TPEMRD/2016/WebVTT

Introduction

The HTML <track> element is used as a child of the media elements—<audio> and <video>. It lets you specify timed text tracks (or time-based data), for example to automatically handle subtitles. The tracks are formatted in WebVTT format (.vtt files) — Web Video Text Tracks.

The type of data that track adds to the media is set in the kind attribute, which can take values of subtitles, captions, descriptions, chapters or metadata. The element points to a source file containing timed text that the browser exposes when the user requests additional data.

A media element cannot have more than one track with the same kind, srclang, and label.

Current status

• subtitles: supported
• captions: supported
• descriptions: not supported
  • To support descriptions, we need to integrate "text to voice" backend such as WebSpeech.
• chapters: not supported
  • Bug 883122, native UI in video control.

References

• Track Element
• WebVTT: The Web Video Text Tracks Format
• Getting Started With the Track Element
• MDN Track

Taipei Main Members

Engineers: Benjamin, Alastor

Cross Team Work

• Implement the ::cue pseudo-element (Layout)
• Video Control (UI)

Roadmap

[Stage 1] <We are here - Target milestone: 2016 Q3>

• Finish what we think important.
• Add enough telemetry to know how users use it.

[Stage 2] <Target milestone: TBD in 2016 Q4)

Project Dashboard

Meta Bugs

2 Total; 2 Open (100%); 0 Resolved (0%); 0 Verified (0%);

Ship Bugs (Stage 1)

99 Total; 7 Open (7.07%); 85 Resolved (85.86%); 7 Verified (7.07%);