The worst one was, again, the previous round's own fix.
- Round 7 stopped awaiting the HLS sweep so startup could serve immediately — which
also made it run CONCURRENTLY with playback, and `sweep_orphans` snapshotted the
live-session set BEFORE listing the root and rmtree'd outside the lock. Since
`start_session` reuses a directory path for the same (key, offset, tag), a stale
name can become a live session at any moment. Two guards now: nothing whose mtime
is newer than this process's start is ever deleted, and the live check + rmtree
happen together under the lock, one directory at a time.
- The sweep task is awaited after cancel, so shutdown can't leave it pending.
- `_rate_limiter` used a truthiness test on its timestamp, so a `now()` of exactly
0.0 read as "never ran" — unreachable in production, but `now` exists to be
injected and a test clock starting at 0 is the obvious choice.
- The RSS total-outage error now carries the first underlying error: "all N channels
failed" is also what ONE dead feed id looks like on a small instance, and a red
card the user can't act on is its own kind of dishonest.
- The WebKit fullscreen handling moved into `lib/fullscreen` and PlexPlayer uses it
too — it had the same unprefixed-only reads in three places, including an Escape
branch that would have closed the whole player instead of leaving fullscreen.
- The `--max` CSS comment claimed `inset: 0` did the sizing; Tailwind's `w-full` is
still on the element and wins. Comment now states the real mechanism.
Verified in real Chrome (the pane can't composite or do native fullscreen):
- F fills the 1920x889 viewport; the exit pill renders top-right on the letterbox
band and overlaps NO YouTube control — the collision this round suspected does not
reproduce in this embed (its own buttons sit bottom-left / bottom-right).
- Four real ArrowDown presses while maximised: persisted volume 100 -> 80, with the
level flash visible on screen.
- A real click on the exit pill un-maximises and returns focus to the card.
- lib/fullscreen driven from a real click: enter (innerHeight 889 -> 1024), the
change listener fires exactly once per transition, exit returns to 889.
Backend suite 150 -> 158; the new sweep tests are mutation-checked, and they read
their cutoff from the filesystem rather than a clock (the container VM and the
bind-mounted host disagree by enough to make a clock-based assertion flaky).
- the sweep guard anchors the rating_key to digits: the round-2 widening had
degenerated to "anything ending in _<digits>" (backup_2024, release_10)
- RSS counts apply-side failures too, so a read-only database no longer reports
a wholly failed poll as "ok — new=0, failed=0"
- the player reads/writes its volume directly (readAccount/writeAccount): the
persisted-object hook rendered nothing and cost a second write per settle
- new tests: the sweep guard's accept/reject table, and run_ffmpeg's threading
(drain, cancel while silent, stall watchdog, stderr tail on a nonzero exit)
- the breaker sentinel is checked one way (isinstance) at all four sites
- run_rss_poll is typed dict[str, int]
All three new test groups were mutation-checked: reverting each fix turns them
red (or, for the cancel/stall pair, hangs — which is the bug itself).
