Files
jellytau/docs/traceability.md
T
dtourolle 6a712c46cb fix(player): send subtitle tracks to ExoPlayer on Android (UR-020)
Selecting a subtitle on Android did nothing. The Kotlin side has been
complete for a long time — JellyTauPlayer.load() parses a subtitles JSON
array into MediaItem.SubtitleConfigurations and setSubtitleTrack() drives a
TrackSelectionOverride — but nothing ever reached it.

VideoPlayer built the list and then threw it away: it resolved every
subtitle stream's URL into a subtitleTracks array and the
commands.playerPlayItem({...}) call two lines below passed only streamUrl,
title, id, videoCodec and needsTranscoding. PlayItemRequest had no subtitle
field to put them in, so create_media_item hardcoded subtitles: vec![],
android/mod.rs serialized "[]" across JNI, and every MediaItem reached
ExoPlayer with zero SubtitleConfigurations. A later set_subtitle_track then
found no text track groups and logged "Invalid subtitle track index".

PlayItemRequest now carries the tracks (defaulted, so the background-audio
handoff and next-episode callers are unchanged) and create_media_item
threads them onto the MediaItem.

Serialization: SubtitleTrack is reused verbatim rather than given an
IPC-specific twin, and deliberately keeps snake_case. The same struct feeds
two consumers that both spell mime_type — the JNI JSON that
JellyTauPlayer.load() reads with optString("mime_type"), and the generated
binding the frontend types against. camelCasing it would not fail the build
or the IPC; Kotlin would silently fall back to its default MIME type for
every track. UT-146 asserts the exact serialized keys so a future
rename_all cannot pass unnoticed.

The index mapping was NOT already correct. setSubtitleTrack(n) indexes
ExoPlayer's filtered text track groups, i.e. the position of the sideloaded
configuration — but the menu passed its own {#each} row number, which counts
every subtitle *stream*, including ones whose URL failed to resolve and were
therefore never sideloaded. One failed URL and every track below it selected
the wrong subtitle. The position is now looked up in the exact array that
was sent (nativeSubtitleArrayIndex), and a stream that was never sent maps
to "off" rather than to a guessed position.

The resolution loop also reuses resolveSubtitleTracks() from the Linux fix
instead of duplicating it, which fans the URL requests out in parallel
rather than awaiting them one per stream before playback can start. The
awaits are safe where they sit: the native-mode pitfall is about Svelte
lifecycle calls after an await, and nothing is registered here — the
background-audio subscriptions above still run synchronously.

No Kotlin change was needed.

Tests (UT-145, UT-146, UT-147) were written first and failed: PlayItemRequest
had no subtitles field to compile against, nativeSubtitleTracks and
nativeSubtitleArrayIndex did not exist, and the playerPlayItem call carried
no subtitles key.

TRACES: UR-020 | IR-016, JA-008 | UT-145, UT-146, UT-147
2026-08-11 20:03:19 +02:00

280 KiB

Code Traceability Matrix

Generated: 8/11/2026, 7:48:06 PM

Summary

  • Total Files Scanned: 341
  • Total TRACES Found: 600
  • Requirements Covered:
    • User Requirements (UR): 67
    • Integration Requirements (IR): 18
    • Development Requirements (DR): 131
    • Jellyfin API Requirements (JA): 28

Requirements by Type

User Requirements (UR)

UR-002, UR-003, UR-004, UR-005, UR-007, UR-008, UR-009, UR-010, UR-011, UR-012, UR-013, UR-014, UR-015, UR-016, UR-017, UR-018, UR-019, UR-020, UR-021, UR-022, UR-023, UR-024, UR-025, UR-026, UR-027, UR-028, UR-029, UR-030, UR-031, UR-032, UR-033, UR-034, UR-035, UR-036, UR-038, UR-039, UR-040, UR-041, UR-042, UR-043, UR-044, UR-045, UR-046, UR-047, UR-048, UR-049, UR-050, UR-051, UR-052, UR-053, UR-054, UR-055, UR-056, UR-057, UR-058, UR-059, UR-060, UR-061, UR-062, UR-063, UR-064, UR-065, UR-066, UR-067, UR-068, UR-069, UR-071

Integration Requirements (IR)

IR-003, IR-004, IR-009, IR-010, IR-011, IR-012, IR-013, IR-014, IR-015, IR-016, IR-020, IR-023, IR-025, IR-026, IR-027, IR-028, IR-030, IR-031

