The crates.io tarball of webrtc-audio-processing-sys 2.0.3 is missing
the vendored C++ submodule — the bundled build fails with 'Directory
does not contain a valid build tree' when meson tries to configure
the ./webrtc-audio-processing subdirectory. Cargo clones git deps with
submodules auto-initialized since ~1.27, so pulling from the upstream
git repo (pinned to tag v2.0.3) gives us the full source tree.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Adds gold-standard Linux echo cancellation: in-app WebRTC AEC3 (Audio
Processing Module) via the webrtc-audio-processing crate, using the
same algorithm as Chrome WebRTC, Zoom, Teams, and Jitsi. Runs entirely
in-process, so it works identically on ALSA / PulseAudio / PipeWire
systems — no dependency on user-configured echo-cancel modules.
Architecture:
- New crates/wzp-client/src/audio_linux_aec.rs module (~470 lines).
Contains LinuxAecCapture and LinuxAecPlayback, both using CPAL
under the hood but routing samples through a shared
Arc<webrtc_audio_processing::Processor>. The playback path tees
each 20 ms frame into APM.process_render_frame as the echo
reference BEFORE handing the samples to CPAL's output callback.
The capture path runs APM.process_capture_frame on each mic frame
in place before pushing to the audio ring buffer. This is the
"tee the playback ring" approach that Zoom/Teams/Jitsi use.
- New `linux-aec` feature in wzp-client pulling in the
webrtc-audio-processing crate at v2.x with the `bundled`
sub-feature. Bundled means the vendored PulseAudio WebRTC C++
sources are statically compiled via meson+ninja at cargo build
time — no runtime .so dependency, avoids Debian Bookworm's stale
libwebrtc-audio-processing-dev 0.3 package (which predates AEC3).
Dep is target-gated to Linux, so enabling the feature on non-Linux
is a no-op.
- lib.rs re-exports LinuxAecCapture/LinuxAecPlayback as
AudioCapture/AudioPlayback when `linux-aec` is on, otherwise
falls back to the CPAL audio_io path. Shared public API
(start/ring/stop/Drop) means downstream code is unchanged.
- New `linux-aec` feature in wzp-desktop forwards to
wzp-client/linux-aec so `cargo tauri build -- --features
wzp-desktop/linux-aec` builds the AEC variant.
APM configuration:
- EchoCancellation: High suppression, delay-agnostic mode on,
extended filter on, stream_delay_ms=60 initial hint
- NoiseSuppression: High
- HighPassFilter: on
- AGC: off (can fight Opus encoder's own gain staging + adaptive
quality controller; add later if users report low mic level)
Frame size handling:
- Pipeline uses 20 ms frames (960 samples @ 48 kHz mono)
- APM requires strict 10 ms (480 samples) per call
- Each 20 ms frame is split into two 480-sample halves, APM called
twice, halves stitched back
- Same pattern for render and capture sides
- Carry-buffer logic handles the case where CPAL delivers samples in
arbitrary chunk sizes that don't divide 960
Build infrastructure:
- scripts/Dockerfile.linux-desktop-builder adds meson, ninja-build,
python3, clang for the webrtc-audio-processing bundled build
- scripts/build-linux-desktop-docker.sh takes a new --aec flag that
enables the linux-aec feature and renames the output artifacts
with an `-aec` suffix so noAEC and AEC variants can coexist on disk
Task #30.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- CreateEventW is gated behind Win32_Security in the windows crate
because its signature takes SECURITY_ATTRIBUTES; add to features.
- Remove unused HANDLE import.
- Wrap GetId() and PWSTR::to_string() in explicit unsafe { ... }
blocks for Rust 2024 edition's unsafe_op_in_unsafe_fn lint.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Adds a direct WASAPI microphone capture path for the Windows desktop
build that opens the default communications endpoint via
IMMDeviceEnumerator -> IAudioClient2 -> SetClientProperties with
AudioCategory_Communications, turning on Windows's communications
audio processing chain (AEC, noise suppression, automatic gain
control). The communications AEC operates at the OS level and uses
the system render mix as the reference signal, so echo from our
existing CPAL playback stream is cancelled automatically with no
per-process reference plumbing.
Architecture:
- New crates/wzp-client/src/audio_wasapi.rs module (~280 lines).
Event-driven capture loop on a dedicated thread; pushes PCM into
the same lock-free AudioRing used by the CPAL path. Same public
API as audio_io::AudioCapture so downstream code is unchanged.
