<track>
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
O **elemento HTML <track>
**é usado como filho dos elementos de mídia<audio>
e <video>
. Ele permite que você especifique faixas de texto temporizadas (ou dados baseados em tempo), por exemplo, para lidar automaticamente com legendas. As faixas são formatadas em WebVTT format (arquivos .vtt
) — Web Video Text Tracks or Timed Text Markup Language (TTML).
Experimente
Categorias de conteúdo | Nenhuma |
---|---|
Conteúdo permitido | Nenhum, é um empty element. |
Omissão de tag | Como é um elemento vazio, a tag inicial deve estar presente e a tag final não deve estar presente. |
Permite Parentes | Um elemento de mídia, antes de qualquer conteúdo de fluxo. |
Funções ARIA permitidas | Nenhum |
Interface DOM | HTMLTrackElement |
Atributos
Este elemento inclui os atributos globais.
default
-
This attribute indicates that the track should be enabled unless the user's preferences indicate that another track is more appropriate. This may only be used on one
track
element per media element. kind
-
How the text track is meant to be used. If omitted the default kind is
subtitles
. If the attribute is not present, it will use thesubtitles
. If the attribute contains an invalid value, it will usemetadata
. (Versions of Chrome earlier than 52 treated an invalid value assubtitles
.) The following keywords are allowed:-
subtitles
- Subtitles provide translation of content that cannot be understood by the viewer. For example dialogue or text that is not English in an English language film.
- Subtitles may contain additional content, usually extra background information. For example the text at the beginning of the Star Wars films, or the date, time, and location of a scene.
-
captions
- Closed captions provide a transcription and possibly a translation of audio.
- It may include important non-verbal information such as music cues or sound effects. It may indicate the cue's source (e.g. music, text, character).
- Suitable for users who are deaf or when the sound is muted.
-
descriptions
- Textual description of the video content.
- Suitable for users who are blind or where the video cannot be seen.
-
chapters
- Chapter titles are intended to be used when the user is navigating the media resource.
-
metadata
- Tracks used by scripts. Not visible to the user.
-
label
-
A user-readable title of the text track which is used by the browser when listing available text tracks.
src
-
Address of the track (
.vtt
file). Must be a valid URL. This attribute must be specified and its URL value must have the same origin as the document — unless the<audio>
or<video>
parent element of thetrack
element has acrossorigin
attribute. srclang
-
Language of the track text data. It must be a valid BCP 47 language tag. If the
kind
attribute is set tosubtitles
, thensrclang
must be defined.
Usage notes
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
.
Examples
<video controls poster="/images/sample.gif">
<source src="sample.mp4" type="video/mp4" />
<source src="sample.ogv" type="video/ogv" />
<track kind="captions" src="sampleCaptions.vtt" srclang="en" />
<track kind="descriptions" src="sampleDescriptions.vtt" srclang="en" />
<track kind="chapters" src="sampleChapters.vtt" srclang="en" />
<track kind="subtitles" src="sampleSubtitles_de.vtt" srclang="de" />
<track kind="subtitles" src="sampleSubtitles_en.vtt" srclang="en" />
<track kind="subtitles" src="sampleSubtitles_ja.vtt" srclang="ja" />
<track kind="subtitles" src="sampleSubtitles_oz.vtt" srclang="oz" />
<track kind="metadata" src="keyStage1.vtt" srclang="en" label="Key Stage 1" />
<track kind="metadata" src="keyStage2.vtt" srclang="en" label="Key Stage 2" />
<track kind="metadata" src="keyStage3.vtt" srclang="en" label="Key Stage 3" />
<!-- Fallback -->
...
</video>
Especificações
Specification |
---|
HTML Standard # the-track-element |
Compatibilidade com navegadores
BCD tables only load in the browser