Interstice — verification report

Every result below was decided by the app's own trace on a device run. Pictures illustrate; they decide nothing.

The app in motion, with sound: the 2:32 demo video.

RELEASE · 2026-10-22T18:30:03.493Z · Vega Virtual Device, aarch64, OS 1.2 (TV Ship/102282480) · Release aarch64, SDK 0.24.12112 · clip: 20 s of Tears of Steel, 4 segments, packaged · app 64a5b72 · package 0.2.0 · capture grpc · keys inputd-cli · selftest 4/4 passing scenarios shown able to fail

VARIANT · 2026-10-22T18:32:50.127Z · Vega Virtual Device, aarch64, OS 1.2 (TV Ship/102282480) · Release aarch64 + INTERSTICE_E2E, SDK 0.24.12112 · e2e-fixture: first 60 s of Tears of Steel, host-served · app 64a5b72+dirty · package 0.2.0 · capture grpc · keys inputd-cli · selftest 8/8 passing scenarios shown able to fail · Release package restored: yes

The app's acceptance criteria

21 criteria: 4 automated · 4 fixture · 1 blocked · 9 out of scope · 2 manual · 2 hardware. RELEASE results are the submitted binary. FIXTURE results ran a test build against a labelled stand-in track that is not the product's and never ships.

id	criterion	class	evidence
AC1	the app runs on the Vega simulator and plays the demo asset end to end	automated the 20 s clip, not the full film	S01 pass S06 pass
AC2	every screen state — loading, playing, error, empty — has a focusable element, and BACK during playback has a stated destination	automated	S01 pass S04 pass S16 pass
AC3	description can be toggled on and off from the remote without interrupting playback	fixture	S11 pass
AC4	description cues play inside real dialogue gaps and never overlap dialogue	fixture inside the window; says nothing about dialogue (decisions.fixture_track)	S07 pass S10 pass
AC5	the main track ducks to limits.ad.duck_target_pct during a cue and returns to full afterwards	automated the volume property was applied and restored; AUDIBLE only if defects D3 yields sound	S07 pass S14 pass
AC6	seeking and held-direction key repeat resync the scheduler without firing a cue per key event	blocked	S17 blocked
AC7	the description track is produced end to end by the pipeline from asset plus subtitles — no cue text is hand-written	out of scope	—
AC8	a failed or missing track produces a stated visible and spoken state, not silence	automated	S13 pass S19 pass
AC9	the live capture layer, if it ships, is off by default and names where the frame goes before the first send	out of scope	—
AC10	react-native-tv-audio-description is public, licensed, documented, and has a runnable example, with commits inside the submission window	out of scope	—
AC11	FRICTION-LOG.md holds dated entries written during the build, not reconstructed at the end	out of scope	—
AC12	the demo video is under 3 minutes, in English, and shows the app running on the target platform	out of scope	—
AC13	every Devpost field is submitted before 2026-10-23 12:00 PT, with the primary track and both mini challenges declared	out of scope	—
AC14	the author watches the demo asset end to end with the description track and rates every cue 1–5 against the picture; track mean and % failed are recorded and the worst cues are regenerated before the demo video is recorded	manual	—
AC15	the control surface is exercised under VoiceView: every control is reachable and announces its state, and the demo video shows it	hardware	—
AC16	the submission package cites at least one sourced figure on audio-description coverage; the figure and its source enter the registry before the prose	out of scope	—
AC17	three verbosity levels (concise/standard/detailed) are selectable from the remote, rescale max_words_per_cue per limits.ad.verbosity_scales, and are demonstrated in the demo	fixture	S12 pass
AC18	a dramatis personae pass precedes per-gap description and is fed into every C9 prompt alongside rolling context; cue coherence is checked during the AC14 watch	out of scope	—
AC20	at least one blind/low-vision viewer validates the track before Phase 5 (20–30 min, with/without comparison, consent on file); anonymized quote retained for SUBMISSION.md/video	manual	—
AC23	the app plays the full-length demo asset without exceeding memory on the worst device in the matrix: limits.mse_buffer holds, SourceBuffer.remove() runs behind the playhead, and no QuotaExceededError is raised across an end-to-end watch	hardware S18 on the Virtual Device supports it and cannot close it	—
AC24	a stall — bytes running short mid-playback — produces a stated visible and spoken state rather than a frozen picture, and a seek outside the buffered window either resolves or says why it cannot	fixture	S15 pass

