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Is there a way to get Chrome to “forget” a device to test navigator.usb.requestDevice, navigator.serial.requestPort?

I'm hoping to migrate from using WebUSB to SerialAPI (which is explained nicely here).
Current Code:
try {
let device = await navigator.usb.requestDevice({
filters: [{
usbVendorId: RECEIVER_VENDOR_ID
}]
})
this.connect(device)
} catch (error) {
console.log(DEVICE_NAME + ': Permission Denied')
}
New Code:
try {
let device = await navigator.serial.requestPort({
filters: [{
usbVendorId: RECEIVER_VENDOR_ID
}]
})
this.connect(device)
} catch (error) {
console.log(DEVICE_NAME + ': Permission Denied')
}
The new code appears to work, but I think it's because the browser has already requested the device via the old code.
I've tried restarting Chrome as well as clearing all of the browsing history. Even closed the USB-claiming page and claimed the device with another app (during which it returns the DOMException: Unable to claim interface error), but Chrome doesn't seem to want to ask again. It just happily streams the data with the previous connection.
My hope was that using SerialAPI would be a way to avoid fighting over the USB with other processes, or at least losing to them.
Update
I had forgotten about:
Failed to execute 'requestPort' on 'Serial': "Must be handling a user gesture to show a permission request"
Does this mean that the user will need to use a button to connect to the device via SerialUSB? I think with WebUSB I was able to make the connect window automatically pop up.

For both APIs, as is noted in the update, a user gesture is required in order to call the requestDevice() or requestPort() method. It is not possible to automatically pop up this prompt. (If there is that's a bug so please let the Chrome team know so we can fix it.)
Permissions granted to a site through the WebUSB API and Web Serial API are currently tracked separately so permission to access a device through one will not automatically translate into the other.
There is not currently a way to programatically forget a device permission. That would require the navigator.permissions.revoke() method which has been abandoned. You can however manually revoke permission to access the device by clicking on the "lock" icon in the address bar while visiting the site or going to chrome://settings/content/usbDevices (for USB devices) and chrome://settings/content/serialPorts (for serial ports).

To get Chrome to "forget" the WebUSB device previously paired via navigator.usb.requestDevice API:
Open the page paired to the device you want to forget
Click on the icon in the address bar
Click x next to device. If nothing is listed, then there are no paired devices for this web page.

The new code was NOT working. It just appeared to be because Chrome was already paired with the port via the old code. There is no way the "new code" could have worked because, as noted in Kalido's comment, the SerialAPI (due to its power) requires a user gesture to connect.
The code I'm using to actually connect and get data is basically built up from a few pieces from the above links in the OP:
navigator.serial.addEventListener('connect', e => {
// Add |e.target| to the UI or automatically connect.
console.log("connected");
});
navigator.serial.addEventListener('disconnect', e => {
// Remove |e.target| from the UI. If the device was open the disconnection can
// also be observed as a stream error.
console.log("disconnected");
});
console.log(navigator.serial);
document.addEventListener('DOMContentLoaded', async () => {
const connectButton = document.querySelector('#connect') as HTMLInputElement;
if (connectButton) {
connectButton.addEventListener('click', async () => {
try {
// Request Keiser Receiver from the user.
const port = await navigator.serial.requestPort({
filters: [{ usbVendorId: 0x2341, usbProductId: not_required }]
});
try {
// Open and begin reading.
await port.open({ baudRate: 115200 });
} catch (e) {
console.log(e);
}
while (port.readable) {
const reader = port.readable.getReader();
try {
while (true) {
const { value, done } = await reader.read();
if (done) {
// Allow the serial port to be closed later.
reader.releaseLock();
break;
}
if (value) {
console.log(value);
}
}
} catch (error) {
// TODO: Handle non-fatal read error.
console.log(error);
}
}
} catch (e) {
console.log("Permission to access a device was denied implicitly or explicitly by the user.");
console.log(e);
console.log(port);
}
}
}
The device-specific Vendor and Product IDs would obviously change from device to device. In the above example I have inserted an Arduino vendor ID.
It doesn't answer the question of how to get Chrome to "forget", but I'm not sure if that's relevant when using SerialAPI because of the required gesture.
Hopefully someone with more experience will be able to post a more informative answer.

