Struct Track 

pub struct Track;

The <track> element - specifies timed text tracks for media elements.

Purpose

The <track> element provides text tracks for <audio> and <video> elements. These tracks include subtitles, captions, descriptions, chapters, and metadata. Tracks are in WebVTT format and can be displayed or processed programmatically to enhance media accessibility and user experience.

Content Categories

• None (used only within <audio> and <video> elements)

Permitted Content Model

• None (void element)

Common Use Cases

• Subtitles for foreign language translation
• Closed captions for deaf and hard-of-hearing users
• Audio descriptions for blind and low-vision users
• Chapter markers for video navigation
• Metadata tracks for programmatic access

Key Attributes

• kind: Type of track (“subtitles”, “captions”, “descriptions”, “chapters”, “metadata”)
• src: URL of the track file (WebVTT format, required)
• srclang: Language of the track text (required for subtitles)
• label: User-readable title for the track
• default: Enable this track by default

Example

<!-- Video with multiple subtitle tracks -->
<video controls>
  <source src="/videos/movie.mp4" type="video/mp4">
  <track kind="subtitles" src="/subs/en.vtt" srclang="en" label="English" default>
  <track kind="subtitles" src="/subs/es.vtt" srclang="es" label="Español">
  <track kind="subtitles" src="/subs/fr.vtt" srclang="fr" label="Français">
</video>

<!-- Video with captions and descriptions -->
<video controls>
  <source src="/videos/tutorial.mp4" type="video/mp4">
  <track kind="captions" src="/captions/en.vtt" srclang="en" label="English Captions" default>
  <track kind="descriptions" src="/descriptions/en.vtt" srclang="en" label="Audio Descriptions">
  <track kind="chapters" src="/chapters/en.vtt" srclang="en" label="Chapters">
</video>

<!-- Audio with chapter markers -->
<audio controls>
  <source src="/audio/podcast.mp3" type="audio/mpeg">
  <track kind="chapters" src="/chapters/podcast.vtt" srclang="en" label="Episode Chapters">
  <track kind="metadata" src="/metadata/podcast.vtt">
</audio>

Accessibility

• Use kind="captions" for accessibility (includes sound effects and speaker identification)
• Use kind="subtitles" for translation only
• Provide descriptions for visual content that isn’t conveyed through audio
• Ensure track files are in proper WebVTT format
• Set appropriate default tracks based on user preferences

WHATWG Specification

• 4.8.11 The track element

Trait Implementations

impl HtmlElement for Track

const TAG: &'static str = "track"

The HTML tag name (e.g., “div”, “span”, “img”).

const VOID: bool = true

Whether this is a void element (self-closing, no children allowed).

impl CanContain<Track> for Audio

impl CanContain<Track> for Video