speech-api/SpeechRecognition-concurrentMediaStreamTrack-manual.https.html

<!DOCTYPE html>
<html lang="en">
<title>SpeechRecognition Concurrent MediaStreamTracks</title>

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
async function getAudioTrackFromFile(filePath) {
    const audioContext = new AudioContext();
    const response = await fetch(filePath);
    const arrayBuffer = await response.arrayBuffer();
    const audioBuffer = await audioContext.decodeAudioData(arrayBuffer);
    const source = audioContext.createBufferSource();
    source.buffer = audioBuffer;

    const destination = audioContext.createMediaStreamDestination();
    source.connect(destination);
    source.start();

    return destination.stream.getAudioTracks()[0];
}

promise_test(async (t) => {
    const lang = "en-US";
    window.SpeechRecognition = window.SpeechRecognition || window.webkitSpeechRecognition;

    // Create two SpeechRecognition instances
    const speechRecognition1 = new SpeechRecognition();
    speechRecognition1.processLocally = false;
    speechRecognition1.lang = lang;
    const speechRecognition2 = new SpeechRecognition();
    speechRecognition2.processLocally = false;
    speechRecognition2.lang = lang;

    const audioTrack1 = await getAudioTrackFromFile("/media/speech.wav");
    const audioTrack2 = await getAudioTrackFromFile("/media/speech.wav");

    assert_true(audioTrack1 instanceof MediaStreamTrack, "Audio track 1 should be a valid MediaStreamTrack");
    assert_true(audioTrack2 instanceof MediaStreamTrack, "Audio track 2 should be a valid MediaStreamTrack");

    const recognitionPromise1 = new Promise((resolve) => {
        speechRecognition1.onresult = (event) => {
            const transcript = event.results[0][0].transcript;
            resolve(transcript);
        };
    });

    const recognitionPromise2 = new Promise((resolve) => {
        speechRecognition2.onresult = (event) => {
            const transcript = event.results[0][0].transcript;
            resolve(transcript);
        };
    });

    speechRecognition1.start(audioTrack1);
    speechRecognition2.start(audioTrack2);

    const transcript1 = await recognitionPromise1;
    const transcript2 = await recognitionPromise2;

    assert_equals(transcript1.toLowerCase(), "this is a sentence in a single segment", "Speech recognition 1 should correctly recognize speech");
    assert_equals(transcript2.toLowerCase(), "this is a sentence in a single segment", "Speech recognition 2 should correctly recognize speech");
}, "Two SpeechRecognition instances should simultaneously recognize speech from audio files.");
</script>
</html>