- the volume keys no longer defer to a scrollable card while in fullscreen
(mirrored into a ref: the keydown handler is bound once and state would be stale)
- the debounced volume flush writes straight to storage; persisting inside a
setState updater is not guaranteed to run for an unmounting component
- the HLS sweep also matches the original {key}_{start} directory naming, which
is what the oldest leftovers on disk actually use
- run_rss_poll returns {new, failed} so an egress outage stops rendering as
"ok — 0" in the scheduler card and the audit log; /api/sync/rss reports it too
- drop the unused poll_rss_channel (it silently gained a new exception)
- _Breaker.run is generic, so a call site keeps its item-id type
- test helper instead of the generator-throw idiom
- HLS sweep only deletes directories matching the session-name shape; the root
is admin-configurable and may be a shared path
- playlist unwrap picks the first entry that actually downloaded, not entries[0]
- concat quoting keeps backslashes literal (ffmpeg treats them so inside '')
- ArrowUp/Down defer while the focused element can still scroll that way
- the staging fallback skips yt-dlp working files (.part-Frag/.ytdl/.temp/.fNNN)
- the boot HLS sweep runs off the event loop
- volume persistence is debounced (was a setItem per wheel notch) and a spin no
longer loses notches to the iframe's lagging getVolume
- _Breaker.run owns the whole open/call/record protocol; four call sites shrink
- should_prune extracted and unit-tested, plus RSS error-vs-empty tests
- the worker exits non-zero when the schema never lands
- pick the produced file safely: Path("") is Path("."), which passes .exists(),
so a missing yt-dlp filepath skipped the staging fallback and crashed in
with_name ("PosixPath('.') has an empty name") on non-YouTube sources
- unwrap a playlist/multi_video extraction to the entry that carries the media
- run_ffmpeg: drain stderr while it runs (a full 64KB pipe blocked ffmpeg
forever and hung the worker thread), 1s cancel polling, stall watchdog and a
bounded wait on exit
- escape apostrophes/backslashes in the ffmpeg concat list (pre-0.51.0 names)
- sweep orphaned HLS segment dirs at startup (nothing else ever reaped them)
stream.py enforced a hardcoded _MAX_SESSIONS = 4 and never read the
DB-overridable plex_max_transcodes ConfigSpec, so the Configuration → Plex →
"Max concurrent transcodes" knob was dead (same env-vs-DB drift class as the
Downloads/Admin fixes). _enforce_cap(cap) now takes the cap from
sysconfig.get_int(db, "plex_max_transcodes") (>=1 so playback can't be capped to
zero). Bumped the config default 1→4 so the effective default matches the old
hardcoded cap (no behavior change for non-overriders; the knob now works).
- Multi-audio items now ship every audio track as an HLS rendition in one session
(stream.py var_stream_map -> master.m3u8), so hls.js switches audio CLIENT-SIDE with
no ffmpeg restart, same timeline, no gap/drift. /session gains ?multi=1 (forces HLS
even for direct-playable multi-audio files); K is probed from the video variant seg.
- Restore the selected audio track on AUDIO_TRACKS_UPDATED, not MANIFEST_PARSED (the
renditions aren't parsed yet on MANIFEST_PARSED, so the set was dropped -> after F5 the
UI showed the restored track but playback stayed on the default).
- Resume position now survives F5: a pagehide keepalive beacon (plexProgressBeacon)
saves the current position on reload/close/navigate, since React effect cleanup does
not run on a full reload; seekTo writes the target into absRef immediately so a save
right after a seek is accurate.
Streaming / subtitle sync (the core fix):
- stream.py: add -copyts so HLS segments carry the true absolute PTS, and measure
the real keyframe start K from seg_0 (ffprobe) -> return it as the session start.
Fixes the seconds-long subtitle lead caused by using the requested seek offset
instead of the keyframe ffmpeg actually lands on with video stream-copy.
- Add -noaccurate_seek so the re-encoded audio starts at the same keyframe as the
video (was starting (X-K)s later -> seconds of silence after each seek/audio switch).
- Compensate the fixed ~1.0s lag hls.js introduces for non-zero-start copyts streams,
folded into the session start so the clock, seeking and the subtitle shift are all
content-accurate.
- /subtitle gains an offset param; _shift_vtt shifts absolute cues onto the session's
zero-based clock and DROPS fully-past cue blocks (collapsing them to 0->0 made every
past cue active at currentTime 0 on resume -> a pile-up until playback advanced).
Audio:
- /session + stream.py gain an audio A/V-sync offset (-itsoffset, full +/-, second
input only when non-zero).
Player settings & personalization (per-account, persisted -> survive F5):
- storage.ts: useAccountPersistedObject (per-account JSON prefs blob).
- PlexPlayer: volume/mute, audio+subtitle language (index-based match, fixes the F5
audio-revert), sync offsets, seek steps, subtitle style, auto-hide, play intent.
