ytLlive/HANDOFF.md

HANDOFF — session state

Current operational state, read right after TASKS.md. Trust this file as the truth of what is in flight — do not re-derive from git/fs unless it points at a problem. Conventions: schema.md. Rewrite this file at session end, compaction, or any interruption.

Session state (last updated: 2026-08-12)

• Branch: main. TASK 4 ship step 4 (WASAPI audio capture) is built and tested but NOT committed — the working tree is dirty with the audio layer (6 new files in Services/Audio/ + ytLive.Tests/AudioMixerTests.cs, the NAudio.Wasapi 2.2.1 package reference, the THIRD-PARTY-NOTICES entry, the MainViewModel wiring, the FfmpegEncoder.cs:139 CS8602 fix) and its memory updates (TASKS.md, ai.md, Services/index.md, HANDOFF.md). Ready to commit when the user says so.

• Finished this session: TASK 4 ship step 4 — the live audio capture layer: IAudioSource/AudioSample seam, WasapiLoopbackAudioSource (WasapiLoopbackCapture on the default render device), WasapiMicAudioSource (WasapiCapture, NAudio device resolved by FriendlyName matching MicSourceName via a re-read Func<string?> provider, default-endpoint fallback), AudioMixer (owns both sources, starts/stops with go-live, feeds the pure AudioLevelMeter → MicLevelChanged), WaveToFloat (IEEE-float / PCM16 / extensible). MainViewModel constructs the mixer, BeginGoLive success → Start(), StopStream → Stop(), MicLevelChanged marshalled to the UI thread → AudioLevel. Loopback samples are currently dropped (the encoder's AAC mix, ship step 5, consumes them). Build: 0 warnings (a pre-existing CS8602 in FfmpegEncoder.cs:139 surfaced during the rebuild and was fixed with process!). Tests: 139 passing (was 122; +17 new audio).

• Landmines:

  • WaveFormatExtensible.SubFormat is a Guid in NAudio 2.x, not a WaveFormatEncoding — compare it to NAudio.Dmo.AudioMediaSubtypes.MEDIASUBTYPE_IEEE_FLOAT (the IEEE-float subtype constant; it lives in the NAudio.Dmo namespace, not CoreAudioApi).
  • Use the NAudio.Wasapi 2.2.1 feature package, not the NAudio meta-package — the wasapi types come from that package (WasapiCapture in NAudio.CoreAudioApi, WasapiLoopbackCapture in NAudio.Wave); NAudio.Core comes in transitively.
  • The audio meter is an exponential smoother (0.2 factor) — a single pushed sample only moves 20% toward its RMS. Tests must push repeatedly before asserting a converged level.
  • Tests never instantiate MainViewModel directly except the round-clip integration test (a real MainWindow), which never goes live — so the mixer is constructed but never started there; NAudio types are only constructed, never touching devices. Keep it that way.
  • Mic device resolution must re-read MicSourceName at each Start (the app persists only the DisplayName, not a device ID).
  • Windows-only: all capture runs only while live (privacy indicator otherwise).

• Next step: TASK 4 ship step 5 — the frame-pipeline wiring (CameraManager/ScreenCaptureManager → compositor resolver → encoder construction, plus the loopback → encoder AAC mix). Nothing else queued — do not expand the task queue on your own.

• Secret/DB/port facts live: OAuth client id/secret in Helpers/OAuthCredentials.cs; OAuth session token in Helpers/TokenStore.cs (DPAPI → %APPDATA%\ytLlive\ytLlive.auth); layout DB %APPDATA%\ytLlive\ytLlive.db (schema v8; SocialEntry.Software column is a column-presence migration like the others, no version bump); OAuth callback http://localhost:8765/oauth2/callback; crash log %APPDATA%\ytLlive\startup.log.