Deep-review round 3: the only surviving finding — a comment-drift nit. The
fallback's cull-yield comment named the route's 'Not available yet' path, but a
culled-key segment request actually returns 'No active playback session' (the
substantive invariant — never a None that 404s as file-not-found — is unchanged).
Reworded to match the route. Concurrency + correctness came back clean.
Deep-review round 2 on the round-1 fix:
- Race (medium): the round-1 identity guard did the supersede check and the
respawn in TWO separate _lock sections. A newer same-key session installed in
the gap was still torn down by _spawn's unconditional pop+kill (the round-1
comment even had the direction backwards). Fold the check into _spawn via a
new replace_only= param: the identity test and the pop+replace now share ONE
lock, so the respawn is a true no-op when superseded/culled.
- Honest states (low): the superseded branch returned current_session(key),
which is None when the key was cap-culled during our out-of-lock wait; the
route turns None into a dishonest 'Media file not found on disk' 404 for a
file that exists. Yield 'current_session(key) or s' so a culled session
degrades to the route's retryable 'not available yet' path instead.
- Hygiene: _want_hw docstring corrected (it is a test-only shim now; production
decides via _select_encode) and the two stale _want_hw references refreshed
(stream.py header, config.py plex_transcode_hw).
- tests: the cap-cull no-respawn/no-None sub-case; the _opencl_present except
OSError branch (glob raising, not just empty); tightened a tautological -vf
assertion. Backend gate green (ruff + full pytest).
Deep-review round 1 on feature/plex-hdr-hw-tonemap:
- F1 (correctness): _select_encode gated tonemap on bit-depth alone, so a
10-bit *SDR* (bt709) source got the HDR hable tone curve applied, visibly
altering an SDR picture where only a 10->8-bit downconvert was needed. Split
the ffprobe gate into a 3-way classifier (_probe_video_kind: hwsafe / hdr /
sdr10); only true-HDR (PQ/HLG) takes the OpenCL tonemap graph, 10-bit SDR
drops to software libx264 (an exact downconvert). Applies to both auto and on.
- F2 (race): the runtime HW->SW fallback popped+killed _sessions[key] with no
identity check. Because wait_for blocks OUTSIDE _lock, a concurrent same-key
_spawn (rapid seek-restart) or _enforce_cap cull could kill this session; the
fallback then respawned software over the NEWER session and breached the
transcode cap. Guard the respawn: only fall back if _sessions[key] is still
this session, else yield the currently-registered one.
- tests: 3-way classifier (incl. HLG + empty-probe), real _opencl_present glob,
real wait_for proc fast-fail branch, tonemap-variant fallback, the F1
regressions (auto + on), the supersede/no-respawn race, and the on/opencl
matrix cell. Backend gate green (ruff + full pytest).
Upgrade mode-3's 10-bit/HDR branch from "route to software libx264" (BUG 1's
behaviour) to a full-GPU pipeline: VAAPI decode → OpenCL tonemap (hable,
HDR10/HLG → bt709 SDR nv12) → h264_vaapi. Gen 9.5 (UHD 630) can't tonemap in
the VAAPI VPP (tonemap_vaapi fails), so OpenCL is the only HW route — proven on
the prod iGPU at ~4.2x realtime, ~1 CPU core.
- stream.py: `_select_encode` returns (hw, tonemap); a 10-bit/HDR HW-decodable
source picks the tonemap graph when the OpenCL runtime is present, else drops
to software. `_opencl_present` gates on a registered ICD. `_venc_opts` /
`_hwaccel_in_opts` gain the tonemap variant (named vaapi+opencl devices,
`-filter_hw_device ocl`, hwmap→tonemap_opencl→hwmap reverse). `_want_hw` kept
as the hw-half wrapper. The runtime HW→SW fallback still backstops a session
that emits no segment.
- Dockerfile: add the Intel NEO OpenCL runtime (intel-opencl-icd). It was removed
from Debian trixie, so it's pulled from bookworm (22.43 still supports Gen 9.5;
the .deb runs on the trixie base — verified live). Harmless without /dev/dri.
- route + FE: thread `tonemap` through the session response; the stats overlay
mode row reads "transcode · GPU · HDR→SDR" for the tonemap path.
- tests: tonemap command branch, the (hw, tonemap) selection matrix (auto/on ×
8-bit/10-bit × opencl), start_session tonemap wiring, and the fmtMode tag.
Adds a movie-scoped "Playback" filter to the Plex feed so a user can isolate items by how
they play — the groundwork for collecting HW-transcodable (or no-transcode) versions.
