# Building from source using Cerbero

If you just want to use GStreamer, please visit the download page. We provide pre-built binaries for Windows, macOS, Android, and iOS.

Cerbero is a cross-platform build aggregator for Open Source projects that builds and creates native packages for different platforms, architectures and distributions. It supports both native compilation and cross compilation and can run on macOS, Linux, and Windows.

You should use Cerbero to build GStreamer if you:

1. Want to do GStreamer development for Android, iOS, or UWP, or
2. Have to build GStreamer packages for distribution or deployment, or
3. Need plugins with external dependencies without Meson ports

However, if you are a developer who wants to work on the GStreamer code itself on Linux, Windows, or macOS, it is much more convenient to use gst-build. Please refer to Building using Meson.

## Minimum Requirements

Cerbero provides bootstrapping facilities for all platforms, but it still needs a minimum base to bootstrap on top of.

### Linux Setup

On Linux, you will only need a distribution with python >= 3.6. Cerbero will use your package manager to install all other required packages during bootstrap.

### macOS Setup

On macOS you will need to have install the following software:

- XCode
- Python 3.6+ https://www.python.org/downloads/

Cerbero will build all other required packages during bootstrap.

### Windows Setup

The initial setup on Windows is somewhat longer since the required packages must be installed manually. Detailed steps on what you need to install are at the bottom of the page.

## Download the sources

To build GStreamer using Cerbero, you first need to download Cerbero:

    $ git clone https://gitlab.freedesktop.org/gstreamer/cerbero

This will build the latest unreleased GStreamer code.

Despite the presence of `setup.py` this tool does not need installation. It is invoked via the `cerbero-uninstalled` script, which should be invoked as `./cerbero-uninstalled`, or you can create an alias to it in your `.bashrc` file.

You can build a specific release by checking out that tag, for example `git checkout 1.18.4`. Building a release tag will cause Cerbero to use the release tarballs instead of git repositories when fetching gstreamer recipes for building.

You can also build the latest unreleased 'stable branch' code, for instance for 1.18 you'd do: `git checkout 1.18`, or `git clone -b 1.18 [...]`, which will fetch the corresponding stable branches when building gstreamer recipes.

You can also use git worktrees, which may be more convenient when building several different versions of gstreamer since the build artefacts always go into the `build` directory inside the git repository.

## Bootstrap to setup environment

Before using cerbero for the first time, you will need to run the bootstrap command. This command installs the missing parts of the build system using the packages manager when available, and also downloads the necessary toolchains when building for Windows/MinGW or Android.

Note that this will take a while (a couple hours or even more on Windows).

    $ ./cerbero-uninstalled bootstrap

On Linux and macOS, this will use `sudo` to make changes to the system.

The bootstrap process will then install or build all packages required to build GStreamer.

## Build GStreamer

To generate GStreamer binaries, use the following command:

    $ ./cerbero-uninstalled package gstreamer-1.0

This will fetch and build all required GStreamer components and create packages for your distribution, then place them in the Cerbero source directory.

A list of supported packages to build can be retrieved using:

    $ ./cerbero-uninstalled list-packages

Packages are composed of 0 (in case of a meta package) or more components that can be built separately if desired. The components are defined as individual recipes and can be listed with:

    $ ./cerbero-uninstalled list

To build an individual recipe and its dependencies, do the following:

    $ ./cerbero-uninstalled build <recipe_name>

Or to build or force a rebuild of a recipe without building its dependencies use:

    $ ./cerbero-uninstalled buildone <recipe_name>

To wipe everything and start from scratch:

    $ ./cerbero-uninstalled wipe

Once built, the binaries built by all the recipes will be installed inside a auto-detected prefix inside the `build` directory in the Cerbero source tree.

## Cross Compilation

If you're using Cerbero to cross-compile to iOS, Android, Cross-MinGW, or UWP, you must select the appropriate config file and pass it to all steps: bootstrap, build, package, etc.

For example if you're on Linux and you want to build for Android Universal, you must run:

    # Bootstrap for Android Universal on Linux
    $ ./cerbero-uninstalled -c config/cross-android-universal.cbc bootstrap

    # Build everything and package for Android Universal
    $ ./cerbero-uninstalled -c config/cross-android-universal.cbc package gstreamer-1.0

Here's a list of config files for each target machine:

#### Linux Targets

Target | Config file
--- | ---
MinGW 32-bit | `cross-win32.cbc`
MinGW 64-bit | `cross-win64.cbc`
Android Universal | `cross-android-universal.cbc`
Android ARM64 | `cross-android-arm64.cbc`
Android ARMv7 | `cross-android-armv7.cbc`
Android x86 | `cross-android-x86.cbc`
Android x86_64 | `cross-android-x86-64.cbc`

#### macOS Targets

Target | Config file
--- | ---
macOS System Framework | `osx-x86-64.cbc`
iOS Universal | `cross-ios-universal.cbc`
iOS ARM64 | `cross-ios-arm64.cbc`
iOS ARMv7 | `cross-ios-armv7.cbc`
iOS x86 | `cross-ios-x86.cbc`
iOS x86_64 | `cross-ios-x86-64.cbc`