- New `windows-aec` feature in wzp-client that pulls in the
`windows` crate (Microsoft's official Rust COM bindings) gated to
target_os = "windows" only. Enabling the feature on non-Windows
targets is a no-op since both the module and the dep are
cfg(target_os = "windows").
- lib.rs re-exports WasapiAudioCapture as AudioCapture when the
feature is on, otherwise falls back to the CPAL AudioCapture.
AudioPlayback is always the CPAL one — no reason to swap it.
- desktop/src-tauri/Cargo.toml Windows target enables the new
feature: `features = ["audio", "windows-aec"]`.
Implementation notes:
- Uses eCommunications role (not eConsole) for GetDefaultAudioEndpoint
— the user-configured "communications" device that Teams/Zoom
pick up, and the one Windows's AEC is tuned for.
- Requests 48 kHz mono i16 with AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM +
SRC_DEFAULT_QUALITY so Windows handles any format conversion in
the audio engine instead of rejecting our format.
- Event-driven with SetEventHandle / WaitForSingleObject — no
polling, minimal CPU cost between packets.
- 200 ms wait timeout so the capture thread polls `running` often
enough for Drop to stop cleanly even if the audio engine stalls
(e.g. device unplug).
Task #24.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
First step of the Windows x86_64 desktop build: stop pulling
coreaudio-rs into the Windows dependency graph so the project can at
least run `cargo check --target x86_64-pc-windows-msvc`. Software AEC
is already disabled in engine.rs so there's nothing else to stub — the
macOS-specific VPIO path is skipped via #[cfg(target_os = "macos")] on
both sides and Windows falls through to the plain CPAL
AudioCapture/AudioPlayback branch that already existed.
crates/wzp-client/Cargo.toml
- coreaudio-rs optional dep moved under [target.'cfg(target_os = "macos")']
- `vpio` feature now uses `dep:coreaudio-rs` syntax and the gated dep
- Enabling `vpio` on Windows/Linux is a no-op at resolution time
crates/wzp-client/src/lib.rs
- `pub mod audio_vpio` is now #[cfg(all(feature = "vpio", target_os = "macos"))]
- Previously `vpio` alone was enough to try to compile the Core Audio
bindings, which would fail on non-Apple targets the moment the
feature flag was flipped on
desktop/src-tauri/Cargo.toml
- [target.'cfg(not(target_os = "android"))'] removed — was leaking
vpio into Windows/Linux via the catch-all.
- macOS: wzp-client with features = ["audio", "vpio"]
- Windows: wzp-client with features = ["audio"]
- Linux: wzp-client with features = ["audio"]
- Android: wzp-client with default-features = false (unchanged)
- Dropped the unused direct coreaudio-rs = "0.11" dep on macOS —
wzp-desktop's own sources never call Core Audio directly.
Verified via `cargo tree --target x86_64-pc-windows-msvc -p wzp-desktop`
that the Windows target now resolves wzp-client with cpal but without
coreaudio-rs. macOS target still resolves with coreaudio (direct via
vpio feature and transitively via cpal). macOS `cargo check` still
builds cleanly.
Cross-compile from macOS hit a cargo-xwin + llvm-lib setup issue in
ring's build.rs, so the actual `cargo check --target
x86_64-pc-windows-msvc` did not complete locally. Build verification
belongs on the user's Windows x86_64 host where MSVC is present
natively.
See tasks #23 (this one), #24 (Voice Capture DSP / WASAPI Communications
for OS-level AEC on Windows), and #25 (aarch64-pc-windows-msvc support).
WZP-S-2: Relay token authentication
- New --auth-url flag: relay calls POST {url} with bearer token
- Clients must send SignalMessage::AuthToken as first signal
- Relay validates against featherChat's /v1/auth/validate endpoint
- Rejects unauthenticated clients before they join rooms
- New auth.rs module with validate_token() + tests
WZP-S-3: featherChat signaling bridge
- New featherchat.rs module for CallSignal interop
- WzpCallPayload: wraps SignalMessage + relay_addr + room name
- encode_call_payload/decode_call_payload for JSON serialization
- CallSignalType enum mirrors featherChat's variant
- signal_to_call_type maps WZP signals to FC types
Protocol: Added SignalMessage::AuthToken { token } variant
129 tests passing across all crates.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- cpal is now behind an 'audio' feature flag (off by default)
- --live mode requires --features audio at build time
- --send-tone and --record work on headless servers without audio libs
- Linux build script no longer installs libasound2-dev
Build for headless: cargo build --release
Build with mic/speakers: cargo build --release --features audio
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
