JavaScript

Overview

Use the JavaScript/Emscripten bindings for browser-based score following, real-time processing, and offline descriptor analysis.

Loading Releases

Installation

Load the generated OpenScofo JavaScript/WASM module in your web project. See the descriptor test page for a working browser example.

Minimal Example

OpenScofo().then((mod) => {
    const scofo = new mod.OpenScofo(48000, 2048, 512);
    scofo.load_score(scoreText);
});

Reference Table

API

API	Purpose
`new mod.OpenScofo(sampleRate, blockSize, hopSize)`	create an engine
`load_score(scoreText)`	load score text
`process_block(audioBuffer)`	process one audio frame
`set_db_threshold(value)`	set silence threshold
`set_tuning(a4)`	set A4 tuning
`set_current_event(index)`	force score event
`load_onnx_model(path)`	load ONNX model
`get_live_bpm()`	return estimated BPM
`get_event_index()`	return current event index
`get_states()`	return Markov states
`get_audio_description()`	return descriptors

Types

Type	Use
`VectorDouble`	numeric buffers passed to the engine
`Description`	descriptor values for a block
`MarkovState`	score-following state

Score Actions

Use the JavaScript API to inspect score action data after processing blocks. Host behavior is application-defined; see Platform Integrations.

Descriptors

Description exposes values such as mfcc, logmelspectrum, chroma, onset, silence, loudness, flux, centroid, flatness, zcr, pitch, pitch_confidence, db, and rms.

Complete Example

OpenScofo().then((mod) => {
    const scofo = new mod.OpenScofo(44100, 1024, 512);
    scofo.load_score(scoreText);

    const buffer = new mod.VectorDouble();
    // Fill buffer with audio samples.

    scofo.process_block(buffer);

    const bpm = scofo.get_live_bpm();
    const event = scofo.get_event_index();
    const desc = scofo.get_audio_description();
});

Remarks

Errors from the internal logger are forwarded to JavaScript: error and critical become exceptions; info and debug print to the console. ONNX loading requires correct file access in the Emscripten environment.