Getting Started

This page is the shortest path from zero to a working icey program.

If you need every build knob, install prefix, or platform package detail, use the installation guide. If you are still figuring out which subsystem you need, start with the module map.

Quick Start

cmake_minimum_required(VERSION 3.21)
project(myapp)

include(FetchContent)
FetchContent_Declare(icey
  GIT_REPOSITORY https://github.com/nilstate/icey.git
  GIT_TAG 2.4.3
)
FetchContent_MakeAvailable(icey)

add_executable(myapp src/main.cpp)
target_link_libraries(myapp PRIVATE icey::base icey::net icey::http)

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Available Targets

Building from Source

If you want a local build without installing system-wide:

git clone https://github.com/nilstate/icey.git
cd icey
cmake -B build -DCMAKE_BUILD_TYPE=Release -DBUILD_TESTS=ON
cmake --build build --parallel $(nproc)
ctest --test-dir build --output-on-failure

Then use find_package in your project:

find_package(icey REQUIRED)
target_link_libraries(myapp PRIVATE icey::base icey::net icey::http)

See the installation guide for the full build/install path, platform-specific dependencies, and CMake options.

Enabling Optional Modules

icey auto-detects optional system dependencies and builds the matching modules when they are available.

• icey::av (FFmpeg): install libavcodec-dev libavformat-dev libavutil-dev libswscale-dev libswresample-dev (Ubuntu/Debian) or ffmpeg (Homebrew). Point CMake at a custom build with -DFFmpeg_ROOT=/path/to/ffmpeg. The av module builds when FFmpeg is found.
• icey::webrtc (libdatachannel): requires the av prerequisites above plus libdatachannel. libdatachannel is fetched automatically via FetchContent when the webrtc module is enabled and its prerequisites are present.
• icey::crypto, icey::net, icey::stun, icey::turn (OpenSSL): install libssl-dev (Ubuntu/Debian) or openssl (Homebrew). These modules build when OpenSSL is found.

For the full build matrix and all user-settable options, use installation.md.

What You Can Build

Stream a webcam to any browser

150 lines of C++. Camera capture, H.264 encoding, WebRTC transport, Symple signalling. Open a browser, see video.

session.IncomingCall += [&](const std::string& peerId) {
    session.accept();
};

session.StateChanged += [&](wrtc::PeerSession::State state) {
    if (state == wrtc::PeerSession::State::Active) {
        stream.attachSource(capture.get());
        stream.attach(&session->media().videoSender(), 5);
        stream.start();
    }
};

See webcam-streamer or read WebRTC in 150 Lines of C++.

Record a browser's camera server-side

Browser sends WebRTC, your C++ server decodes with FFmpeg, writes to any format. Server-side recording without cloud vendor lock-in.

See media-recorder.

Media pipeline

Camera to encoder to network in four lines:

PacketStream stream;
stream.attachSource(videoCapture);
stream.attach(new av::MultiplexPacketEncoder(opts), 5);
stream.attach(socket, 10);
stream.start();

WebRTC peer session

wrtc::PeerSession::Config config;
config.rtcConfig.iceServers.emplace_back("stun:stun.l.google.com:19302");
config.media.videoCodec = av::VideoCodec("H264", "libx264", 1280, 720, 30);

wrtc::SympleSignaller signaller(client);
wrtc::PeerSession session(signaller, config);

session.IncomingCall += [&](const std::string& peerId) {
    session.accept();
};

session.StateChanged += [&](wrtc::PeerSession::State state) {
    if (state == wrtc::PeerSession::State::Active)
        startStreaming(session);
};

Your First Program

A minimal HTTP echo server:

#include "icy/http/server.h"
#include "icy/loop.h"

int main() {
    icy::http::Server srv{"0.0.0.0", 8080};
    srv.Connection += [](icy::http::ServerConnection::Ptr conn) {
        conn->Payload += [](icy::http::ServerConnection& conn,
                            const icy::MutableBuffer& buf) {
            conn.send(icy::bufferCast<const char*>(buf), buf.size());
            conn.close();
        };
    };
    srv.start();
    icy::uv::runLoop();
    return 0;
}

Next Steps

• Read the module map if you want the dependency picture first.
• Go straight to a guide if you know the subsystem:
  • Base
  • HTTP
  • WebRTC
  • TURN
• Explore the samples and apps in each module's src/*/samples or src/*/apps directories.
• Read the contributing guide if you want to work on icey itself.