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Building OBS Studio
If you want to develop for OBS, please visit our Discord and get to know the devs or have questions answered!
Also, if there is something in this guide you want to change/improve on, it is recommended that you talk about it with the devs in Discord or IRC first.
Please note that any install directions/packages for Linux/FreeBSD distributions listed as Unofficial means that they are community provided, and any support for those packages should be directed at the appropriate distro/package maintainers.
Dependency | Available Pre-Built (macOS and Windows) |
---|---|
FFmpeg | YES |
x264 | YES |
cURL |
YES (required on Windows only) |
mbedTLS | YES |
Chromium Embedded Framework | YES |
Qt | YES |
We suggest having a current version of Git and CMake installed on the build system. macOS and Linux systems also require the Ninja build system to be installed, CCache can be installed to speed up consecutive builds as well and is supported by the build system.
OBS Studio's CMake will automatically download prebuilt dependencies on Windows and macOS. Check out the OS-specific build instructions pages for more detail on available functionality.
OBS uses CMake to create build environments for different platforms and IDEs. As a modular project, each module can introduce its own build options and requirements, which are gathered and managed by CMake when invoking it.
While these build options are detected and set automatically by CMake, they can also be changed after build configuration has finished or can be changed via overrides at configuration time.
This article explains some intricacies of OBS' CMake build system structure and the available options to change its behavior.
Instead of defining CMake options when invoking CMake, it is recommended to create a CMake Preset that defines the options. Custom presets can be defined in CMakeUserPresets.json. Officially defined presets are located in CMakePresets.json.
OBS requires at least CMake v3.28 or newer due to many quality-of-life changes introduced in this version. On Windows and macOS the most current CMake version (as of writing v3.31) is preferred, even if the current feature level is capped to v3.30.
Due to OBS' modular structure, some build configuration settings are available globally, while others are introduced by modules. They are listed here in order of appearance (as defined by each CMakeLists.txt
file, which is processed procedurally by CMake).
Variable | Description | Default | OS |
---|---|---|---|
CMAKE_BUILD_TYPE | Sets the build configuration (available values are Debug , RelWithDebInfo , Release and MinSizeRel ) |
RelWithDebInfo |
All |
CMAKE_INSTALL_PREFIX | Sets either an absolute installation path or path relative to the build directory |
rundir inside build directory (install on macOS) |
All |
CMAKE_PREFIX_PATH | Additional search path for dependencies, use semicolons to seperate multiple paths | None | All |
CMAKE_OSX_ARCHITECTURES | Specify architecture(s) to build binaries for (available values are x86_64 and arm64 ) |
x86_64 |
macOS |
CMAKE_OSX_DEPLOYMENT_TARGET | Minimum macOS versions to deploy binaries for |
10.13 for x86_64, 11.0 for arm64
|
macOS |
CEF_ROOT_DIR | Specify root directory of pre-built Chromium Embedded Framework (required for Browser source plugin) | None | All |
VLC_PATH | Specify directory of downloaded VLC source files (required for VLC source plugin) | None | macOS and Windows |
Variable | Description | Default | OS |
---|---|---|---|
ENABLE_UI | Enable building with UI (main OBS application) | ON |
All |
ENABLE_SCRIPTING | Enable scripting functionality (Lua and/or Python) | ON |
All |
ENABLE_RELOCATABLE | Use a portable directory structure for OBS installation | OFF |
Linux |
ENABLE_PORTABLE_CONFIG | Enable support for portable config file location | OFF |
All |
OBS_VERSION_OVERRIDE | Specify OBS version for configured build | Most recent Git tag | All |
OBS_BUILD_NUMBER | Continuous build number for configured build | Automatically incremented on local builds | All |
OBS_CODESIGN_IDENTITY | Identity to use for code signing on macOS | - |
macOS |
OBS_CODESIGN_TEAM | Team to use for code signing on macOS | None | macOS |
Variable | Description | Default | OS |
---|---|---|---|
ENABLE_PLUGINS | Enable building with plugins | ON |
All |
ENABLE_WAYLAND | Enable support for Wayland compositor | ON |
Linux |
ENABLE_PIPEWIRE | Enable support for Pipewire graphics processing engine | ON |
Linux |
Variable | Description | Default | OS |
---|---|---|---|
ENABLE_AJA | Enable building with AJA NTV2 support | ON |
All |
ENABLE_COREAUDIO_ENCODER | Enable support for CoreAudio encoder | ON |
