Replace libsox with stub library (#3497)

Summary:
This commit updates the way libsox is integrated to torchaudio

1. We stop statically linking libsox, so torchaudio will not ship libsox.
2. We link libsox dynamically. Users are expected to install libsox by themselves.
3. We use stab library to build torchaudio.

Pull Request resolved: https://github.com/pytorch/audio/pull/3497

Differential Revision: D47803706

Pulled By: mthrok

fbshipit-source-id: 31b05495d81069186fa52d67beea360cc7e817a8

.github/scripts/unittest-linux/install.sh

@@ -75,7 +75,7 @@ fi
 # Note: installing librosa via pip fail because it will try to compile numba.
 (
     set -x
-    conda install -y -c conda-forge ${NUMBA_DEV_CHANNEL} 'librosa==0.10.0' parameterized 'requests>=2.20' 'ffmpeg>=5,<7'
+    conda install -y -c conda-forge ${NUMBA_DEV_CHANNEL} sox libvorbis 'librosa==0.10.0' parameterized 'requests>=2.20' 'ffmpeg>=5,<7'
     pip install kaldi-io SoundFile coverage pytest pytest-cov 'scipy==1.7.3' expecttest unidecode inflect Pillow sentencepiece pytorch-lightning 'protobuf<4.21.0' demucs tinytag pyroomacoustics flashlight-text git+https://github.com/kpu/kenlm
 )
 # Install fairseq

.github/workflows/build_docs.yml

@@ -63,7 +63,7 @@ jobs:
 
         echo "::endgroup::"
         echo "::group::Install TorchAudio"
-        conda install --quiet --yes pkg-config cmake>=3.18.0 ninja
+        conda install --quiet --yes cmake>=3.18.0 ninja
         pip3 install --progress-bar off -v -e . --no-use-pep517
 
         echo "::endgroup::"
@@ -75,7 +75,7 @@ jobs:
         conda install \
           --quiet --yes \
           -c conda-forge \
-          pandoc doxygen pysoundfile
+          sox libvorbis pandoc doxygen pysoundfile
         pip install --progress-bar off \
             git+https://github.com/kpu/kenlm/ flashlight-text \
             -r docs/requirements.txt -r docs/requirements-tutorials.txt

.github/workflows/integration-test.yml

@@ -24,7 +24,7 @@ jobs:
     - name: Install dependencies
       run: |
         sudo add-apt-repository -y ppa:jonathonf/ffmpeg-4
-        sudo apt install -y -qq pkg-config libavfilter-dev libavdevice-dev
+        sudo apt install -y -qq libavfilter-dev libavdevice-dev
     - name: Install packages
       run: |
         python -m pip install --quiet --upgrade pip

.github/workflows/unittest-linux-cpu.yml

@@ -50,6 +50,8 @@ jobs:
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_AUDIO_OUT_DEVICE=true
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_MACOS=true
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_TEMPORARY_DISABLED=true
+        export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_SOX_DECODER=true
+        export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_SOX_ENCODER=true
         echo '::endgroup::'
 
         set -euxo pipefail

.github/workflows/unittest-linux-gpu.yml

@@ -38,6 +38,8 @@ jobs:
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_CUDA_SMALL_MEMORY=true
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_ON_PYTHON_310=true
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_TEMPORARY_DISABLED=true
+        export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_SOX_DECODER=true
+        export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_SOX_ENCODER=true
 
         # Set CHANNEL
         if [[(${GITHUB_EVENT_NAME} = 'pull_request' && (${GITHUB_BASE_REF} = 'release'*)) || (${GITHUB_REF} = 'refs/heads/release'*) ]]; then
@@ -63,7 +65,7 @@ jobs:
 
         echo "::endgroup::"
         echo "::group::Install TorchAudio"
-        conda install --quiet --yes pkg-config 'cmake>=3.18.0' ninja
+        conda install --quiet --yes 'cmake>=3.18.0' ninja
         pip3 install --progress-bar off -v -e . --no-use-pep517
 
         echo "::endgroup::"
@@ -76,7 +78,7 @@ jobs:
           --quiet --yes \
           -c conda-forge \
           -c numba/label/dev \
-          'librosa==0.10.0' parameterized 'requests>=2.20'
+          sox libvorbis 'librosa==0.10.0' parameterized 'requests>=2.20'
         pip3 install --progress-bar off \
           kaldi-io \
           SoundFile \

