Files
jellytau/docs/specs
dtourolle 11d9d760d8 feat(player): native video on Linux, and one contract for every player (v0.11.0)
mpv now decodes video on Linux, drawn into a framebuffer we own and blitted
into the default vbox's draw handler. Tauri's widget tree is untouched, so an
upgrade that assumes its own layout cannot invalidate this. Direct play means
the original file, hardware decoding, and no server transcode at all — where
previously every desktop video was re-encoded to h264 for the browser engine,
whatever the file actually was. Off by default: JELLYTAU_NATIVE_VIDEO=1.

That settles finding 2 of playback-backend-unification.md — "native video
cannot be composited with a Tauri webview" — by demonstration rather than
argument, on X11 and Wayland both.

Turning it on exposed nine defects, none of them mpv's. Each was the same
mistake in a different place: a capability written down as a compile-time fact
about the platform, or a state asserted instead of confirmed.

  DR-238/246  a seek routed by the stream's container rather than by what the
              engine could do with it - correct only while one player handled
              those streams, silent the moment another did
  DR-239      a property handled but never observed, so the play/pause button
              waited for an event that could not arrive
  DR-240      fullscreen expanding the document while the window stayed put
  DR-241      a seek issued before the engine had a file, failed, and discarded
              - which is why resume began at zero
  DR-247      a Linux-only gate outliving the caller that made it Linux-only,
              breaking the Android build outright
  DR-250      a stop aimed at whichever renderer bookkeeping believed was in
              charge, missing the one actually making sound
  DR-251      a duration of zero believed, leaving the seek bar no scale
  DR-252      a junk float converted to a Duration, panicking the backend the
              instant a length-less stream appeared

So the MediaPlayer contract (DR-242 … DR-247): `open` carries a start position,
so no caller sequences load-then-seek and none can race an engine's load;
`seek` states a destination and leaves in-place-versus-re-open to the engine;
`snapshot` is one coherent read; and `Phase::Opening` names the window where
intent used to be lost. One conformance suite runs against every engine —
FakePlayer and mpv under cargo test, ExoPlayer instrumented on a device — so an
engine is either correct or visibly failing.

Two of the nine were introduced during this work and caught on hardware, not by
any suite: an over-broad capability that grouped ExoPlayer with mpv, and the
Duration panic. The suites test engines that behave. That is recorded in
docs/native-player-verification.md, which asks for the exact action sequences
that found them.

Verified: all automated gates, conformance (mpv 9/9, legacy 8/9 by design,
ExoPlayer 7/7 on device), and manual desktop and Android passes on real
hardware.

Known open and deliberately shipped: resume reads local progress and never the
server's; the background-audio handoff still declares a state swap it does not
confirm (the symptom is now impossible, the race is not); and `bun run
android:dev` builds an APK carrying the release application id, whose failure
message advises an uninstall that would destroy app data. Fix that last one
before anyone else builds for Android.

Squashed from worktree-linux-native-video, which keeps the per-defect history.
2026-08-23 10:51:45 +02:00
..

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-232. 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 primaryImageTagimageId (~30 sites); player/session/reporting tick math; stream.type
libmpv2-migration.md LICENSE The libmpvlibmpv2 crate swap
read-through-media-cache.md DR-126…128, DR-133…138 — cache entries are download rows; local playback of downloads DR-122/124/125 — the read-through capture. DR-121 shipped as backend-owned stream selection and left this spec
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
desktop-native-video.md mpv draws video on every desktop platform, then the webview <video> path and hls.js are deleted. Converts a measured 7% direct-play rate toward Android's 85%. Stacked on backend-owned stream selection.
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. The adaptive-bitrate question it was waiting on is answered: the server publishes one EXT-X-STREAM-INF, so there is no ladder for mpv to lose (DR-229). StreamSelection (DR-225) is the contract to consume.

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