The webcam's frames reach the compositor later than the mic's samples reach the audio
pipe, so the voice runs ahead of the lips. The existing lip-sync offset could not fix
that: it delays the WHOLE mix, which drags desktop and alert audio — neither of which
has a camera to follow — out of sync in the process.
So the delay line learned channels (mono for a source, stereo for the mix, offset always
in milliseconds so the frame count is what stays constant), and FillAndMix runs a second
line over micChunk before the mix. Slider-side: presets off / 150 / 200 in the LIP-SYNC
bay under the whole-mix control, persisted as Audio.MicSyncOffsetMs.
Default 175 ms is the creator's own number for a C920 pipeline (they asked for
+150..+200). It is a setting, not a constant, because the right figure belongs to the
camera and the machine — a faster camera wants less, no camera wants none.
Both delay lines are reconfigured every tick, so the 2026-09-12 trap still applies and is
documented at both sites: a Configure that reallocates discards the buffered voice every
10 ms.
673 pass, 0 warnings. Ear check pending: this is an audio change.
591 green, 0 warnings.
- `Scene.SceneMutesMic` / `SceneMutesDesktop` are **nullable booleans**: null = leave the mix alone, so
a scene is passive until the creator says otherwise. Schema columns added, NULL for every existing
layout except one deliberate default.
- **Applied once when the scene takes the PROGRAM output** (`TransitionToScene`, only when live or
recording). Staging a scene offline is auditioning, not a stream edit — the test asserts that.
- **The creator is boss:** a manual mute survives any transition into a scene with no opinion; a scene
that does have one wins on its next entry. `SetMicMuted`/`SetGameMuted` are idempotent so a repeated
"mute" cannot clobber the level that unmute would restore.
- **BRB ships muted** (creator spec) for new layouts *and* via a one-time migration for existing rows
where the creator has never expressed an opinion.
- UI: two three-state checkboxes under the layers list ("When this scene goes live"), styled with
`PropertyPillCheck` so the theme test holds.
`SceneAudioTests` covers the whole rule in one integration test: default state, offline staging does
nothing, live entry mutes, manual unmute survives a passive scene, an opinionated scene wins, desktop
untouched, and all three states roundtrip through save/reload.
Needs the creator's eye: the checkboxes are new chrome in the left panel (indeterminate = passive).
Creator, plainly: "the entire point of a ticker is to tick… so, tick." The static strip was my
reading of an earlier exchange; it is gone.
How it ticks without becoming the compositor's most expensive layer:
- `ScoreboardRenderer.RenderRun` rasterises the run ONCE per value change at its natural width plus
a gap.
- `ScoreboardPresenter` crops a 1920-wide window at a moving offset each tick — a row-wise byte
copy, no text layout, no re-raster.
- `TickScoreboard` runs on the existing 30 Hz meter clock and only while the strip is shown, so a
hidden or disabled scoreboard costs nothing.
The dev simulation uses the same path, so what is previewed is what ships.
Test updated to the real contract: no tick → identical pixels; a tick → different pixels; a value
change → re-rasterised run. (The old test asserted frame-instance identity, which a cropped window
can never satisfy.)
Reported: no activity in the master meter.
Cause: `MasterLevel` measures the buffer the ENCODER receives, and that buffer only exists while the
mix is being pulled — streaming or recording. Idle, nothing fills it, so the master read zero while
the bays below it moved. A master that is dead between sessions is a gap in the design.
Now: while a session runs the master shows the measured mix (unchanged); idle it shows an estimate
computed from the same measured sources and the same gains the mix applies
(`MeterScale.MonitorFraction`, pure + tested). Two ladders can therefore never tell contradictory
stories about whether audio exists.
Guard: MeterScaleTests pins the estimate — silence reads zero, a quiet source at unity is visible,
two sources add, and gain is applied in the LINEAR domain like the mix (scaling the display fraction
would be a different, wrong curve).
Reported: TRAX plays audibly but no ladder registers anywhere.
Two distinct faults, one of them mine:
1. The meter readouts were refreshed only from the MIC's level callback. With a silent or absent
mic there is no tick, so a playing TRAX never updated its ladder — the level was measured, the
UI simply never asked for it. Meters now have a 20 Hz DispatcherTimer of their own.
