videojs-http-streaming (VHS)

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Play HLS, DASH, and future HTTP streaming protocols with video.js, even where they're not
natively supported.

Included in video.js 7 by default! See the video.js 7 blog post

Maintenance Status: Stable

Video.js Compatibility: 6.0, 7.0

Table of Contents generated with DocToc

- Installation
- NPM
- CDN
- Releases
- Manual Build
- Contributing
- Troubleshooting
- Talk to us
- Getting Started
- Compatibility
- Via MSE
- Native only
- Flash Support
- DRM
- Documentation
- Options
- How to use
- Initialization
- Source
- List
- withCredentials
- useCueTags
- overrideNative
- blacklistDuration
- bandwidth
- useBandwidthFromLocalStorage
- enableLowInitialPlaylist
- limitRenditionByPlayerDimensions
- smoothQualityChange
- allowSeeksWithinUnsafeLiveWindow
- customTagParsers
- Runtime Properties
- hls.playlists.master
- hls.playlists.media
- hls.systemBandwidth
- hls.bandwidth
- hls.throughput
- hls.selectPlaylist
- hls.representations
- hls.xhr
- hls.stats
- Events
- loadedmetadata
- HLS Usage Events
- Presence Stats
- Use Stats
- In-Band Metadata
- Segment Metadata
- Hosting Considerations
- Known Issues
- Fragmented MP4 Support
- Testing
- Debugging
- Release History
- Building
- Development
- Tools
- Commands

Installation

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To install videojs-http-streaming with npm run

``bash
npm install --save @videojs/http-streaming
`

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Select a version of VHS from the CDN

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Download a release of videojs-http-streaming

$3

Download a copy of this git repository and then follow the steps in Building

Contributing

See CONTRIBUTING.md

Troubleshooting

See our troubleshooting guide

Talk to us

Drop by our slack channel (#playback) on the [Video.js slack][slack-link].

Getting Started

This library is included in video.js 7 by default, if you are using an older version of video.js then
get a copy of videojs-http-streaming and include it in your page along with video.js:

`html

src="https://example.com/index.m3u8"
type="application/x-mpegURL">




`

Check out our live example if you're having trouble.

Is it recommended to use the element or load a source with player.src(sourceObject) in order to prevent the video element from playing the source natively where HLS is supported.

Compatibility

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- Chrome
- Firefox
- Internet Explorer 11 Windows 10 or 8.1

Using the overrideNative option
- Chrome Android
- Edge

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- Mac Safari
- iOS Safari

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This plugin does not support Flash playback. Instead, it is recommended that users use the videojs-flashls-source-handler plugin as a fallback option for browsers that don't have a native
HLS/DASH player or support for Media Source Extensions.

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DRM is supported through videojs-contrib-eme. In order to use DRM, include the videojs-contrib-eme plug, initialize it, and add options to either the plugin or the source.

Detailed option information can be found in the videojs-contrib-eme README.

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 project addresses that situation by providing a polyfill for HLS
on browsers that have support for Media Source
Extensions.
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.

Check out the full documentation for details on how HLS works
and advanced configuration. A description of the adaptive switching
behavior is available, too.

videojs-http-streaming supports a bunch of HLS features. Here
are some highlights:

- video-on-demand and live playback modes
- backup or redundant streams
- mid-segment quality switching
- AES-128 segment encryption
- CEA-608 captions are automatically translated into standard HTML5
[caption text tracks][0]
- In-Manifest WebVTT subtitles are automatically translated into standard HTML5
subtitle tracks
- Timed ID3 Metadata is automatically translated into HTML5 metedata
text tracks
- Highly customizable adaptive bitrate selection
- Automatic bandwidth tracking
- Cross-domain credentials support with CORS
- Tight integration with video.js and a philosophy of exposing as much
as possible with standard HTML APIs
- Stream with multiple audio tracks and switching to those audio tracks
(see the docs folder) for info
- Media content in
fragmented MP4s
instead of the MPEG2-TS container format.