What this report cannot show

Audible ducking. The trace shows the volume property set and restored. Whether a listener hears the film get quieter is checked on hardware.
VoiceView. It cannot be switched on in the Virtual Device. "What the viewer is told" below is what the app hands to the screen reader, not what the screen reader did with it.
The memory bound on a real Fire TV. Every run here is on the Virtual Device.
That every cue avoids dialogue. On the generated track, S07 checks the first cue against its window; all 55 described cues were rated by watching the whole film (the app set's AC14, mean 4.51 of 5). Fixture windows are declared, not derived from subtitles.

The submitted build

PASS

S01 · The viewer opens the app and lands on the title list with a title focused.

RELEASE · covers AC1, AC2

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
Audio description on, standard, 56 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

2.6s wait — asset.segments
3.1s shot — The title list on launch
4.7s keys — ENTER
4.7s wait — app.play

Decided by

✓ app.mode e2e=false
✓ asset.segments n=(checked) init=set
✓ app.play id=tears-of-steel

full trace · 6.4 s

PASS

S04 · The viewer presses BACK during playback and is on the list again, able to start over.

RELEASE · covers AC2

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
Audio description on, standard, 56 descriptions
The video paused while it loads more. Press back to return to the list.
Loading title
Audio description on, standard, 56 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

2.6s wait — asset.segments
4.2s keys — ENTER
6.5s wait — player.progress
8.1s keys — BACK
8.1s wait — player.back
8.6s shot — Back on the list
10.2s keys — ENTER
10.2s wait — player.opened

Decided by

✓ player.back from=playing
✓ app.play id=tears-of-steel ×2 (saw 2)
✓ player.opened ×2 (saw 2)

full trace · 11.8 s

PASS

S06 · The viewer plays the film; the buffer runs ahead of the picture and lets go behind it.

RELEASE · covers AC1

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
Audio description on, standard, 56 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

2.8s wait — asset.segments
4.3s keys — ENTER
4.3s wait — player.play
4.9s shot — The film playing
51.6s wait — player.progress
52.4s wait — buffer.evicted

Decided by

✓ asset.segments n=(checked)
✓ player.opened → player.play → player.progress
✓ player.progress pos_ms=(checked)
✓ buffer.evicted held=(checked)
✓ buffer.evicted held=(checked) ×0 (saw 0)
✓ buffer.complete ×0 (saw 0)
✓ buffer.failed ×0 (saw 0)

Cannot show: The whole film, and memory: this run watches 45 s of 12 min on the Virtual Device. AC23 names the worst device in the matrix and an end-to-end watch.

full trace · 55.0 s

PASS

S07 · The film's first generated cue speaks inside its gap, over the film, and the film comes back to full.

RELEASE · covers AC4, AC5

The first generated cue, with the film ducked under it

(CC) Blender Foundation | mango.blender.org

band: the window · block: the film ducked, from duck to restore · 30 s shown

What the viewer is told

Loading title
Audio description on, standard, 56 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

3.0s wait — asset.segments
4.5s keys — ENTER
5.8s wait — audio.duck
6.4s shot — During the first generated cue
15.9s wait — audio.restored

Decided by

✓ loader.load ok=true cues=56
✓ loader.load ok=true → controls.announce kind=ready
✓ scheduler.fire id=cue_0-11500 → audio.duck id=cue_0-11500 to_pct=25 → player.progress → cue.audio state=ended → audio.restored id=cue_0-11500
✓ audio.duck id=cue_0-11500 … audio.restored id=cue_0-11500 inside [0, 11500] ms (was 174 … 10289)

Cannot show: That a listener heard the film get quieter (closes on hardware), and that the cue avoids dialogue beyond this first gap.

full trace · 21.0 s

The test build, with faults injected

PASS

S10 · Three cues each start and finish inside their window.

