pdesantis/README.md

## README.md

      
    Raw
  

              README.md
            
          
    To use:

Load in Electron Fiddle
Run
Open the Developer console and observe the log messages


## index.html
<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Hello World!</title>
  </head>
  <body>
    <h1>Hello World!</h1>
    <!-- All of the Node.js APIs are available in this renderer process. -->
    We are using Node.js <script>document.write(process.versions.node)</script>,
    Chromium <script>document.write(process.versions.chrome)</script>,
    and Electron <script>document.write(process.versions.electron)</script>.

    <script>
      // You can also require other files to run in this process
      require('./renderer.js')
    </script>
  </body>
</html>

## main.js
// Modules to control application life and create native browser window
const {app, BrowserWindow} = require('electron')

// Keep a global reference of the window object, if you don't, the window will
// be closed automatically when the JavaScript object is garbage collected.
let mainWindow

function createWindow () {
  // Create the browser window.
  mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
      nodeIntegration: true
    }
  })

  // and load the index.html of the app.
  mainWindow.loadFile('index.html')

  // Open the DevTools.
  // mainWindow.webContents.openDevTools()

  // Emitted when the window is closed.
  mainWindow.on('closed', function () {
    // Dereference the window object, usually you would store windows
    // in an array if your app supports multi windows, this is the time
    // when you should delete the corresponding element.
    mainWindow = null
  })
}

// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
// Some APIs can only be used after this event occurs.
app.on('ready', createWindow)

// Quit when all windows are closed.
app.on('window-all-closed', function () {
  // On OS X it is common for applications and their menu bar
  // to stay active until the user quits explicitly with Cmd + Q
  if (process.platform !== 'darwin') {
    app.quit()
  }
})

app.on('activate', function () {
  // On OS X it's common to re-create a window in the app when the
  // dock icon is clicked and there are no other windows open.
  if (mainWindow === null) {
    createWindow()
  }
})

// In this file you can include the rest of your app's specific main process
// code. You can also put them in separate files and require them here.

## renderer.js
// This file is required by the index.html file and will
// be executed in the renderer process for that window.
// All of the Node.js APIs are available in this process.

const workletString = `
class PcmAudioWorkletProcessorWorklet extends AudioWorkletProcessor {
    process(inputs, outputs, parameters) {
        if (inputs.length === 0) {
            throw new Error('PcmAudioWorkletProcessorWorklet has no inputs');
        }
        const input = inputs[0];

        if (input.length === 0) {
            // This input has no channels, so stop processing
            return false;
        }

        const firstChannelSamples = input[0];

        // Send the input, and transfer ownership of the buffers
        this.port.postMessage(firstChannelSamples, [firstChannelSamples.buffer]);

        return true;
    }
}

registerProcessor('pcm-audio-worklet-processor', PcmAudioWorkletProcessorWorklet);
`;

async function listAudioInputs() {
    const devices = await navigator.mediaDevices.enumerateDevices();
    return devices.filter((device) => device.kind === 'audioinput');
}

async function getDefaultInput(fallbackToFirstInput = true) {
    const audioInputs = await listAudioInputs();
    const defaultDevice = audioInputs.find((device) => device.deviceId === 'default');
    if (defaultDevice) {
        return defaultDevice;
    }
    return fallbackToFirstInput && audioInputs.length > 0 ? audioInputs[0] : undefined;
}

async function getAudioStream(device) {
    try {
        const constraints = {
            audio: {
                deviceId: device.deviceId,
            },
        };
        return navigator.mediaDevices.getUserMedia(constraints);
    } catch (e) {
        trackError(e, 'get-microphone-stream');
        throw e;
    }
}

async function createRecordingPipeline(device) {
    const stream = await getAudioStream(device);
    const audioTracks = stream.getAudioTracks();
    if (audioTracks.length === 0) {
        throw new Error('Microphone stream has no audio tracks');
    }
    const sampleRate = audioTracks[0].getSettings().sampleRate;
    if (sampleRate === undefined) {
        throw new Error('Audio input has undefined sample rate');
    }

    const context = new AudioContext({ sampleRate, latencyHint: 'interactive' });
    if (context.sampleRate !== sampleRate) {
        console.warn(
            `AudioContext.sampleRate (${
                context.sampleRate
            }) differs from requested sampleRate (${sampleRate})`,
        );
    }
    console.log(`requested sample rate: ${sampleRate}`);
    console.log(`audio context sample rate: ${context.sampleRate}`);

    const sourceNode = context.createMediaStreamSource(stream);
    const blob = new Blob([workletString], { type: 'text/javascript' });
    const workletUrl = URL.createObjectURL(blob);

    await context.audioWorklet.addModule(workletUrl);
    const workletNode = new AudioWorkletNode(context, 'pcm-audio-worklet-processor');

    sourceNode.connect(workletNode);
    const destinationNode = context.createMediaStreamDestination();
    workletNode.connect(destinationNode);

    let messagesReceived = 0;
    let lastLogAt = performance.now();
    workletNode.port.onmessage = (event) => {
        const data = event.data;

        // messagesReceived++;
        messagesReceived += data.length;

        const now = performance.now();
        if (now > lastLogAt + 1000) {
            // const diff = now - lastMessageAt;
            // const rate = (1000 / diff).toFixed(0);
            // const rate = 1000 / diff;
            // console.log(`${rate} sample rate`);

            console.log(`${messagesReceived} sample rate`);
            console.log(data.length);

            lastLogAt = now;
            messagesReceived = 0;
        }
        // lastMessageAt = now;
    };
}

async function goGoGo() {
    const device = await getDefaultInput();
    await createRecordingPipeline(device);
}

goGoGo();
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title>Hello World!</title>
	</head>
	<body>
	<h1>Hello World!</h1>
	<!-- All of the Node.js APIs are available in this renderer process. -->
	We are using Node.js <script>document.write(process.versions.node)</script>,
	Chromium <script>document.write(process.versions.chrome)</script>,
	and Electron <script>document.write(process.versions.electron)</script>.

