Preview modal audio, five rounds:
- True track-change crossfade: scheduleSettle no longer silences the
outgoing clip at t=0; preview_load's equal-power fade owns both ramps,
gated on the incoming voice's first Playing event (audible_marks), with
failure/overstay fallbacks. CROSSFADE_MS = 340 — locked to the reel's
card-slide so audio and visuals land together.
- Two-neighbour lease prefetch + a 15-min on-disk clip byte-cache
(recent_clips): steps in BOTH directions crossfade in ~15 ms; revisits
never re-download.
- Adaptive settle (isolated steps fire immediately, bursts coalesce) and
anticipatory auto-advance (step at clip end minus 400 ms) so auto-play
crossfades over the tail instead of gapping.
- Session resume memory: revisited tracks continue where they left off
(decoder-level start offset via play_local_from/resume_at); finished
tracks restart from the top.
- Open/close crossfades with the MAIN player: fade-pause with the
desired-paused latch landing at ramp end, fade-resume from the paused
position; MAIN_FADE_GEN guards; focus handshake relaxation documented
in focusBridge.
Volume normalization (Settings > Playback, default on):
- Dependency-free BS.1770/EBU R128 meter in the player crate (K-weighting,
400 ms gated blocks, incremental) + analyzer that reads the same growing
file playback streams from — first plays are measured at download speed.
- Gain layered under user volume; audible start GATED on a preliminary
measurement (10 s of audio or 800 ms budget) so the level is right from
the first sample and never changes mid-track; prelim boosts capped 3 dB,
peak-aware clipping guard, persistent loudness-cache.json.
- Gapless boundaries get their own sample-accurate gain via
SetNextNormGainDb, fed by preload analysis.
Debug overlay (Ctrl+Shift+D): process-tree CPU / PDH GPU / working-set +
private-commit RAM / network rates / FPS / current-track download progress
read from the backend's own StreamProgress / live normalization state /
preview session phase. Polls only while visible.
131 JS + player + app tests green; every path verified live over CDP.
Rust (2A):
- metadata: deezer_track_uncached (fresh mint, cache-updating, paced) and
fetch_preview_media — dedicated client whose custom redirect policy
re-validates every hop against the media allowlist; bounded body read
(cap enforced on received bytes, not Content-Length's promise); Date
header captured for provider-clock lease math. httpdate dep added.
- src-tauri/preview.rs: second Player instance + soulstream:preview event
channel; preview_resolve (fresh mint → host gate → MIME gate → ID3v2
shell strip → MPEG sync check → clip file + opaque lease id → safe_for_ms
mirroring lease.js); preview_load with start_paused via the
desired-paused latch; preview_control/dispose; player_pause_acked
exposing the Phase 0.4 ack on the MAIN player. 9 unit tests.
JS (2B):
- api.js: preview command surface (opaque lease ids only).
- nativeTransport.js: stamps {sessionId, generation, sessionKey} onto
backend events; cleared context makes stragglers dispatch nothing.
- productionResolver.js: DTO → MediaLease, failure classes preserved.
- focusBridge.js: production coordinator binding with the documented
renderer-side generation invariant (buffering counter + gateway).
- service.js: the orchestrator — settle window, resolve→load→play under
focus, single capped retry, one forward lease prefetch with safe-window
expiry, stale re-checks before every transport command, close/handoff.
The service constructs its transport around its own dispatch — the
factory signature exists because a pre-built transport silently loses
the event wiring (caught by test).
70 JS tests passing (npm test); metadata 46 + app preview 9 in cargo.
The previous .git directory was found gutted (only info/ remained), so
history is unrecoverable locally. This commit restores version control
with the tree exactly as it stands: the working app, the preview-tracks
launcher on the artist hero, the scrollable-track-previews design bundle
(docs + approved mockups), and the Phase 0 validation artifacts.
KeelrLeek