.github/workflows/unittest-macos-cpu.yml

@@ -49,6 +49,8 @@ jobs:
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_MOD_sentencepiece=true
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_AUDIO_OUT_DEVICE=true
         export TORCHAUDIO_TEST_ALLOW_SKIP_IF_TEMPORARY_DISABLED=true
+        export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_SOX_DECODER=true
+        export TORCHAUDIO_TEST_ALLOW_SKIP_IF_NO_SOX_ENCODER=true
         echo '::endgroup::'
 
         set -euxo pipefail

CONTRIBUTING.md

@@ -49,13 +49,11 @@ torchaudio.
 conda install pytorch -c pytorch-nightly
 ```
 
-### Install build dependencies
+### Install build/runtime dependencies
 
 ```bash
 # Install build-time dependencies
 pip install cmake ninja
-# [optional for sox]
-conda install pkg-config
 # [optional for ffmpeg]
 conda install ffmpeg
 ```

docs/source/build.jetson.rst

@@ -121,7 +121,7 @@ Verify the installation by checking the version and CUDA device accessibility.
 
 .. code-block::
 
-   pip install cmake ninja pkg-config
+   pip install cmake ninja
 
 2. Install dependencies
 ~~~~~~~~~~~~~~~~~~~~~~~

docs/source/build.linux.rst

@@ -22,7 +22,7 @@ Here, we install nightly build.
 
 .. code-block::
 
-   conda install cmake ninja pkg-config
+   conda install cmake ninja
 
 4. Clone the torchaudio repository
 ----------------------------------

docs/source/build.rst

@@ -10,7 +10,6 @@ TorchAudio integrates PyTorch for numerical computation and third party librarie
    - `GCC <https://gcc.gnu.org/>`_ (Linux)
    - `Clang <https://clang.llvm.org/>`_ (macOS)
    - `MSVC <https://visualstudio.microsoft.com>`_  2019 or newer (Windows)
-- `pkg-config <https://www.freedesktop.org/wiki/Software/pkg-config/>`_ (Linux/macOS, if building sox extension)
 - `CUDA toolkit <https://developer.nvidia.com/cudnn>`_ and `cuDNN <https://developer.nvidia.com/cudnn>`_ (if building CUDA extension)
 
 Most of the tools are available in `Conda <https://conda.io/>`_, so we recommend using conda.

packaging/torchaudio/meta.yaml

@@ -14,7 +14,6 @@ requirements:
   host:
     - python
     - setuptools
-    - pkg-config  # [not win]
     - cmake
     - ninja
     - pytorch-mutex 1.0 {{ build_variant }}  # [not osx ]

setup.py

@@ -4,7 +4,6 @@ import os
 import re
 import shutil
 import subprocess
-import sys
 from pathlib import Path
 
 import torch
@@ -83,18 +82,6 @@ def _get_packages(branch_name, tag):
     return find_packages(exclude=exclude)
 
 
-def _init_submodule():
-    print(" --- Initializing submodules")
-    try:
-        subprocess.check_call(["git", "submodule", "init"])
-        subprocess.check_call(["git", "submodule", "update"])
-    except Exception:
-        print(" --- Submodule initalization failed")
-        print("Please run:\n\tgit submodule update --init --recursive")
-        sys.exit(1)
-    print(" --- Initialized submodule")
-
-
 def _parse_url(path):
     with open(path, "r") as file_:
         for line in file_:
@@ -104,18 +91,6 @@ def _parse_url(path):
                 yield url
 
 
-def _parse_sources():
-    third_party_dir = ROOT_DIR / "third_party"
-    libs = ["sox"]
-    archive_dir = third_party_dir / "archives"
-    archive_dir.mkdir(exist_ok=True)
-    for lib in libs:
-        cmake_file = third_party_dir / lib / "CMakeLists.txt"
-        for url in _parse_url(cmake_file):
-            path = archive_dir / os.path.basename(url)
-            yield path, url
-
-
 def _fetch_archives(src):
     for dest, url in src:
         if not dest.exists():
@@ -123,13 +98,6 @@ def _fetch_archives(src):
             torch.hub.download_url_to_file(url, dest, progress=False)
 
 
-def _fetch_third_party_libraries():
-    # Revert this when a submodule is added again
-    # _init_submodule()
-    if os.name != "nt":
-        _fetch_archives(_parse_sources())
-
-
 def _main():
     sha = _run_cmd(["git", "rev-parse", "HEAD"])
     branch = _run_cmd(["git", "rev-parse", "--abbrev-ref", "HEAD"])
@@ -143,7 +111,6 @@ def _main():
     print("-- Building version", version)
 