#### Windows Targets

On Windows, config files are used to select the architecture and variants are used to select the toolchain (MinGW, MSVC, UWP):

Target | Config file | Variant
--- | --- | ---
MinGW x86 | `win32.cbc` |
MinGW x86_64 | `win64.cbc` |
MSVC x86 | `win32.cbc` | visualstudio
MSVC x86_64 | `win64.cbc` | visualstudio
UWP x86 | `win32.cbc` | uwp
UWP x86_64 | `win64.cbc` | uwp
UWP ARM64 | `cross-win-arm64.cbc` | uwp
UWP Universal | `cross-uwp-universal.cbc` | (implicitly uwp)

Example usage:

    # Target MinGW 32-bit
    $ ./cerbero-uninstalled -c config/win32.cbc package gstreamer-1.0

    # Target MSVC 64-bit
    $ ./cerbero-uninstalled -c config/win64.cbc -v visualstudio package gstreamer-1.0

    # Target UWP, x86_64
    $ ./cerbero-uninstalled -c config/win64.cbc -v uwp package gstreamer-1.0

    # Target UWP, Cross ARM64
    $ ./cerbero-uninstalled -c config/cross-win-arm64.cbc -v uwp package gstreamer-1.0

    # Target UWP, All Supported Arches
    $ ./cerbero-uninstalled -c config/cross-uwp-universal.cbc package gstreamer-1.0

## Tips for CI setup

Cerbero can split its bootstrap and package commands into stages which can be useful for CI setups. For example, you might want to do any system setup (such as installing packages) and also fetch all sources to cache them when building your CI image:

    $ ./cerbero-uninstalled fetch-bootstrap
    $ ./cerbero-uninstalled fetch-package gstreamer-1.0
    # This will use "sudo"
    $ ./cerbero-uninstalled bootstrap --system=yes --toolchains=no --build-tools=no --offline

Then inside your CI job, you will not need root for the remaining steps:

    $ ./cerbero-uninstalled bootstrap --system=no --toolchains=yes --build-tools=yes --offline
    # When building a non-tagged commit, this will update the git repos for all gstreamer recipes
    $ ./cerbero-uninstalled fetch-package gstreamer-1.0
    $ ./cerbero-uninstalled package gstreamer-1.0 --offline

For more inspiration, see GStreamer's GitLab CI setup.

## Enabling Optional Features with Variants

Cerbero controls optional and platform-specific features with `variants`. You can see a full list of available variants by running:

    $ ./cerbero-uninstalled --list-variants

Some variants are enabled by default while others are not. You can enable a particular variant by doing one of the following:

- Either invoke `cerbero-uninstalled` with the `-v` argument, for example:

    $ ./cerbero-uninstalled -v variantname [-c ...] package gstreamer-1.0

- Or, edit `~/.cerbero/cerbero.cbc` and add `variants = ['variantname']` at the bottom. Create the file if it doesn't exist.

Multiple variants can either be separated by a comma or with multiple `-v` arguments, for example the following are equivalent:

    $ ./cerbero-uninstalled -v variantname1,variantname2 [-c ...] package gstreamer-1.0
    $ ./cerbero-uninstalled -v variantname1 -v variantname2 [-c ...] package gstreamer-1.0

To explicitly disable a variant, use `novariantname` instead.

In the case of multiple enabling/disable of the same variant, then the last condition on the command line will take effect. e.g. if novariantname is last then variantname is disabled.

### Enabling Qt5 Support

Starting with version 1.15.2, Cerbero has built-in support for building the Qt5 QML GStreamer plugin. You can toggle that on by enabling the `qt5` variant.

You must also tell Cerbero where your Qt5 installation prefix is. You can do it by setting the `QMAKE` environment variable to point to the `qmake` that you want to use, f.ex. `/path/to/Qt5.12.0/5.12.0/ios/bin/qmake`

When building for Android Universal with Qt < 5.14, instead of `QMAKE`, you must set the `QT5_PREFIX` environment variable pointed to the directory inside your prefix which contains all the android targets, f.ex. `/path/to/Qt5.12.0/5.12.0`.

Next, run `package`:

    $ export QMAKE='/path/to/Qt5.12.0/5.12.0/<target>/bin/qmake'
    $ ./cerbero-uninstalled -v qt5 [-c ...] package gstreamer-1.0

This will try to build the Qt5 QML plugin and error out if Qt5 could not be found or if the plugin could not be built. The plugin will be automatically added to the package outputted.

NOTE: The package outputted will not contain a copy of the Qt5 libraries in it. You must link to them while building your app yourself.

## Enabling Hardware Codec Support

Starting with version 1.15.2, Cerbero has built-in support for building and packaging hardware codecs for Intel and Nvidia. If the appropriate variant is enabled, the plugin will either be built or Cerbero will error out if that's not possible.

### Intel Hardware Codecs

For Intel, the variant to enable is `intelmsdk` which will build the `msdk` plugin.

