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

Name	Type	Description
params?	Object	-
params.volume?	number	Default 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

Name	Type	Description
params	Object	A 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

Name	Type	Description
params	object	-
params.url	string	URL 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

Name	Type	Description
params	object	-
params.duration?	number	How long to play ringtone, in seconds.
params.name	RingtoneName	Name of the ringtone to play.

Returns

Object

Example

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

---

Silence

▸ Static Silence(params): Object

A silence interval.

Parameters

Name	Type	Description
params	object	-
params.duration	number	How long to play silence, in seconds.

Returns

Object

Example

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

---

TTS

▸ Static TTS(params): Object

A TTS media.

Parameters

Name	Type	Description
params	object	-
params.gender?	'female' | 'male'	Gender of the voice. Defaults to female.
params.language?	string	Language of the text in ISO 639-1 (language name) + ISO 3166 (country code). Defaults to en-US. Supported languages can be found here.
params.text	string	Text 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?	string	Voice 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",
});