Development Requirements (DR)

DR-001, DR-002, DR-003, DR-004, DR-005, DR-006, DR-007, DR-009, DR-010, DR-011, DR-012, DR-013, DR-014, DR-015, DR-016, DR-017, DR-018, DR-020, DR-021, DR-022, DR-023, DR-024, DR-025, DR-026, DR-027, DR-028, DR-029, DR-030, DR-032, DR-033, DR-034, DR-035, DR-036, DR-037, DR-038, DR-039, DR-040, DR-041, DR-043, DR-044, DR-045, DR-047, DR-048, DR-049, DR-050, DR-051, DR-052, DR-053, DR-054, DR-055, DR-056, DR-057, DR-058, DR-059, DR-060, DR-061, DR-062, DR-063, DR-064, DR-065, DR-066, DR-067, DR-068, DR-069, DR-070, DR-074, DR-075, DR-076, DR-077, DR-078, DR-079, DR-080, DR-081, DR-082, DR-083, DR-084, DR-085, DR-086, DR-087, DR-088, DR-089, DR-090, DR-091, DR-092, DR-093, DR-095, DR-096, DR-097, DR-098, DR-099, DR-100, DR-101, DR-102, DR-103, DR-104, DR-105, DR-106, DR-107, DR-108, DR-109, DR-110, DR-111, DR-112, DR-113, DR-114, DR-115, DR-116, DR-117, DR-118, DR-119, DR-120, DR-123, DR-126, DR-127, DR-128, DR-129, DR-130, DR-131, DR-132, DR-133, DR-134, DR-135, DR-136, DR-137, DR-140, DR-141, DR-142, DR-143, DR-147, DR-148, DR-149

Jellyfin API Requirements (JA)

JA-001, JA-002, JA-003, JA-004, JA-005, JA-007, JA-008, JA-010, JA-011, JA-012, JA-016, JA-017, JA-019, JA-020, JA-021, JA-022, JA-023, JA-024, JA-025, JA-026, JA-028, JA-029, JA-030, JA-031, JA-032, JA-033, JA-034, JA-035

Detailed Mapping

IR-003

Locations: 2 file(s)

IR-004

Locations: 1 file(s)

IR-009

Locations: 6 file(s)

IR-010

Locations: 2 file(s)

IR-011

Locations: 1 file(s)

IR-012

Locations: 2 file(s)

IR-013

Locations: 3 file(s)

IR-014

Locations: 6 file(s)

IR-015

Locations: 1 file(s)

IR-016

Locations: 16 file(s)

IR-020

Locations: 8 file(s)

IR-023

Locations: 1 file(s)

IR-025

Locations: 2 file(s)

IR-026

Locations: 1 file(s)

IR-027

Locations: 1 file(s)

IR-028

Locations: 1 file(s)

IR-030

Locations: 2 file(s)

IR-031

Locations: 2 file(s)

DR-001

Locations: 17 file(s)

DR-002

Locations: 2 file(s)

DR-003

Locations: 2 file(s)

DR-004

Locations: 9 file(s)

DR-005

Locations: 13 file(s)

DR-006

Locations: 2 file(s)

DR-007

Locations: 9 file(s)

DR-009

Locations: 12 file(s)

DR-010

Locations: 1 file(s)

DR-011

Locations: 9 file(s)

DR-012

Locations: 7 file(s)

DR-013

Locations: 5 file(s)

DR-014

Locations: 4 file(s)

DR-015

Locations: 6 file(s)

DR-016

Locations: 3 file(s)

DR-017

Locations: 3 file(s)

DR-018

Locations: 1 file(s)

DR-020

Locations: 8 file(s)

DR-021

Locations: 3 file(s)

DR-022

Locations: 1 file(s)

DR-023

Locations: 8 file(s)

DR-024

Locations: 4 file(s)

DR-025

Locations: 1 file(s)

DR-026

Locations: 2 file(s)

DR-027

Locations: 2 file(s)

DR-028

Locations: 18 file(s)

DR-029

Locations: 10 file(s)

DR-030

Locations: 18 file(s)

DR-032

Locations: 1 file(s)

DR-033

Locations: 2 file(s)

DR-034

Locations: 2 file(s)

DR-035

Locations: 7 file(s)

DR-036

Locations: 12 file(s)

DR-037

Locations: 12 file(s)

DR-038

Locations: 9 file(s)

