Remove frames_per_chunk argument from save (#780)

In #779, we plan to remove `frames_per_chunk` parameter from `save` function, but it will take some time before we can land #779, so we go ahead and remove the parameter first to reduce the conflict caused by interface change.

torchaudio/backend/sox_io_backend.py

@@ -87,7 +87,6 @@ def save(
         sample_rate: int,
         channels_first: bool = True,
         compression: Optional[float] = None,
-        frames_per_chunk: int = 65536,
 ):
     """Save audio data to file.
 
@@ -115,8 +114,6 @@ def save(
                 ``8`` is default and highest compression.
             - OGG/VORBIS: number from -1 to 10; -1 is the highest compression and lowest
                 quality. Default: ``3``.
-        frames_per_chunk: The number of frames to process (convert to ``int32`` internally
-            then write to file) at a time.
     """
     if compression is None:
         ext = str(filepath)[-3:].lower()
@@ -131,7 +128,7 @@ def save(
         else:
             raise RuntimeError(f'Unsupported file type: "{ext}"')
     signal = torch.classes.torchaudio.TensorSignal(tensor, sample_rate, channels_first)
-    torch.ops.torchaudio.sox_io_save_audio_file(filepath, signal, compression, frames_per_chunk)
+    torch.ops.torchaudio.sox_io_save_audio_file(filepath, signal, compression)
 
 
 load_wav = load

torchaudio/csrc/register.cpp

@@ -44,7 +44,7 @@ static auto registerLoadAudioFile = torch::RegisterOperators().op(
 static auto registerSaveAudioFile = torch::RegisterOperators().op(
     torch::RegisterOperators::options()
         .schema(
-            "torchaudio::sox_io_save_audio_file(str path, __torch__.torch.classes.torchaudio.TensorSignal signal, float compression, int frames_per_chunk) -> ()")
+            "torchaudio::sox_io_save_audio_file(str path, __torch__.torch.classes.torchaudio.TensorSignal signal, float compression) -> ()")
         .catchAllKernel<
             decltype(sox_io::save_audio_file),
             &sox_io::save_audio_file>());

torchaudio/csrc/sox_io.cpp

@@ -123,8 +123,7 @@ c10::intrusive_ptr<TensorSignal> load_audio_file(
 void save_audio_file(
     const std::string& file_name,
     const c10::intrusive_ptr<TensorSignal>& signal,
-    const double compression,
-    const int64_t frames_per_chunk) {
+    const double compression) {
   const auto tensor = signal->getTensor();
   const auto sample_rate = signal->getSampleRate();
   const auto channels_first = signal->getChannelsFirst();
@@ -154,6 +153,7 @@ void save_audio_file(
     tensor_ = tensor_.t();
   }
 
+  const int64_t frames_per_chunk = 65536;
   for (int64_t i = 0; i < tensor_.size(0); i += frames_per_chunk) {
     auto chunk = tensor_.index({Slice(i, i + frames_per_chunk), Slice()});
     chunk = unnormalize_wav(chunk).contiguous();

torchaudio/csrc/sox_io.h

@@ -33,8 +33,8 @@ c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal> load_audio_file(
 void save_audio_file(
     const std::string& file_name,
     const c10::intrusive_ptr<torchaudio::sox_utils::TensorSignal>& signal,
-    const double compression = 0.,
-    const int64_t frames_per_chunk = 65536);
+    const double compression = 0.);
+
 } // namespace sox_io
 } // namespace torchaudio