- Hotkeys A (cycle audio) / S (cycle subtitle), mouse-wheel volume, Ctrl+arrow fine
seek, per-user plain/fine seek-step + auto-hide toggle.
- Subtitle appearance: size / colour / vertical position / background via ::cue + line.
- UI: split into a Tracks quick-menu + a tabbed gear panel (Sync | Playback | Subtitle);
both dismiss on outside-click; edge-aware control tooltips.
- i18n en/hu/de for all new strings.
Selecting a subtitle restarted the HLS session with `-map 0:s:{ord}`, assuming an
EMBEDDED stream. Films whose subs are external sidecar .srt files (Plex reports
them, but they aren't in the mkv) matched no stream; the master-playlist's
declared subtitle group then made ffmpeg fail → "Playback couldn't start".
Subtitles now go through a new GET /api/plex/subtitle/{rk}/{ord} → text/vtt
(external subs fetched from Plex via the stream key + SRT→VTT; embedded text subs
extracted with ffmpeg; image subs → 415), served as native <video><track> that
the browser overlays. So choosing/switching a subtitle is instant with NO session
restart, and stream.py drops all subtitle muxing (`-sn`, no master playlist).
Image-based subs (PGS/VobSub) are marked text=false and hidden in the picker.
Verified on prod's Nymphomaniac Vol. II: HU sidecar → 1693 WebVTT cues, no crash.
Backend: item detail returns audio_streams + subtitle_streams (from Plex Part.Stream
ordinals). The HLS session accepts audio/subtitle stream ordinals — the selected audio
is mapped (transcoded to AAC), a selected subtitle is muxed in as a WebVTT rendition
via a MASTER playlist (-master_pl_name + -var_stream_map sgroup:subs) so ffmpeg keeps
it in sync per-session. Selecting a track forces the HLS path (even for direct files).
Generic /stream/{rk}/hls/{filename} endpoint serves the master/media/vtt/ts artifacts.
Frontend: gear menu lists real audio + subtitle tracks; changing one restarts the
session at the current position (seek-restart mechanism). hls.js subtitle enabled on
SUBTITLE_TRACKS_UPDATED (not just MANIFEST_PARSED, else the VTT is never fetched).
Cues auto-nudged to line 88% (the full-height <video> clips a default bottom-edge cue).
Controls no longer auto-hide while the menu is open. plex.player.* i18n en/hu/de.
Verified in a real browser (2 Broke Girls S1E1, 2 audio + 2 subs): menu shows the real
tracks, enabling English subtitles renders them correctly positioned; backend master
playlist + vtt segments validated over HTTP.
Validated end-to-end on a real remux file (h264+ac3 mkv). The riskiest part of the
Plex epic — on-the-fly playback from the local file — now proven.
- app/plex/stream.py: seek-restart HLS session model (one ffmpeg per item, restarted
at a seek offset via -ss). Video stream-COPY (I/O-bound, CPU-light — fine on the
GPU-less prod host) + audio→aac only when not already aac. Maps first video+audio,
drops subtitles (no VTT rendition clutter). Session cap + idle reaper.
- routes: POST /stream/{rk}/session?start= (direct→raw url, remux→HLS session,
transcode→501 P3), GET /stream/{rk}/file (206 range, direct), /index.m3u8, /seg_n.ts.
- KEY FINDINGS (hard-won): (1) ffmpeg -hls_playlist_type VOD does NOT write the
playlist mid-run (only at finalize) → use EVENT (append-only, appears immediately),
which suits the seek-restart model; (2) naive per-segment copy + keyframe-indexed
extraction are both unreliable (non-uniform/imprecise segments) — ffmpeg's own HLS
muxer is the only correct segmenter; (3) dev slowness was the Windows /downloads
bind-mount write + SMB read → PLEX_HLS_DIR env points scratch at fast container-local
/var/tmp on dev (prod keeps download_root, fast local disk).
peter