change liblivekit to dll and link protobuf statically

CMakeLists.txt

@@ -8,6 +8,7 @@ project(livekit VERSION ${LIVEKIT_VERSION} LANGUAGES C CXX)
 
 set(LIVEKIT_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 set(LIVEKIT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
 option(LIVEKIT_BUILD_EXAMPLES "Build LiveKit examples" OFF)
 
@@ -60,10 +61,8 @@ endif()
 
 
 if(MSVC)
-  # Use dynamic CRT (/MD) for compatibility with Qt and other /MD libraries.
-  # The livekit_ffi.dll isolates the /MT libwebrtc dependency, so livekit.lib
-  # can safely use /MD.
-  set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
+  # Force /MD or /MDd for ALL targets (including FetchContent subprojects)
+  set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL" CACHE STRING "" FORCE)
   add_compile_options(/utf-8)
 endif()
 
@@ -85,24 +84,32 @@ set(FFI_PROTO_FILES
 set(PROTO_BINARY_DIR ${LIVEKIT_BINARY_DIR}/generated)
 file(MAKE_DIRECTORY ${PROTO_BINARY_DIR})
 
-# Try to find Protobuf via CONFIG mode first (vcpkg), then fall back to MODULE mode (apt/brew)
-find_package(Protobuf CONFIG QUIET)
-if(NOT Protobuf_FOUND)
-  find_package(Protobuf REQUIRED)
-endif()
+# Livekit static protobuf.
+include(protobuf)
 
-# Ensure protoc executable is found (some systems may not set Protobuf_PROTOC_EXECUTABLE)
+# Ensure protoc executable is found (when using Livekit Protobuf, it should set Protobuf_PROTOC_EXECUTABLE already)
 if(NOT Protobuf_PROTOC_EXECUTABLE)
   find_program(Protobuf_PROTOC_EXECUTABLE NAMES protoc REQUIRED)
 endif()
 message(STATUS "Using protoc: ${Protobuf_PROTOC_EXECUTABLE}")
 
 add_library(livekit_proto OBJECT ${FFI_PROTO_FILES})
+if(TARGET protobuf::libprotobuf)
+  set(LIVEKIT_PROTOBUF_TARGET protobuf::libprotobuf)
+else()
+  message(FATAL_ERROR "No protobuf library target found (expected protobuf::libprotobuf)")
+endif()
 target_include_directories(livekit_proto PRIVATE
-  "$<BUILD_INTERFACE:${PROTO_BINARY_DIR}>"
+  "${PROTO_BINARY_DIR}"
   ${Protobuf_INCLUDE_DIRS}
 )
-target_link_libraries(livekit_proto PRIVATE protobuf::libprotobuf)
+target_link_libraries(livekit_proto PRIVATE ${LIVEKIT_PROTOBUF_TARGET})
+if(TARGET absl::base)
+  get_target_property(_absl_inc absl::base INTERFACE_INCLUDE_DIRECTORIES)
+  if(_absl_inc)
+    target_include_directories(livekit_proto PRIVATE ${_absl_inc})
+  endif()
+endif()
 
 # Manually generate protobuf files to avoid path prefix issues
 set(PROTO_SRCS)
@@ -268,7 +275,7 @@ add_custom_target(build_rust_ffi
 
 # Note: protozero_plugin.o removal is no longer needed since we use dynamic libraries on Unix
 
-add_library(livekit STATIC
+add_library(livekit SHARED
   src/audio_frame.cpp
   src/audio_source.cpp
   src/audio_stream.cpp
@@ -318,8 +325,7 @@ target_include_directories(livekit
 target_link_libraries(livekit
   PRIVATE
     livekit_ffi
-  PUBLIC
-    protobuf::libprotobuf
+    ${LIVEKIT_PROTOBUF_TARGET}
 )
 
 message(STATUS "Protobuf: version=${Protobuf_VERSION}; protoc=${Protobuf_PROTOC_EXECUTABLE}")
@@ -465,7 +471,7 @@ if(APPLE)
   find_library(FW_METALKIT       MetalKit       REQUIRED)
   find_library(FW_SCREENCAPTUREKIT ScreenCaptureKit REQUIRED)
 
-  target_link_libraries(livekit PUBLIC
+  target_link_libraries(livekit PRIVATE
     ${FW_COREAUDIO}
     ${FW_AUDIOTOOLBOX}
     ${FW_COREFOUNDATION}
@@ -485,40 +491,11 @@ if(APPLE)
     ${FW_SCREENCAPTUREKIT}
   )
 