DR-039

Locations: 8 file(s)

DR-040

Locations: 3 file(s)

DR-041

Locations: 2 file(s)

DR-043

Locations: 1 file(s)

DR-044

Locations: 1 file(s)

DR-045

Locations: 1 file(s)

DR-047

Locations: 15 file(s)

DR-048

Locations: 6 file(s)

DR-049

Locations: 1 file(s)

DR-050

Locations: 1 file(s)

DR-051

Locations: 3 file(s)

DR-052

Locations: 20 file(s)

DR-053

Locations: 1 file(s)

DR-054

Locations: 1 file(s)

DR-055

Locations: 2 file(s)

DR-056

Locations: 1 file(s)

DR-057

Locations: 1 file(s)

DR-058

Locations: 1 file(s)

DR-059

Locations: 1 file(s)

DR-060

Locations: 1 file(s)

DR-061

Locations: 2 file(s)

DR-062

Locations: 6 file(s)

DR-063

Locations: 17 file(s)

DR-064

Locations: 5 file(s)

DR-065

Locations: 2 file(s)

DR-066

Locations: 5 file(s)

DR-067

Locations: 3 file(s)

DR-068

Locations: 1 file(s)

DR-069

Locations: 1 file(s)

DR-070

Locations: 1 file(s)

DR-074

Locations: 17 file(s)

DR-075

Locations: 1 file(s)

DR-076

Locations: 2 file(s)

DR-077

Locations: 2 file(s)

DR-078

Locations: 7 file(s)

DR-079

Locations: 2 file(s)

DR-080

Locations: 2 file(s)

DR-081

Locations: 2 file(s)

DR-082

Locations: 20 file(s)

DR-083

Locations: 19 file(s)

DR-084

Locations: 2 file(s)

DR-085

Locations: 15 file(s)

DR-086

Locations: 1 file(s)

DR-087

Locations: 3 file(s)

DR-088

Locations: 2 file(s)

DR-089

Locations: 4 file(s)

DR-090

Locations: 1 file(s)

DR-091

Locations: 2 file(s)

DR-092

Locations: 2 file(s)

DR-093

Locations: 4 file(s)

DR-095

Locations: 1 file(s)

DR-096

Locations: 1 file(s)

DR-097

Locations: 9 file(s)

DR-098

Locations: 4 file(s)

DR-099

Locations: 2 file(s)

DR-100

Locations: 2 file(s)

DR-101

Locations: 8 file(s)

DR-102

Locations: 7 file(s)

DR-103

Locations: 6 file(s)

DR-104

Locations: 1 file(s)

DR-105

Locations: 10 file(s)

DR-106

Locations: 7 file(s)

DR-107

Locations: 2 file(s)

DR-108

Locations: 5 file(s)

DR-109

Locations: 6 file(s)

DR-110

Locations: 8 file(s)

DR-111

Locations: 5 file(s)

DR-112

Locations: 6 file(s)

DR-113

Locations: 4 file(s)

DR-114

Locations: 2 file(s)

DR-115

Locations: 16 file(s)

DR-116

Locations: 11 file(s)

DR-117

Locations: 7 file(s)

DR-118

Locations: 5 file(s)

DR-119

Locations: 15 file(s)

DR-120

Locations: 19 file(s)

DR-123

Locations: 7 file(s)

DR-126

Locations: 2 file(s)

DR-127

Locations: 6 file(s)

DR-128

Locations: 3 file(s)

DR-129

Locations: 8 file(s)

DR-130

Locations: 7 file(s)

DR-131

Locations: 16 file(s)

DR-132

Locations: 12 file(s)

DR-133

Locations: 2 file(s)

DR-134

Locations: 1 file(s)

DR-135

Locations: 5 file(s)

DR-136

Locations: 3 file(s)

DR-137

Locations: 17 file(s)

DR-140

Locations: 2 file(s)

DR-141

Locations: 2 file(s)

DR-142

Locations: 11 file(s)

DR-143

Locations: 11 file(s)

DR-147

Locations: 5 file(s)

DR-148

Locations: 1 file(s)

DR-149

Locations: 2 file(s)

JA-001

Locations: 1 file(s)

JA-002

Locations: 2 file(s)

JA-003

Locations: 1 file(s)

JA-004

Locations: 3 file(s)

JA-005

Locations: 1 file(s)

JA-007

Locations: 1 file(s)

