Revert "Remove BC code"

This reverts commit abbb52e.

torchaudio/backend/sox_io_backend.py

@@ -111,7 +111,7 @@ def load(
             ``[channel, time]`` else ``[time, channel]``.
     """
     sample_rate = -1 if sample_rate is None else sample_rate
-    signal = torch.ops.torchaudio.sox_io_load_audio_file(
+    signal = torch.ops.torchaudio.sox_io_load_audio_file_v1(
         filepath, frame_offset, num_frames, normalize, channels_first, sample_rate)
     return signal.get_tensor(), signal.get_sample_rate()
 

torchaudio/csrc/register.cpp

@@ -51,6 +51,9 @@ TORCH_LIBRARY(torchaudio, m) {
   m.def(
       "torchaudio::sox_io_load_audio_file",
       &torchaudio::sox_io::load_audio_file);
+  m.def(
+      "torchaudio::sox_io_load_audio_file_v1",
+      &torchaudio::sox_io::load_audio_file_v1);
   m.def(
       "torchaudio::sox_io_save_audio_file",
       &torchaudio::sox_io::save_audio_file);

torchaudio/csrc/sox_io.cpp

@@ -48,6 +48,15 @@ c10::intrusive_ptr<SignalInfo> get_info(const std::string& path) {
 }
 
 c10::intrusive_ptr<TensorSignal> load_audio_file(
+    const std::string& path,
+    const int64_t frame_offset,
+    const int64_t num_frames,
+    const bool normalize,
+    const bool channels_first) {
+  return load_audio_file_v1(path, frame_offset, num_frames, channels_first, -1);
+}
+
+c10::intrusive_ptr<TensorSignal> load_audio_file_v1(
     const std::string& path,
     const int64_t frame_offset,
     const int64_t num_frames,

torchaudio/csrc/sox_io.h

@@ -23,7 +23,16 @@ struct SignalInfo : torch::CustomClassHolder {
 
 c10::intrusive_ptr<SignalInfo> get_info(const std::string& path);
 
+// ver. 0
 c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal> load_audio_file(
+    const std::string& path,
+    const int64_t frame_offset = 0,
+    const int64_t num_frames = -1,
+    const bool normalize = true,
+    const bool channels_first = true);
+
+// ver. 1 sample_rate is added
+c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal> load_audio_file_v1(
     const std::string& path,
     const int64_t frame_offset = 0,
     const int64_t num_frames = -1,