Video
A video is a recording of moving visual images.
Syntax
The syntax for representing this component varies depending on the authoring format:
| Authoring format | Syntax and example |
|---|---|
| XDITA |
|
| HDITA |
|
| MDITA |
There is no specific support in the MDITA core profile. If needed, use an HDITA snippet. |
Usage information
The video component is modeled on the HTML5 <video> element.
A video resource can be referenced by @href, @keyref, and
nested media-source components.
Playback behaviors such as auto-playing, looping, and muting are determined by attributes. When not specified, the default behavior is determined by the user agent that is used to present the media.
Rendering expectations
The video resource typically is rendered in the main flow of the content.
Processors SHOULD scale the video resource when values are provided
for the
@height and @width
attributes. The following expectations apply:- If a height value is specified and no width value is specified, processors SHOULD scale the width by the same factor as the height.
- If a width value is specified and no height value is specified, processors SHOULD scale the height by the same factor as the width.
- If both a height value and width value are specified, implementations MAY ignore one of the two values when they are unable to scale to each direction using different factors.
When a video resource cannot be rendered in
a meaningful way, processors SHOULD render the contents of the
<fallback> element, if it is present.
Attributes
The available attributes vary based on the authoring format:
- XDITA and HDITA
- The following attributes are available on this element: ID
attributes, link relationship attributes, localization attributes, universal
attributes,
@props, and the attributes listed below. - MDITA
- There is no attribute support for the MDITA core profile. For the MDITA extended profile, attributes can be specified by using the HDITA representation.
@autoplay- Specifies whether the resource automatically plays when it is presented. The following values are recognized: true and false. The default value is true.
@controls- Specifies whether the presentation of the resource includes user interface controls. The following values are recognized: true and false. The default value is true.
@height- Indicates the vertical dimension for the resulting display. The value of this attribute is a real number expressed in decimal notation, optionally followed by a unit of measure. The following units of measurement are supported: cm, em, in, mm, pc, pt, and px (centimeters, ems, inches, millimeters, picas, points, and pixels, respectively). The default unit is px (pixels). Possible values include:5, 5in, and 10.5cm.
@loop- Specifies whether the resource loops when played. The following values are recognized: true and false. The default value is true.
@muted- Specifies whether the resource is muted. The following values are recognized: true and false. The default value is true.
@tabindex- Specifies whether the video resource can be focused and where
it participates in sequential keyboard navigation. See
@tabindexin the HTML specification (WHATWG version). @width- Indicates the horizontal dimension for the resulting display. The value of this attribute is a real number expressed in decimal notation, optionally followed by a unit of measure. The following units of measurement are supported: cm, em, in, mm, pc, pt, and px (centimeters, ems, inches, millimeters, picas, points, and pixels, respectively). The default unit is px (pixels). Possible values include:5, 5in, and 10.5cm.
For this element, the following considerations apply:
- The
@formatattribute specifies the MIME type for the resource. This attribute enables processors to avoid loading unsupported resources. If@formatis not specified and@keyrefis specified, the effective type for the key named by the@keyrefattribute is used as the value. If an explicit@formatis not specified on either the<video>element or key definition, processors can use other means, such the URI file extension, to determine the effective MIME type of the resource. - The
@hrefattribute specifies the absolute or relative URI of the video resource. If@hrefis specified, also specify@format.
Examples
This section is non-normative.
The following example demonstrates the use of video in an XDITA topic.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE topic PUBLIC "-//OASIS//DTD LIGHTWEIGHT DITA Topic//EN" "lw-topic.dtd">
<topic id="sensei-promise">
<title>The Sensei Sushi Promise</title>
<body>
<video height="300px"
loop="false"
muted="false"
poster="sensei-video.jpg"
width="400px">
<desc>Video about the Sensei Sushi promise.</desc>
<fallback>
<image href="video-not-available.png">
<alt>This video cannot be displayed.</alt>
</image>
</fallback>
<media-source href="sensei-video.mp4"/>
<media-source href="sensei-video.ogg"/>
<media-source href="sensei-video.webm"/>
<media-track srclang="en" value="sensei-video.vtt"/>
</video>
</body>
</topic>The following example demonstrates the use of video in an HDITA topic.
<!DOCTYPE html>
<title>The Sensei Sushi Promise</title>
<body>
<article id="sensei-promise">
<h1>The Sensei Sushi Promise</h1>
<video height="300" width="400" title="Video about the Sensei Sushi promise" controls poster="sensei-video.jpg">
<source src="sensei-video.mp4"/>
<source src="sensei-video.ogg"/>
<source src="sensei-video.webm"/>
<track srclang="en" src="sensei-video.vtt"/>
<img src="video-not-available.png" alt="This video cannot be displayed."/>
</video>
</article>
</body>