-  target_link_options(livekit INTERFACE "LINKER:-ObjC")
-endif()
-
-if(Protobuf_VERSION VERSION_GREATER_EQUAL 6.0)
-  find_package(absl CONFIG QUIET)
-  if(NOT absl_FOUND)
-    find_package(Abseil QUIET)
-  endif()
-
-  if(absl_FOUND)
-    target_link_libraries(livekit PUBLIC
-      absl::log
-      absl::check
-      absl::strings
-      absl::base
-    )
-  elseif(Abseil_FOUND)
-    target_link_libraries(livekit PUBLIC
-      Abseil::log
-      Abseil::check
-      Abseil::strings
-      Abseil::base
-    )
-  else()
-    message(FATAL_ERROR
-      "Protobuf ${Protobuf_VERSION} requires Abseil but no CMake package was found.\n"
-      "Install Abseil or use Protobuf < 6.")
-  endif()
-else()
-  message(STATUS "Protobuf < 6 detected; skipping Abseil linking.")
+  target_link_options(livekit PRIVATE "LINKER:-ObjC")
 endif()
 
 if(WIN32)
-  target_link_libraries(livekit PUBLIC
+  target_link_libraries(livekit PRIVATE
     ntdll
     userenv
     winmm
@@ -535,7 +512,7 @@ endif()
 
 if(UNIX AND NOT APPLE)
   find_package(OpenSSL REQUIRED)
-  target_link_libraries(livekit PUBLIC OpenSSL::SSL OpenSSL::Crypto)
+  target_link_libraries(livekit PRIVATE OpenSSL::SSL OpenSSL::Crypto)
 endif()
 
 if(MSVC)
@@ -582,42 +559,6 @@ if(WIN32)
       CONFIGURATIONS Debug
     )
   endif()
-
-  # Protobuf
-  if(TARGET protobuf::libprotobuf)
-    install(IMPORTED_RUNTIME_ARTIFACTS protobuf::libprotobuf
-      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    )
-    install(FILES
-      $<TARGET_PROPERTY:protobuf::libprotobuf,IMPORTED_IMPLIB_RELEASE>
-      DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      CONFIGURATIONS Release RelWithDebInfo MinSizeRel
-    )
-    install(FILES
-      $<TARGET_PROPERTY:protobuf::libprotobuf,IMPORTED_IMPLIB_DEBUG>
-      DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      CONFIGURATIONS Debug
-    )
-  endif()
-
-  # Abseil
-  if(TARGET absl::abseil_dll)
-    install(IMPORTED_RUNTIME_ARTIFACTS absl::abseil_dll
-      RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    )
-    install(FILES
-      $<TARGET_PROPERTY:absl::abseil_dll,IMPORTED_IMPLIB_RELEASE>
-      DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      CONFIGURATIONS Release RelWithDebInfo MinSizeRel
-    )
-    install(FILES
-      $<TARGET_PROPERTY:absl::abseil_dll,IMPORTED_IMPLIB_DEBUG>
-      DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      CONFIGURATIONS Debug
-    )
-  endif()
 endif()
 
 # Install public headers

cmake/LiveKitConfig.cmake.in

@@ -1,12 +1,4 @@
 @PACKAGE_INIT@
 
-include(CMakeFindDependencyMacro)
-
-find_dependency(Protobuf CONFIG REQUIRED)
-find_dependency(absl CONFIG QUIET)
-if(NOT absl_FOUND)
-  find_dependency(Abseil REQUIRED)
-endif()
-
 include("${CMAKE_CURRENT_LIST_DIR}/LiveKitTargets.cmake")
 