Four classes derived from the stored `playable` + a new `transcode_hw` facet:
- Direct Play (direct), Direct Stream (remux)
- Transcode · HW — playable=transcode AND the iGPU can hardware-transcode it
- Transcode · SW — playable=transcode, software libx264 only
The HW/SW split is precise, not codec-only: a 10-bit/HDR HEVC is HW-decodable yet breaks the
VAAPI nv12 pipeline (the same case plex/stream special-cases), so it must count as SW.
Backend:
- New PlexItem columns (migration 0077): transcode_hw, video_bit_depth, media_probed_at.
Migration backfills transcode_hw codec-only so the filter works immediately.
- `plex.sync.transcode_hw_capable` is the single classifier; the HW-decodable codec set moves
to sync as `HW_DECODABLE_CODECS` and plex.stream imports it, so the catalog facet and the
runtime encoder choice can't disagree by codec.
- Bit-depth backfill (`_probe_media_batch`, wired into sync): probes only HW-decodable transcode
items' video Stream for bit-depth + HDR and refines a 10-bit/HDR HEVC to software. Bounded
per run, watermarked by media_probed_at. A codec change resets the watermark (stale probe).
- Filter + self-excluded facet on a shared `playback_class_expr` CASE (movie-leg only — a show
is an aggregate with no single class). transcode_hw threaded onto the feed/detail/card JSON.
Frontend:
- Multi-select "Playback" Combobox in the sidebar (movie scope, facet-empty drop-out), active
chips, 4-way corner-dot badge (green/blue/amber/red) + tooltip, and an info-page playback chip
with a codec · bit-depth subtitle. New `bg-info` (blue) token, i18n HU/EN parity.
- Fix a regression where the card's playback dot lost its hover tooltip: the full-card reveal
overlay swallowed the cursor; the dot now sits above it (z-20).
Gate: backend full lane + frontend typecheck/lint/knip/prettier/vitest all green. Browser-UAT'd
on localdev (filter narrows to the SW set, facet counts, badge colour + tooltip, info chip).
A 10-bit/HDR HEVC source (e.g. an HDR10 x265 file) died at scale_vaapi=format=nv12
on the UHD 630 (Gen 9.5 VPP: "VAProfile not supported"); ffmpeg produced 0 segments
and the item never played, with no fallback — a retry just re-picked the failing HW
path. An 8-bit HEVC and the same file on libx264 both work.
Two defenses:
- `_want_hw` auto mode now also gates on an 8-bit-SDR source via a new
`_probe_video_hwsafe` ffprobe (bit depth from pix_fmt/bits_per_raw_sample, HDR from
color_transfer) — a 10-bit/HDR source takes the software libx264 path, which
downconverts to yuv420p cleanly. The Plex mirror stores no bit-depth signal, so this
is probed at session start. "on" still trusts the admin and skips the gate.
- `start_session` adds a runtime HW→SW fallback: a HW session that emits no first
segment respawns on libx264 and reports hw=False (the route/stats overlay honestly
show CPU). `wait_for` gained an optional `proc` so a dead ffmpeg fails fast instead
of burning the 25s budget before the fallback fires.
Tests: TestProbeVideoHwsafe (parsing + probe-failure-assumes-safe), the 10-bit auto
gate + "on" skip in TestWantHw, and the no-segment HW→SW respawn in
TestTranscodeStartSession. Backend lane green.
Eight verified findings from the sprint deep-review:
- Transcode cap: _enforce_cap now counts only transcode sessions, so a
live remux (stream-copy) stream can no longer be LRU-evicted mid-play —
matching the config comment + the HU/EN Config hint that promise remux
is uncapped.
- Player Back: the browser/mouse Back interceptor (BackClose) now also
mounts for the stats overlay and up-next card, so Back closes them first
instead of ejecting the whole player (keyboard/Esc already did).
- Honest cold-start: loadSession clears sessionIsTranscode up front, so a
transcode->direct/remux switch no longer flashes a stale "Preparing
stream..." during the session request.
- Stats overlay a11y: the close (X) buttons in the stats, help and info
overlays now read as "Close"/"Bezaras" (new plex.player.close key), not
"Back"; dropped aria-live from the per-second stat grid so a screen
reader is not flooded with telemetry.
Tests: route-level transcode routing (transcode item -> HLS re-encode
session, remux stays copy, direct opens none); start_session threading the
preset/crf/max_height knobs + hw/preexec into the ffmpeg argv; UpNextCard
countdown auto-advance, Play-now, Cancel and the S?-E? heading fallback.