Windows (cannot be disabled on macOS) |
ENABLE_DECKLINK | Enable building with Decklink support | ON |
All |
ENABLE_ALSA | Enable building with Advanced Linux Sound Architecture (ALSA) support | ON |
Linux |
ENABLE_JACK | Enable support for JACK audio server | OFF |
Linux |
ENABLE_PULSEAUDIO | Enable Pulse Audio support | ON |
Linux |
ENABLE_V4L2 | Enable Video4Linux v2 support | ON |
Linux |
ENABLE_VIRTUALCAM | Enable building with Virtual Camera modules | ON |
Windows and macOS |
VIRTUALCAM_GUID | Specify global unique identifier (GUID) for Virtual Camera Plugin | None | Windows |
ENABLE_BROWSER | Enable buidling Browser Source plugin | ON |
All |
ENABLE_BROWSER_LEGACY | Enable building Browser Source plugin with legacy CEF version 3770 | OFF |
Windows |
ENABLE_BROWSER_SHARED_TEXTURE | Enable building Browser Source plugin with shared texture support | ON |
Windows and macOS |
ENABLE_BROWSER_QT_LOOP | Enable building Browser source plugin with Qt message loop | ON |
macOS |
ENABLE_BROWSER_PANELS | Enable building Browser source plugin with support for browser panels | ON |
All |
ENABLE_FFMPEG_LOGGING | Enable more verbose logging for FFmpeg-based operations | OFF |
All |
ENABLE_SPEEXDSP | Enable noise suppression using SpeexDSP | ON |
All |
ENABLE_RNNOISE | Enable noise suppression using RNNoise | ON |
All |
ENABLE_NVAFX | Enable noise suppression using NVidia Audio Effects SDK | ON |
Windows |
ENABLE_LIBFDK | Enable building support for Fraunhofer AAC codec | OFF |
All |
ENABLE_RTMPS | Enable support for TLS-based RTMP connections | AUTO |
All |
ENABLE_VST | Enable VST plugin support | ON |
All |
ENABLE_OSS | Enable building with Open Sound System support | ON |
Linux |
ENABLE_SERVICE_UPDATES | Enable automatic streaming service updates | OFF |
All |
ENABLE_SNDIO | Enable sndio framework support | OFF |
Linux |
ENABLE_FREETYPE | Enable support for FreeType 2 based text rendering | ON |
macOS and Linux |
ENABLE_VLC | Enable support for VLC-based sources | ON |
All |
All these commands implicitly expect to be run from within the OBS source code directory checked out via git
including all submodules (check the Installing and Building page for more details):
Just running cmake
triggers an "in-source" build (meaning: build artifacts are placed with the source code directory structure). Due to OBS' modular structure this build variant is not allowed, instead an "out-of-source" build needs to be configured.
To create a build configuration in a desired subdirectory run cmake -S . -B <YOUR_BUILD_DIR>
. This will configure OBS with most modules available to the host operating system enabled.
To change the CMake generator (and the build tool used to compile the project) pass a compatible generator name via the -G
switch. Supported generators by CMake and OBS are:
- Unix Makefiles
- Ninja
- Xcode
- Visual Studio 17 2022
Other generators are supported by CMake but have neither been tested nor are officially supported by the OBS team.
To change a configuration option, supported variables can be passed via the -D
switch. E.g. to disable building with the browser plugin, pass -DENABLE_BROWSER=OFF
. While CMake supports several values as binary switches, within OBS ON
or OFF
are used.
These changes are additive, as CMake stores these options as "cache variables" in a file called CMakeCache.txt
in the specified build directory and reads from this file when cmake
is run again. As such cache options can either be changed in this file directly, or overwritten by specifying new values for them via the -D
switch (see above).
CMake build configurations can also be managed using graphical user interfaces: On Windows cmake-gui
is installed with the CMake package available for the platform and allows selection of source and build directories (-S
and -B
switches respectively) as well as direct manipulation of all cache variables. Detailed instructions for this GUI are available in the Installation and Building article.
On POSIX-based systems a ncurses
-based user interface is available via the ccmake
command which allows editing of cache variables. Note that due to CMake's internal processes, a configuration step (via the c
shortcut) needs to be repeated until no new cache variables are created by it. Only then will the generation step (g
shortcut) be made available.
Whether changes to CMake script files themselves or to cache variables, CMake needs to be run again to "pick up" on these changes and apply them (as build system files are generated according to these changes). When using the GUI a repeat run of configuration and generation steps should be enough to pick up those changes; when using the command line a repeat invocation of cmake -S . -B <YOUR_BUILD_DIR>
will do the same.
