Expose AudioMetadata

``torchaudio.info`` returns ``AudioMetaData``. It should be exposed as public API.

docs/source/backend.rst

@@ -38,7 +38,7 @@ Structures used to report the metadata of audio files.
 AudioMetaData
 -------------
 
-.. autoclass:: torchaudio.backend.common.AudioMetaData
+.. autoclass:: torchaudio.AudioMetaData
 
 .. py:module:: torchaudio.backend.sox_io_backend
 

torchaudio/__init__.py

@@ -1,4 +1,4 @@
-from torchaudio import (  # noqa: F401
+from . import (  # noqa: F401
     _extension,
     compliance,
     datasets,
@@ -11,6 +11,8 @@
     transforms,
     utils,
 )
+from .backend.common import AudioMetaData
+
 
 try:
     from .version import __version__, git_version  # noqa: F401
@@ -34,6 +36,7 @@ def _is_backend_dispatcher_enabled():
 
 
 __all__ = [
+    "AudioMetaData",
     "io",
     "compliance",
     "datasets",

torchaudio/backend/common.py

@@ -1,8 +1,11 @@
+from dataclasses import dataclass
+
+
+@dataclass
 class AudioMetaData:
-    """Return type of ``torchaudio.info`` function.
+    """AudioMetaData()
 
-    This class is used by :py:mod:`"sox_io" backend<torchaudio.backends.sox_io_backend>` and
-    :py:mod:`"soundfile" backend<torchaudio.backends.soundfile_backend>`.
+    Return type of :py:func:`torchaudio.info` function.
 
     :ivar int sample_rate: Sample rate
     :ivar int num_frames: The number of frames
@@ -27,27 +30,8 @@ class AudioMetaData:
             * ``UNKNOWN`` : None of above
     """
 
-    def __init__(
-        self,
-        sample_rate: int,
-        num_frames: int,
-        num_channels: int,
-        bits_per_sample: int,
-        encoding: str,
-    ):
-        self.sample_rate = sample_rate
-        self.num_frames = num_frames
-        self.num_channels = num_channels
-        self.bits_per_sample = bits_per_sample
-        self.encoding = encoding
-
-    def __str__(self):
-        return (
-            f"AudioMetaData("
-            f"sample_rate={self.sample_rate}, "
-            f"num_frames={self.num_frames}, "
-            f"num_channels={self.num_channels}, "
-            f"bits_per_sample={self.bits_per_sample}, "
-            f"encoding={self.encoding}"
-            f")"
-        )
+    sample_rate: int
+    num_frames: int
+    num_channels: int
+    bits_per_sample: int
+    encoding: str