sync_replay_project/docs/ROADMAP.md

Roadmap

Backlog and epics, in order. Done work lives in git history. Check an item off by deleting it in the same commit as the code. Wire changes also edit PROTOCOL.md.

Backlog

1. Auto-skip OP/ED (undecided): who decides and how (shared for the server, personal, per show) is open. Constraint: a skip is a seek and seeks are shared, and only real ranges (segments, OP/ED chapters) should ever be skipped.

2. Files: next episode from Files (by parsed episode, with the countdown, and under Up next's "Continues with"). Later: tracking for file series.

3. yt-dlp follow-ups (see ARCHITECTURE "yt-dlp"): check that the bundled Windows libmpv has the ytdl hook (Lua) and plays edl:// URLs through media_kit; if not, resolve in the app and open the relay tracks' formats. YouTube: yt-dlp wants a JS runtime (deno) for full extraction. Formats that need yt-dlp's cookies.

   • Live streams through the relay (today refused: the sync model needs a fixed duration and seeking).
   • tool/relay_e2e.dart: a two-track case (bytes and pieces) over a shaped source link. Pieces on a slow source: a cold piece can take longer than media_kit's 5 s network-timeout; if it does, fetch the first pieces before setting relay.live.
   • Pieces, unverified so far: the 403/410 re-resolve against a real expiring HLS (signed segment URLs), HLS discontinuities / ad splicing, Windows' bundled ffmpeg with extensionless piece URLs (p/<i>; fine with ffmpeg 9 on Linux).
   • Thumbnails and scrubbing previews of a relayed media with tracks should open the video track's URL alone, not the EDL.

4. AniList account: sign in (OAuth via a localhost callback), "My list" filter on the Schedule from the user's AniList lists. This is the Schedule's personal tracking; AnimeFlow has no per-user follow.

5. Ops: leaf_widgets (the Up next popover's LeafPopover) is a local path dependency: make it a git dependency like fox_utils before the next release (CI cannot see the path), or go back to the app's popover route. Check shaders on Windows; the relay e2e "source drops uncleanly and resumes" fails about half the time under the full suite.

6. Windows: first real use. CI builds and publishes watch-together-<ver>-windows-x64.zip (libmpv bundled) and runs the updater tests on NTFS; a friend has joined from it. Still unchecked: fullscreen controls, hosting (firewall prompt), in-app update from one release to the next. The rest of the desktop tests are not in CI.

7. Relay follow-ups (see ARCHITECTURE "Relay"). First real use: owner's PC -> VPS -> friend, Jellyfin and a file. Then:

   • Source takeover: when the source leaves, another member with an account on that Jellyfin (or the same file: name, size, hash) takes over instead of the buffer running dry.
   • "Bob can't open this link — relay it?": offer the relay to whoever put a direct link up when a viewer's player fails to open it.
   • Preload relayed Up next items (see ARCHITECTURE "Getting ready"): today a link passed on "through me", another member's file, a server-fetched link and the host's own file are opened cold by everyone but their source when they go up (their relay or /m starts with the swap), so the gate waits for the slowest open. Plan (wire change): the server holds a second, small relay for Up next's first item, keyed by its queue id. Its adder's app dials a second source for it as soon as it is first (/r/.../source naming the queue id); a server-fetched item starts its fetch then; state.queue[0].relay (live, tracks) tells viewers when and how to open /r/<sid>/<token>/q/<queueId>/<name> in their preload player. The buffer keeps only the head and tail pins plus about 32 MiB ahead of the viewers until the swap, pulls nothing while nobody preloads, and is dropped when the item stops being first. A swap with queueId turns it into the media's relay (same buffer; the q/ URL keeps working for that media, so the preloads match and are promoted). The host's file: the hosting app hands the server the first item's path early and /m serves it under a next/ name until the swap.

8. Jellyfin (epic, below).

9. Smaller items

   • Video output robustness: if media_kit's hardware path regresses to software (see ARCHITECTURE, Media: render mode), vendor a media_kit_video fix that builds the EGL display from GDK's native display. The video freeze after GPU idle is not explained by this; next suspect is media_kit's context switching on the raster thread with NVIDIA.
   • Link conveniences: a link swap in session updates the remembered media; show the open link with an open-in-browser button.
   • Time UI: remaining time, scrubber preview.
   • mpv / mpv.net shortcut parity.
   • Chaos suite: host drop 5 s / 30 s, viewer stall, 20-seek storm, long outage with cache exhaustion (tool/shaper.dart --kill-after); assert no OOM, no stuck session, drift recovers.
   • Chat history pane (today: activity log only).
   • Images in chat (paste a screenshot; server memory only): possible, not wanted yet.
   • HTTP: move the app's clients (Jellyfin, AniList, AnimeFlow, updater) to dio from fox_utils when touching them, for retries/interceptors.
   • TLS: document a reverse proxy in front of the server.
   • Up next follow-ups (see ARCHITECTURE "Up next"): getting the first item ready only resolves its link; fetching its first seconds early through the relay would make relayed starts instant too. A member whose reconnect lands as a new member loses its "through me" links and files in the queue (skipped as gone); the key could follow the member. A whole season or a pick list at once ("Add the rest of the season").
   • Sidecar subtitles.

Epic: Jellyfin

What is left (the rest is in ARCHITECTURE.md, "Jellyfin in a session"):

• Auto-advance cancel for everyone (the next episode and Up next): today Cancel is per screen (the designated swapper's Cancel stops the swap; a seek stops all). A shared cancel needs a wire message.
• Sidecar (external) subtitle streams of Jellyfin items: only embedded tracks are mapped to mpv today.

Deferred

P2P, Android. Never: transcoding, web clients.