OBS uses "Modern CMake" which differentiates from patterns and practices used by CMake before version 2.8/3 - for the full details please refer to An Introduction To Modern CMake.
Here are some general rules of thumb (lifted from the article mentioned above):
- Do not use global functions: This includes
link_directories
,include_libraries
, and similar. - Don't add unneeded
PUBLIC
requirements: You should avoid forcing something on users that is not required (-Wall
). Make thesePRIVATE
instead. - Don't
GLOB
files: Make or another tool will not know if you add files without rerunning CMake. Note that CMake 3.12 adds aCONFIGURE_DEPENDS
flag that makes this far better if you need to use it. - Do not link to built files directly: Always link to targets if available.
- Never skip
PUBLIC/PRIVATE
when linking: This causes all future linking to be keyword-less.
- Treat CMake as code: It is code. It should be as clean and readable as all other code.
- Think in targets: Your targets should represent concepts. Make an (
IMPORTED
)INTERFACE
target for anything that should stay together and link to that. - Export your interface: You should be able to run from build or install.
- Write a
Config.cmake
file: This is what a library author should do to support clients. - Make
ALIAS
targets to keep usage consistent: Usingadd_subdirectory
andfind_package
should provide the same targets and namespaces. - Combine common functionality into clearly documented functions or macros: Functions are better usually.
- Use lowercase function names: CMake functions and macros can be called lower or upper case. Always use lower case. Upper case is for variables.
- Use
cmake_policy
and/or range of versions: Policies change for a reason. Only piecemeal setOLD
policies if you have to.
-
Using (internal) finder variables to add libraries and their include directories:
LEGACY: --------------- find_package(MyLibrary) link_directores(${MY_LIBRARY_INCLUDE_DIRS}) include_libraries(${MY_LIBRARY_LIB}) MODERN: --------------- find_package(MyLibrary) target_link_libraries(my_target PRIVATE My_Library::My_Library)
NOTE: If the package does not create an imported library target (
My_Library::My_Library
), an issue should be filed with the respective library maintainer(s) to drop the outdatedFindXYZ.cmake
pattern and update to CMake'sexport
function to create a CMake package. In the interim the finder module can be patched to create namespaced imported targets (see some examples in OBS'CMake/Modules
directory. -
Gathering source files in variables and adding them at the bottom of the script:
LEGACY: --------------- set(mytarget_SOURCES my_source.c) set(mytarget_HEADERS include/my_headers.h) add_library(my_target SHARED ${mytarget_SOURCES} ${mytarget_HEADERS) MODERN: --------------- add_library(my_target SHARED) target_sources(my_target include/my_headers.h)
-
Polluting the build environment with local compilation requirements
LEGACY: --------------- set(CMAKE_CXX_STANDARD 17) set(CMAKE_CXX_STANDARD_REQUIRED ON) set(CMAKE_CXX_EXTENSIONS OFF) add_compile_options(-Wextra -Wvla -Wno-unused-function -Wno-missing-field-initializers -fno-strict-aliasing) add_link_options(/INCREMENTAL) MODERN: --------------- target_compile_features(my_target PRIVATE cxx_std_17) target_compile_options(my_target PRIVATE -Wextra PUBLIC -fno-strict-aliasing) target_link_options(my_target PRIVATE LINKER:-z,defs)
NOTE: The correct use of
PRIVATE
andPUBLIC
is important here:PRIVATE
target properties only apply to the target itself, whilePUBLIC
options are also inherited by targets linking to this target. Also note theLINKER:
prefix for the link options - this allows CMake to use the compiler specific linker flags (e.g-Xlinker -z -Xlinker defs
for Clang and-Wl,-z,defs
for GNU GCC).
This cannot be stressed enough: In Modern CMake everything revolves around targets, which allows CMake to resolve dependencies and relationships using target properties and the information contained within. E.g. when linking target_a
with target_b
(via target_link_libraries()
) CMake will look up the INTERFACE_INCLUDE_DIRECTORIES
property on target_b
to yield the directory containing library headers, as well as INTERFACE_LINK_LIBRARIES
which will contain the actual library files in the file system. Required compile options and defines are also read from INTERFACE_COMPILE_OPTIONS
and INTERFACE_COMPILE_DEFINITIONS
respectively and added to target_a
's compile options automatically.
Using namespaces (My_Library::My_Library
) when specifying targets for linking has the added benefit of ensuring a target reference (instead of a file reference), as colons are invalid for file names in many file systems.