human-experience-filter-art/sessions/0021/SESSION-0021.0-TRANSCRIPT-2026-06-26T08-12--2026-06-26T08-20.md

Session 0021.0 — Transcript

App: human-experience-filter-art Start: 2026-06-26T08-12 (PST) End: 2026-06-26T08-20 (PST) Type: executing-plans (operator-driven hotfix/revision of session 0020's audio feature) Posture: yolo Claude-Session: e0cc053a-41fa-416d-a4f5-493f14984e75 Status: FINALIZED

Launch prompt

Show video unchecked doesn't turn off the video. Make "show video" just "Video" and have a toggle like "Dev Mode" has. I can't hear any audio when "soundtrack (follows altitude)" is selected. Let's just have Audio as off/on like Video for now and get rid of white noise.

Pre-state

• Session 0020 had just merged the audio feature to main (Visual×Audio split, per-altitude soundtracks, pink white-noise, A/B crossfade). The operator tested it live and reported three issues.

Session arc

1. Diagnosis (the key work). Both reported bugs were reproduced only in the operator's real browser — neither appeared in headless Chromium or WebKit (installed playwright install webkit to test Safari's engine). Root causes:
   • Video-off doesn't blank: #vid (<video>) and #paint (WebGL <canvas>) are GPU-composited layers; the #black cover had auto z-index, so on a real GPU (Safari/Chrome) the video layer can composite above it despite DOM order. Headless software-raster hides this.
   • No soundtrack audio: real Safari/iOS unlocks an <audio> element only when play() is called synchronously inside the user gesture; the 0020 gesture played in an async continuation (after await fetch), which Chrome allows but Safari blocks. Headless WebKit relaxes autoplay, so it passed. This is the session's main lesson: Playwright headless relaxes both GPU compositing and autoplay, so the 0020 E2E couldn't have caught either — real device / by-eye review is required.
2. Fixes (branch session-0021):
   • Video + Audio are now Dev-Mode-style on/off toggles (.dev-switch), wired on change. Audio on → soundtrack; white-noise deferred (removed from the live control; AUDIO_SOURCES={off,soundtrack}; the pure pink-noise machinery + tests stay for later).
   • Video-off: .black gets z-index:50 + translateZ(0) (own layer) and the video layers are set opacity:0 on video-off (belt-and-suspenders blanking).
   • Safari audio: the tap-to-start gesture now primes both A/B <audio> elements synchronously in-gesture (set src, vol 0, play().then(pause)), unlocking the later async crossfades.
   • Server: player/audio.py resolver + controls.py/state.py + /api/alteration drop white-noise; build_audio_media.py stops emitting the noise bed.
3. Verify + ship. Updated unit/contract/E2E tests; rewrote the 3 E2E for the new toggles (click the visible .dev-switch-track; wait for the opacity transition). 288 passed, 2 skipped. Re-verified in both Chromium and WebKit: Audio toggle plays cosmos/pillars.loop.mp3, video-off sets vid+paint opacity 0 with #black shown, zero JS errors; screenshotted the new toggle UI. Merged session-0021 → main and pushed. (Also untracked a stray docs/.threads/*.json editor artifact swept in by git add -A, and gitignored .threads/.)

Deferred decisions

No low-confidence calls. All three changes were explicit operator requests; the root-cause fixes (GPU z-index/layer-hide; Safari in-gesture unlock) are the standard remedies for these well-known browser behaviors.

Cut state

• main @ fddb6d6 (merge of session-0021), clean, pushed.
• 288 tests + 3 Playwright E2E pass (2 skipped: opt-in media integration).
• White-noise is deferred, not deleted: tools/pipeline/audio_ops.white_noise_args + audio_run.generate_white_noise + their tests remain; only the live control + the build-script emission were removed.
• Unvalidated by this session: real-device audio (Safari autoplay) and real-GPU video-off — headless can't exercise either; needs the operator's by-ear/by-eye pass.

Operator plate

• Video + Audio are simple on/off toggles (Dev-Mode style). Audio on = the current altitude's soundtrack. The two real-browser bugs should now be fixed — but please confirm on a real device (especially iPad/Safari).
• Deferred: white-noise (easy to re-add as a 3rd Audio position), the per-altitude music layer, the networked-control-surface build, Pi renderer.

Next /goal

/goal by-ear/by-eye review the audio + Video/Audio toggles on a REAL device (esp. iPad/Safari — headless can't validate Safari autoplay or GPU compositing), then source/compose the deferred per-altitude music layer per docs/audio-candidate-pool.md (or re-enable white-noise as a 3rd Audio position if wanted)