Offline storage & playback

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Documentation sections

• Scope of support
• Offline player settings
• Offline API events
• Offline API methods
• Error management
• Implementation example

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Scope of support

Since Radiant Media Player 5, we support download, storage and playback for offline content. This feature is provided as an event-driven API that allows developers to build an offline logic on top of the player. Our implementation is based on Shaka player offline capabilities which use IndexedDB for storage. Offline storage and playback support through hls.js or progressive download is not provided.

This feature should help developers building media applications with Radiant Media Player to comply with Google Progressive Web Apps requirements.

While the player should provide a straight-forward approach to adding offline support to your application or site, we recommend developers looking to implement this feature to first familiarise themselves with general offline concepts and limitations. This article, this article and this article should help.

Offline support is only provided for on-demand video streaming. Live and DVR streaming are not supported for offline storage and playback due to their nature.

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Supported features

Supported streaming protocols:

• DASH (CMAF / fMP4 or WebM)
• CMAF / fMP4 HLS
• HLS TS (TS support is provided through mux.js)

Unsupported:

• Offline DRM (item on the roadmap)

Untested:

• Audio-only offline support

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Supported environments

Supported:

• Latest Chrome, Firefox, MS Edge, Safari for Desktop
• Latest Chrome for Android

Unsupported:

• iOS Safari (Shaka player does not go on iOS, only native HLS is currently available and Apple does not provide an offline API)

Untested:

• Cordova-based apps for Android (item on the roadmap)
• Electron-based apps for Desktop (item on the roadmap)

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Offline player settings

shakaOffline: Boolean

Enables or not offline features in Radiant Media Player. Default: false.

shakaOfflinePreferredTrackQuality: Number

Specifies which quality to download for offline storage when multiple choices are available.

• -4: uses Shaka player default selection algorithm which generally selects the highest non-HD quality
• -3: pick the highest available quality
• -2: pick the lowest available quality
• -1: pick the upper average quality
• n (where n is an integer >= 0): pick the n^th quality

Default: -1.

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Offline API events

• downloadstarted fires when download of content for offline playback has started, after download method has been called
• downloadprogress fires each time new data is appended to offline storage for a given running download
• downloadcompleted fires when download of content for offline playback has completed, after download method has been called
• downloadlistavailable fires when the current download list is available for query, after calling listDownloadedContent API method
• downloadremoved fires when the targeted download has been removed from storage, after calling removeDownload API method

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Offline API methods

isOnline()

rmp.isOnline();

Returns Boolean stating if the targeted device is online or offline. This method is based on window.navigator.onLine API. It should be thus noted that a true result may not necessary mean that the viewer has a public access to the Internet as she/he may just be in an Intranet or proxied environment. On the other hand a false result always mean the user has no public Internet connection.

hasDownloadSupport()

rmp.hasDownloadSupport();

Returns Boolean stating if the targeted device can download, store and play offline content.

listDownloadedContent() asynchronous

rmp.listDownloadedContent();

Request the player to query the current list of downloaded content. This method is asynchronous and will provide result through the getDownloadedList API method when the downloadlistavailable event fires.

getDownloadedList()

rmp.getDownloadedList();

This method must be queried when the downloadlistavailable event fires. It will provide an Array representing the list of currently stored media item by the player (an empty Array is returned if no item is currently stored). Each item of the Array will have its information stored as an Object with the following structure:

{
  appMetadata: Object
  duration: Number
  expiration: Number
  offlineUri: String
  originalManifestUri: String
  size: Number
}

download() asynchronous

rmp.download();

Request the player to start downloading content for offline storage. This downloadcompleted event will fire when download has finished, while the downloadstarted and downloadprogress events will give you status information about the download.

getDownloadProgress()

rmp.getDownloadProgress();

This method must be queried when downloadprogress event fire and will return a Number between 0 and 1 representing the progress for the current download. Returns -1 if this value is not available.

loadDownload(storedItem) asynchronous

rmp.loadDownload(content);

When a downloaded item has been listed with the getDownloadedList API method, this item can be passed to the loadDownload API method to start playing this item. When playback starts for a stored item the player will fire a playing. If the player was not able to load and player the stored item a warning event will fire.

removeDownload(storedItem) asynchronous

rmp.removeDownload(content);

When a downloaded item has been listed with the getDownloadedList API method, this item can be passed to the removeDownload API method to be removed from storage. When a item has been removed from storage, the downloadremoved event will fire.

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Offline API error management

The player will fire the following warning event through the offline API. See the error management docs for more information.

• 3001: storage has not been initialized ( shakaOffline setting is set to false or stream is not on-demand)
• 3002: could not download offline content
• 3003: could not list offline downloaded content
• 3004: could not remove offline downloaded content
• 3005: could not load offline content - invalid input
• 3006: could not query temporary storage usage and availability
• 3007: offline storage is not supported in this environment

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Implementation example

To help you get started we have released a full usage example with source code here.