watson-stt-websocket.js

    async authorize() {
        const { dispatch } = this.props;
        if (!this.stream) {
            try {
                this.stream = await navigator.mediaDevices.getUserMedia({ audio:true, video:false });
            } catch(ex) {
                // TODO: add detailed possible explanations for the error returned
                // if no mic plugged in
                // if mic in use by another application
                return dispatch(errorListen(`Failed to get permission to use your microphone. Error returned was: "${ex.message}"`));
            }
            this.recorder = new MediaRecorder(this.stream);
            this.recorder.addEventListener('stop', this.handleRecordingStop, false);
            this.recorder.addEventListener('dataavailable', this.handleRecordingData, false);
        }
        console.log('ok authorized');
        this.start();
    }
    startRecording() {
        console.log('will start watson who will start recording');
        this.chunks = [];
        this.startSTT();
    }
    stopRecording() {
        console.log('will now stop');
        this.recorder.stop();
    }
    is_stt_listening = false
    handleRecordingData = e => {
        // console.log('data available, e:', e);
        const chunk = e.data;
        this.chunks.push(chunk);
        this.sendChunks();
    }
    handleRecordingStop = e => {
        console.log('stopped, e:', e);
        const { chunks } = this;
        this.chunks = null;
        console.log('chunks:', chunks);
    }
    ///// watson stuff
    websocket = null
    content_type = 'audio/ogg'
    sendChunks = () => {
        if (this.is_stt_listening && this.chunks.length) {
            const chunks = this.chunks;
            const blob = new Blob([chunks], { type:this.content_type });
            if (blob.size >= 100) {
                // if not 100 i get this error in onmessage:
                // watson websocket got message, e: message { target: WebSocket, isTrusted: true, data: "{ "error": "Stream was 13 bytes but needs to be at least 100 bytes." }", origin: "wss://stream.watsonplatform.net", lastEventId: "", ports: Object, currentTarget: WebSocket, eventPhase: 2, bubbles: false, cancelable: false, defaultPrevented: false }
                this.chunks = []; // create a new array for chunks, as i sent the current ones
                console.log('blob:', blob.size, blob);
                console.log('will now send blob to watson');
                this.is_stt_listening = false;
                this.websocket.send(blob);
                console.log('sending stop message to watson');
                this.websocket.send(JSON.stringify({ 'action':'stop' }));
            }
        }
    }
    startSTT = async () => {
        this.is_stt_listening = false;
        console.log('will now start watson')
        const token = await getToken();

        this.websocket = new WebSocket(`wss://stream.watsonplatform.net/speech-to-text/api/v1/recognize?watson-token=${token}`);
        this.websocket.onopen = this.handleSTTOpen;
        this.websocket.onclose = this.handleSTTClose;
        this.websocket.onmessage = this.handleSTTMessage;
        this.websocket.onerror = this.handleSTTError;

        console.log('started watson');

        this.recorder.start(1000);

        console.log('started recording');
    }
    handleSTTOpen = e => {
        console.log('watson websocket opened, e:', e);
        // watson websocket opened, e: open { target: WebSocket, isTrusted: true, currentTarget: WebSocket, eventPhase: 2, bubbles: false, cancelable: false, defaultPrevented: false, composed: false, timeStamp: 2447.905853517878, cancelBubble: false, originalTarget: WebSocket }
        this.websocket.send(JSON.stringify({
            action: 'start',
            'content-type': this.content_type
        }));
    }
    handleSTTClose = e => {
        console.log('watson websocket closed, e:', e);
        // watson websocket closed, e: close { target: WebSocket, isTrusted: true, wasClean: true, code: 1011, reason: "see the previous message for the error details.", currentTarget: WebSocket, eventPhase: 2, bubbles: false, cancelable: false, defaultPrevented: false, composed: false }
        this.websocket = null;
    }
    handleSTTMessage = e => {
        console.log('watson websocket got message, e:', e);
        const { dispatch } = this.props;
        const data = JSON.parse(e.data);
        if (data.error) {
            this.stop();
            dispatch(errorListen(`Server failed during speech to text process. Error returned was: "${data.error}"`));
        } else if (data.state && data.state === 'listening') {
            this.is_stt_listening = true;
            this.sendChunks();
        }
        // watson websocket got message, e: message { target: WebSocket, isTrusted: true, data: "{"state": "listening" }", origin: "wss://stream.watsonplatform.net", lastEventId: "", ports: Object, currentTarget: WebSocket, eventPhase: 2, bubbles: false, cancelable: false, defaultPrevented: false }
        // watson websocket got message, e: message { target: WebSocket, isTrusted: true, data: "{"error": "Session timed out." }", origin: "wss://stream.watsonplatform.net", lastEventId: "", ports: Object, currentTarget: WebSocket, eventPhase: 2, bubbles: false, cancelable: false, defaultPrevented: false }
    }
    handleSTTError = e => {
        console.warn('watson websocket got error, e:', e);
    }
    stopSTT = () => {
        console.log('will now stop watson');
        this.websocket.close();
        console.log('stopped watson');
    }