py::object* fileobj, uint64_t size, char* buffer);
+
+#endif // TORCH_API_INCLUDE_EXTENSION_H
+
 } // namespace sox_utils
 } // namespace torchaudio
 #endif