NEVO

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Low-latency encrypted VoIP application — C++20 client/server architecture.

Features

• Low-latency audio: miniaudio capture/playback + Opus codec with in-band FEC
• Encrypted voice: XChaCha20-Poly1305 AEAD with automatic key rotation
• NAT traversal: STUN binding + TCP fallback voice tunnel
• Channel system: hierarchical channel tree with permissions
• Qt 6 UI: dockable channel/user panels, connection bar, audio settings
• Server dashboard: real-time session monitoring, user management
• Cross-platform: Windows / Linux / macOS

Tech Stack

Component	Technology
Language	C++20
Build	CMake 3.21+
UI	Qt 6 (Widgets)
Async I/O	Boost.Asio (coroutines)
Audio	miniaudio + Opus
Encryption	libsodium (XChaCha20-Poly1305)
Protocol	Protobuf (hand-written generated headers)
Storage	SQLite3
Logging	spdlog (embedded stub with fmt-style formatting)

Directory Structure

NEVO/
├── cmake/                  # CMake helper modules
├── proto/                  # Protobuf schema definitions
│   └── generated/          # Hand-written C++ protobuf replacements
├── 3rdparty/               # Embedded dependencies (miniaudio, spdlog stub)
├── src/
│   ├── core/               # Shared core library
│   │   ├── audio/          # AudioEngine, Opus, JitterBuffer, Mixer, VAD
│   │   ├── common/         # Result<T>, Logger, Types
│   │   ├── protocol/       # PacketCodec, frame encoding
│   │   └── permission/     # Permission system
│   ├── network/            # Network library
│   │   ├── TcpConnection   # Async TCP with frame protocol
│   │   ├── UdpSocket       # Async UDP
│   │   ├── VoiceCrypto     # Encryption/decryption
│   │   ├── NatTraversal    # STUN client
│   │   └── SslWrapper      # TLS support
│   ├── client/             # Client application
│   │   ├── ClientCore      # Client lifecycle & state machine
│   │   ├── NetworkManager  # Client network orchestration
│   │   └── AudioInput/Output
│   ├── server/             # Server application
│   │   ├── ServerCore      # Server lifecycle
│   │   ├── ClientSession   # Per-connection handler
│   │   ├── Database        # SQLite persistence
│   │   └── ui/             # Server dashboard (Qt)
│   └── ui/                 # Client UI (Qt 6)
│       ├── MainWindow      # Main window with dockable panels
│       ├── ChannelTreeModel
│       ├── UserListModel
│       └── ConnectionBar
└── tests/                  # Unit & integration tests (GTest)

Building

Prerequisites

Dependency	Required	Notes
CMake 3.21+	Yes
C++20 compiler	Yes	MSVC 2022, GCC 12+, Clang 15+
Qt 6	Yes	Core, Widgets modules
Boost 1.80+	Optional	system, lockfree, endian, context
OpenSSL	Optional	TLS support
Opus	Optional	Audio codec (stub without)
libsodium	Optional	Voice encryption (stub without)
SQLite3	Optional	Server persistence (stub without)

Build Commands

# Configure
cmake -B build -DCMAKE_BUILD_TYPE=Release

# Build
cmake --build build --parallel

# Build with tests
cmake -B build -DBUILD_TESTING=ON
cmake --build build --parallel
ctest --test-dir build

Conditional Compilation

All optional dependencies degrade gracefully via compile-time flags:

Flag	Effect when OFF
NEVO_HAS_BOOST	No network/client modules (coroutine stubs)
NEVO_HAS_OPUS	Opus encode/decode returns silence/stub
NEVO_HAS_SODIUM	No voice encryption (plaintext)
NEVO_HAS_SQLITE	No server database (in-memory only)
NEVO_HAS_OPENSSL	No TLS (plaintext TCP)

Running

Server

./nevo_server [--tcp-port 24430] [--udp-port 24431] [--db server.db] \
              [--threads 4] [--log-level info]

Client

Launch the GUI application. Use the Connect dialog to enter server address, port, and credentials.

Configuration

Server Config File (JSON)

Create server_config.json:

{
    "tcp_port": 24430,
    "udp_port": 24431,
    "db_path": "server.db",
    "threads": 4,
    "log_level": "info",
    "server_name": "NEVO Server",
    "max_users": 100,
    "welcome_message": "Welcome to the NEVO server!"
}

Priority: CLI arguments > config file > defaults.

Client Settings

Client settings are automatically persisted via QSettings:

• Last server address/port
• Username
• Audio input/output volume
• VAD/PTT mode selection

Docker

# Build image
docker build -t nevo-server .

# Run
docker-compose up -d

Testing

cmake -B build -DBUILD_TESTING=ON
cmake --build build
ctest --test-dir build --output-on-failure

Test coverage includes: Result, Channel, Permission, Opus codec, JitterBuffer, AudioMixer, AudioMemoryPool, TcpConnection, VoiceCrypto, NatTraversal, Server integration.

License

All rights reserved.