[0]: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/track

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#### How to use

##### Initialization
You may pass in an options object to the hls source handler at player
initialization. You can pass in options just like you would for other
parts of video.js:

`javascript
// html5 for html hls
videojs(video, {
html5: {
hls: {
withCredentials: true
}
}
});
`

##### Source
Some options, such as withCredentials can be passed in to hls during
player.src

`javascript

var player = videojs('some-video-id');

player.src({
src: 'https://d2zihajmogu5jn.cloudfront.net/bipbop-advanced/bipbop_16x9_variant.m3u8',
type: 'application/x-mpegURL',
withCredentials: true
});
`

#### List
##### withCredentials
* Type: boolean
* can be used as a source option
* can be used as an initialization option

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.

##### useCueTags
* Type: boolean
* can be used as an initialization option

When the useCueTags property is set to true, a text track is created with
label 'ad-cues' and kind 'metadata'. The track is then added to
player.textTracks(). Changes in active cue may be
tracked by following the Video.js cue points API for text tracks. For example:

`javascript
let textTracks = player.textTracks();
let cuesTrack;

for (let i = 0; i < textTracks.length; i++) {
  if (textTracks[i].label === 'ad-cues') {
    cuesTrack = textTracks[i];
  }
}

cuesTrack.addEventListener('cuechange', function() {
let activeCues = cuesTrack.activeCues;

  for (let i = 0; i < activeCues.length; i++) {
let activeCue = activeCues[i];

    console.log('Cue runs from ' + activeCue.startTime +
' to ' + activeCue.endTime);
  }
});
`

##### overrideNative
* Type: boolean
* can be used as an initialization option

Try to use videojs-http-streaming even on platforms that provide some
level of HLS support natively. There are a number of platforms that
technically play back HLS content but aren't very reliable or are
missing features like CEA-608 captions support. When overrideNative
is true, if the platform supports Media Source Extensions
videojs-http-streaming will take over HLS playback to provide a more
consistent experience.

`javascript
// via the constructor
var player = videojs('playerId', {
html5: {
hls: {
overrideNative: true
}
}
});

// via the source
var player = videojs('playerId');

player.src({
src: 'https://example.com/index.m3u8',
type: 'application/x-mpegURL',
overrideNative: true
});
`

##### blacklistDuration
* Type: number
* can be used as an initialization option

When the blacklistDuration property is set to a time duration in seconds,
if a playlist is blacklisted, it will be blacklisted for a period of that
customized duration. This enables the blacklist duration to be configured
by the user.

##### bandwidth
* Type: number
* can be used as an initialization option

When the bandwidth property is set (bits per second), it will be used in
the calculation for initial playlist selection, before more bandwidth
information is seen by the player.

##### useBandwidthFromLocalStorage
* Type: boolean
* can be used as an initialization option
If true, bandwidth and throughput values are stored in and retrieved from local
storage on startup (for initial rendition selection). This setting is false by default.

##### enableLowInitialPlaylist
* Type: boolean
* can be used as an initialization option

When enableLowInitialPlaylist is set to true, it will be used to select
the lowest bitrate playlist initially. This helps to decrease playback start time.
This setting is false by default.

##### limitRenditionByPlayerDimensions
* Type: boolean
* can be used as an initialization option

When limitRenditionByPlayerDimensions is set to true, rendition
selection logic will take into account the player size and rendition
resolutions when making a decision.
This setting is true by default.

##### smoothQualityChange
* Type: boolean
* can be used as a source option
* can be used as an initialization option

When the smoothQualityChange property is set to true, a manual quality
change triggered via the representations API will use
smooth quality switching rather than the default fast (buffer-ejecting)
quality switching. Using smooth quality switching will mean no loading spinner
will appear during quality switches, but will cause quality switches to only
be visible after a few seconds.

Note that this _only_ affects quality changes triggered via the representations
API; automatic quality switches based on available bandwidth will always be
smooth switches.

##### allowSeeksWithinUnsafeLiveWindow
* Type: boolean
* can be used as a source option

When allowSeeksWithinUnsafeLiveWindow is set to true, if the active playlist is live
and a seek is made to a time between the safe live point (end of manifest minus three
times the target duration,
see the hls spec
for details) and the end of the playlist, the seek is allowed, rather than corrected to
the safe live point.

This option can help in instances where the live stream's target duration is greater than
the segment durations, playback ends up in the unsafe live window, and there are gaps in
the content. In this case the player will attempt to seek past the gaps but end up seeking
inside of the unsafe range, leading to a correction and seek back into a previously played
content.

The property defaults to false.