     _make_version_file(version, sha)
-    _fetch_third_party_libraries()
 
     with open("README.md") as f:
         long_description = f.read()

third_party/sox/CMakeLists.txt

-find_package(PkgConfig REQUIRED)
+include(FetchContent)
 
-include(ExternalProject)
-
-set(INSTALL_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../install)
-set(ARCHIVE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../archives)
-set(patch_dir ${PROJECT_SOURCE_DIR}/third_party/patches)
-set(COMMON_ARGS --quiet --disable-shared --enable-static --prefix=${INSTALL_DIR} --with-pic --disable-dependency-tracking --disable-debug --disable-examples --disable-doc)
-
-# To pass custom environment variables to ExternalProject_Add command,
-# we need to do `${CMAKE_COMMAND} -E env ${envs} <COMMANAD>`.
-# https://stackoverflow.com/a/62437353
-# We constrcut the custom environment variables here
-set(envs
-  "PKG_CONFIG_PATH=${INSTALL_DIR}/lib/pkgconfig"
-  "LDFLAGS=-L${INSTALL_DIR}/lib $ENV{LDFLAGS}"
-  "CFLAGS=-I${INSTALL_DIR}/include -fvisibility=hidden $ENV{CFLAGS}"
-)
-
-ExternalProject_Add(amr
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://sourceforge.net/projects/opencore-amr/files/opencore-amr/opencore-amr-0.1.5.tar.gz
-  URL_HASH SHA256=2c006cb9d5f651bfb5e60156dbff6af3c9d35c7bbcc9015308c0aff1e14cd341
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/amr/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/amr/configure ${COMMON_ARGS}
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-ExternalProject_Add(lame
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://downloads.sourceforge.net/project/lame/lame/3.99/lame-3.99.5.tar.gz
-  URL_HASH SHA256=24346b4158e4af3bd9f2e194bb23eb473c75fb7377011523353196b19b9a23ff
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/lame/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/lame/configure ${COMMON_ARGS} --enable-nasm
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-ExternalProject_Add(ogg
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://ftp.osuosl.org/pub/xiph/releases/ogg/libogg-1.3.3.tar.gz
-  URL_HASH SHA256=c2e8a485110b97550f453226ec644ebac6cb29d1caef2902c007edab4308d985
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/ogg/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/ogg/configure ${COMMON_ARGS}
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-ExternalProject_Add(flac
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS ogg
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://ftp.osuosl.org/pub/xiph/releases/flac/flac-1.3.2.tar.xz
-  URL_HASH SHA256=91cfc3ed61dc40f47f050a109b08610667d73477af6ef36dcad31c31a4a8d53f
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/flac/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/flac/configure ${COMMON_ARGS} --with-ogg --disable-cpplibs --disable-xmms-plugin
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-ExternalProject_Add(vorbis
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS ogg
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://ftp.osuosl.org/pub/xiph/releases/vorbis/libvorbis-1.3.6.tar.gz
-  URL_HASH SHA256=6ed40e0241089a42c48604dc00e362beee00036af2d8b3f46338031c9e0351cb
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/vorbis/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/vorbis/configure ${COMMON_ARGS} --with-ogg
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-ExternalProject_Add(opus
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS ogg
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://ftp.osuosl.org/pub/xiph/releases/opus/opus-1.3.1.tar.gz
-  URL_HASH SHA256=65b58e1e25b2a114157014736a3d9dfeaad8d41be1c8179866f144a2fb44ff9d
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/opus/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/opus/configure ${COMMON_ARGS} --with-ogg
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-ExternalProject_Add(opusfile
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS opus
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
-  URL https://ftp.osuosl.org/pub/xiph/releases/opus/opusfile-0.12.tar.gz
-  URL_HASH SHA256=118d8601c12dd6a44f52423e68ca9083cc9f2bfe72da7a8c1acb22a80ae3550b
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/opusfile/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/opusfile/configure ${COMMON_ARGS} --disable-http
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-# OpenMP is by default compiled against GNU OpenMP, which conflicts with the version of OpenMP that PyTorch uses.
-# See https://github.com/pytorch/audio/pull/1026
-# TODO: Add flags like https://github.com/suphoff/pytorch_parallel_extension_cpp/blob/master/setup.py
-set(SOX_OPTIONS
-  --disable-openmp
-  --with-amrnb
-  --with-amrwb
-  --with-flac
-  --with-lame
-  --with-oggvorbis
-  --with-opus
-  --without-alsa
-  --without-ao
-  --without-coreaudio
-  --without-oss
-  --without-id3tag
-  --without-ladspa
-  --without-mad
-  --without-magic
-  --without-png
-  --without-pulseaudio
-  --without-sndfile
-  --without-sndio
-  --without-sunaudio
-  --without-waveaudio
-  --without-wavpack
-  --without-twolame
-  )
-
-set(SOX_LIBRARIES
-  ${INSTALL_DIR}/lib/libsox.a
-  ${INSTALL_DIR}/lib/libopencore-amrnb.a
-  ${INSTALL_DIR}/lib/libopencore-amrwb.a
-  ${INSTALL_DIR}/lib/libmp3lame.a
-  ${INSTALL_DIR}/lib/libFLAC.a
-  ${INSTALL_DIR}/lib/libopusfile.a
-  ${INSTALL_DIR}/lib/libopus.a
-  ${INSTALL_DIR}/lib/libvorbisenc.a
-  ${INSTALL_DIR}/lib/libvorbisfile.a
-  ${INSTALL_DIR}/lib/libvorbis.a
-  ${INSTALL_DIR}/lib/libogg.a
-  )
-
-set(sox_depends
-  ogg flac vorbis opusfile lame amr
-  )
-
-ExternalProject_Add(sox
-  PREFIX ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS ${sox_depends}
-  DOWNLOAD_DIR ${ARCHIVE_DIR}
+FetchContent_Declare(
+  sox_src
   URL https://downloads.sourceforge.net/project/sox/sox/14.4.2/sox-14.4.2.tar.bz2
   URL_HASH SHA256=81a6956d4330e75b5827316e44ae381e6f1e8928003c6aa45896da9041ea149c
-  PATCH_COMMAND cp ${patch_dir}/config.guess ${patch_dir}/config.sub ${CMAKE_CURRENT_BINARY_DIR}/src/sox/
-  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E env ${envs} ${CMAKE_CURRENT_BINARY_DIR}/src/sox/configure ${COMMON_ARGS} ${SOX_OPTIONS}
-  BUILD_BYPRODUCTS ${SOX_LIBRARIES}
-  DOWNLOAD_NO_PROGRESS ON
-  LOG_DOWNLOAD ON
-  LOG_UPDATE ON
-  LOG_CONFIGURE ON
-  LOG_BUILD ON
-  LOG_INSTALL ON
-  LOG_MERGED_STDOUTERR ON
-  LOG_OUTPUT_ON_FAILURE ON
-)
-
-add_library(libsox INTERFACE)
-add_dependencies(libsox sox)
-target_include_directories(libsox INTERFACE ${INSTALL_DIR}/include)
-target_link_libraries(libsox INTERFACE ${SOX_LIBRARIES})
+  PATCH_COMMAND ""
+  CONFIGURE_COMMAND ""
+  BUILD_COMMAND ""
+  )
+# FetchContent_MakeAvailable will parse the downloaded content and setup the targets.
+# We want to only download and not build, so we run Populate manually.
+if(NOT sox_src_POPULATED)
+  FetchContent_Populate(sox_src)
+endif()
+
+add_library(sox SHARED stub.c)
+if(APPLE)
+  set_target_properties(sox PROPERTIES SUFFIX .dylib)
+endif(APPLE)
+target_include_directories(sox PUBLIC ${sox_src_SOURCE_DIR}/src)