JA-008

Locations: 8 file(s)

JA-010

Locations: 2 file(s)

JA-011

Locations: 2 file(s)

JA-012

Locations: 2 file(s)

JA-016

Locations: 1 file(s)

JA-017

Locations: 1 file(s)

JA-019

Locations: 1 file(s)

JA-020

Locations: 1 file(s)

JA-021

Locations: 6 file(s)

JA-022

Locations: 3 file(s)

JA-023

Locations: 3 file(s)

JA-024

Locations: 2 file(s)

JA-025

Locations: 4 file(s)

JA-026

Locations: 3 file(s)

JA-028

Locations: 1 file(s)

JA-029

Locations: 3 file(s)

JA-030

Locations: 2 file(s)

JA-031

Locations: 2 file(s)

JA-032

Locations: 10 file(s)

JA-033

Locations: 7 file(s)

JA-034

Locations: 3 file(s)

JA-035

Locations: 2 file(s)

UR-002

Locations: 19 file(s)

UR-003

Locations: 20 file(s)

UR-004

Locations: 28 file(s)

UR-007

Locations: 16 file(s)

UR-023

Locations: 24 file(s)

UR-025

Locations: 42 file(s)

UR-027

Locations: 23 file(s)

UR-029

Locations: 5 file(s)

UR-034

Locations: 10 file(s)

UR-035

Locations: 5 file(s)

UR-038

Locations: 1 file(s)

UR-040

Locations: 42 file(s)

UR-048

Locations: 6 file(s)

UR-049

Locations: 22 file(s)

UR-052

Locations: 23 file(s)

UR-055

Locations: 27 file(s)

UR-056

Locations: 17 file(s)

UR-057

Locations: 1 file(s)

UR-058

Locations: 11 file(s)

UR-062

Locations: 17 file(s)

UR-063

Locations: 10 file(s)

UR-064

Locations: 7 file(s)

UR-067

Locations: 39 file(s)

UR-068

Locations: 14 file(s)

IT-003

Locations: 1 file(s)

IT-004

Locations: 1 file(s)

IT-016

Locations: 1 file(s)

IT-017

Locations: 1 file(s)

UT-003

Locations: 1 file(s)

UT-004

Locations: 1 file(s)

UT-005

Locations: 1 file(s)

UT-012

Locations: 1 file(s)

UT-026

Locations: 2 file(s)

UT-027

Locations: 1 file(s)

UT-028

Locations: 1 file(s)

UT-029

Locations: 1 file(s)

UT-030

Locations: 1 file(s)

UT-031

Locations: 1 file(s)

UT-032

Locations: 1 file(s)

UT-033

Locations: 1 file(s)

UT-042

Locations: 1 file(s)

UT-043

Locations: 1 file(s)

UT-062

Locations: 1 file(s)

UT-066

Locations: 1 file(s)

UT-083

Locations: 1 file(s)

UT-084

Locations: 1 file(s)

UT-091

Locations: 2 file(s)

UT-094

Locations: 1 file(s)

UT-095

Locations: 1 file(s)

UT-096

Locations: 1 file(s)

UT-097

Locations: 1 file(s)

UT-106

Locations: 3 file(s)

UR-014

Locations: 1 file(s)

UR-022

Locations: 1 file(s)

UR-031

Locations: 2 file(s)

UR-042

Locations: 1 file(s)

UR-044

Locations: 1 file(s)

UR-046

Locations: 1 file(s)

UR-047

Locations: 1 file(s)

UR-060

Locations: 7 file(s)

UR-066

Locations: 6 file(s)

UR-069

Locations: 23 file(s)

UR-071

Locations: 45 file(s)

IT-013

Locations: 4 file(s)

UT-061

Locations: 9 file(s)

UR-026

Locations: 19 file(s)

UT-098

Locations: 1 file(s)

UT-116

Locations: 4 file(s)

UT-117

Locations: 7 file(s)

UR-005

Locations: 73 file(s)

UR-009

Locations: 15 file(s)

UR-011

Locations: 11 file(s)

UR-017

Locations: 10 file(s)

UR-020

Locations: 23 file(s)

UR-036

Locations: 3 file(s)

UR-050

Locations: 9 file(s)

UR-053

Locations: 17 file(s)

UT-010

Locations: 1 file(s)

UT-024

Locations: 1 file(s)

UT-052

Locations: 1 file(s)

