mime-chat/tests/audio.js
2021-03-02 08:42:30 -06:00

149 lines
3.4 KiB
JavaScript

const speech = require('@google-cloud/speech');
const portAudio = require('naudiodon');
// const rs = fs.createReadStream('rawAudio.wav');
// Creates a client
const client = new speech.SpeechClient();
const encoding = 'LINEAR16';
const sampleRateHertz = 16000;
const languageCode = 'en-US';
const config = {
encoding: encoding,
sampleRateHertz: sampleRateHertz,
languageCode: languageCode,
};
/**
* Note that transcription is limited to 60 seconds audio.
* Use a GCS file for audio longer than 1 minute.
*/
async function transcribeSpeech (audio) {
const request = {
config: config,
audio: audio,
};
// Detects speech in the audio file. This creates a recognition job that you
// can wait for now, or get its result later.
const [operation] = await client.longRunningRecognize(request);
// Get a Promise representation of the final result of the job
const [response] = await operation.promise();
const transcription = response.results
.map(result => result.alternatives[0].transcript)
.join('\n');
console.log(`Transcription: ${transcription}`);
}
const audioInput = [];
// Create an instance of AudioIO with inOptions (defaults are as below), which will return a ReadableStream
const ia = new portAudio.AudioIO({
inOptions: {
channelCount: 1,
sampleFormat: 16,
sampleRate: 16000,
deviceId: -1,
closeOnError: false,
},
});
ia.setEncoding('base64');
ia.start();
ia.on('data', (chunk) => {
const buf = Buffer.from(chunk, 'base64');
audioInput.push(buf);
});
const ao = new portAudio.AudioIO({
outOptions: {
sampleFormat: 16,
channelCount: 1,
sampleRate: 16000,
deviceId: -1,
closeOnError: false,
}
});
ao.start();
async function processAudio() {
const buf = Buffer.concat(audioInput);
play(audioInput);
while(audioInput.length) { audioInput.pop() }
transcribeSpeech({
content: buf
});
}
function play(input) {
let i = 0;
// format buffers into half their size to account for writable highwaterMark.
const audio = bufSplit(input);
// call this fuction after last audio chunk has been written.
const callback = () => {
// TODO: clear portAudio writable buffer on write end.
}
write();
// iterate through audio array and write buffers to portAudio writable.
function write() {
let chunk;
let ok = true;
do {
chunk = audio[i];
if (i === audio.length - 1) {
// write last chunk.
ao.write(chunk, null, callback);
} else {
// check for backpreassure.
ok = ao.write(chunk, null);
}
i++;
} while (i < audio.length && ok);
if (i < audio.length) {
// Had to stop early!
// Write some more once it drains.
ao.once('drain', write);
}
}
}
// utility function used by play func
function bufSplit(input){
const result = [];
input.forEach((b) => {
// split buffer into two.
result.push(b.slice(0, b.length / 2), b.slice(b.length / 2, b.length));
});
return result;
}
setTimeout(async () => {
ia.pause();
processAudio();
}, 3000);
setTimeout(() => {
ia.resume();
}, 5000)
setTimeout(async () => {
ia.pause();
processAudio();
}, 8000);
setTimeout(() => {
ia.resume();
}, 10000)
setTimeout(async () => {
ia.pause();
processAudio();
}, 15000);