Vosklet/API.md

API reference

JS' window object

Function/Object	Description
Promise<Module> loadVosklet()	Load Vosklet module interface

Shared interface

Function/Object	Description
delete()	Delete this object, see why this is neccessary.

Module object

Function/Object	Description
Promise<Model> createModel(path: string, url: string, id: string) Promise<SpkModel> createSpkModel(path: string, url: string, id: string)	Create a Model or SpkModel, model files must be directly under the model root, and compressed model must be in .tgz format. If: - path contains valid model files and id is the same, there will not be a fetch from url. - path doesn't contain valid model files, or if it contains valid model files but id is different, there will be a fetch from url, and the model is stored with id. Models are thread-safe, reuse them as much as possible!
Promise<Recognizer> createRecognizer(model: Model, sampleRate: float) Promise<Recognizer> createRecognizerWithSpkModel(model: Model, spkModel: spkModel, sampleRate: float) Promise<Recognizer> createRecognizerWithGrm(model: Model, grammar: string, sampleRate: float)	Create a Recognizer, it will use model's thread if it's the first user of model, else it will use a new thread.
setLogLevel(lvl: int)	Set Vosk's log level (default: 0: Info) -2: Error -1: Warning 1: Verbose 2: More verbose 3: Debug
Promise<AudioWorkletNode> createTransferer(ctx: AudioContext, bufferSize: int)	Create a node that transfer its inputs back to the main thread with custom buffer size (must be multiple of 128). Its port's onmessage handler can be set to get audio data. Has 1 input with 1 channel and 0 output. The the higher the size, the lesser the audio breaks up, but the higher the latency. Recomended value is around 128 * 150.
cleanUp()	A convenience function that call delete() on all objects and revoke all URLs. Put this at the end of your code!
epMode	Endpointer modes (enum)

Recognizer object

Function/Object	Description
acceptWaveform(audioData: Float32Array)	Recognize audio data in a Float32Array with elements from -1.0 to 1.0.
setPartialWords(partialWords: bool)	See Vosk's description (default: false)
setWords(words: bool)	See Vosk's description (default: false)
setNLSML(nlsml: bool)	See Vosk's description (default: false)
setMaxAlternatives(alts: int)	See Vosk's description (default: false)
setGrm(grm: string)	See Vosk's description (default: none)
setSpkModel(mdl: SpkModel)	See Vosk's description (default: none)
setEndpointerMode(mode: epMode)	See Vosk's description (default: ANSWER_DEFAULT)
setEndpointerDelays(tStartMax: float, tEnd: float, tMax: float)	See Vosk's description

Event	Description
partialResult	There is a partial recognition result, check the event's detail property
result	There is a full recognition result, check the event's detail property

User agent notes

SharedArrayBuffer

Vosklet require SharedArrayBuffer to share threads' data, so these response headers must be set:

• Cross-Origin-Embedder-Policy ---> require-corp
• Cross-Origin-Opener-Policy ---> same-origin

If you can't set them, you may use a hacky workaround at src/addCOI.js.

Compilation

Changing any option to non-default values requires recompilation

git clone --depth=1 https://github.com/msqr1/Vosklet &&
cd Vosklet/src &&
[Options] make

Option	Description	Default value
MAX_MEMORY	Set max memory, valid suffixes: kb, mb, gb, tb or none (bytes)	375mb, 300mb as recommended plus 75mb typical uncompressed model size (loaded to memory)
MAX_THREADS	Set the max number of threads (>=1), this should be equal to the number of model or speaker model that is used in the program	1 (1 recognizer, 1 model, 0 speaker model)
COMPILE_JOBS	Set the number of jobs (threads) when building	$(nproc)
EMSDK	Set EMSDK's path (will install EMSDK in root folder if unset)	../emsdk