With HTML 5, browsers can natively support the playback of video files. The
html5 video provider gives the videoplay.dart library support to show and
control those videos.
TODO need a deeper description.
The videoplay.dart library allows setting only a single source video ID.
However, due to the fragmented nature of HTML 5 video support, there isn't
just one video format that all browsers support. Therefore, most sites will
need to provide multiple encodings of the same video file.
If you're providing the site that has a set of supported encodings (or you
reference a site that has a set of supported encodings), then you'll want to
define these in the Html5ProviderAttributes.
However, if you're letting the user point to any video on the web, and it could be hosted with any number of encodings, but the user gave a URL with an extension, then you'll want the option that strips off the extension and tries to add in all the supported variations.
By default, the system assumes that you're letting the user point to any video file on the Internet, so it will try to add all supported video file variations. This seems to work well even in the situations where you have hosted files with a limited subset of extensions, and you use URIs without an extension.
TODO show how to set this up. For now, you can look at the Dart code
documentation in lib/html5.dart.