Subsection 4.29.1 Video Element
The
<video>
element is used to embed a video in output formed from HTML. Subsections below describe the different ways to indicate the source of the video. The video may be placed inside a <figure>
or can be a panel of a <sidebyside>
. The former will have a caption, be numbered, and hence can be the target of a cross-reference (<xref>
). The latter is anonymous, but allows for horizontal layout, and combinations with other panels.Size is controlled by a
@width
attribute expressed as a percentage (on the <video>
element when used in a figure, or as part of the <sidebyside>
layout parameters). Height is controlled by giving the aspect ratio with the @aspect
attribute on the <video>
element. The value can be a ratio expressed like 4:3
or a decimal number computed from the width divided by the height, such as 1.333
. The default for videos is a 16:9 aspect ratio, which is very common, so you may not need to specify this attribute.Options include specifying a
@start
and an @end
in seconds as integers (no units) if you only want to highlight a key portion of a video. The @play-at
attribute can take the following valuesembed
- Play in place (the default action).
popout
- Play in new window or tab, at 150% width.
select
- Provide the reader the choice of the other two options.
In an educational setting, sometimes the preview images provided by YouTube can be distracting, or for an author-provided video you may wish to provide your own preview image. The
@preview
attribute can take on the following valuesgeneric
- PreTeXt supplies a Play-button image.
default
- Whatever the video playback provides. This is identical to simply not including
@attribute
at all - Path to an image file
- Typically, this will be a relative path, starting with
images/
. This image will be used as preview for the online version and the print version.