Also brings UpNextCard.tsx / plexStats.ts / plexStats.test.ts to prettier.
The software-fallback re-encode now runs deprioritized and admin-configurable.
The SW transcode ffmpeg child is niced (preexec_fn → os.nice, applied per-child
because the Popen lives in the long-lived API process, which must NOT itself be
niced — unlike the download worker's whole-process _deprioritize) so a CPU-bound
re-encode can't starve request handling or playback; the VAAPI path needs none of
it.
New sysconfig knobs (plex group, rendered on the admin Configuration page, i18n
HU/EN): plex_transcode_hw (auto/on/off, layered onto _want_hw), plex_transcode_
preset, plex_transcode_crf, plex_transcode_max_height (software-only downscale-to
cap; the GPU path encodes at source resolution). plex_max_transcodes stays the
concurrency cap (comment corrected — the fallback is shipped, not "later").
pytest extends the command-builder + _want_hw coverage (preset/crf/max_height
plumbing, the on/off/auto policy). Browser-UAT'd: max_height=240 drops the live
resolution to 330x240; the SW ffmpeg child runs at nice 10 (ppid=api process).
Non-h264 items (playable="transcode": HEVC/VP9/AV1/MPEG-2/XviD…) now play by
re-encoding the video to H.264 inside the existing HLS session, instead of the
old HTTP 501. VAAPI hardware encode (h264_vaapi, full GPU decode→scale→encode
pipeline) where the render node is present and the source is HW-decodable;
libx264 software fallback otherwise (yuv420p 8-bit, -threads reserve-one-core).
The re-encode mints a keyframe at every segment boundary (-force_key_frames) so
the HLS muxer still cuts independent segments and seeking works; everything else
— -copyts, the HLS tail, multi-audio renditions, the AAC audio path — is the
same machinery as remux, so hls.js/subtitles/seeking are unchanged. The session
route returns transcode/hw so the player can surface the active mode.
pytest pins both command branches (software + VAAPI shape) and the HW-selection
gate (render node present AND source HW-decodable). Browser-UAT'd on the XviD
fixture (Winning London): 501→plays, real 528×384 H.264 frames, 0 dropped, seek
lands clean; stats overlay Mode row reads "transcode".
The Plex player stalled ~2s a few seconds into every auto-advanced next
episode. Root cause: each auto-advance spins up a cold ffmpeg HLS remux
session, and for a fresh start (start_s==0) start_session returned
immediately with zero buffer — hls.js drained the first segment, then
rebuffered waiting for the still-warming ffmpeg to write the next one.
Once ffmpeg gets ahead (stream-copy is faster than realtime) it never
stalls again.
- stream.py: before reporting a session ready, wait for the first
_WARMUP_SEGMENTS (3) video segments to exist — the seg0 wait is now
unconditional (was start_s>0 only) and warm-up runs for all starts.
Best-effort and bounded: stop at the first segment not ready in time.
- PlexPlayer.tsx: a loading/buffering spinner. The existing overlay only
covered the INITIAL load (!ready); add a `buffering` state driven by the
video's waiting/stalled/seeking (set) and playing/canplay/seeked/pause
(clear) events so a mid-playback stall or in-flight seek reads as
"loading" instead of a frozen frame, and surface a fatal loadError even
once playback has started. Spinner uses the shared Loader2.
Merges roadmap E6·item1 (spinner while loading/seeking) into this fix,
since the server-side warm-up deliberately holds ready a beat longer.
Tests: 3 new in test_plex_stream.py (warm-up waits for the first few
segments; stops at the first missing one; no warm-up when seg0 never
arrives). Gate: backend pytest 460 (Docker lane), FE tsc/lint/knip/
prettier + vitest 483.
Found by running the round-8 fix in the real container instead of trusting the
unit test: a directory created 2ms AFTER `_PROCESS_START` was stamped with an
mtime 2ms BEFORE it, so the sweep deleted it as a leftover. The two sides come
from different clocks — a file's mtime from the kernel's coarse clock (one timer
tick of lag), `time.time()` from the fine one — and the unit test could not see it
because it supplies an artificial cutoff.
The window is small and lands exactly where it hurts: the sweep runs at boot, so
the session at risk is one started in the first instants after startup — the case
the guard exists for. Keep-side slack of 2s; the cost is that a leftover from the
last seconds before a restart survives until the next one.
Verified in the container: a backdated leftover is swept, a directory created by
this run is kept, and a registered live session with an old mtime is kept — 1 of 3.
Test pins the skew (mutation-checked: with the grace at 0 it goes red).
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