UT-060

Locations: 3 file(s)

UT-071

Locations: 1 file(s)

UT-085

Locations: 2 file(s)

UT-086

Locations: 2 file(s)

UT-087

Locations: 2 file(s)

UT-088

Locations: 1 file(s)

UT-089

Locations: 1 file(s)

UT-090

Locations: 1 file(s)

UT-092

Locations: 3 file(s)

UT-093

Locations: 2 file(s)

UT-104

Locations: 7 file(s)

UT-105

Locations: 3 file(s)

UT-107

Locations: 6 file(s)

UT-118

Locations: 1 file(s)

UT-119

Locations: 2 file(s)

UT-121

Locations: 2 file(s)

UT-123

Locations: 2 file(s)

UT-124

Locations: 1 file(s)

UT-131

Locations: 1 file(s)

UT-132

Locations: 1 file(s)

UT-133

Locations: 1 file(s)

UT-134

Locations: 1 file(s)

UT-135

Locations: 1 file(s)

UT-136

Locations: 1 file(s)

UT-137

Locations: 1 file(s)

UT-138

Locations: 1 file(s)

UT-139

Locations: 1 file(s)

UT-140

Locations: 1 file(s)

UT-144

Locations: 3 file(s)

UT-145

Locations: 5 file(s)

UR-008

Locations: 2 file(s)

UR-010

Locations: 15 file(s)

UR-012

Locations: 9 file(s)

UR-013

Locations: 2 file(s)

UR-015

Locations: 13 file(s)

UR-016

Locations: 2 file(s)

UR-018

Locations: 3 file(s)

UR-019

Locations: 12 file(s)

UT-146

Locations: 3 file(s)

UR-021

Locations: 5 file(s)

UR-024

Locations: 2 file(s)

UR-028

Locations: 2 file(s)

UR-030

Locations: 2 file(s)

UR-032

Locations: 7 file(s)

UR-033

Locations: 12 file(s)

UR-039

Locations: 1 file(s)

UR-041

Locations: 1 file(s)

UR-043

Locations: 2 file(s)

UR-045

Locations: 1 file(s)

UR-054

Locations: 6 file(s)

UR-059

Locations: 6 file(s)

UR-061

Locations: 4 file(s)

UT-143

Locations: 5 file(s)

UT-147

Locations: 8 file(s)

UR-051

Locations: 2 file(s)

UR-065

Locations: 22 file(s)

UT-014

Locations: 2 file(s)

UT-015

Locations: 2 file(s)

UT-016

Locations: 2 file(s)

UT-017

Locations: 2 file(s)

UT-018

Locations: 2 file(s)

UT-019

Locations: 2 file(s)

UT-020

Locations: 2 file(s)

UT-021

Locations: 2 file(s)

UT-022

Locations: 2 file(s)

UT-023

Locations: 2 file(s)

UT-025

Locations: 2 file(s)

UT-044

Locations: 1 file(s)

UT-051

Locations: 1 file(s)

UT-059

Locations: 3 file(s)

UT-067

Locations: 1 file(s)

UT-072

Locations: 1 file(s)

UT-073

Locations: 1 file(s)

UT-074

Locations: 1 file(s)

UT-075

Locations: 1 file(s)

UT-076

Locations: 1 file(s)

UT-077

Locations: 1 file(s)

UT-078

Locations: 1 file(s)

UT-079

Locations: 1 file(s)

UT-080

Locations: 1 file(s)

UT-081

Locations: 1 file(s)

UT-082

Locations: 1 file(s)

UT-099

Locations: 3 file(s)

UT-100

Locations: 6 file(s)

UT-101

Locations: 4 file(s)

UT-102

Locations: 2 file(s)

UT-103

Locations: 6 file(s)

UT-108

Locations: 2 file(s)

UT-109

Locations: 1 file(s)

UT-110

Locations: 1 file(s)

UT-111

Locations: 3 file(s)

UT-112

Locations: 2 file(s)

UT-113

Locations: 2 file(s)

UT-114

Locations: 2 file(s)

UT-115

Locations: 2 file(s)

UT-120

Locations: 2 file(s)

UT-122

Locations: 11 file(s)

UT-125

Locations: 3 file(s)

UT-126

Locations: 2 file(s)

UT-127

Locations: 11 file(s)

UT-130

Locations: 2 file(s)

UT-141

Locations: 2 file(s)

UT-142

Locations: 1 file(s)