cmake/protobuf.cmake

@@ -0,0 +1,130 @@
+# cmake/protobuf.cmake
+#
+# Vendored Protobuf (static) + protobuf-lite + protoc for codegen.
+# Also fetches Abseil because protobuf >= 22 commonly requires it.
+#
+# Exposes:
+#   - Protobuf_PROTOC_EXECUTABLE  (generator expression: $<TARGET_FILE:protobuf::protoc>)
+#   - Protobuf_INCLUDE_DIRS       (best-effort; prefer target include dirs)
+#   - Target protobuf::libprotobuf-lite
+#   - Target protobuf::protoc
+
+include(FetchContent)
+
+option(LIVEKIT_USE_SYSTEM_PROTOBUF "Use system-installed Protobuf instead of vendoring" OFF)
+
+set(LIVEKIT_PROTOBUF_VERSION "25.3" CACHE STRING "Vendored Protobuf version")
+set(LIVEKIT_ABSEIL_VERSION  "20240116.2" CACHE STRING "Vendored Abseil version")
+
+if(LIVEKIT_USE_SYSTEM_PROTOBUF)
+  find_package(Protobuf CONFIG QUIET)
+  if(NOT Protobuf_FOUND)
+    find_package(Protobuf REQUIRED)
+  endif()
+
+  if(NOT Protobuf_PROTOC_EXECUTABLE)
+    find_program(Protobuf_PROTOC_EXECUTABLE NAMES protoc REQUIRED)
+  endif()
+  message(STATUS "Using system protoc: ${Protobuf_PROTOC_EXECUTABLE}")
+  return()
+endif()
+
+# ---- Abseil (needed by protobuf on many versions) ----
+# Fetch Abseil and make it available as CMake targets (absl::...)
+FetchContent_Declare(
+  livekit_abseil
+  URL "https://github.com/abseil/abseil-cpp/archive/refs/tags/${LIVEKIT_ABSEIL_VERSION}.tar.gz"
+  DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+)
+
+# ---- Protobuf ----
+FetchContent_Declare(
+  livekit_protobuf
+  URL "https://github.com/protocolbuffers/protobuf/releases/download/v${LIVEKIT_PROTOBUF_VERSION}/protobuf-${LIVEKIT_PROTOBUF_VERSION}.tar.gz"
+  DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+)
+
+# Configure protobuf build: static libs, no tests/examples.
+# Build static only
+set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
+
+# Disable installs/exports in subprojects (avoids export-set errors)
+set(protobuf_INSTALL OFF CACHE BOOL "" FORCE)
+set(ABSL_ENABLE_INSTALL OFF CACHE BOOL "" FORCE)
+set(utf8_range_ENABLE_INSTALL   OFF CACHE BOOL "" FORCE) 
+
+set(protobuf_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_CONFORMANCE OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_PROTOC_BINARIES ON CACHE BOOL "" FORCE)
+set(protobuf_WITH_ZLIB OFF CACHE BOOL "" FORCE)
+
+set(protobuf_ABSL_PROVIDER "package" CACHE STRING "" FORCE)
+
+if(MSVC)
+  set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL" CACHE STRING "" FORCE)
+endif()
+
+# Make abseil available first so protobuf can find absl:: targets.
+FetchContent_MakeAvailable(livekit_abseil)
+
+# A workaround to remove the -Xarch_x86_64 / -msse4 flags that could fail the compilation.
+if(APPLE AND (CMAKE_SYSTEM_PROCESSOR MATCHES "arm64|aarch64"))
+  foreach(t
+    absl_random_internal_randen_hwaes_impl
+    absl_random_internal_randen_hwaes
+  )
+    if(TARGET ${t})
+      foreach(prop COMPILE_OPTIONS INTERFACE_COMPILE_OPTIONS)
+        get_target_property(_opts ${t} ${prop})
+        if(_opts)
+          list(FILTER _opts EXCLUDE REGEX "^-Xarch_x86_64$")
+          list(FILTER _opts EXCLUDE REGEX "^-msse4\\.1$")
+          list(FILTER _opts EXCLUDE REGEX "^-maes$")
+          set_target_properties(${t} PROPERTIES ${prop} "${_opts}")
+        endif()
+      endforeach()
+    endif()
+  endforeach()
+endif()
+
+
+
+# Some protobuf versions look for absl via find_package(absl CONFIG).
+# The abseil project usually provides targets directly, but not a config package.
+# To help protobuf, ensure absl targets exist (they should after MakeAvailable).
+if(NOT TARGET absl::base)
+  message(FATAL_ERROR "Abseil targets not found after FetchContent_MakeAvailable(livekit_abseil)")
+endif()
+
+# Now make protobuf available.
+FetchContent_MakeAvailable(livekit_protobuf)
+
+# Protobuf targets: modern protobuf exports protobuf::protoc etc.
+if(TARGET protobuf::protoc)
+  set(Protobuf_PROTOC_EXECUTABLE "$<TARGET_FILE:protobuf::protoc>" CACHE STRING "protoc (vendored)" FORCE)
+elseif(TARGET protoc)
+  set(Protobuf_PROTOC_EXECUTABLE "$<TARGET_FILE:protoc>" CACHE STRING "protoc (vendored)" FORCE)
+else()
+  message(FATAL_ERROR "Vendored protobuf did not create a protoc target")
+endif()
+
+# Prefer protobuf-lite
+if(TARGET protobuf::libprotobuf-lite)
+  # ok
+elseif(TARGET libprotobuf-lite)
+  add_library(protobuf::libprotobuf-lite ALIAS libprotobuf-lite)
+else()
+  message(FATAL_ERROR "Vendored protobuf did not create protobuf-lite target")
+endif()
+
+# Include dirs: prefer target usage; keep this var for your existing CMakeLists.
+get_target_property(_pb_includes protobuf::libprotobuf INTERFACE_INCLUDE_DIRECTORIES)
+if(NOT _pb_includes)
+  # common fallback
+  set(_pb_includes "${livekit_protobuf_SOURCE_DIR}/src")
+endif()
+set(Protobuf_INCLUDE_DIRS "${_pb_includes}" CACHE STRING "Protobuf include dirs" FORCE)
+
+message(STATUS "Using vendored Protobuf v${LIVEKIT_PROTOBUF_VERSION}")
+message(STATUS "Using vendored protoc: ${Protobuf_PROTOC_EXECUTABLE}")

