Add depreaction warnings to file-like object support in sox_io (#3033)

Summary: Pull Request resolved: https://github.com/pytorch/audio/pull/3033

Reviewed By: hwangjeff

Differential Revision: D42966938

Pulled By: mthrok

fbshipit-source-id: 4889735c244690889f02bf57212489ad333389f7

torchaudio/backend/sox_io_backend.py

 import os
+import warnings
 from typing import Optional, Tuple
 
 import torch
@@ -47,6 +48,14 @@ else:
     _fallback_load_fileobj = _fail_load_fileobj
 
 
+_deprecation_message = (
+    "File-like object support in sox_io backend is deprecated, "
+    "and will be removed in v2.1. "
+    "See https://github.com/pytorch/audio/issues/2950 for the detail."
+    "Please migrate to the new dispatcher, or use soundfile backend."
+)
+
+
 @torchaudio._extension.fail_if_no_sox
 def info(
     filepath: str,
@@ -94,6 +103,7 @@ def info(
             buffer_size = get_buffer_size()
             if format == "mp3":
                 return _fallback_info_fileobj(filepath, format, buffer_size)
+            warnings.warn(_deprecation_message)
             sinfo = torchaudio.lib._torchaudio_sox.get_info_fileobj(filepath, format)
             if sinfo is not None:
                 return AudioMetaData(*sinfo)
@@ -222,6 +232,7 @@ def load(
                     format,
                     buffer_size,
                 )
+            warnings.warn(_deprecation_message)
             ret = torchaudio.lib._torchaudio_sox.load_audio_fileobj(
                 filepath, frame_offset, num_frames, normalize, channels_first, format
             )
@@ -402,6 +413,7 @@ def save(
     """
     if not torch.jit.is_scripting():
         if hasattr(filepath, "write"):
+            warnings.warn(_deprecation_message)
             torchaudio.lib._torchaudio_sox.save_audio_fileobj(
                 filepath,
                 src,

torchaudio/sox_effects/sox_effects.py

 import os
+import warnings
 from typing import List, Optional, Tuple
 
 import torch
@@ -155,6 +156,14 @@ def apply_effects_tensor(
     return torch.ops.torchaudio.sox_effects_apply_effects_tensor(tensor, sample_rate, effects, channels_first)
 
 
+_deprecation_message = (
+    "File-like object support in sox_io backend is deprecated, "
+    "and will be removed in v2.1. "
+    "See https://github.com/pytorch/audio/issues/2950 for the detail."
+    "Please migrate to the new dispatcher, or use soundfile backend."
+)
+
+
 @torchaudio._extension.fail_if_no_sox
 def apply_effects_file(
     path: str,
@@ -274,6 +283,7 @@ def apply_effects_file(
     """
     if not torch.jit.is_scripting():
         if hasattr(path, "read"):
+            warnings.warn(_deprecation_message)
             ret = torchaudio.lib._torchaudio_sox.apply_effects_fileobj(path, effects, normalize, channels_first, format)
             if ret is None:
                 raise RuntimeError("Failed to load audio from {}".format(path))