usse vcpkg just for the libsndfile build chain

Tools/CMake/vcpkg/ports/opus/fix-pkgconfig-version.patch

@@ -0,0 +1,15 @@
+diff --git a/cmake/OpusPackageVersion.cmake b/cmake/OpusPackageVersion.cmake
+index 447ce3b..15ebd8e 100644
+--- a/cmake/OpusPackageVersion.cmake
++++ b/cmake/OpusPackageVersion.cmake
+@@ -4,7 +4,9 @@ endif()
+ set(__opus_version INCLUDED)
+ 
+ function(get_package_version PACKAGE_VERSION PROJECT_VERSION)
+-
++  set(PACKAGE_VERSION "0" CACHE STRING "opus package version")
++  set(PROJECT_VERSION "0" CACHE STRING "opus project version")
++  return()
+   find_package(Git)
+   if(GIT_FOUND AND EXISTS "${CMAKE_CURRENT_LIST_DIR}/.git")
+     execute_process(COMMAND ${GIT_EXECUTABLE}

Tools/CMake/vcpkg/ports/opus/portfile.cmake

@@ -0,0 +1,57 @@
+set(LOCAL_ARCHIVE "$ENV{VCPKG_LIB_SOURCE_ROOT}/xiph-opus-v1.5.2.tar.gz")
+
+vcpkg_extract_source_archive(
+    SOURCE_PATH
+    ARCHIVE "${LOCAL_ARCHIVE}"
+    PATCHES fix-pkgconfig-version.patch
+)
+
+vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
+    FEATURES
+        avx2 AVX2_SUPPORTED
+)
+
+set(STACK_PROTECTOR ON)
+set(ADDITIONAL_OPUS_OPTIONS "")
+if(VCPKG_TARGET_IS_MINGW)
+    set(STACK_PROTECTOR OFF)
+    string(APPEND VCPKG_C_FLAGS "-D_FORTIFY_SOURCE=0")
+    string(APPEND VCPKG_CXX_FLAGS "-D_FORTIFY_SOURCE=0")
+    if(VCPKG_TARGET_ARCHITECTURE MATCHES "^(ARM|arm)64$")
+        list(APPEND ADDITIONAL_OPUS_OPTIONS "-DOPUS_USE_NEON=OFF") # for version 1.3.1 (remove for future Opus release)
+        list(APPEND ADDITIONAL_OPUS_OPTIONS "-DOPUS_DISABLE_INTRINSICS=ON") # for HEAD (and future Opus release)
+    endif()
+elseif(VCPKG_TARGET_IS_WINDOWS)
+    if(VCPKG_CRT_LINKAGE STREQUAL "static")
+        list(APPEND ADDITIONAL_OPUS_OPTIONS "-DOPUS_STATIC_RUNTIME=ON")
+    endif()
+elseif(VCPKG_TARGET_IS_EMSCRIPTEN)
+    set(STACK_PROTECTOR OFF)
+endif()
+
+vcpkg_cmake_configure(
+    SOURCE_PATH "${SOURCE_PATH}"
+    OPTIONS ${FEATURE_OPTIONS}
+        -DPACKAGE_VERSION=${VERSION}
+        -DOPUS_STACK_PROTECTOR=${STACK_PROTECTOR}
+        -DOPUS_INSTALL_PKG_CONFIG_MODULE=ON
+        -DOPUS_INSTALL_CMAKE_CONFIG_MODULE=ON
+        -DOPUS_BUILD_PROGRAMS=OFF
+        -DOPUS_BUILD_TESTING=OFF
+        ${ADDITIONAL_OPUS_OPTIONS}
+    MAYBE_UNUSED_VARIABLES
+        OPUS_USE_NEON
+        OPUS_DISABLE_INTRINSICS
+)
+vcpkg_cmake_install()
+vcpkg_copy_pdbs()
+
+vcpkg_cmake_config_fixup(CONFIG_PATH lib/cmake/Opus)
+vcpkg_fixup_pkgconfig(SYSTEM_LIBRARIES m)
+
+
+file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/debug/lib/cmake"
+                    "${CURRENT_PACKAGES_DIR}/lib/cmake"
+                    "${CURRENT_PACKAGES_DIR}/debug/include")
+
+vcpkg_install_copyright(FILE_LIST "${SOURCE_PATH}/COPYING")

Tools/CMake/vcpkg/ports/opus/vcpkg.json

@@ -0,0 +1,23 @@
+{
+  "name": "opus",
+  "version": "1.5.2",
+  "port-version": 1,
+  "description": "Totally open, royalty-free, highly versatile audio codec",
+  "homepage": "https://github.com/xiph/opus",
+  "license": "BSD-3-Clause",
+  "dependencies": [
+    {
+      "name": "vcpkg-cmake",
+      "host": true
+    },
+    {
+      "name": "vcpkg-cmake-config",
+      "host": true
+    }
+  ],
+  "features": {
+    "avx2": {
+      "description": "Builds the library with avx2 instruction set"
+    }
+  }
+}