Locking the screen kept a video's audio playing whether or not the background-audio button was on. Reported as "audio only mode is always active even if not selected". The button (UR-040) was built for the WebView <video> path, where losing visibility kills the decode: it chose between handing off to a native audio stream and letting playback stop. Native video then became the default renderer (DR-188), and on that path playback runs through ExoPlayer inside a MediaSessionService -- a foreground media service whose entire purpose is to keep playing while the app is hidden. Nothing stopped it, and nothing in the codebase paused on background. So the button governed a handoff that no longer had a gap to bridge. There was no interruption to paper over, and a user who never touched it got background playback anyway. The gating made it self-concealing: MainActivity.onStop only dispatched 'jellytau-background' when backgroundAudioEnabled was already true. The one notification that the app had gone away was itself conditional on the setting, so with the button OFF nothing could react even in principle. onStop and onStart now fire unconditionally and carry the two facts only the activity knows -- whether the toggle is armed, and whether Android put the window into picture-in-picture. What to do about it is decided in Rust (player/background_policy.rs), because it depends on whether the item has a picture to lose: video + toggle off -> Pause video + toggle on -> HandOffToAudio music, either -> KeepPlaying (no picture to give up) picture-in-picture -> KeepPlaying (the window is still on screen) It takes no renderer parameter on purpose. Two renderers with two behaviours and one toggle reaching only one of them is what produced the defect; a rule that cannot see the renderer cannot reproduce it. Two failure modes are deliberate. A decision call that fails leaves playback alone rather than risking silence mid-listen. An event with no detail -- older Kotlin against newer JS -- reads as "armed, not PiP", degrading to the previous behaviour instead of pausing unexpectedly. Foregrounding resumes only what backgrounding paused: a video the user paused themselves before locking stays paused. Written test-first per CLAUDE.md. The stub encoded today's behaviour (nothing ever pauses) and failed exactly as reported -- `left: KeepPlaying, right: Pause` -- before the rule was implemented. Verified on a device, R8-minified, both directions: [player_background_action] video=true armed=false pip=false -> Pause [player_background_action] video=true armed=true pip=false -> HandOffToAudio UR-040 / DR-224 / UT-211.
Specs index
Feature specs for JellyTau. Start a new one from SPEC-TEMPLATE.md and run it past SPEC-REVIEW-CHECKLIST.md before accepting it.
What lives here
Only work that has not shipped. Once a spec is fully implemented its design is folded into the architecture docs — which are the maintained description of the build — and the spec file is deleted. Git history keeps the original, including its rejected alternatives and acceptance criteria; the architecture docs keep the reasoning that a future change still needs.
So: a file in this directory is a promise, not a description. If you want to know how something works, read docs/architecture/. If you want to know what is planned, read here.
Status vocabulary
| Status | Meaning |
|---|---|
| Proposed | Written, not accepted. Nothing built. |
| Accepted | Agreed as the design; implementation not started or not finished. |
| Partially implemented | Some parts shipped; the spec names what is left. |
| Design authority | No code of its own — it records a decision later specs act on. |
Next free requirement ids (always re-check requirements.md before allocating): UR-079, IR-033, DR-225. Three specs below suggested ids that have since been taken by other work; each carries a ⚠️ note at the top.
Partially implemented
| Spec | What landed | What is left |
|---|---|---|
| frontend-domain-model.md | Catalog surface: MediaKind, from_jellyfin isolated, ticks → ms |
primaryImageTag → imageId (~30 sites); player/session/reporting tick math; stream.type |
| libmpv2-migration.md | LICENSE |
The libmpv → libmpv2 crate swap |
| read-through-media-cache.md | DR-126…128, DR-133…138 — cache entries are download rows; local playback of downloads | DR-121/122/124/125 — the player quality selector and the read-through capture |
| scoped-search-boundary-implementation.md | Stage 1: SearchScope owned by Rust (DR-063…067) |
Stage 2: result-side grouping (GROUP_ITEM_TYPES still in searchScope.ts) |
Not started
| Spec | Blocked on / note |
|---|---|
| backend-owned-stream-selection.md | Rust owns direct-play-vs-transcode, transport and quality; players consume one StreamSelection. Phase 1 (delete the .m3u8 sniff) stands alone. Unblocks Linux native video. |
| build-provenance.md | build.rs is still bare. ⚠️ suggested id DR-093 is taken. |
| player-facade-enforcement.md | ~60 commands.player* sites still outside the facade; no lint rule. ⚠️ suggested id DR-095 is taken. |
| windows-native-audio-backend.md | Blocked on the libmpv2 swap. ⚠️ suggested id IR-030 is taken. |
| linux-native-video-spike.md | Spike run 2026-08-21: compositing works on Linux, X11 and Wayland. G1-G6 green bar the Tauri default_vbox() half of G1. Needs an implementation spec that answers adaptive bitrate. |
Design authority
| Spec | Role |
|---|---|
| playback-backend-unification.md | Why video cannot unify onto one native engine and audio can. The audio half has since shipped on Android; Windows has not. |
| scoped-search-boundary.md | The boundary design the check:boundary rule came from. Stage 1 built. |
| scoped-search.md | Superseded in part — its "frontend only, no Rust changes" decision is the leak the boundary spec reversed. UX still current. |
Where the shipped specs went
Sixteen specs were folded into the architecture docs and deleted (2026-08-21). Where to look for each:
| Shipped work | Now documented in |
|---|---|
| Account menu & global chrome | 02-svelte-frontend.md — App Shell and Chrome |
| Library mosaic | 02-svelte-frontend.md — Library Mosaic |
| Series current-episode navigation | 02-svelte-frontend.md — Series and Episode Navigation |
| Downloads as an offline library | 02-svelte-frontend.md — Downloaded Browse |
| Favourites browsing | 01-rust-backend.md — Favorites System |
| Streaming bitrate cap | 01-rust-backend.md — Streaming quality ladder |
| Locally-indexed search | 03-data-flow.md — Search Flow; 01-rust-backend.md — Background workers |
| Offline downloaded-only filter | 06-downloads-and-offline.md — Offline Catalog Visibility |
| Audio equalizer · Android audio settings parity | 05-platform-backends.md — Audio settings on ExoPlayer |
| Android native video spike | 05-platform-backends.md — Native Video Compositing |
| Video background audio | 05-platform-backends.md — Background Audio Handoff |
| Traceability gate repair | traceability-ci.md |
| Boundary tripwire hardening | scripts/check-frontend-boundary.sh (its header is the spec) |
| Playback docs corrections · req-coverage script removal | Nothing to document — both were corrections that have been applied |