Simplified C++ interface for sox_io's get_info_file() (#1232)

Co-authored-by: Prabhat Roy <prabhatroy@fb.com>

torchaudio/backend/sox_io_backend.py

@@ -11,24 +11,6 @@ import torchaudio
 from .common import AudioMetaData
 
 
-@torch.jit.unused
-def _info(
-        filepath: str,
-        format: Optional[str] = None,
-) -> AudioMetaData:
-    if hasattr(filepath, 'read'):
-        sinfo = torchaudio._torchaudio.get_info_fileobj(filepath, format)
-        return AudioMetaData(*sinfo)
-    sinfo = torch.ops.torchaudio.sox_io_get_info(os.fspath(filepath), format)
-    return AudioMetaData(
-        sinfo.get_sample_rate(),
-        sinfo.get_num_frames(),
-        sinfo.get_num_channels(),
-        sinfo.get_bits_per_sample(),
-        sinfo.get_encoding(),
-    )
-
-
 @_mod_utils.requires_module('torchaudio._torchaudio')
 def info(
         filepath: str,
@@ -61,14 +43,12 @@ def info(
         AudioMetaData: Metadata of the given audio.
     """
     if not torch.jit.is_scripting():
-        return _info(filepath, format)
+        if hasattr(filepath, 'read'):
+            sinfo = torchaudio._torchaudio.get_info_fileobj(filepath, format)
+            return AudioMetaData(*sinfo)
+        filepath = os.fspath(filepath)
     sinfo = torch.ops.torchaudio.sox_io_get_info(filepath, format)
-    return AudioMetaData(
-        sinfo.get_sample_rate(),
-        sinfo.get_num_frames(),
-        sinfo.get_num_channels(),
-        sinfo.get_bits_per_sample(),
-        sinfo.get_encoding())
+    return AudioMetaData(*sinfo)
 
 
 @_mod_utils.requires_module('torchaudio._torchaudio')

torchaudio/csrc/sox/io.cpp

@@ -10,38 +10,6 @@ using namespace torchaudio::sox_utils;
 namespace torchaudio {
 namespace sox_io {
 
-SignalInfo::SignalInfo(
-    const int64_t sample_rate_,
-    const int64_t num_channels_,
-    const int64_t num_frames_,
-    const int64_t bits_per_sample_,
-    const std::string encoding_)
-    : sample_rate(sample_rate_),
-      num_channels(num_channels_),
-      num_frames(num_frames_),
-      bits_per_sample(bits_per_sample_),
-      encoding(encoding_){};
-
-int64_t SignalInfo::getSampleRate() const {
-  return sample_rate;
-}
-
-int64_t SignalInfo::getNumChannels() const {
-  return num_channels;
-}
-
-int64_t SignalInfo::getNumFrames() const {
-  return num_frames;
-}
-
-int64_t SignalInfo::getBitsPerSample() const {
-  return bits_per_sample;
-}
-
-std::string SignalInfo::getEncoding() const {
-  return encoding;
-}
-
 namespace {
 
 std::string get_encoding(sox_encoding_t encoding) {
@@ -77,7 +45,7 @@ std::string get_encoding(sox_encoding_t encoding) {
 
 } // namespace
 
-c10::intrusive_ptr<SignalInfo> get_info_file(
+std::tuple<int64_t, int64_t, int64_t, int64_t, std::string> get_info_file(
     const std::string& path,
     c10::optional<std::string>& format) {
   SoxFormat sf(sox_open_read(
@@ -90,10 +58,10 @@ c10::intrusive_ptr<SignalInfo> get_info_file(
     throw std::runtime_error("Error opening audio file");
   }
 
-  return c10::make_intrusive<SignalInfo>(
+  return std::make_tuple(
       static_cast<int64_t>(sf->signal.rate),
-      static_cast<int64_t>(sf->signal.channels),
       static_cast<int64_t>(sf->signal.length / sf->signal.channels),
+      static_cast<int64_t>(sf->signal.channels),
       static_cast<int64_t>(sf->encoding.bits_per_sample),
       get_encoding(sf->encoding.encoding));
 }
@@ -347,15 +315,6 @@ void save_audio_fileobj(
 #endif // TORCH_API_INCLUDE_EXTENSION_H
 
 TORCH_LIBRARY_FRAGMENT(torchaudio, m) {
-  m.class_<torchaudio::sox_io::SignalInfo>("SignalInfo")
-      .def("get_sample_rate", &torchaudio::sox_io::SignalInfo::getSampleRate)
-      .def("get_num_channels", &torchaudio::sox_io::SignalInfo::getNumChannels)
-      .def("get_num_frames", &torchaudio::sox_io::SignalInfo::getNumFrames)
-      .def(
-          "get_bits_per_sample",
-          &torchaudio::sox_io::SignalInfo::getBitsPerSample)
-      .def("get_encoding", &torchaudio::sox_io::SignalInfo::getEncoding);
-
   m.def("torchaudio::sox_io_get_info", &torchaudio::sox_io::get_info_file);
   m.def(
       "torchaudio::sox_io_load_audio_file",

torchaudio/csrc/sox/io.h

@@ -11,27 +11,7 @@
 namespace torchaudio {
 namespace sox_io {
 
-struct SignalInfo : torch::CustomClassHolder {
-  int64_t sample_rate;
-  int64_t num_channels;
-  int64_t num_frames;
-  int64_t bits_per_sample;
-  std::string encoding;
-
-  SignalInfo(
-      const int64_t sample_rate_,
-      const int64_t num_channels_,
-      const int64_t num_frames_,
-      const int64_t bits_per_sample_,
-      const std::string encoding_);
-  int64_t getSampleRate() const;
-  int64_t getNumChannels() const;
-  int64_t getNumFrames() const;
-  int64_t getBitsPerSample() const;
-  std::string getEncoding() const;
-};
-
-c10::intrusive_ptr<SignalInfo> get_info_file(
+std::tuple<int64_t, int64_t, int64_t, int64_t, std::string> get_info_file(
     const std::string& path,
     c10::optional<std::string>& format);