VARIANT · FIXTURE · covers AC4

(CC) Blender Foundation | mango.blender.org

band: the window · block: the film ducked, from duck to restore · 30 s shown

What the viewer is told

Loading title
Audio description on, standard, 3 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

2.6s wait — asset.segments
5.6s keys — DOWN ENTER
5.6s wait — app.play
12.3s wait — audio.restored
13.0s shot — After the first cue
32.2s wait — audio.restored

Decided by

✓ audio.duck id=c1 … audio.restored id=c1 inside [4000, 9000] ms (was 4214 … 5780)
✓ audio.duck id=c2 … audio.restored id=c2 inside [14000, 20000] ms (was 14238 … 15901)
✓ audio.duck id=c3 … audio.restored id=c3 inside [24000, 28000] ms (was 24015 … 25641)

Cannot show: That a cue avoids dialogue. These windows are declared by the fixture, not derived from subtitles.

full trace · 33.8 s

PASS

S11 · The viewer switches description off mid-film and back on; the film never stops.

VARIANT · FIXTURE · covers AC3

(CC) Blender Foundation | mango.blender.org

band: the window · block: the film ducked, from duck to restore · 30 s shown

What the viewer is told

Loading title
Audio description on, standard, 3 descriptions
The video paused while it loads more. Press back to return to the list.
Audio description off
Audio description on, standard, 3 descriptions

Steps

2.6s wait — asset.segments
5.7s keys — DOWN ENTER
5.7s wait — app.play
12.4s wait — audio.restored
13.9s keys — ENTER
13.9s wait — controls.toggle
14.5s shot — Description off
27.8s wait — player.progress
29.7s keys — ENTER
29.7s wait — controls.toggle
32.3s wait — audio.restored

Decided by

✓ no audio.duck id=c2 between controls.toggle to=false and controls.toggle to=true [emitter: the package DescriptionAudio.speak -> audio.duck]
✓ no player.stalled between controls.toggle to=false and audio.restored id=c3 [emitter: src/screens/PlayerScreen.tsx onStalled -> player.stalled]
✓ controls.toggle to=false → player.progress → controls.toggle to=true → audio.duck id=c3
✓ audio.duck id=c2 ×0 (saw 0)

full trace · 33.5 s

PASS

S12 · The viewer moves between concise, standard and detailed while watching.

VARIANT · FIXTURE · covers AC17

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
Audio description on, standard, 3 descriptions
The video paused while it loads more. Press back to return to the list.
Audio description on, concise, 2 descriptions
Audio description on, standard, 3 descriptions

Steps

2.6s wait — asset.segments
5.6s keys — DOWN ENTER
5.6s wait — app.play
5.6s wait — loader.load
6.9s wait — player.progress
10.2s keys — DOWN ENTER
10.2s wait — loader.load
10.7s shot — Concise selected
15.5s keys — DOWN DOWN ENTER
15.5s wait — loader.miss
19.0s wait — player.progress

Decided by

✓ loader.load path=/standard/ ok=true cues=3 → controls.verbosity to=concise → loader.load path=/concise/ ok=true cues=2 → controls.verbosity to=detailed → loader.miss path=/detailed/ → loader.load path=/standard/ ok=true cues=3 → player.progress
✓ no player.stalled between controls.verbosity to=concise and player.progress pos_ms=(checked) [emitter: src/screens/PlayerScreen.tsx onStalled -> player.stalled]

full trace · 20.3 s

PASS

S13 · The track file is corrupt; the app says something different from "missing" and the film plays.