You must set the `INTELMEDIASDKROOT` env var to point to your Intel Media SDK prefix, or you must have the SDK's pkgconfig prefix in `PKG_CONFIG_PATH`

On Windows, `INTELMEDIASDKROOT` automatically set by the installer. On Linux, if you need to set this, you must set it to point to the directory that contains the mediasdk `include` and `lib64` dirs.

For VA-API, the variant to enable is `vaapi` which will build the gstreamer-vaapi plugins with all options enabled if possible.

### Nvidia Hardware Codecs

Since 1.17.1, the `nvcodec` plugin does not need access to the Nvidia Video SDK or the CUDA SDK. It now loads everything at runtime. Hence, it is now enabled by default on all platforms.

## Enabling Visual Studio Support

Starting with version 1.15.2, Cerbero supports building all GStreamer recipes, all mandatory dependencies (such as glib, libffi, zlib, etc), and some external dependencies with Visual Studio. You must explicitly opt-in to this by enabling the `visualstudio` variant:

    $ python ./cerbero-uninstalled -v visualstudio package gstreamer-1.0

If you already have a Cerbero build, it is highly recommended to run the `wipe` command before switching to building with Visual Studio.

Some plugins that require external dependencies will be automatically disabled when running in this mode.

Currently, most recipes that use Meson (`btype = BuildType.MESON`) and those that have the `can_msvc` recipe property set to `True` are built with Visual Studio.

## Installing Minimum Requirements on Windows

IMPORTANT: Using cerbero on Windows with the GCC/MinGW toolchain requires a 64-bit operating system. The toolchain is only available for 64-bit and it can produce 32-bit or 64-bit binaries.

These steps are necessary for using Cerbero on Windows.

#### Install Python 3.6 or newer (either 32-bit or 64-bit)

Download the Windows executable installer and run it.

- On the first page of the installer, select the following:

- On the second page, the defaults are fine

- Third page, you must select the following options:

- Enabled or Install .NET 3.5.1 Framework

- On Windows 10, remove the Windows Store path entry from the PATH variable in the system settings. Otherwise, Cerbero will try to use the dummy Windows Store version of Python

#### Install Git for Windows

Download the Git for Windows installer and run it.

- First page is the license

- Next page is `Select Components`, the defaults are fine, enable whatever else you prefer

- Next `Choosing the default editor used by Git`, select whatever you prefer

- Next `Adjusting your PATH environment`, you must select as shown in the screenshot

- Next `Choosing HTTPS transport backend`, default is fine

- Next `Configuring the line ending conversions`, you must select as shown in the screenshot

- Next `Configuring the terminal emulator`, default is fine

- Next `Configuring extra options`, defaults are fine

Git will be installed at `C:\Program Files\Git`.

#### Install MSYS/MinGW

Download the `mingw-get-setup` executable installer and run it.

- First page, keep all the options as-is

- Second page will download the latest package catalogue and base packages

- Once done, the MinGW Installation Manager will open, select the following packages under Basic Setup:

Then, click on the `Installation` menu and select `Apply Changes`. MSYS will be installed at `C:\MinGW`.

IMPORTANT: After installation, you must create a shortcut on the desktop to `C:\MinGW\msys\1.0\msys.bat` which will run the MinGW shell. You must run Cerbero from inside that.

NOTE: Cerbero does not use the MinGW compiler toolchain shipped with MSYS. We download our own custom GCC toolchain during bootstrap.

NOTE: MSYS is not the same as MSYS2, and the GStreamer project does not support running Cerbero inside the MSYS2 environment. Things may work or they may break, and you get to keep the pieces.

#### Install Visual Studio 2015 or newer

This is needed for correctly generating import libraries for recipes built with MinGW. Both the Community build and the Professional build are supported.

You must install the latest Windows 10 SDK when installing Visual Studio as shown below. You do not need any older Windows SDKs.

If you want to build for UWP (aka Universal Windows Platform), you have to use VS 2017 or newer, and you must also select the Universal Windows Platform workload:

You can find all versions of Visual Studio at: https://visualstudio.microsoft.com/vs/older-downloads/

#### Install other tools

- CMake: http://www.cmake.org/cmake/resources/software.html

- WiX 3.11.1 installer: https://github.com/wixtoolset/wix3/releases/tag/wix3111rtm

#### Important Windows-specific Notes

You should add the cerbero git directory to the list of excluded folders in your anti-virus, or you will get random build failures when Autotools does file operations such as renames and deletions. It will also slow your build by about 3-4x.

Cerbero must be run in the MingGW shell, which is accessible from the main menu or desktop. If it is not, create a shortcut on the desktop to `C:\MinGW\msys\1.0\msys.bat`

The path to your `$HOME` must not contain spaces. If your Windows username contains spaces, you can create a new directory in `/home` and execute:

If you are using Windows 10, it is also highly recommended to enable "Developer Mode" in Windows Settings as shown below.

    $ echo 'export HOME=/home/newdir' > ~/.profile

Then restart your shell and type `cd` to go to the new home directory.

Note that inside the shell, `/` is mapped to `C:\Mingw\msys\1.0\`

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