set SDLMIXER_VENDORED to ON and vendor the required libraries into libs/SDL3_mixer/external

disable SDLMIXER_VORBIS_VORBISFILE
add ogg v1.3.5-SDL
add opus v1.4.x-SDL
add opusfile v0.13-git-SDL

libs/SDL3_mixer/external/opusfile/cmake/FindOgg.cmake

@@ -0,0 +1,7 @@
+find_package(Ogg CONFIG)
+if(NOT TARGET Ogg::ogg)
+  find_package(PkgConfig REQUIRED)
+  pkg_check_modules(Ogg REQUIRED IMPORTED_TARGET ogg)
+  set_target_properties(PkgConfig::Ogg PROPERTIES IMPORTED_GLOBAL TRUE)
+  add_library(Ogg::ogg ALIAS PkgConfig::Ogg)
+endif()

libs/SDL3_mixer/external/opusfile/cmake/FindOpus.cmake

@@ -0,0 +1,7 @@
+find_package(Opus CONFIG)
+if(NOT TARGET Opus::opus)
+  find_package(PkgConfig REQUIRED)
+  pkg_check_modules(Opus REQUIRED IMPORTED_TARGET opus)
+  set_target_properties(PkgConfig::Opus PROPERTIES IMPORTED_GLOBAL TRUE)
+  add_library(Opus::opus ALIAS PkgConfig::Opus)
+endif()

libs/SDL3_mixer/external/opusfile/cmake/OpusFileConfig.cmake.in

@@ -0,0 +1,52 @@
+@PACKAGE_INIT@
+
+# Ported from CMakeFindDependencyMacro.cmake (finding configs and using pkgconfig as fallback)
+set(cmake_quiet_arg)
+if(${CMAKE_FIND_PACKAGE_NAME}_FIND_QUIETLY)
+  set(cmake_quiet_arg QUIET)
+endif()
+set(cmake_required_arg)
+if(${CMAKE_FIND_PACKAGE_NAME}_FIND_REQUIRED)
+  set(cmake_required_arg REQUIRED)
+endif()
+
+find_package(Ogg CONFIG ${cmake_quiet_arg})
+if(NOT TARGET Ogg::ogg)
+  find_package(PkgConfig REQUIRED ${cmake_quiet_arg})
+  pkg_check_modules(Ogg ${cmake_required_arg} ${cmake_quiet_arg} IMPORTED_TARGET ogg)
+  set_target_properties(PkgConfig::Ogg PROPERTIES IMPORTED_GLOBAL TRUE)
+  add_library(Ogg::ogg ALIAS PkgConfig::Ogg)
+endif()
+
+if (NOT TARGET Ogg::ogg)
+  set(${CMAKE_FIND_PACKAGE_NAME}_NOT_FOUND_MESSAGE "${CMAKE_FIND_PACKAGE_NAME} could not be found because dependency Ogg could not be found.")
+  set(${CMAKE_FIND_PACKAGE_NAME}_FOUND False)
+  return()
+endif()
+
+find_package(Opus CONFIG ${cmake_quiet_arg})
+if(NOT TARGET Opus::opus)
+  find_package(PkgConfig REQUIRED ${cmake_quiet_arg})
+  pkg_check_modules(Opus ${cmake_required_arg} ${cmake_quiet_arg} IMPORTED_TARGET opus)
+  set_target_properties(PkgConfig::Opus PROPERTIES IMPORTED_GLOBAL TRUE)
+  add_library(Opus::opus ALIAS PkgConfig::Opus)
+endif()
+
+if (NOT TARGET Opus::opus)
+  set(${CMAKE_FIND_PACKAGE_NAME}_NOT_FOUND_MESSAGE "${CMAKE_FIND_PACKAGE_NAME} could not be found because dependency Opus could not be found.")
+  set(${CMAKE_FIND_PACKAGE_NAME}_FOUND False)
+  return()
+endif()
+
+set(cmake_fd_required_arg)
+set(cmake_fd_quiet_arg)
+
+if (NOT @OP_DISABLE_HTTP@)
+  include(CMakeFindDependencyMacro)
+  find_dependency(OpenSSL)
+endif()
+
+# Including targets of opusfile
+include("${CMAKE_CURRENT_LIST_DIR}/OpusFileTargets.cmake")
+
+check_required_components(OpusFile)

