Day 1 of the upgrade plan (output/reports/kon-upgrade-plan-2026-04-17.md
in the CORBEL workspace). Fixes the HANDOVER.md blocker: native live
transcription was capturing silence because PulseAudio/PipeWire monitor
sources (speaker loopback) were winning the device-selection race —
they deliver zero-valued bytes that satisfied the original
"any device that produces data within 350ms" check.
WHAT CHANGED:
crates/audio/src/capture.rs (rewrite):
- New `DeviceInfo` struct (serde-derived) for the Settings device picker
- New `MicrophoneCapture::list_devices()` enumerates inputs with metadata
- New `MicrophoneCapture::start_with_device(name)` for explicit selection
- Refactored `start()` with monitor-source filtering by name pattern
(.monitor suffix, "Monitor of " prefix, "loopback" substring) and
RMS-energy validation in a 350ms window
- Two-pass selection: real inputs first, monitor sources only as
last-resort fallback with explicit warning log
- Drop counter (Arc<AtomicU64>) tracks chunks dropped by `try_send`
failure under load — Codex review caught this as a silent-failure risk
- `dropped_chunks()` accessor for the live session
- Verbose tracing at every step for diagnosis
- Unit test for monitor-name detection
- `cargo check -p kon-audio` passes clean
crates/audio/src/lib.rs:
- Re-export `DeviceInfo`
crates/audio/Cargo.toml:
- Add serde dependency (for DeviceInfo derives)
src-tauri/src/commands/audio.rs:
- New `list_audio_devices` Tauri command (returns Vec<DeviceInfo>)
src-tauri/src/lib.rs:
- Register `list_audio_devices` in invoke_handler
src/lib/pages/SettingsPage.svelte:
- New "Audio" section with microphone picker dropdown
- Auto-populates on mount via `list_audio_devices`
- Refresh button + clear messaging about monitor sources
- Likely-monitor entries marked disabled in the dropdown
- Auto mode is the default (empty string in settings.microphoneDevice)
src/lib/stores/page.svelte.js:
- New `microphoneDevice` field in defaults (empty = auto-select)
NEXT STEPS (per the upgrade plan):
- Wire `microphoneDevice` from settings into `MicrophoneCapture::start_with_device`
in the live and standalone capture paths (currently both still call
the auto-selecting `start()`)
- Test on real hardware (Wayland + multiple input devices)
- Codex sanity-check of this diff is running in parallel; addendum to
follow if anything substantive comes back
Refs: /home/jake/Documents/CORBEL-Projects/kon/HANDOVER.md
output/reports/kon-upgrade-plan-2026-04-17.md (CORBEL workspace)
- VAD stubbed: voice_activity_detector and silero-vad-rust both pin ort rc.10
which conflicts with transcribe-rs requiring ort rc.12. Stubbed until ort
ecosystem aligns at 2.0.0 stable. All audio treated as speech (matches v0.2).
- Refreshed Cargo.lock to resolve ort rc.12 + whisper-rs 0.16 correctly
- clippy clean
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