##### customTagParsers
* Type: Array
* can be used as a source option

With customTagParsers you can pass an array of custom m3u8 tag parser objects. See https://github.com/videojs/m3u8-parser#custom-parsers

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Runtime properties are attached to the tech object when HLS is in
use. You can get a reference to the HLS source handler like this:

`javascript
var hls = player.tech().hls;
`

If you were thinking about modifying runtime properties in a
video.js plugin, we'd recommend you avoid it. Your plugin won't work
with videos that don't use videojs-http-streaming and the best plugins
work across all the media types that video.js supports. If you're
deploying videojs-http-streaming on your own website and want to make a
couple tweaks though, go for it!

#### hls.playlists.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.

#### hls.playlists.media
Type: function

A function that can be used to retrieve or modify the currently active
media playlist. The active media playlist is referred to when
additional video data needs to be downloaded. Calling this function
with no arguments returns the parsed playlist object for the active
media playlist. Calling this function with a playlist object from the
master playlist or a URI string as specified in the master playlist
will kick off an asynchronous load of the specified media
playlist. Once it has been retreived, it will become the active media
playlist.

#### hls.systemBandwidth
Type: number

systemBandwidth is a combination of two serial processes' bitrates. The first
is the network bitrate provided by bandwidth and the second is the bitrate of
the entire process after that (decryption, transmuxing, and appending) provided
by throughput. This value is used by the default implementation of selectPlaylist
to select an appropriate bitrate to play.

Since the two process are serial, the overall system bandwidth is given by:
systemBandwidth = 1 / (1 / bandwidth + 1 / throughput)

#### hls.bandwidth
Type: number

The number of bits downloaded per second in the last segment download.

Before the first video segment has been downloaded, it's hard to
estimate bandwidth accurately. The HLS tech uses a starting value of 4194304 or 0.5 MB/s. If you
have a more accurate source of bandwidth information, you can override
this value as soon as the HLS tech has loaded to provide an initial
bandwidth estimate.

#### hls.throughput
Type: number

The number of bits decrypted, transmuxed, and appended per second as a cumulative average across active processing time.

#### hls.selectPlaylist
Type: function

A function that returns the media playlist object to use to download
the next segment. It is invoked by the tech 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.

Overridding this function with your own is very powerful but is overkill
for many purposes. Most of the time, you should use the much simpler
function below to selectively enable or disable a playlist from the
adaptive streaming logic.

#### hls.representations
Type: function

It is recommended to include the videojs-contrib-quality-levels plugin to your page so that videojs-http-streaming will automatically populate the QualityLevelList exposed on the player by the plugin. You can access this list by calling player.qualityLevels(). See the videojs-contrib-quality-levels project page for more information on how to use the api.

Example, only enabling representations with a width greater than or equal to 720:

`javascript
var qualityLevels = player.qualityLevels();

for (var i = 0; i < qualityLevels.length; i++) {
var quality = qualityLevels[i];
if (quality.width >= 720) {
quality.enabled = true;
} else {
quality.enabled = false;
}
}
`

If including videojs-contrib-quality-levels is not an option, you can use the representations api. To get all of the available representations, call the representations() method on player.hls. This will return a list of plain objects, each with width, height, bandwidth, and id properties, and an enabled() method.

`javascript
player.hls.representations();
`

To see whether the representation is enabled or disabled, call its enabled() method with no arguments. To set whether it is enabled/disabled, call its enabled() method and pass in a boolean value. Calling .enabled(true) will allow the adaptive bitrate algorithm to select the representation while calling .enabled(false) will disallow any selection of that representation.

Example, only enabling representations with a width greater than or equal to 720:

`javascript
player.hls.representations().forEach(function(rep) {
if (rep.width >= 720) {
rep.enabled(true);
} else {
rep.enabled(false);
}
});
`

#### hls.xhr
Type: function

The xhr function that is used by HLS internally is exposed on the per-
player hls object. While it is possible, we do not recommend replacing
the function with your own implementation. Instead, the xhr provides
the ability to specify a beforeRequest function that will be called
with an object containing the options that will be used to create the
xhr request.

Example:
`javascript
player.hls.xhr.beforeRequest = function(options) {
options.uri = options.uri.replace('example.com', 'foo.com');

return options;
};
`

The global videojs.Hls also exposes an xhr property. Specifying a
beforeRequest function on that will allow you to intercept the options
for all requests in every player on a page. For consistency across
browsers the video source should be set at runtime once the video player
is ready.

