video.js HLS Plugin
A video.js plugin that plays HLS video on platforms that don't support it but have Flash.
Getting Started
Download the plugin. On your web page:
<script src="video.js"></script>
<script src="videojs-hls.min.js"></script>
<script>
var player = videojs('video');
player.hls('http://example.com/video.m3u8');
player.play();
</script>
Documentation
HTTP Live Streaming (HLS) has become a de-facto standard for streaming video on mobile devices thanks to its native support on iOS and Android. There are a number of reasons independent of platform to recommend the format, though:
- Supports (client-driven) adaptive bitrate selection
- Delivered over standard HTTP ports
- Simple, text-based manifest format
- No proprietary streaming servers required
Unfortunately, all the major desktop browsers except for Safari are missing HLS support. That leaves web developers in the unfortunate position of having to maintain alternate renditions of the same video and potentially having to forego HTML-based video entirely to provide the best desktop viewing experience.
This plugin attempts to address that situation by providing a polyfill for HLS on browsers that have Flash support. You can deploy a single HLS stream, code against the regular HTML5 video APIs, and create a fast, high-quality video experience across all the big web device categories.
The videojs-hls plugin is still working towards a 1.0 release so it may not fit your requirements today. Specifically, there is no support for:
- Alternate audio and video tracks
- Subtitles
- Segment codecs other than H.264 with AAC audio
- Internet Explorer < 10
Plugin Options
You may pass in an options object to the hls plugin upon initialization. This object may contain one of the following properties:
withCredentials
Type: boolean
When the withCredentials
property is set to true
, all XHR requests for
manifests and segments would have withCredentials
set to true
as well. This
enables storing and passing cookies from the server that the manifests and
segments live on. This has some implications on CORS because when set, the
Access-Control-Allow-Origin
header cannot be set to *
, also, the response
headers require the addition of Access-Control-Allow-Credentials
header which
is set to true
.
See html5rocks's article
for more info.
Runtime Properties
player.hls.master
Type: object
An object representing the parsed master playlist. If a media playlist is loaded directly, a master playlist with only one entry will be created.
player.hls.media
Type: object
An object representing the currently selected media playlist. This is the playlist that is being referred to when a additional video data needs to be downloaded.
player.hls.mediaIndex
Type: number
The index of the next video segment to be downloaded from
player.hls.media
.
player.hls.selectPlaylist
Type: function
A function that returns the media playlist object to use to download
the next segment. It is invoked by the plugin immediately before a new
segment is downloaded. You can override this function to provide your
adaptive streaming logic. You must, however, be sure to return a valid
media playlist object that is present in player.hls.master
.
Events
loadedmetadata
Fired after the first media playlist is downloaded for a stream.
loadedmanifest
Fired immediately after a new master or media playlist has been downloaded. By default, the plugin only downloads playlists as they are needed.
Hosting Considerations
Unlike a native HLS implementation, the HLS plugin has to comply with the browser's security policies. That means that all the files that make up the stream must be served from the same domain as the page hosting the video player or from a server that has appropriate CORS headers configured. Easy instructions are available for popular webservers and most CDNs should have no trouble turning CORS on for your account.
MBR Rendition Selection Logic
In situations where manifests have multiple renditions, the player will go through the following algorithm to determine the best rendition by bandwidth and viewport dimensions.
- Start on index 0 as defined in the HLS Spec (link above)
- On a successful load complete per segment determine the following;
- player.hls.bandwidth set to value as segment byte size over download time
- Viewport width/height as determined by player.width()/player.height()
- Playlists mapped and sorted by BANDWIDTH less than or equal to 1.1x player.hls.bandwidth
- Best playlist variant by BANDWIDTH determined
- Subset of bandwidth appropriate renditions mapped
- Subset validated for RESOLUTION attributes less than or equal to player dimensions
- Best playlist variant by RESOLUTION determined
- Result is as follows;
- [Best RESOLUTION variant] OR [Best BANDWIDTH variant] OR [inital playlist in manifest]
Release History
- 0.5.0: cookie-based content protection support (see
withCredentials
) - 0.4.0: Live stream support
- 0.3.0: Performance fixes for high-bitrate streams
- 0.2.0: Basic playback and adaptive bitrate selection
- 0.1.0: Initial release