@simplito/privmx-webendpoint/dist/webStreams/audio/ActiveSpeakerDetector.js

PrivMX Web Endpoint library

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.ActiveSpeakerDetector = exports.DEFAULTS = void 0;
exports.DEFAULTS = {
    rmsEmaAlpha: 0.2, // szybka reakcja na mowę
    noiseEmaAlpha: 0.02, // wolna adaptacja tła
    thresholdOffset: 6, // dB (jeśli RMS w dB)
    activityWindowMs: 400,
    holdMs: 200,
};
class ActiveSpeakerDetector {
    opts;
    speakers = new Map();
    activeSpeaker = null;
    constructor(opts) {
        this.opts = opts;
    }
    onFrame({ id, rms, timestamp }) {
        const state = this.getOrCreateState(id, rms);
        state.emaRms = this.opts.rmsEmaAlpha * rms + (1 - this.opts.rmsEmaAlpha) * state.emaRms;
        if (state.emaRms < state.noiseFloor + this.opts.thresholdOffset) {
            state.noiseFloor =
                this.opts.noiseEmaAlpha * state.emaRms +
                    (1 - this.opts.noiseEmaAlpha) * state.noiseFloor;
        }
        const adaptiveThreshold = state.noiseFloor + this.opts.thresholdOffset;
        if (state.emaRms >= adaptiveThreshold) {
            state.lastAboveThresholdTs = timestamp;
            state.activeSince = timestamp;
            state.active = true;
        }
        else {
            state.active = false;
            state.activeSince = 0;
        }
        return this.selectActiveSpeakers(timestamp);
    }
    selectActiveSpeakers(now) {
        let bestId = null;
        let bestRms = -Infinity;
        for (const [id, state] of this.speakers.entries()) {
            state.active =
                now - state.lastAboveThresholdTs <= this.opts.activityWindowMs &&
                    now - state.activeSince < this.opts.holdMs;
        }
        return Array.from(this.speakers.values());
    }
    getOrCreateState(id, rms) {
        let state = this.speakers.get(id);
        if (!state) {
            state = {
                streamId: id,
                emaRms: rms,
                noiseFloor: rms,
                lastAboveThresholdTs: -Infinity,
                active: false,
                activeSince: 0,
            };
            this.speakers.set(id, state);
        }
        return state;
    }
}
exports.ActiveSpeakerDetector = ActiveSpeakerDetector;