examples/CMakeLists.txt

@@ -8,14 +8,13 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 # This ensures SDL3 and other shared libs are loaded from bin/ not _deps/
 if(UNIX)
   if(APPLE)
-    set(CMAKE_BUILD_RPATH "@executable_path")
-    set(CMAKE_INSTALL_RPATH "@executable_path")
+    set(CMAKE_BUILD_RPATH "@loader_path;@loader_path/../lib")
+    set(CMAKE_INSTALL_RPATH "@loader_path;@loader_path/../lib")
   else()
-    set(CMAKE_BUILD_RPATH "$ORIGIN")
-    set(CMAKE_INSTALL_RPATH "$ORIGIN")
+    set(CMAKE_BUILD_RPATH "$ORIGIN:$ORIGIN/../lib")
+    set(CMAKE_INSTALL_RPATH "$ORIGIN:$ORIGIN/../lib")
   endif()
   set(CMAKE_BUILD_RPATH_USE_ORIGIN TRUE)
-  # Disable using the default RPATH from linked libraries
   set(CMAKE_SKIP_BUILD_RPATH FALSE)
   set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
 endif()
@@ -47,12 +46,9 @@ add_executable(SimpleRoom
 
 target_include_directories(SimpleRoom PRIVATE ${EXAMPLES_PRIVATE_INCLUDE_DIRS})
 
-# Link protobuf::libprotobuf directly to get proper include directories
-# (livekit links it PRIVATELY so its headers aren't propagated)
 target_link_libraries(SimpleRoom
     PRIVATE
         livekit
-        protobuf::libprotobuf
         SDL3::SDL3
 )
 
@@ -107,7 +103,6 @@ target_link_libraries(SimpleRpc
   PRIVATE
     nlohmann_json::nlohmann_json
     livekit
-    protobuf::libprotobuf
 )
 
 add_executable(SimpleDataStream
@@ -119,7 +114,6 @@ target_include_directories(SimpleDataStream PRIVATE ${EXAMPLES_PRIVATE_INCLUDE_D
 target_link_libraries(SimpleDataStream
   PRIVATE
     livekit
-    protobuf::libprotobuf
 )
 
 add_custom_command(
@@ -135,14 +129,9 @@ if(WIN32)
   # Get the livekit library output directory (where DLLs are copied during main build)
   set(LIVEKIT_LIB_DIR $<TARGET_FILE_DIR:livekit>)
 
-  # Protobuf DLL name depends on configuration (libprotobufd.dll for Debug, libprotobuf.dll for Release)
-  set(PROTOBUF_DLL_NAME $<IF:$<CONFIG:Debug>,libprotobufd.dll,libprotobuf.dll>)
-
   # List of DLLs to copy (using generator expressions for config-dependent names)
   set(REQUIRED_DLLS
     "livekit_ffi.dll"
-    "${PROTOBUF_DLL_NAME}"
-    "abseil_dll.dll"
   )
 
   # Copy DLLs to each example's output directory