Example
`javascript
videojs.Hls.xhr.beforeRequest = function(options) {
/*
* Modifications to requests that will affect every player.
*/

return options;
};

var player = videojs('video-player-id');
player.ready(function() {
this.src({
src: 'https://d2zihajmogu5jn.cloudfront.net/bipbop-advanced/bipbop_16x9_variant.m3u8',
type: 'application/x-mpegURL',
});
});
`

For information on the type of options that you can modify see the
documentation at https://github.com/Raynos/xhr.

#### hls.stats
Type: object

This object contains a summary of HLS and player related stats.

| Property Name | Type | Description |
| --------------------- | ------ | ----------- |
| bandwidth | number | Rate of the last segment download in bits/second |
| mediaRequests | number | Total number of media segment requests |
| mediaRequestsAborted | number | Total number of aborted media segment requests |
| mediaRequestsTimedout | number | Total number of timedout media segment requests |
| mediaRequestsErrored | number | Total number of errored media segment requests |
| mediaTransferDuration | number | Total time spent downloading media segments in milliseconds |
| mediaBytesTransferred | number | Total number of content bytes downloaded |
| mediaSecondsLoaded | number | Total number of content seconds downloaded |
| buffered | array | List of time ranges of content that are in the SourceBuffer |
| currentTime | number | The current position of the player |
| currentSource | object | The source object. Has the structure {src: 'url', type: 'mimetype'} |
| currentTech | string | The name of the tech in use |
| duration | number | Duration of the video in seconds |
| master | object | The master playlist object |
| playerDimensions | object | Contains the width and height of the player |
| seekable | array | List of time ranges that the player can seek to |
| timestamp | number | Timestamp of when hls.stats was accessed |
| videoPlaybackQuality | object | Media playback quality metrics as specified by the W3C's Media Playback Quality API |




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Standard HTML video events are handled by video.js automatically and
are triggered on the player object.

#### loadedmetadata

Fired after the first segment is downloaded for a playlist. This will not happen
until playback if video.js's metadata setting is none

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Usage tracking events are fired when we detect a certain HLS feature, encoding setting,
or API is used. These can be helpful for analytics, and to pinpoint the cause of HLS errors.
For instance, if errors are being fired in tandem with a usage event indicating that the
player was playing an AES encrypted stream, then we have a possible avenue to explore when
debugging the error.

Note that although these usage events are listed below, they may change at any time without
a major version change.

HLS usage events are triggered on the tech with the exception of the 3 hls-reload-error
events, which are triggered on the player.

#### Presence Stats

Each of the following usage events are fired once per source if (and when) detected:

| Name | Description |
| ------------- | ------------- |
| hls-webvtt | master manifest has at least one segmented WebVTT playlist |
| hls-aes | a playlist is AES encrypted |
| hls-fmp4 | a playlist used fMP4 segments |
| hls-demuxed | audio and video are demuxed by default |
| hls-alternate-audio | alternate audio available in the master manifest |
| hls-playlist-cue-tags | a playlist used cue tags (see useCueTags(#usecuetags) for details) |
| hls-bandwidth-from-local-storage | starting bandwidth was retrieved from local storage (see useBandwidthFromLocalStorage(#useBandwidthFromLocalStorage) for details) |
| hls-throughput-from-local-storage | starting throughput was retrieved from local storage (see useBandwidthFromLocalStorage(#useBandwidthFromLocalStorage) for details) |

#### Use Stats

Each of the following usage events are fired per use:

| Name | Description |
| ------------- | ------------- |
| hls-gap-skip | player skipped a gap in the buffer |
| hls-player-access | player.hls was accessed |
| hls-audio-change | a user selected an alternate audio stream |
| hls-rendition-disabled | a rendition was disabled |
| hls-rendition-enabled | a rendition was enabled |
| hls-rendition-blacklisted | a rendition was blacklisted |
| hls-timestamp-offset | a timestamp offset was set in HLS (can identify discontinuities) |
| hls-unknown-waiting | the player stopped for an unknown reason and we seeked to current time try to address it |
| hls-live-resync | playback fell off the back of a live playlist and we resynced to the live point |
| hls-video-underflow | we seeked to current time to address video underflow |
| hls-error-reload-initialized | the reloadSourceOnError plugin was initialized |
| hls-error-reload | the reloadSourceOnError plugin reloaded a source |
| hls-error-reload-canceled | an error occurred too soon after the last reload, so we didn't reload again (to prevent error loops) |




