Cheetah Speech-to-Text
Node.js API

API Reference for the Node.js Cheetah SDK (npm)

Cheetah

class Cheetah { }

Class for the Cheetah Speech-to-Text engine.

Cheetah can be initialized using the class constructor(). Resources should be cleaned when you are done using the release() method.

Cheetah.constructor()

Cheetah.constructor(
  accessKey: string,
  options: CheetahOptions = {}
)

Cheetah constructor.

Parameters

• accessKey string : AccessKey obtained from Picovoice Console.
• options CheetahOptions: Optional configuration arguments:
  • modelPath string : Path to the file containing model parameters (.pv).
  • libraryPath string : Path to the Cheetah dynamic library (.node).
  • endpointDuration number : Duration of endpoint in seconds. A speech endpoint is detected when there is a chunk of audio (with a duration specified herein) after an utterance without any speech in it. Set duration to 0 to disable this. Default is 1 second.
  • enableAutomaticPunctuation boolean : Whether to enable automatic punctuation. Default is false.

Returns

• Cheetah: An instance of Cheetah platform.

Cheetah.release()

Cheetah.release()

Releases resources acquired by Cheetah.

Cheetah.frameLength

Cheetah.frameLength

Getter for number of audio samples per frame.

Returns

• number: Number of audio samples per frame.

Cheetah.sampleRate

Cheetah.sampleRate()

Getter for audio sample rate accepted by Cheetah.

Returns

• number: Audio sample rate accepted by Cheetah.

Cheetah.version

Cheetah.version()

Getter for version.

Returns

• string: Current Cheetah version.

Cheetah.process()

Cheetah.process(pcm)

Processes a frame of the incoming audio stream with the speech-to-text engine. The number of samples per frame can be attained by calling .frameLength. The incoming audio needs to have a sample rate equal to .sampleRate and be 16-bit linearly-encoded. Cheetah operates on single-channel audio.

Parameters

• pcm Array<number> : A frame of audio samples.

Returns

• [string, boolean]: Transcription of any newly-transcribed speech (if none is available then an empty string is returned) and a flag indicating if an endpoint has been detected.

Cheetah.flush()

Cheetah.flush()

Marks the end of the audio stream, flushes internal state of the object, and returns any remaining transcribed text.

Returns

• string: Any remaining transcribed text. If none is available then an empty string is returned.

Errors

Exceptions thrown if an error occurs within Cheetah Speech-to-Text engine.

Exceptions:

class PvStatusOutOfMemoryError        extends Error {}
class PvStatusIoError                 extends Error {}
class PvStatusInvalidArgumentError    extends Error {}
class PvStatusStopIterationError      extends Error {}
class PvStatusKeyError                extends Error {}
class PvStatusInvalidStateError       extends Error {}
class PvStatusRuntimeError            extends Error {}
class PvStatusActivationError         extends Error {}
class PvStatusActivationLimitReached  extends Error {}
class PvStatusActivationThrottled     extends Error {}
class PvStatusActivationRefused       extends Error {}