The content type (MIME type) of the media resource, represented by a value from the following list:
'application/dash+xml': The media resource is an MPEG-DASH stream.
'application/vnd.apple.mpegurl': The media resource is an HLS stream.
'video/webm' and other formats: The media resource should use native HTML5 playback if supported by the browser.
- Available since v2.4.0.