third_party/sox/stub.c

+#include <sox.h>
+
+int sox_add_effect(
+    sox_effects_chain_t* chain,
+    sox_effect_t* effp,
+    sox_signalinfo_t* in,
+    sox_signalinfo_t const* out) {
+  return -1;
+}
+int sox_close(sox_format_t* ft) {
+  return -1;
+}
+
+sox_effect_t* sox_create_effect(sox_effect_handler_t const* eh) {
+  return NULL;
+}
+
+sox_effects_chain_t* sox_create_effects_chain(
+    sox_encodinginfo_t const* in_enc,
+    sox_encodinginfo_t const* out_enc) {
+  return NULL;
+}
+
+void sox_delete_effect(sox_effect_t* effp) {}
+void sox_delete_effects_chain(sox_effects_chain_t* ecp) {}
+
+int sox_effect_options(sox_effect_t* effp, int argc, char* const argv[]) {
+  return -1;
+}
+
+const sox_effect_handler_t* sox_find_effect(char const* name) {
+  return NULL;
+}
+
+int sox_flow_effects(
+    sox_effects_chain_t* chain,
+    int callback(sox_bool all_done, void* client_data),
+    void* client_data) {
+  return -1;
+}
+
+const sox_effect_fn_t* sox_get_effect_fns(void) {
+  return NULL;
+}
+
+const sox_format_tab_t* sox_get_format_fns(void) {
+  return NULL;
+}
+
+sox_globals_t* sox_get_globals(void) {
+  return NULL;
+}
+
+sox_format_t* sox_open_read(
+    char const* path,
+    sox_signalinfo_t const* signal,
+    sox_encodinginfo_t const* encoding,
+    char const* filetype) {
+  return NULL;
+}
+
+sox_format_t* sox_open_write(
+    char const* path,
+    sox_signalinfo_t const* signal,
+    sox_encodinginfo_t const* encoding,
+    char const* filetype,
+    sox_oob_t const* oob,
+    sox_bool overwrite_permitted(char const* filename)) {
+  return NULL;
+}
+
+const char* sox_strerror(int sox_errno) {
+  return NULL;
+}
+
+size_t sox_write(sox_format_t* ft, const sox_sample_t* buf, size_t len) {
+  return 0;
+}
+
+int sox_init() {
+  return -1;
+};
+int sox_quit() {
+  return -1;
+};

