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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​

Creates a playlist for playing, in sequence, a TTS message, 1 second of silence, and 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

Examples​

Voice.Playlist.TTS({
  text: "Welcome to SignalWire!",
  gender: "male",
  language: "en-US",
});

Using SSML:

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",
});