Refactor sox pybind source code (#2636)

Summary:
Pull Request resolved: https://github.com/pytorch/audio/pull/2636

At the early stage of torchaudio extension module,
`torchaudio/csrc/pybind` directory was created so that
all the code defining Python interface would be placed
there and there will be only one extension module called
`torchaudio._torchaudio`.

However, the codebase has been evolved in a way separate
extensions are defined for each feature (third party
dependency) for the sake of more moduler file organization.

What is left in `csrc/pybind` is libsox Python bindings.
This commit moves it under `csrc/sox`.

Follow-up rename `torchaudio._torchaudio` to `torchaudio._torchaudio_sox`.

Reviewed By: carolineechen

Differential Revision: D38829253

fbshipit-source-id: 3554af45a2beb0f902810c5548751264e093f28d

torchaudio/csrc/CMakeLists.txt

@@ -163,12 +163,13 @@ if(USE_FFMPEG)
 endif()
 
 ################################################################################
+# TODO: Rename this to _torchaudio_sox.so
 # _torchaudio.so
 ################################################################################
 if (BUILD_TORCHAUDIO_PYTHON_EXTENSION)
   set(
     EXTENSION_SOURCES
-    pybind/pybind.cpp
+    sox/pybind/pybind.cpp
     )
   #----------------------------------------------------------------------------#
   # START OF CUSTOMIZATION LOGICS
@@ -177,10 +178,10 @@ if (BUILD_TORCHAUDIO_PYTHON_EXTENSION)
     list(
       APPEND
       EXTENSION_SOURCES
-      pybind/sox/effects.cpp
-      pybind/sox/effects_chain.cpp
-      pybind/sox/io.cpp
-      pybind/sox/utils.cpp
+      sox/pybind/effects.cpp
+      sox/pybind/effects_chain.cpp
+      sox/pybind/io.cpp
+      sox/pybind/utils.cpp
       )
   endif()
   #----------------------------------------------------------------------------#

torchaudio/csrc/pybind/sox/effects.cpp → torchaudio/csrc/sox/pybind/effects.cpp

-#include <torchaudio/csrc/pybind/sox/effects.h>
-#include <torchaudio/csrc/pybind/sox/effects_chain.h>
-#include <torchaudio/csrc/pybind/sox/utils.h>
+#include <torchaudio/csrc/sox/pybind/effects.h>
+#include <torchaudio/csrc/sox/pybind/effects_chain.h>
+#include <torchaudio/csrc/sox/pybind/utils.h>
 
 using namespace torchaudio::sox_utils;
 

torchaudio/csrc/pybind/sox/effects_chain.cpp → torchaudio/csrc/sox/pybind/effects_chain.cpp

 #include <sox.h>
-#include <torchaudio/csrc/pybind/sox/effects_chain.h>
-#include <torchaudio/csrc/pybind/sox/utils.h>
+#include <torchaudio/csrc/sox/pybind/effects_chain.h>
+#include <torchaudio/csrc/sox/pybind/utils.h>
 
 using namespace torchaudio::sox_utils;
 

torchaudio/csrc/pybind/sox/io.cpp → torchaudio/csrc/sox/pybind/io.cpp

-#include <torchaudio/csrc/pybind/sox/effects.h>
-#include <torchaudio/csrc/pybind/sox/effects_chain.h>
-#include <torchaudio/csrc/pybind/sox/io.h>
-#include <torchaudio/csrc/pybind/sox/utils.h>
 #include <torchaudio/csrc/sox/io.h>
+#include <torchaudio/csrc/sox/pybind/effects.h>
+#include <torchaudio/csrc/sox/pybind/effects_chain.h>
+#include <torchaudio/csrc/sox/pybind/io.h>
+#include <torchaudio/csrc/sox/pybind/utils.h>
 #include <torchaudio/csrc/sox/types.h>
 
 #include <utility>

torchaudio/csrc/pybind/pybind.cpp → torchaudio/csrc/sox/pybind/pybind.cpp

 #include <torch/extension.h>
 
 #ifdef INCLUDE_SOX
-#include <torchaudio/csrc/pybind/sox/effects.h>
-#include <torchaudio/csrc/pybind/sox/io.h>
+#include <torchaudio/csrc/sox/pybind/effects.h>
+#include <torchaudio/csrc/sox/pybind/io.h>
 #endif
 
 PYBIND11_MODULE(_torchaudio, m) {

torchaudio/csrc/pybind/sox/utils.cpp → torchaudio/csrc/sox/pybind/utils.cpp

-#include <torchaudio/csrc/pybind/sox/utils.h>
+#include <torchaudio/csrc/sox/pybind/utils.h>
 
 namespace torchaudio::sox_utils {