2. If the player's own meter still reads 0 while playing, the samples are not reaching the device
(or metering is not attached). That now writes ONE line to startup.log after 2s — so the next
report says which side is broken instead of another round of guessing.
Note: TRAX rides the desktop loopback, so once the mix captures it the GAME ladder should move too;
if it does not, the loopback endpoint and the music's output device differ.
Creator: "why is there no meter for when trax is playing?"
Routing answer: TRAX rides the desktop loopback, so it already moved the GAME ladder — there was no
separate TRAX signal in the mix. But that ladder cannot answer the question a deaf creator actually
has: "is the music producing sound at all?" The play glyph cannot either — an open file with a dead
decoder still reports Playing.
So the player now measures its own output: \`MusicPlayer\` wraps the volume stage in an NAudio
\`MeteringSampleProvider\` and exposes \`Level\`; \`ITraxPlayer.Level\` keeps the fake honest. The VM maps
it through the same display scale (\`TraxMeterFraction\`), zeroed when not playing, and the TRAX bay
carries a 24-segment ladder above its fader.
This reverses my earlier "no ladder, nothing honest to show" — the honest thing arrived with a real
measurement. TraxBayTests flipped accordingly (it now asserts the ladder AND its source).
Unit 9, the one that matters most for this creator.
MASTER STRIP (top, nearest the preview):
- one ladder fed by the MEASURED mix — `AudioMixer` now measures the buffer the encoder receives
(`MasterLevel`, `MasterImbalanceDb`), so the master cannot show a source instead of the output
- `-12.4 dB` readout, and ONE L/R flag that appears above a 6 dB gap instead of a second ladder
- bitrate / FPS / dropped / duration from the existing health poll
MONO OUTPUT:
- `AudioFold.ToMono` averages each stereo pair into both channels, applied after the limiter and
the sync delay, so the stream AND the recording get what was folded
- `MonoOutput` is persisted (`Audio.MonoOutput`) and restored at startup: an accessibility switch
that resets each session is an accessibility failure
- one click in the strip, remembered forever
Guard: AudioFoldTests (hard-left reaches the right at half amplitude, hard-right — the inaudible
case — reaches the left, centred material keeps its level, mono buffers untouched) and
MasterStripTests (the strip binds the measured mix + the switch, the store round-trips it, and the
fold is the tested helper rather than new arithmetic). 33 audio tests green.
Unit 8. Re-houses the shipped TASK 22 offset in the dock:
- slider −200…+200 ms, snapping to 5 ms ticks (the existing property still clamps and persists)
- readable readout: "0 ms (aligned)" when right, signed otherwise ("+50 ms", "−120 ms")
- presets 0 / +50 / +100; 0 IS the detent — a button is easier to hit than a snap, and "the lip-sync
is right" deserves one click.
Guard: SyncBayTests pins the binding, the readout, the presets and the snapping, and that the
offset stays the persisted property (no second source of truth).
Unit 6. Mirrors the mic bay for the desktop/game bed, plus the badge that matters to a creator who
cannot hear the duck: it shows while the ducker is actually attenuating, and it prints the gain the
mixer applied (−12.0 DUCK by design).
- `AudioMixer.DuckGain` exposes `AutoDucker.CurrentGain` instead of leaving it internal.
- VM: `GameVolumeDb` / `GameVolumeDbLabel` (fader face), `GameMeterFraction` (measured level),
`IsGameDucking` + `GameDuckLabel` refreshed on the level tick — the same moment the ducker runs,
so the badge cannot lag behind the mix.
- The bay: header chip + source, ladder, mute dot (uses the meter band, so mute reads at a glance),
dB readout, fader.
Guard: GameBayTests — the dock binds all four, `AutoDucker.DuckGain` is −12.04 dB and the label is
produced through the same dB scale as the faders, and the mixer property exists so the badge cannot
become a hardcoded number.
Unit 5. The dock's first working bay:
- 24-segment ladder fed by `MicMeterFraction` — the MEASURED display level (already scaled by the
volume and zeroed when muted), never the gain setting.
