adapt-contrib-media

Media is a presentation component bundled with the Adapt framework.

It is a media playback component for audio and video. It uses HTML5 audio and video for browsers that support it and Flash/Silverlight fallbacks for browsers that don't.

The component uses MediaElement.js (v2.21.2), a player with a number of useful features including subtitles and accessible (and CSS-skinnable) controls. MediaElement.js carries the MIT license compatible with Adapt.

Visit the Media wiki for more information about its functionality and for explanations of key properties.

Installation

As one of Adapt's core components, Media is included with the installation of the Adapt framework and the installation of the Adapt authoring tool.

• If Media has been uninstalled from the Adapt framework, it may be reinstalled. With the Adapt CLI installed, run the following from the command line:
  adapt install adapt-contrib-media

  Alternatively, this component can also be installed by adding the following line of code to the adapt.json file:
  "adapt-contrib-media": "*"
  Then running the command:
  adapt install
  (This second method will reinstall all plug-ins listed in adapt.json.)

• If Media has been uninstalled from the Adapt authoring tool, it may be reinstalled using the Plug-in Manager.

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Settings Overview

The attributes listed below are used in components.json to configure Media, and are properly formatted as JSON in example.json. Visit the Media wiki for more information about how they appear in the authoring tool.

Attributes

core model attributes: These are inherited by every Adapt component. Read more.

_component (string): This value must be: media.

_classes (string): CSS class name to be applied to Media’s containing div. The class must be predefined in one of the Less files. Separate multiple classes with a space.

_layout (string): This defines the horizontal position of the component in the block. Acceptable values are full, left or right.

instruction (string): This optional text appears above the component. It is frequently used to guide the learner’s interaction with the component.

_setCompletionOn (string): This determines when Adapt will register this component as having been completed by the user. Acceptable values are inview (triggered when the component is fully displayed within the viewport), play (triggered when playback is initiated), or ended (triggered when the video has reached the end of playback).

_useClosedCaptions (boolean): If set to true, video will allow for Closed Captions and the cc object will be required. The default is false.

_allowFullScreen (boolean): Determines whether fullscreen mode is available or not. Note that changing this setting has no effect in Internet Explorer 9 as this browser does not support fullscreen mode for HTML video.

_startLanguage (string): If using closed captions with multiple languages, use this property to specify which language should be shown by default. The value of this property must match one of the srclang values.

_media (object): The media attributes group will contain different values depending on the type of media: video or audio.
For video it contains values for mp4, webm, ogv, poster, and cc. The properties mp4, webm and ogv are all optional, but at least one is required (see below for alternate properties for YouTube/Vimeo video).
For audio it contains mp3 and ogg. As with video, both are optional, but at least one is required.
The decision to include more than one file format is typically based on the browser/s used by the targeted audience. The mostly widely supported video file format is mp4 (specifically H.264/MPEG-4 Part 10 AVC). The most widely supported audio format is mp3.

mp4 (string): File name (including path) of the video file. Path should be relative to the src folder (e.g., course/en/video/video-1.mp4).

webm (string): File name (including path) of the video file. Path should be relative to the src folder (e.g., course/en/video/video-1.webm).

ogv (string): File name (including path) of the video file. Path should be relative to the src folder (e.g., course/en/video/video-1.ogv).

poster (string): File name (including path) of the optional image to be shown while the video is downloading, or until the user hits the play button. If this is not included, the first frame of the video will be used instead. Path should be relative to the src folder (e.g., course/en/images/video-1.jpg).

cc (array): Closed captions in multiple languages may be provided. Each object in this list contains values for srclang and src.

srclang (string): The language of the closed captions (e.g., en for English). Acceptable values can be found at http://www.w3schools.com/tags/ref_language_codes.asp.

src (string): File name (including path) of the closed captions resource accepted by <track> (i.e., the VTT file). Path should be relative to the src folder (e.g., course/en/video/big_buck_bunny_sub.vtt).

mp3 (string): File name (including path) of the audio file. Path should be relative to the src folder (e.g., course/en/audio/audio-1.mp3).

ogg (string): File name (including path) of the audio file. Path should be relative to the src folder (e.g., course/en/audio/audio-1.ogg).

_transcript (object): The transcript attributes group contains values for _inlineTranscript, _externalTranscript, inlineTranscriptButton, inlineTranscriptCloseButton, inlineTranscriptBody, transcriptLinkButton, and transcriptLink.

_setCompletionOnView (boolean): This determines if Adapt will register this component as having been completed by the user when the inline transcript is opened. This is true by default.

_inlineTranscript (boolean): Determines whether the button that toggles the display of the inline transcript text will be displayed or not.

_externalTranscript (boolean): Determines whether the button that links to the optional external transcript will be displayed or not.

inlineTranscriptButton (string): This text appears on the button that toggles the visibility of the inline transcript text. It is displayed when the inline transcript text is hidden. If no text is provided, the transcriptLink will be displayed on the button.

inlineTranscriptCloseButton (string): This text appears on the button that toggles the visibility of the inline transcript. It is displayed when the inline transcript text is visible.

inlineTranscriptBody (string): This optional text appears below the video. If provided, its visibility is toggled by clicking the transcript button. It is hidden by default.

transcriptLinkButton (string): This text appears on the button that links to the optional external transcript. If no text is provided, the transcriptLink will be displayed on the button.

transcriptLink (string): File name (including path) of the optional external transcript. Path should be relative to the src folder (e.g., course/en/pdf/video01_transcript.pdf).

_playerOptions (object): This optional object can be used to customize the player. Visit the MediaElement website for a list of what options are available. Options are configured in components.json. See example.json for a suggested configuration.

Note:
The _playerOptions feature is experimental. As these settings are not implemented by the Adapt community, there is no guarantee that all features and combinations thereof will be compatible with your device set up.

JSON Examples

The attributes described above focus on the component's use with standard video. They are properly formatted as JSON in example.json The same model can be applied to the component's use with audio and YouTube videos.

Standard video example:

"_media": {
    "mp4": "course/en/video/video.mp4",
    "ogv": "course/en/video/video.ogv"
},

YouTube video example:

"_media": {
    "source": "//www.youtube.com/watch?v=RT-KmgAgxuo",
    "type": "video/youtube"
},

Vimeo video example:

"_media": {
    "source": "//player.vimeo.com/video/96961553",
    "type": "video/vimeo"
},

Audio example:

"_media": {
    "mp3": "course/en/audio/audio.mp3",
    "ogg": "course/en/audio/audio.ogg"
},

Accessibility

Media has two elements that have been assigned a label using the aria-label attribute: ariaRegion and transcriptButton. These labels are not visible elements. They are utilized by assistive technology such as screen readers. Should the label texts need to be customised, they can be found within the globals object in properties.schema.

Limitations

Version number: 2.0.5 Framework versions: 2.0
Author / maintainer: Adapt Core Team with contributors
Accessibility support: WAI AA
RTL support: yes
Cross-platform coverage: Chrome, Chrome for Android, Firefox (ESR + latest version), Edge 12, IE 11, IE10, IE9, IE8, IE Mobile 11, Safari for iPhone (iOS 8+9), Safari for iPad (iOS 8+9), Safari 8, Opera