Cheetah Speech-to-Text
React Native API

API Reference for the React Native Cheetah SDK (npm)

Cheetah

class Cheetah { }

Class for the Cheetah Speech-to-Text engine.

Cheetah.create()

public static async create(
  accessKey: string,
  modelPath: string,
  options: CheetahOptions = {}
): Promise<Cheetah>

Cheetah constructor.

Parameters

• accessKey string : AccessKey obtained from Picovoice Console.
• modelPath string : Path to the file containing model parameters (.pv). Can be relative to the assets/resource folder or an absolute path to the file on device.
• options CheetahOptions: Optional configuration arguments:
  • device string : String representation of the device (e.g., CPU or GPU) to use for inference. If set to best, the most suitable device is selected automatically. If set to gpu, the engine uses the first available GPU device. To select a specific GPU device, set this argument to gpu:${GPU_INDEX}, where ${GPU_INDEX} is the index of the target GPU. If set to cpu, the engine will run on the CPU with the default number of threads. To specify the number of threads, set this argument to cpu:${NUM_THREADS}, where ${NUM_THREADS} is the desired number of threads.
  • 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.

Returns

• Promise<Cheetah>: An instance of Cheetah platform.

Cheetah.delete()

async delete()

Releases resources acquired by Cheetah.

Cheetah.frameLength

get frameLength()

Getter for number of audio samples per frame.

Returns

• number: Number of audio samples per frame.

Cheetah.sampleRate

get sampleRate()

Getter for audio sample rate accepted by Cheetah.

Returns

• number: Audio sample rate accepted by Cheetah.

Cheetah.version

get version()

Getter for version.

Returns

• string: Current Cheetah version.

Cheetah.process()

async process(frame: number[]): Promise<CheetahTranscript>

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

• frame number[] : A frame of audio samples.

Returns

• Promise<CheetahTranscript>: A CheetahTranscript object that contains 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()

async flush(): Promise<CheetahTrancript>

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

Returns

• Promise<CheetahTranscript>: Any remaining transcribed text in a CheetahTranscript object. If none is available then an empty string is returned.

Cheetah.getAvailableDevices()

public static async getAvailableDevices()

Gets all available devices that Cheetah can use for inference. Each entry in the list can be the device argument of the constructor.

Returns

• Promise<string[]>: Array of all available devices that Cheetah can use for inference.

CheetahError

class CheetahError extends Error { }

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

Exceptions:

class CheetahActivationError           extends CheetahError { }
class CheetahActivationLimitError      extends CheetahError { }
class CheetahActivationRefusedError    extends CheetahError { }
class CheetahActivationThrottledError  extends CheetahError { }
class CheetahIOError                   extends CheetahError { }
class CheetahInvalidArgumentError      extends CheetahError { }
class CheetahInvalidStateError         extends CheetahError { }
class CheetahKeyError                  extends CheetahError { }
class CheetahMemoryError               extends CheetahError { }
class CheetahRuntimeError              extends CheetahError { }
class CheetahStopIterationError        extends CheetahError { }

CheetahOptions

type CheetahOptions = {
  endpointDurationSec?: number
  enableAutomaticPunctuation?: boolean;
}

Cheetah options type.

• endpointDurationSec 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 to 0 to disable endpoint detection.
• enableAutomaticPunctuation boolean : Flag to enable automatic punctuation insertion.

CheetahTranscript

type CheetahTranscript = {
    transcript: string;
    isEndpoint: boolean;
}

Cheetah options type.

• transcript string : Any newly-transcribed speech. If none is available then an empty string is returned.
• isEndpoint boolean : Flag indicating if an endpoint has been detected.