- Fader in dB via `MicVolumeDb` (−60 … +6, 0 = unity) with a mono-weight readout
(`MicVolumeDbLabel`), so "−6.0 dB" is what the creator reads instead of "0.50".
- Mute button whose dot uses the existing MicStatusBrush; clicking the device name opens the mic
picker, so the label stays the control (the KISS rule: one place to change the mic).
The preview's own mic row stays for now — it is removed in the final unit, after the dock bays are
complete, so nothing is lost if a bay misbehaves.
Guard: MicBayTests — the bay binds the dB face and the measured level (not the gain), the fader
range IS the scale's range, the VM surface exists, and mute still zeroes the ladder.
The state colours the view-models hand to bindings — top bar, REC/ON-AIR dots, health banner,
meter bands, toast tints — were hex literals in C#. They now resolve from Themes/Tokens.xaml
through `Helpers/ThemeBrush`, so the values live in one place. Without an Application (unit tests)
the helper returns a neutral grey: visibly wrong rather than silently plausible.
Four tokens the code needed and the document lacked, added to DESIGN.md (so the doc-is-the-contract
guard demanded their brushes): info-container #3a3b52, success-container #1d5c38,
warning-container #b8860b, test-container #9c6f1c (the test-stream gold bar).
Also fixed by this: the top bar still painted the RETIRED brand red #e94560 when live — the
standard's #ff5451 now, and `OnAirSignTests` (which pinned the old value) says so. BarOn/BarOff
became properties rather than static fields, because a static field would resolve tokens before
the Application exists.
Verified: DesignTokensTests, GameMeterHonestyTests, NotificationAreaIntegrationTests,
OnAirSignTests, SessionTeardownTests — 38 tests green.
Last inconsistency from the sweep: several VM-side state colours are still literals, and after
the palette moved they disagreed with everything around them — the top bar's LIVE state would
have painted the retired pink-red while the tile beside it used the standard red.
Values aligned (tokenisation of these sites is its own unit — they are strings bound to
Background/Foreground, so the fix is a VM->Brush refactor, not a find/replace):
- live / on-air / recorder dot: #e94560 -> #ff5451 (the standard red)
- error banner: #8f1f1f -> #93000a (error-container)
- audio meter bands follow the doc's stated thresholds: nominal cyan #38bdf8, caution amber
#ffb95f, peak #ff5451 — they were green/yellow/red, which contradicted DESIGN.md's own table
GameMeterHonestyTests pinned the old band colours; its intent (the meter scales by volume) is
unchanged, so the two colour expectations now name the new bands.
Positive offsets still delay the whole mix via the delay line (lip-sync fix);
negative offsets now ARM once at StartLive and drop |N| ms off the pipe's write
head so audio events land earlier when audio runs BEHIND video. Slider relabeled
AUDIO SYNC, Min −500, locked while live/recording (IsEditMode). LayoutStore and
VM clamp to −500..500.
OBS reference for eat-the-head negative sync: https://obsproject.com/kb/obs-studio/buffering-time (negative sync values pull audio earlier by discarding buffered player audio).
Test: StartLive_NegativeOffset_AdvancesAudio_ByDroppingTheStreamHead (6x0.9 head
must be eaten before 0.2 bed reaches the wire).
Creator report 2026-09-01: with the desktop slider dragged to 20%, the game bar's
meter stayed pegged yellow/red. Root cause: the mic meter's formula (level x volume)
was cloned to the game bar WITHOUT the x-volume factor, and the clone inherited a
false premise — that WASAPI loopback capture tracks the endpoint volume. Tonight's
observation disproves it (the tap is pre-endpoint-volume), so both the meter (display)
and the mix (AudioGainProvider.LoopbackGain, fixed in 5ead064) must scale it themselves.
ai.md's two 'loopback scales with the slider' sentences corrected in the same pass.
Test seam: VolumePushOverride (internal static, mirrors LayoutPathOverride pattern) so
the test never hijacks the machine's real volume. GameMeterHonestyTests (RealApp +
temp DB): unity -> hot/red, 20% -> ~1/5 width/green, push observed.