	<script>
	// You can also require other files to run in this process
	require('./renderer.js')
	</script>
	</body>
	</html>
	// Modules to control application life and create native browser window
	const {app, BrowserWindow} = require('electron')

	// Keep a global reference of the window object, if you don't, the window will
	// be closed automatically when the JavaScript object is garbage collected.
	let mainWindow

	function createWindow () {
	// Create the browser window.
	mainWindow = new BrowserWindow({
	width: 800,
	height: 600,
	webPreferences: {
	nodeIntegration: true
	}
	})

	// and load the index.html of the app.
	mainWindow.loadFile('index.html')

	// Open the DevTools.
	// mainWindow.webContents.openDevTools()

	// Emitted when the window is closed.
	mainWindow.on('closed', function () {
	// Dereference the window object, usually you would store windows
	// in an array if your app supports multi windows, this is the time
	// when you should delete the corresponding element.
	mainWindow = null
	})
	}

	// This method will be called when Electron has finished
	// initialization and is ready to create browser windows.
	// Some APIs can only be used after this event occurs.
	app.on('ready', createWindow)

	// Quit when all windows are closed.
	app.on('window-all-closed', function () {
	// On OS X it is common for applications and their menu bar
	// to stay active until the user quits explicitly with Cmd + Q
	if (process.platform !== 'darwin') {
	app.quit()
	}
	})

	app.on('activate', function () {
	// On OS X it's common to re-create a window in the app when the
	// dock icon is clicked and there are no other windows open.
	if (mainWindow === null) {
	createWindow()
	}
	})

	// In this file you can include the rest of your app's specific main process
	// code. You can also put them in separate files and require them here.
	// This file is required by the index.html file and will
	// be executed in the renderer process for that window.
	// All of the Node.js APIs are available in this process.

	const workletString = `
	class PcmAudioWorkletProcessorWorklet extends AudioWorkletProcessor {
	process(inputs, outputs, parameters) {
	if (inputs.length === 0) {
	throw new Error('PcmAudioWorkletProcessorWorklet has no inputs');
	}
	const input = inputs[0];

	if (input.length === 0) {
	// This input has no channels, so stop processing
	return false;
	}

	const firstChannelSamples = input[0];

	// Send the input, and transfer ownership of the buffers
	this.port.postMessage(firstChannelSamples, [firstChannelSamples.buffer]);

	return true;
	}
	}

	registerProcessor('pcm-audio-worklet-processor', PcmAudioWorkletProcessorWorklet);
	`;

	async function listAudioInputs() {
	const devices = await navigator.mediaDevices.enumerateDevices();
	return devices.filter((device) => device.kind === 'audioinput');
	}

	async function getDefaultInput(fallbackToFirstInput = true) {
	const audioInputs = await listAudioInputs();
	const defaultDevice = audioInputs.find((device) => device.deviceId === 'default');
	if (defaultDevice) {
	return defaultDevice;
	}
	return fallbackToFirstInput && audioInputs.length > 0 ? audioInputs[0] : undefined;
	}

	async function getAudioStream(device) {
	try {
	const constraints = {
	audio: {
	deviceId: device.deviceId,
	},
	};
	return navigator.mediaDevices.getUserMedia(constraints);
	} catch (e) {
	trackError(e, 'get-microphone-stream');
	throw e;
	}
	}

	async function createRecordingPipeline(device) {
	const stream = await getAudioStream(device);
	const audioTracks = stream.getAudioTracks();
	if (audioTracks.length === 0) {
	throw new Error('Microphone stream has no audio tracks');
	}
	const sampleRate = audioTracks[0].getSettings().sampleRate;
	if (sampleRate === undefined) {
	throw new Error('Audio input has undefined sample rate');
	}

	const context = new AudioContext({ sampleRate, latencyHint: 'interactive' });
	if (context.sampleRate !== sampleRate) {
	console.warn(
	`AudioContext.sampleRate (${
	context.sampleRate
	}) differs from requested sampleRate (${sampleRate})`,
	);
	}
	console.log(`requested sample rate: ${sampleRate}`);
	console.log(`audio context sample rate: ${context.sampleRate}`);

	const sourceNode = context.createMediaStreamSource(stream);
	const blob = new Blob([workletString], { type: 'text/javascript' });
	const workletUrl = URL.createObjectURL(blob);

	await context.audioWorklet.addModule(workletUrl);
	const workletNode = new AudioWorkletNode(context, 'pcm-audio-worklet-processor');

	sourceNode.connect(workletNode);
	const destinationNode = context.createMediaStreamDestination();
	workletNode.connect(destinationNode);

	let messagesReceived = 0;
	let lastLogAt = performance.now();
	workletNode.port.onmessage = (event) => {
	const data = event.data;

	// messagesReceived++;
	messagesReceived += data.length;

	const now = performance.now();
	if (now > lastLogAt + 1000) {
	// const diff = now - lastMessageAt;
	// const rate = (1000 / diff).toFixed(0);
	// const rate = 1000 / diff;
	// console.log(`${rate} sample rate`);

	console.log(`${messagesReceived} sample rate`);
	console.log(data.length);

	lastLogAt = now;
	messagesReceived = 0;
	}
	// lastMessageAt = now;
	};
	}

	async function goGoGo() {
	const device = await getDefaultInput();
	await createRecordingPipeline(device);
	}

	goGoGo();