libs/SDL3_mixer/external/opusfile/cmake/OpusFilePackageVersion.cmake

@@ -0,0 +1,71 @@
+if(__opusfile_version)
+  return()
+endif()
+set(__opusfile_version INCLUDED)
+
+function(get_package_version PACKAGE_VERSION PROJECT_VERSION)
+
+  find_package(Git)
+  if(GIT_FOUND AND EXISTS "${CMAKE_CURRENT_LIST_DIR}/.git")
+    execute_process(COMMAND ${GIT_EXECUTABLE}
+                    --git-dir=${CMAKE_CURRENT_LIST_DIR}/.git describe
+                    --tags --match "v*" OUTPUT_VARIABLE OPUSFILE_PACKAGE_VERSION)
+    if(OPUSFILE_PACKAGE_VERSION)
+      string(STRIP ${OPUSFILE_PACKAGE_VERSION}, OPUSFILE_PACKAGE_VERSION)
+      string(REPLACE \n
+                     ""
+                     OPUSFILE_PACKAGE_VERSION
+                     ${OPUSFILE_PACKAGE_VERSION})
+      string(REPLACE ,
+                     ""
+                     OPUSFILE_PACKAGE_VERSION
+                     ${OPUSFILE_PACKAGE_VERSION})
+
+      string(SUBSTRING ${OPUSFILE_PACKAGE_VERSION}
+                       1
+                       -1
+                       OPUSFILE_PACKAGE_VERSION)
+      message(STATUS "Opus package version from git repo: ${OPUSFILE_PACKAGE_VERSION}")
+    endif()
+  endif()
+
+  if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/package_version"
+         AND NOT OPUSFILE_PACKAGE_VERSION)
+    # Not a git repo, lets' try to parse it from package_version file if exists
+    file(STRINGS package_version OPUSFILE_PACKAGE_VERSION
+         LIMIT_COUNT 1
+         REGEX "PACKAGE_VERSION=")
+    string(REPLACE "PACKAGE_VERSION="
+                   ""
+                   OPUSFILE_PACKAGE_VERSION
+                   ${OPUSFILE_PACKAGE_VERSION})
+    string(REPLACE "\""
+                   ""
+                   OPUSFILE_PACKAGE_VERSION
+                   ${OPUSFILE_PACKAGE_VERSION})
+    # In case we have a unknown dist here we just replace it with 0
+    string(REPLACE "unknown"
+                   "0"
+                   OPUSFILE_PACKAGE_VERSION
+                   ${OPUSFILE_PACKAGE_VERSION})
+      message(STATUS "Opus package version from package_version file: ${OPUSFILE_PACKAGE_VERSION}")
+  endif()
+
+  if(OPUSFILE_PACKAGE_VERSION)
+    string(REGEX
+      REPLACE "^([0-9]+.[0-9]+\\.?([0-9]+)?).*"
+               "\\1"
+               OPUSFILE_PROJECT_VERSION
+               ${OPUSFILE_PACKAGE_VERSION})
+  else()
+    # fail to parse version from git and package version
+    message(WARNING "Could not get package version.")
+    set(OPUSFILE_PACKAGE_VERSION 0)
+    set(OPUSFILE_PROJECT_VERSION 0.0)
+  endif()
+
+  message(STATUS "Opus project version: ${OPUSFILE_PROJECT_VERSION}")
+
+  set(PACKAGE_VERSION ${OPUSFILE_PACKAGE_VERSION} PARENT_SCOPE)
+  set(PROJECT_VERSION ${OPUSFILE_PROJECT_VERSION} PARENT_SCOPE)
+endfunction()