VARIANT · FIXTURE · covers AC8

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
The description track for this title could not be read. Playback continues without description.
The video paused while it loads more. Press back to return to the list.

Steps

2.6s wait — asset.segments
5.5s keys — DOWN ENTER
5.5s wait — app.play
5.5s wait — ad.state
6.1s shot — The unreadable-track state, on screen
13.3s wait — player.progress

Decided by

✓ ad.state kind=malformed
✓ ad.state kind=missing ×0 (saw 0)
✓ controls.announce kind=malformed → player.progress → player.progress

full trace · 14.8 s

PASS

S14 · One cue has no audio; the film must not be left quiet.

VARIANT · FIXTURE · covers AC5

band: the window · block: the film ducked, from duck to restore · 30 s shown

What the viewer is told

Loading title
Audio description on, standard, 3 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

2.6s wait — asset.segments
5.5s keys — DOWN ENTER
5.5s wait — app.play
20.5s wait — audio.failed
31.9s wait — audio.restored

Decided by

✓ audio.duck id=c2 → audio.failed id=c2 → audio.restored id=c2 → player.progress
✓ audio.restored id=c2 → audio.duck id=c3 → audio.restored id=c3

Cannot show: The audible level. The restore is the volume property returning to 100%.

full trace · 33.7 s

PASS

S15 · The bytes run short mid-film; the viewer is told, and playback resumes when they arrive.

VARIANT · FIXTURE · covers AC24

Stalled: the picture is frozen and the app says so

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
Audio description on, standard, 3 descriptions
The video paused while it loads more. Press back to return to the list.

Steps

2.7s wait — asset.segments
5.8s keys — DOWN ENTER
5.8s wait — app.play
37.5s wait — player.progress
42.5s wait — overlay.shown
43.5s shot — Stalled: the picture is frozen and the app says so
43.5s release — held fixture requests answered
43.6s wait — player.resumed
43.8s wait — player.progress

Decided by

✓ player.progress pos_ms=(checked) → player.stalled → overlay.shown status=stalled → player.resumed from=stalled → overlay.cleared → player.progress

full trace · 45.4 s

PASS

S16 · The title cannot be opened; the viewer is told and BACK still works.

VARIANT · FIXTURE · covers AC2

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
Audio description on, standard, 3 descriptions
This title could not be played. Network request failed
Loading title
Audio description on, standard, 56 descriptions

Steps

2.6s wait — asset.segments
5.6s keys — DOWN ENTER
5.6s wait — app.play
5.6s wait — overlay.shown
6.0s shot — The error state
7.6s keys — BACK
7.6s wait — player.back
9.1s keys — ENTER
9.1s wait — app.play

Decided by

✓ overlay.shown status=error → player.back from=error → app.play id=tears-of-steel

full trace · 10.6 s

BLOCKED

S17 · The viewer holds a direction to seek; the scheduler resyncs once.

VARIANT · FIXTURE · covers AC6

blocked by D6 — the app has no seek control

PASS

S19 · The title has no description track; the app says so and the film plays anyway.

VARIANT · FIXTURE · covers AC8

(CC) Blender Foundation | mango.blender.org

What the viewer is told

Loading title
No description track was found for this title. Playback continues without description.
The video paused while it loads more. Press back to return to the list.

Steps

2.6s wait — asset.segments
5.6s keys — DOWN ENTER
5.6s wait — app.play
5.6s wait — controls.announce
6.4s wait — player.progress
6.9s shot — The missing-track state, on screen
11.6s wait — player.progress

Decided by

✓ controls.announce kind=missing
✓ loader.miss → controls.announce kind=missing
✓ loader.miss → player.progress → player.progress
✓ no player.stalled between player.progress and player.progress pos_ms=(checked) [emitter: src/screens/PlayerScreen.tsx onStalled -> player.stalled]

full trace · 13.1 s