Voice Relay

Encrypted voice relay chat by rooms.

The goal is to provide a relay server able to route audio streams between multiple clients grouped into rooms, with encryption of the exchanges.

Current state: multi-room relay working end to end over WebSocket (voice + text + room commands). Encryption is not wired yet.

Requirements

• JDK 21
• Maven 3.8+

Project structure

src/main/java/com/example/voicerelay/
  audio/            # AudioSettings, Microphone (capture), Speaker (playback), AudioFrame
  codec/            # Codec interface, PcmCodec (passthrough), MuLawCodec (G.711, 2x), CodecRegistry
  protocol/         # Packet, PacketType, InvalidPacketException (binary "home-made RTP")
  transport/        # Handshake, WebSocketFrame, WebSocketConnection (WebSocket from scratch)
  server/           # RelayServer (accept loop), ConnectedClient (one thread per client), Room (broadcast)
  client/           # VoiceClient: capture, receive and console threads

Build and run

Three terminals — start the server first:

# Terminal 1 — the relay server:
mvn -q compile exec:java "-Dexec.mainClass=com.example.voicerelay.server.RelayServer"

# Terminal 2 — alice:
mvn -q compile exec:java "-Dexec.mainClass=com.example.voicerelay.client.VoiceClient" "-Dexec.args=localhost alice general"

# Terminal 3 — bob:
mvn -q compile exec:java "-Dexec.mainClass=com.example.voicerelay.client.VoiceClient" "-Dexec.args=localhost bob general"

Client arguments are <host> <nickname> <room> (defaults: localhost, a random nickname, general).

Speak — everyone in the same room hears you. Type text to chat, /who for the member list, /mute to toggle the microphone, /quit to leave.

Tests

mvn clean test

License

Distributed under the MIT license.