torchaudio/_extension/__init__.py

@@ -8,7 +8,7 @@ try:
     from .fb import _init_ffmpeg
 except ImportError:
     from .utils import _init_ffmpeg
-from .utils import _check_cuda_version, _fail_since_no_ffmpeg, _init_dll_path, _init_sox, _load_lib
+from .utils import _check_cuda_version, _fail_since_no_ffmpeg, _fail_since_no_sox, _init_dll_path, _init_sox, _load_lib
 
 _LG = logging.getLogger(__name__)
 
@@ -51,17 +51,21 @@ if _IS_TORCHAUDIO_EXT_AVAILABLE:
     _IS_ALIGN_AVAILABLE = torchaudio.lib._torchaudio.is_align_available()
 
 
-# Similar to libtorchaudio, sox-related features should be importable when present.
-#
-# Note: This will be change in the future when sox is dynamically linked.
-# At that point, this initialization should handle the case where
-# sox integration is built but libsox is not found.
+# Initialize libsox-related features
 _SOX_INITIALIZED = False
 _USE_SOX = False if os.name == "nt" else eval_env("TORCHAUDIO_USE_SOX", True)
 _SOX_MODULE_AVAILABLE = is_module_available("torchaudio.lib._torchaudio_sox")
 if _USE_SOX and _SOX_MODULE_AVAILABLE:
-    _init_sox()
-    _SOX_INITIALIZED = True
+    try:
+        _init_sox()
+        _SOX_INITIALIZED = True
+    except Exception:
+        # The initialization of sox extension will fail if supported sox
+        # libraries are not found in the system.
+        # Since the rest of the torchaudio works without it, we do not report the
+        # error here.
+        # The error will be raised when user code attempts to use these features.
+        _LG.debug("Failed to initialize sox extension", exc_info=True)
 
 
 if os.name == "nt":
@@ -74,7 +78,7 @@ elif not _SOX_MODULE_AVAILABLE:
         "Please build TorchAudio with libsox support. (BUILD_SOX=1)"
     )
 else:
-    fail_if_no_sox = no_op
+    fail_if_no_sox = no_op if _SOX_INITIALIZED else _fail_since_no_sox
 
 
 # Initialize FFmpeg-related features

torchaudio/_extension/utils.py

@@ -197,6 +197,25 @@ def _check_cuda_version():
     return version
 
 
+def _fail_since_no_sox(func):
+    @wraps(func)
+    def wrapped(*_args, **_kwargs):
+        try:
+            # Note:
+            # We run _init_sox again just to show users the stacktrace.
+            # _init_sox would not succeed here.
+            _init_sox()
+        except Exception as err:
+            raise RuntimeError(
+                f"{func.__name__} requires sox extension which is not available. "
+                "Please refer to the stacktrace above for how to resolve this."
+            ) from err
+        # This should not happen in normal execution, but just in case.
+        return func(*_args, **_kwargs)
+
+    return wrapped
+
+
 def _fail_since_no_ffmpeg(func):
     @wraps(func)
     def wrapped(*_args, **_kwargs):

torchaudio/csrc/sox/CMakeLists.txt

@@ -10,7 +10,7 @@ torchaudio_library(
   libtorchaudio_sox
   "${sources}"
   ""
-  "torch;libsox"
+  "torch;sox"
   ""
   )
 

torchaudio/csrc/sox/utils.h

@@ -2,7 +2,7 @@
 #define TORCHAUDIO_SOX_UTILS_H
 
 #include <sox.h>
-#include <torch/script.h>
+#include <torch/types.h>
 
 namespace torchaudio::sox {