libwebrtc

This repository contains a collection of CMake scripts to help you embed Google's native WebRTC implementation inside your project as simple as this:

cmake_minimum_required(VERSION 3.3)
project(sample)

find_package(LibWebRTC REQUIRED)
include(${LIBWEBRTC_USE_FILE})

set(SOURCE_FILES main.cpp)
add_executable(sample ${SOURCE_FILES})
target_link_libraries(sample ${LIBWEBRTC_LIBRARIES})

It also produces a pkg-config file if you prefer the classic way:

$ g++ `pkg-config --cflags LibWebRTC` main.cpp -o main `pkg-config --libs LibWebRTC`

Status

The following table displays the current state of this project, including supported platforms and architectures.

	x86	x64	arm	arm64
Linux	✔	✔
macOS	-	✔	-	-
Windows	✔	✔

Prerequisites

• CMake 3.3 or later
• Python 2.7 (optional for Windows since it will use the interpreter located inside the depot_tools installation)

Debian & Ubuntu

• Required development packages:

# apt-get install build-essential libglib2.0-dev libgtk2.0-dev libxtst-dev \
                  libxss-dev libpci-dev libdbus-1-dev libgconf2-dev \
                  libgnome-keyring-dev libnss3-dev libasound2-dev libpulse-dev \
                  libudev-dev

• GCC & G++ 4.8 or later, for C++11 support

macOS

• OS X 10.11 or later
• Xcode 7.3.1 or later

Windows

• Windows 7 x64 or later

• Visual Studio 2015 with updates - Download the Installer

  Make sure that you install the following components:

  • Visual C++, which will select three sub-categories including MFC
  • Universal Windows Apps Development Tools
    • Tools (1.4.1) and Windows 10 SDK (10.0.14393)

• Windows 10 SDK with Debugging Tools for Windows or Windows Driver Kit 10 installed in the same Windows 10 SDK installation directory.

Compiling

Clone the repository, create an output directory, browse inside it, then run CMake.

$ git clone https://github.com/aisouard/libwebrtc.git
$ cd libwebrtc
$ mkdir out
$ cd out
$ cmake ..

Windows users must add the Win64 suffix to their Visual Studio generator name if they want to build the library for 64-bit platforms, they'll omit it for 32-bit builds and define the TARGET_CPU variable accordingly.

> cmake -G "Visual Studio 14 2015" -DTARGET_CPU=x86
> cmake -G "Visual Studio 14 2015 Win64"

Then they'll have to open the libwebrtc.sln located inside the current output directory and build the ALL_BUILD project.

Unix users will just have to run the following make commands.

$ make
# make install

The library will be located inside the lib folder of the current output directory. The include folder will contain the header files. CMake scripts will be placed inside the lib/cmake/LibWebRTC directory.

Debug and Release configurations

If you are using XCode or Visual Studio, you can simply switch between the Debug and Release configuration from your IDE. The debugging flags will be appended to the generator's parameters.

Otherwise, you must define the CMAKE_BUILD_TYPE variable to Debug.

$ cmake -DCMAKE_BUILD_TYPE=Debug ..

Using WebRTC in your project

At the time of writing this README file, there's no proper way to detect any installation of the WebRTC library and header files. In the meantime, this CMake script generates and declares a LibWebRTC package that will be very easy to use for your projects.

All you have to do is include the package, then embed the "use file" that will automatically find the required libraries, define the proper compiling flags and include directories.

find_package(LibWebRTC REQUIRED)
include(${LIBWEBRTC_USE_FILE})

target_link_libraries(my-app ${LIBWEBRTC_LIBRARIES})

A pkg-config file is also provided, you can obtain the required compiler and linker flags by specifying LibWebRTC as the package name.

$ pkg-config --cflags --libs LibWebRTC

Fetching a specific revision

The latest working release will be fetched by default, unless you decide to retrieve a specific commit by setting it's hash into the WEBRTC_REVISION CMake variable, or another branch head ref into the WEBRTC_BRANCH_HEAD variable.

$ cmake -DWEBRTC_REVISION=be22d51 ..
$ cmake -DWEBRTC_BRANCH_HEAD=refs/branch-heads/72 ..

If both variables are set, it will focus on fetching the commit defined inside WEBRTC_REVISION.

Managing depot_tools

CMake will retrieve the latest revision of the depot_tools repository. It will get the WebRTC repository's commit date, then check-out depot_tools to the commit having the closest date to WebRTC's, in order to ensure a high compatibility with gclient and other tools.

It is possible to prevent this behavior by specifying the location to your own depot_tools repository by defining the DEPOT_TOOLS_PATH variable.

$ cmake -DDEPOT_TOOLS_PATH=/opt/depot_tools ..

Configuration

The library will be compiled and usable on the same host's platform and architecture. Here are some CMake flags which could be useful if you need to perform cross-compiling.

• BUILD_DEB_PACKAGE

  Generate Debian package, defaults to OFF, available under Linux only.

• BUILD_RPM_PACKAGE

  Generate Red Hat package, defaults to OFF, available under Linux only.

• BUILD_TESTS

  Build WebRTC unit tests and mocked classes such as FakeAudioCaptureModule.

• BUILD_SAMPLE

  Build an executable located inside the sample folder.

• DEPOT_TOOLS_PATH

  Set this variable to your own depot_tools directory. This will prevent CMake from fetching the one matching with the desired WebRTC revision.

• GN_EXTRA_ARGS

  Add extra arguments to the gn gen --args parameter.

• NINJA_ARGS

  Arguments to pass while executing the ninja command.

• TARGET_OS

  Target operating system, the value will be used inside the --target_os argument of the gn gen command. The value must be one of the following:

  • android
  • chromeos
  • ios
  • linux
  • mac
  • nacl
  • win

• TARGET_CPU

  Target architecture, the value will be used inside the --target_cpu argument of the gn gen command. The value must be one of the following:

  • x86
  • x64
  • arm
  • arm64
  • mipsel

• WEBRTC_BRANCH_HEAD

  Set the branch head ref to retrieve, it is set to the latest working one. This variable is ignored if WEBRTC_REVISION is set.

• WEBRTC_REVISION

  Set a specific commit hash to check-out.

Contributing

Feel free to open an issue if you wish a bug to be fixed, to discuss a new feature or to ask a question. I'm open to pull requests, as long as your modifications are working on the three major OS (Windows, macOS and Linux).

Don't forget to put your name and e-mail address inside the AUTHORS file! You can also reach me on Twitter for further discussion.

Acknowledgements

Many thanks to Dr. Alex Gouaillard for being an excellent mentor for this project.

Everything started from his « Automating libwebrtc build with CMake » blog article, which was a great source of inspiration for me to create the easiest way to link the WebRTC library in any native project.

License

Apache License 2.0 © Axel Isouard