Class TwilioMediaStreamParser<P>

constructor

• new TwilioMediaStreamParser<P>(options?): TwilioMediaStreamParser<P>

• Selects documented carrier messages explicitly.

  Type Parameters

  • P extends "legacy" | "carrier" = "legacy"

  Parameters

  • options: {
        protocol?: P;
    } = {}

    • Optional protocol?: P

  Returns TwilioMediaStreamParser<P>

parseIncoming

• parseIncoming(data): null | MediaStreamIncoming

• Parse a raw WebSocket frame from Twilio's media stream.

  Supported Twilio event types:

  • start -- stream established, includes callSid and media format metadata.
  • media -- audio chunk (inbound track only; outbound echoes are discarded to prevent feedback loops).
  • dtmf -- DTMF keypress detected on the audio stream.
  • stop -- stream ended (call hangup or stream disconnect).
  • mark -- named synchronisation marker confirming playback reached a point.

  Messages with missing event or streamSid fields, malformed JSON, or unrecognised event types are silently dropped (return null).

  In the carrier profile (parseCarrierMedia) a start must declare PCMU at 8 kHz mono, the numeric strings sequenceNumber, media.chunk and media.timestamp are read as integers, and a malformed payload is dropped; an unsupported start format, an error event or an oversized frame throws.

  Parameters

  • data: string | Buffer<ArrayBufferLike>

    Raw WebSocket frame payload (always a JSON string from Twilio).

  Returns null | MediaStreamIncoming

  Normalised MediaStreamIncoming event, or null for outbound audio tracks, unknown event types, or malformed messages.

formatOutgoing

• formatOutgoing(audio, streamSid): string

• Formats media for either the retained JSON protocol or the documented carrier profile.

  Parameters

  • audio: Buffer<ArrayBufferLike>
  • streamSid: string

  Returns string

formatConnected

• formatConnected(_streamSid): P extends "carrier"
      ? null
      : string

• Carrier Twilio sends connected to us; only legacy clients receive the old acknowledgement.

  Parameters

  • _streamSid: string

  Returns P extends "carrier"
      ? null
      : string

formatClear

• formatClear(streamSid): null | string

• Clears carrier output; compatibility clients have no mapped clear operation.

  Parameters

  • streamSid: string

  Returns null | string

formatMark

• formatMark(streamSid, name): null | string

• Marks carrier playback; compatibility clients have no mapped checkpoint operation.

  Parameters

  • streamSid: string
  • name: string

  Returns null | string

Readonly protocol