Format
Web Video Text Tracks (WebVTT) Format
Summary
- Name
- Web Video Text Tracks (WebVTT) Format
- Identifiers
-
- PUID: fmt/1454
- MIME: text/vtt
- Format type
- Text (Structured)
- Description
- WebVTT files are used for captioning or subtitling video content. It is a standard created by the World Wide Web Consortium (W3C) for displaying timed text, and is linked to the HTML5 <track> element. The primary purpose of WebVTT files is to add text overlays to a video. Each time interval is specified in the format (HH:)mm:ss.xxx --> (HH:)mm:ss:xxx e.g. 00:00.000 --> 00:02.310 or 01:00:05.000 --> 01:00:07.000. The (HH:) is optional, but if included must have a minimum of 2 digits representing the hour (more than 2 digits may be used), and where both the minute (mm) and second (ss) parts must be between 00 and 59 inclusive.
- Note
- https://www.w3.org/TR/webvtt1/ https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API https://www.iana.org/assignments/media-types/text/vtt
- File extensions
-
vtt - Submitted by
- LIBNOVA / LIBNOVA
- Developed by
- W3C / W3C
- Supported by
- W3C / W3C
Internal signatures
Web Video Text Tracks (WebVTT)
- Description
- Absolute from beginning of file, offset 0-4, magic bytes: WEBVTT {10-40} then a time stamp in the format xx:xx.xxx followed by --> {0-5} followed by xx:xx.xxx (where x is a number).
Byte sequences
- Min Frag Length
- Absolute from BOF
- Offset
- 0
- Max offset
- 4
- Byte Sequence
574542565454{5-400}[30:35][30:39]3A[30:35][30:39]2E[30:39][30:39][30:39]202D2D3E20{0-5}[30:35][30:39]3A[30:35][30:39]2E[30:39][30:39][30:39]- Endianness
- None
Changelog
-
V110
- Release date
- 14 March 2023
-
Added signature
Web Video Text Tracks (WebVTT) Format: Signature researched and samples provided by Digital Preservation Department, The National Archives (UK).
-
Updated
Web Video Text Tracks (WebVTT) Format: Added links to documentation, expanded sig and des. Submitted by Digital Preservation Department, The National Archives (UK).
-
V99
- Release date
- 19 November 2021
-
Updated
Web Video Text Tracks (WebVTT) Format: Max-offset at beginning of file extended. Submitted by The Church of Jesus Christ and the Latter-day Saints.
-
V98
- Release date
- 27 October 2021
-
Added format
Web Video Text Tracks (WebVTT) Format: Full entry added. Submitted by LIBNOVA.
-
Added signature
Web Video Text Tracks (WebVTT) Format: Signature developed and samples provided by LIBNOVA.