Market walk: chapter track
A WebVTT chapter track for the 24 second film in this group, with 12 cues at 2.125 second intervals. The cues are not decoration: each one marks a boundary between two of the twelve generated segments, verified against the measured transitions, so seeking to a cue lands on a join. Chapter tracks over two-second clips have nowhere to seek to; this is the first in this library with somewhere to go.
vtt
text/vtt
- Film
- film-market-walk
- Duration Seconds
- 24
- Segments
- 12
- Synthetic
- true
- Disclosure
- AI-generated / synthetic video. Not a recording of a real person, place or event.
- Schema Version
- 1
Binary vtt: no in-browser preview. Download it above to open in a compatible application.
Specifications
- Film
- film-market-walk
- Duration Seconds
- 24
- Segments
- 12
- Synthetic
- true
- Disclosure
- AI-generated / synthetic video. Not a recording of a real person, place or event.
- Schema Version
- 1
- Cues
- 12
- Boundary Seconds
- 2.125
- Cue Kind
- chapter
Testing contract
Expected to pass- Scenario
- Parse the chapter cues and seek the companion MP4 to each cue start.
- Expected result
- 12 cues parse, the first starts at 00:00:00.000, and each subsequent start is 2.125 seconds after the last.
What is a .vtt file?
WebVTT (VTT) is the W3C subtitle and caption format used by the HTML5 <track> element for timed text on the web. It extends the SubRip model with cue settings, positioning, styling, and metadata, and requires a WEBVTT header. It is the standard format for browser-based captions.
How to use this file
Use an example VTT to test HTML5 <track> caption rendering, cue-setting and positioning parsers, and converters between WebVTT and SRT.
How to use this file for testing
“Market walk: chapter track” is a deterministic Novus Examples fixture for Media accessibility, Subtitle parsing. Containers carrying several subtitle and audio tracks at once, with real language tags and the default, forced, hearing-impaired and visual-impaired flags actually set, for testing track pickers, accessibility menus, and the flag handling that only shows up when more than one track exists.
Documented properties for this file: 12 cues. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such, expect parsers to fail loudly rather than silently accept them.
Media fixtures are short and synthetic by design. Prefer waveform or transcript ground truth in the same group when measuring ASR, trim, upscale, or sync tools; do not assume broadcast-quality masters.
Code examples
<video controls src="clip.mp4">
<track kind="captions" srclang="en" label="English" src="film-market-walk-chapters.vtt" default>
</video>Related files
- vttCoast drift: chapter trackA WebVTT chapter track for the 24 second film in this group, with 12 cues at 2.125 second intervals. The cues are not decoration: each one marks a boundary between two of the twelve generated segments, verified against the measured transitions, so seeking to a cue lands on a join. Chapter tracks over two-second clips have nowhere to seek to; this is the first in this library with somewhere to go.
- vttStreet at dusk: chapter trackA WebVTT chapter track for the 24 second film in this group, with 12 cues at 2.125 second intervals. The cues are not decoration: each one marks a boundary between two of the twelve generated segments, verified against the measured transitions, so seeking to a cue lands on a join. Chapter tracks over two-second clips have nowhere to seek to; this is the first in this library with somewhere to go.
- webmMulti-Track Subtitles: Embedded WebVTT (WebM)WebVTT muxed inside a WebM container, which the Matroska specification allows and almost nothing consumes. No browser surfaces an embedded WebVTT track through the HTML TextTrack API (the web platform expects a separate <track> element pointing at a sidecar file), so this is the fixture for the gap between what a container is permitted to hold and what a player will actually give you. One caveat about this file specifically. Every other fixture in this phase carries byte-identical H.264 video, but the WebM muxer accepts only VP8, VP9 or AV1 video and WebVTT subtitles (that restriction is the container's definition, not a limitation of the tooling), so the picture here is re-encoded to VP9 from the same source frames. Same content, different bytes.
- mkvMulti-Track Subtitles: Forced Narrative (MKV)Two English subtitle tracks in one file: the full dialogue track, and a forced-narrative track that carries only the two moments where on-screen text needs translating. The second track sets the `forced` disposition, which tells a player to display it even when the viewer has subtitles switched off. The forced track is deliberately two cues, not eight. A forced track that repeats the full dialogue is the most common way this feature is got wrong in the wild, and a fixture that reproduced that mistake could not be used to detect it. Useful for checking that a player reads the flag rather than the track order, and that a transcoder preserves it: many drop the disposition silently and the file still looks fine until a viewer turns subtitles off.
- mp4Multi-Track Subtitles: No Subtitle Track (MP4)The control for this group: the same picture with no subtitle track at all. Every other file here differs from this one only by what was muxed in. Worth more than it looks. A track enumerator that returns an empty list, one that returns a single null entry and one that throws are three different behaviours, and none of them can be told apart using a file that has subtitles.
- mkvMulti-Track Subtitles: SDH and Standard (MKV)Standard subtitles and SDH (Subtitles for the Deaf and Hard of Hearing) as two separate English tracks, distinguished only by the `hearing_impaired` disposition. The SDH track adds the non-speech information a deaf viewer would otherwise lose (the tone that is playing, the marker that is moving) in square brackets above each line. Because both tracks are tagged `eng`, any picker that keys on language alone shows two identical-looking entries. That is exactly the bug this file exists to surface: the flag is the only thing that separates them, and it is the thing most often dropped in a remux.
Generated by generation/comfy_film_wave.py. Free for any use, no attribution required, license.