Remove legacy backends (#1311)

torchaudio/datasets/tedlium.py

@@ -153,11 +153,7 @@ class TEDLIUM(Dataset):
         start_time = int(float(start_time) * sample_rate)
         end_time = int(float(end_time) * sample_rate)
 
-        backend = torchaudio.get_audio_backend()
-        if backend == "sox" or (backend == "soundfile" and torchaudio.USE_SOUNDFILE_LEGACY_INTERFACE):
-            kwargs = {"offset": start_time, "num_frames": end_time - start_time}
-        else:
-            kwargs = {"frame_offset": start_time, "num_frames": end_time - start_time}
+        kwargs = {"frame_offset": start_time, "num_frames": end_time - start_time}
 
         return torchaudio.load(path, **kwargs)
 

torchaudio/extension/extension.py

@@ -9,6 +9,7 @@ def _init_extension():
     ext = 'torchaudio._torchaudio'
     if _mod_utils.is_module_available(ext):
         _init_script_module(ext)
+        import torchaudio._torchaudio  # noqa
     else:
         warnings.warn('torchaudio C++ extension is not available.')