getAvailableAudioTracks

Description

Returned object

Returns the list of available audio tracks for the current content.

Each of the objects in the returned array have the following properties:

• active (Boolean): Whether the track is the one currently active or not. Only maximum one audio track can be active at a time.

• id (string): The id used to identify the track. Use it for setting the track via setAudioTrack.

• language (string): The language the audio track is in, as set in the Manifest.

• normalized (string): An attempt to translate the language property into an ISO 639-3 language code (for now only support translations from ISO 639-1 and ISO 639-2 language codes). If the translation attempt fails (no corresponding ISO 639-3 language code is found), it will equal the value of language

• audioDescription (Boolean): Whether the track is an audio description of what is happening at the screen.

• dub (Boolean|undefined): If set to true, this audio track is a "dub", meaning it was recorded in another language than the original. If set to false, we know that this audio track is in an original language. This property is undefined if we do not known whether it is in an original language.

• label (string|undefined): A human readable label that may be displayed in the user interface providing a choice between audio tracks.

  This information is usually set only if the current Manifest contains one.

• representations (Array.<Object>): Representations of this audio track, with attributes:

  • id (string): The id used to identify this Representation.

  • bitrate (Number|undefined): The bitrate of this Representation, in bits per seconds.

    undefined if unknown.

  • codec (string|undefined): The audio codec the Representation is in, as announced in the corresponding Manifest.

  • isSpatialAudio (Boolean|undefined): If set to true, this Representation has spatial audio.

  • isCodecSupported (Boolean|undefined): If true the codec(s) of that Representation is supported by the current platform.

    Note that unless you set the filterPlayableRepresentations option to false, no Representation with a isCodecSupported value of false will be present in this array (they'll all be filtered out).

    undefined (or not set) if support of that Representation is unknown or if does not make sense here.

  • decipherable (Boolean|undefined): If true the Representation can be deciphered (in the eventuality it had DRM-related protection).

    Note that unless you set the filterPlayableRepresentations option to false, no Representation with a isCodecSupported value of false will be present in this array (they'll all be filtered out).

  • contentProtections (Object|undefined): Encryption information linked to this Representation.

    If set to an Object, the Representation is known to be encrypted. If unset or set to undefined the Representation is either unencrypted or we don't know if it is.

    When set to an object, it may contain the following properties:

    • keyIds (Array.<Uint8Array>|undefined): Known key ids linked to that Representation.

Asking for a specific Period

You can also get the list of available audio tracks for a specific Period by calling getAvailableAudioTracks with the corresponding Period's id in argument. Such id can be obtained through the getAvailablePeriods method, the newAvailablePeriods event or the periodChange event.

// example: getting the audio track list for the first Period
const periods = rxPlayer.getAvailablePeriods();
console.log(rxPlayer.getAvailableAudioTracks(periods[0].id);

Including Representations that cannot be played

You can also ask getAvailableAudioTracks to include in its response Representation objects which will not be played because they have their isCodecSupported or decipherable property set to false (those are filtered out by default, as indicated above).

To do this, you can provide an object to getAvailableAudioTracks with a filterPlayableRepresentations property set to false like this:

const audioTrack = player.getAvailableAudioTracks();

You may for example also want to know which Representation are not playable to provide debug information, or to detect deterministically the capabilities of the current device.

Note that this will return the metadata of the available audio tracks only for the current Period. To obtain metadata on all representations for available audio tracks from another Period, you can also set a periodId property:

const periods = rxPlayer.getAvailablePeriods();
console.log(rxPlayer.getAvailableAudioTracks({
    periodId: periods[0].id,
    filterPlayableRepresentations: false,
});

Syntax

// Get list of available audio tracks for the currently-playing Period
const audioTracks = player.getAvailableAudioTracks();

// Also include metadata on the non-playable Representations
const audioTracks = player.getAvailableAudioTracks({
  filterPlayableRepresentations: false,
});

// Get list of available audio tracks for a specific Period
const audioTracks = player.getAvailableAudioTracks(periodId);

// Get list of available audio tracks for a specific Period and also include metadata on
// the non-playable Representations
const audioTracks = player.getAvailableAudioTracks({
  periodId,
  filterPlayableRepresentations: false,
});

• arguments:

  1. arg Object|string|undefined: If set to a string, this is the id of the Period for which you want to get information about the list of available audio tracks.

     If not defined, the information associated to the currently-playing Period will be returned.

     If set to an Object, the following properties can be set (all optional):

     - `periodId` (`string|undefined`): The `id` of the wanted Period, or
       `undefined` (or not set) for the currently-playing Period
     
     - `filterPlayableRepresentations` (`boolean|undefined`): If set to `false`,
       Representation that are considered "non-playable" (which have an unsupported
       mime-type/codec or which are undecipherable) will be included.
     

• return value Array.<Object>