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Playlist

A Playlist object allows you to specify a series of media which should be played in sequence. You can then pass the playlist to the methods that support it, for example Call.play.

Example

In this example, we create a playlist for playing the following items sequentially:

  • A TTS message
  • 1 second of silence
  • An mp3 file
import { Voice } from "@signalwire/realtime-api";

const playlist = new Voice.Playlist({ volume: 1.0 })
.add(
Voice.Playlist.TTS({
text: "Welcome to SignalWire!",
})
)
.add(Voice.Playlist.Silence({ duration: 1 }))
.add(
Voice.Playlist.Audio({
url: "https://cdn.signalwire.com/default-music/welcome.mp3",
})
);

Constructors

constructor

new Playlist(params?)

Instantiates an empty Playlist. Use the add method to add media to this Playlist.

Parameters

NameTypeDescription
params?Object-
params.volume?numberDefault volume to apply to the media in the playlist, between -40dB and +40dB. Default is 0.

Example

const playlist = new Voice.Playlist({ volume: 1.0 });

Properties

media

Get the list of media that have been added to this Playlist.

Syntax: Playlist.media

Returns: NestedArray<Object>


volume

Default volume for the audio in the playlist.

Syntax: Playlist.volume

Returns: undefined | number

Methods

add

add(params): Playlist

Adds the speecified media in series to the Playlist.

Parameters

NameTypeDescription
paramsObjectA media object. See Audio, Ringtone, Silence, and TTS.

Returns

Playlist

Example

A playlist to play some audio, then a short silence, and finally a ringtone.

const playlist = new Voice.DeviceBuilder()
.add(
Voice.Playlist.Audio({
url: "https://cdn.signalwire.com/default-music/welcome.mp3",
})
)
.add(Voice.Playlist.Silence({ duration: 1 }))
.add(Voice.Playlist.Ringtone({ name: "it", duration: 5 }));

call.play(playlist);

Audio

Static Audio(params): Object

An audio media.

Parameters

NameTypeDescription
paramsobject-
params.urlstringURL of media to play.

Returns

Object

Example

Voice.Playlist.Audio({
url: "https://cdn.signalwire.com/default-music/welcome.mp3",
});

Ringtone

Static Ringtone(params): Object

A ringtone media.

Parameters

NameTypeDescription
paramsobject-
params.duration?numberHow long to play ringtone, in seconds.
params.nameRingtoneNameName of the ringtone to play.

Returns

Object

Example

Voice.Playlist.Ringtone({
name: "it",
duration: 30,
});

Silence

Static Silence(params): Object

A silence interval.

Parameters

NameTypeDescription
paramsobject-
params.durationnumberHow long to play silence, in seconds.

Returns

Object

Example

Voice.Playlist.Silence({
duration: 2,
});

TTS

Static TTS(params): Object

A TTS media.

Parameters

NameTypeDescription
paramsobject-
params.gender?'female' | 'male'Gender of the voice. Defaults to female.
params.language?stringLanguage of the text in ISO 639-1 (language name) + ISO 3166 (country code). Defaults to en-US.
Supported languages can be found here.
params.textstringText to play. SSML may be entered as a string wrapped in <speak> tags.
See our supported voices and languages documentation for usage and supported tags.
params.voice?stringVoice to use (takes precedence on gender).
Supported voices can be found here.

Returns

Object

Example

Voice.Playlist.TTS({
text: "Welcome to SignalWire!",
gender: "male",
language: "en-US",
});
SSML Example
Voice.Playlist.TTS({
text: `<speak>
Here are <say-as interpret-as="characters">SSML</say-as> samples.
I can pause <break time="3s"/>.
I can speak in cardinals. Your number is <say-as interpret-as="cardinal">10</say-as>.
Or I can speak in ordinals. You are <say-as interpret-as="ordinal">10</say-as> in line.
Or I can even speak in digits. The digits for ten are <say-as interpret-as="characters">10</say-as>.
I can also substitute phrases, like the <sub alias="World Wide Web Consortium">W3C</sub>.
Finally, I can speak a paragraph with two sentences.
<p><s>This is sentence one.</s><s>This is sentence two.</s></p>
</speak>
`,
voice: "polly.Joey-Neural",
});