Talon 867557eda1 feat(M3): multi-stream & per-channel tuning
Implements docs/roadmap.md M3: multiple concurrent streams per user (MIC +
SCREEN_AUDIO + AUX_DEVICE), independent per-stream receiver gain/mute/noise-
reduction, talk indicators, and enforced per-channel Opus configurability
(mono/stereo, bitrate, frame size, FEC/DTX, application).

Bugs fixed along the way (found while implementing, not pre-existing scope):
- Server hard-coded stream_id=1 for every announce, so a second stream from
  the same user silently overwrote the first in SessionRegistry::set_user_stream.
  Now a per-session counter (ConnSession::next_stream_id_); handle_stream_stop
  validates against announced_stream_ids_ before clearing.
- Client dropped mode/dtx/complexity/application from effective_audio even for
  the single M2 stream -- only sample_rate/bitrate_bps/frame_ms/fec were ever
  applied to OpusParams. Fixed on both the send (handle_stream_announce_result)
  and receive (sync_remote_streams) paths via a shared
  opus_params_from_audio_config() helper.
- OpusEncoder always used OPUS_APPLICATION_VOIP; added OpusParams::application
  and wired it through.
- on_playback's per-stream decode passed the wrong frame_size to opus_decode
  (total samples instead of samples-per-channel), which would have overflowed
  the decode buffer for any stereo stream.
- teardown_voice() raced when called concurrently from run_io()'s own cleanup
  and from disconnect() on a different thread -- both could see
  udp_thread_/talk_timer_thread_ as joinable() at once and race to join() the
  same std::thread (intermittent std::system_error under ctest). Fixed with a
  teardown_mu_ guard instead of carrying the flake forward.

New:
- Per-channel AudioConfig: SessionRegistry now seeds Lobby (mono/24kbps/VOIP/
  FEC+DTX) and a new "Music Room" channel (stereo/128kbps/AUDIO/no DTX);
  handle_stream_announce enforces the channel's config, clamping (not
  overriding) bitrate_bps to its ceiling.
- core/src/core/client.h/.cpp: local-stream state is now a
  std::unordered_map<int, LocalStream> keyed by vc_stream_kind, with
  request_id-correlated announce/result handling (request_id already
  round-tripped on the wire; just wasn't read before). on_capture_frame is
  kind-aware and upmixes mono capture to stereo when a stream's config calls
  for it. set_self_mute's mic_muted now only gates the MIC kind. NS is wired
  through set_remote_stream. New run_talk_timer() thread emits
  VC_EVENT_TALK_STATE from both remote and local edge detection.
- core/src/audio/audio_engine.h/.cpp: kind-keyed injection taps
  (inject_capture), stereo-to-mono downmix at the decode/mix boundary,
  RemoteStream gains recv_ns (lazy ApmProcessor) + noise_reduction_enabled
  and last_voice_ms/talking; new set_stream_noise_reduction() and
  poll_talk_transitions().
- core/src/session/session.h/.cpp: Stream now carries the full AudioConfig,
  not just sample_rate/frame_ms.
- New additive C ABI (core/include/voicecat.h): vc_audio_config +
  vc_get_stream_audio_config (effective Opus config for any stream you own or
  a peer's); vc_test_inject_capture (test-only synthetic PCM injection,
  clearly marked, mirrors AudioEngine::inject_capture).
- tests/test_m3_multistream.cpp: the M3 exit criterion through the real ABI
  (mirrors test_voice_client_abi.cpp's approach, not raw sockets) -- two
  concurrent local streams, independent gain/mute/NS control, per-channel
  config divergence via vc_get_stream_audio_config, talk indicators.

Explicitly out of scope for this pass (tracked in PROGRESS.md, not silently
dropped): VAD/PTT input gate + device enumeration; real WASAPI loopback
capture for SCREEN_AUDIO (synthetic injection only); true stereo playback
output (AudioEngine's mixer/output device stays mono -- Opus itself is fully
stereo-correct on the wire).

ctest --test-dir build/m1-dev: 11/11 green, verified across 3 consecutive
full-suite runs plus 8 standalone runs of the new test.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-06-16 14:12:37 +02:00

VoiceCat

Self-hosted, native voice & text chat in the spirit of classic TeamSpeak / Mumble — channel-based voice, channel + private text, one server you run yourself. Plain TCP (control) and UDP (media), no WebRTC. Encrypted by default. A shared C++ core (libvoicecat) drives native clients (Swift on macOS/iOS, C# on Windows) and the server.

Status: pre-implementation. The design is complete in docs/. The code is an M0 skeleton — it compiles and links, but every subsystem is a stub. See AGENTS.md to start building, and docs/roadmap.md for the milestones.

Read the design first

The docs/ folder is the source of truth. Start at docs/README.md, then architectureprotocolvoicesecuritytech-stackdeploymentroadmap.

Build the skeleton (no dependencies needed yet)

The M0 skeleton builds with just a C++20 compiler + CMake + Ninja — no vcpkg, no third-party libraries, because every subsystem is currently a stub.

cmake --preset dev
cmake --build --preset dev
ctest --preset dev            # runs the smoke test (links the core, calls the C ABI)

Artifacts land in build/dev/bin/ (voicecat-server, vccli).

When you start implementing a subsystem that needs real libraries, build with vcpkg deps:

# one-time: git clone https://github.com/microsoft/vcpkg && ./vcpkg/bootstrap-vcpkg.sh
export VCPKG_ROOT=/path/to/vcpkg            # set VCPKG_ROOT (works on Linux/macOS/Windows)
cmake --preset server-release               # auto-installs deps from vcpkg.json
cmake --build --preset server-release

Layout

docs/         design spec (read this)
core/         libvoicecat — the shared C++ core
  include/    voicecat.h  (the C ABI all clients call)
  proto/      voicecat.proto  (control-plane wire format, source of truth)
  src/        net/ crypto/ codec/ protocol/ session/ audio/  (stubs today)
server/       voicecat-server (headless; links the core)
tools/vccli/  headless test client — drives the protocol from M1 on
clients/      apple/ (Swift, M4)   windows/ (C#, M4)   — placeholders for now
tests/        CTest targets

License

Permissive-only dependencies (no GPL/LGPL) so the project can be redistributed freely, including closed-source. Project license: TBD (see docs/tech-stack.md §5).

Description
Native voice chat server and client
Readme 12 MiB
Languages
C++ 43.9%
Swift 30.6%
C# 17.5%
Shell 3.6%
CMake 2.1%
Other 2.3%