$3

The HLS tech supports timed
metadata
embedded as ID3 tags. When a stream is
encountered with embedded metadata, an in-band metadata text
track
will automatically be created and populated with cues as they are
encountered in the stream. UTF-8 encoded
TXXX
and WXXX ID3
frames are mapped to cue points and their values set as the cue
text. Cues are created for all other frame types and the data is
attached to the generated cue:

`javascript
cue.value.data
`

There are lots of guides and references to using text tracks around
the web.

$3


You can get metadata about the segments currently in the buffer by using the segment-metadata
text track. You can get the metadata of the currently rendered segment by looking at the
track's activeCues array. The metadata will be attached to the cue.value property and
will have this structure

`javascript
cue.value = {
byteLength, // The size of the segment in bytes
bandwidth, // The peak bitrate reported by the segment's playlist
resolution, // The resolution reported by the segment's playlist
codecs, // The codecs reported by the segment's playlist
uri, // The Segment uri
timeline, // Timeline of the segment for detecting discontinuities
playlist, // The Playlist uri
start, // Segment start time
end // Segment end time
};
`

Example:
Detect when a change in quality is rendered on screen
`javascript
let tracks = player.textTracks();
let segmentMetadataTrack;

for (let i = 0; i < tracks.length; i++) {
if (tracks[i].label === 'segment-metadata') {
segmentMetadataTrack = tracks[i];
}
}

let previousPlaylist;

if (segmentMetadataTrack) {
segmentMetadataTrack.on('cuechange', function() {
let activeCue = segmentMetadataTrack.activeCues[0];

if (activeCue) {
if (previousPlaylist !== activeCue.value.playlist) {
console.log('Switched from rendition ' + previousPlaylist +
' to rendition ' + activeCue.value.playlist);
}
previousPlaylist = activeCue.value.playlist;
}
});
}
`

Hosting Considerations

Unlike a native HLS implementation, the HLS tech 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.

Known Issues

Issues that are currenty known. If you want to
help find a solution that would be appreciated!

$3

Edge has native support for HLS but only in the MPEG2-TS container. If
you attempt to play an HLS stream with fragmented MP4 segments, Edge
will stall. Fragmented MP4s are only supported on browser that have
Media Source Extensions available.

Testing

For testing, you run npm run test. You will need Chrome and Firefox for running the tests.

_videojs-http-streaming uses BrowserStack for compatibility testing._

Debugging

videojs-http-streaming makes use of videojs.log for debug logging. You can enable these logs
by setting the log level to debug using videojs.log.level('debug'). You can access a complete
history of the logs using videojs.log.history(). This history is maintained even when the
log level is not set to debug.

hls.stats can also be helpful when debugging. Accessing this object will give you
a snapshot summary of various HLS and player stats. See hls.stats for details
about what this object contains.

__NOTE__: The debug level is only available in video.js v6.6.0+. With earlier versions of
video.js, no debug messages will be logged to console.

Release History

Check out the changelog for a summary of each release.

Building

To build a copy of videojs-http-streaming run the following commands

`bash
git clone https://github.com/videojs/http-streaming
cd http-streaming
npm i
npm run build
`

videojs-http-streaming will have created all of the files for using it in a dist folder

Development

$3

* Download stream locally with the HLS Fetcher
* Simulate errors with Murphy
* Inspect content with Thumbcoil

$3

All commands for development are listed in the package.json file and are run using
`bash
npm run
``

[slack-icon]: http://slack.videojs.com/badge.svg
[slack-link]: http://slack.videojs.com
[travis-icon]: https://travis-ci.org/videojs/http-streaming.svg?branch=master
[travis-link]: https://travis-ci.org/videojs/http-streaming
[issue-stats-link]: http://issuestats.com/github/videojs/http-streaming
[issue-stats-pr-icon]: http://issuestats.com/github/videojs/http-streaming/badge/pr
[issue-stats-issues-icon]: http://issuestats.com/github/videojs/http-streaming/badge/issue
[greenkeeper-icon]: https://badges.greenkeeper.io/videojs/http-streaming.svg
[greenkeeper-link]: https://greenkeeper.io/