Two regressions since 2.9.1 broke subtitles on transcoded playback. Since
a1b6a8971 sidecars load with the media behind a 10s open guard, so a
subtitle URL the server is slow to serve — Jellyfin extracting an
embedded stream while its transcoder spins up — tripped the guard: stop,
reopen without subtitles, "Selected subtitles could not be loaded"
snackbar, and an emptied subtitle menu. Since 2b3853a88 every embedded
Plex subtitle was handed to the player as a sidecar whose URL is the
original container, so a transcode also range-read and demuxed the
source over HTTP — for a 40 GB remux, purely to find a subtitle track —
which is also why PGS never appeared: the client was handed a container
to demux rather than a rendition to play.
Delivery is the server's job again, backported from the AVPlayer branch
(42ba01440, the subtitle subset of 6852ac274, and a3da81e83) and adapted
to main's mpv backend:
Plex burns every embedded track (subtitles=burn); only a real external
file with a /library/streams key stays a client-fetched sidecar. A burn
is a re-encode, so directPlay is withdrawn — a real PMS answers HTTP 400
to directPlay=1 with burn — and the burn is aimed by selecting the
stream on the part first via the selectStreams PUT, because the decision
endpoint ignores subtitleStreamID alongside subtitles=burn. An
unaimable or undeliverable burn (dvb_teletext) refuses the transcode and
falls back to warned direct play rather than welding the wrong language
in or silently dropping the caption. Main's per-preset
directPlay/directStream pinning is kept; verified against a live PMS
that burn works under directStream=0.
Jellyfin never offers image formats as External, so bitmaps fall through
to Encode and are burned; text External is withheld per request when the
effective selection — including the server's DefaultSubtitleStreamIndex —
is embedded, and offered when it is a real file, so a file is delivered
as a file and never fetched twice. The burned row is excluded from the
sidecars; remaining text rows stay extractable, which is how a secondary
track still renders over a transcode. Sidecar URLs now use the format
extension the endpoint expects instead of the reported codec name.
The controls and selection layers learn what burning means: burn
eligibility is the codec's property, so burned rows stay selectable in
the menu; any change away from a burned selection renegotiates with the
server instead of pretending a local switch worked; the visibility
shortcut explains itself instead of doing nothing; and the track manager
is told when the primary is server-rendered so it stops waiting out a
thirty-second deadline for a native track that is already pixels.
Verified: analyzer parity, clean_translations --check --strict, full
flutter test (5749), and decision-level runs against live Plex and
Jellyfin servers — text and PGS burn decisions, the directPlay=1+burn
400, External file delivery, an unchanged no-burn baseline, and a real
burn session serving its playlist. The pre-commit aggregate was bypassed
for pre-existing main-state findings outside this diff: 21 format-drifted
files and three unused test seams in lib/main.dart.
close#1738
Refs #1815, #1622.
* fix(plex): show PGS subtitles when transcoding
Bitmap subtitles (PGS/VOBSUB) disappeared from the menu while transcoding on Plex, leaving only "Off". The MKV transcode already supports them, so embed them in the stream like text subs. Now they show up and can be turned on.
* fix(plex): give bitmap subtitle codecs the right sidecar extension
getSubtitleExtension fell back to .srt for vobsub, pgssub and dvb subs. Map them to .sub/.sup so it stays consistent with isImageSubtitleCodec and any sidecar URL or download uses the correct extension.
edde746