webrtc audio device disconnection and reconnection

I have a video call application based on WebRTC. It is working as expected. However when call is going on, if I disconnect and connect back audio device (mic + speaker), only speaker part is working. The mic part seems to be not working - the other side can't hear anymore.
Is there any way to inform WebRTC to take audio input again once audio device is connected back?

Is there any way to inform WebRTC to take audio input again once audio device is connected back?
Your question appears simple—the symmetry with speakers is alluring—but once we're dealing with users who have multiple cameras and microphones, it's not that simple: If your user disconnects their bluetooth headset they were using, should you wait for them to reconnect it, or immediately switch to their laptop microphone? If the latter, do you switch back if they reconnect it later? These are application decisions.
The APIs to handle these things are: primarily the ended and devicechange events, and the replaceTrack() method. You may also need the deviceId constraint, and the enumerateDevices() method to a handle multiple devices.
However, to keep things simple, let's take the assumptions in your question at face value to explore the APIs:
When the user unplugs their sole microphone (not their camera) mid-call, our job is to resume conversation with it when they reinsert it, without dropping video:
First, we listen to the ended event to learn when our local audio track drops.
When that happens, we listen for a devicechange event to detect re-insertion (of anything).
When that happens, we could check what changed using enumerateDevices(), or simply try getUserMedia again (microphone only this time).
If that succeeds, use await sender.replaceTrack(newAudioTrack) to send our new audio.
This might look like this:
let sender;
(async () => {
try {
const stream = await navigator.mediaDevices.getUserMedia({video: true, audio: true});
pc.addTrack(stream.getVideoTracks()[0], stream);
sender = pc.addTrack(stream.getAudioTracks()[0], stream);
sender.track.onended = () => navigator.mediaDevices.ondevicechange = tryAgain;
} catch (e) {
console.log(e);
}
})();
async function tryAgain() {
try {
const stream = await navigator.mediaDevices.getUserMedia({audio: true});
await sender.replaceTrack(stream.getAudioTracks()[0]);
navigator.mediaDevices.ondevicechange = null;
sender.track.onended = () => navigator.mediaDevices.ondevicechange = tryAgain;
} catch (e) {
if (e.name == "NotFoundError") return;
console.log(e);
}
}
// Your usual WebRTC negotiation code goes here
The above is for illustration only. I'm sure there are lots of corner cases to consider.

Record browser tab with javascript

Is it possible to record the current tab of the browser using just javascript and nothing else? I don't want to use chrome or firefox extension.
What I want to do is that the presenter would like to record his current tab and share it with others.
If it's possible what is the best way to do this?

There is... something that is in the process of being defined: MediaCapture Screen Share API.
This will allow to create a MediaStream from different sources such as the user's screen, or one of their apps' window, or some unclear-to-me "browser" thing.
From this MediaStream, it is easy to record it with the MediaRecorder API.
Currently, no browser has really implemented what is being defined there, but you can get some experimental implementations in Firefox, and, only from extension in Chrome.
This API doesn't really define a way to choose the current tab by default though, so your users will have to select this tab themselves from a prompt.
Live Example that will currently work only in Firefox.
And mandatory code block to be able to link to the fiddle, even though this code will not work anywhere for now!
navigator.getDisplayMedia({ video: true })
.then(stream => {
// we have a stream, we can record it
const chunks = [];
const recorder = new MediaRecorder(stream);
recorder.ondataavailable = e => chunks.push(e.data);
recorder.onstop = e => exportVid(new Blob(chunks));
recorder.start();
// defineWhenWeStopRecorder(recorder)
}, error => {
console.log("Unable to acquire screen capture", error);
});

I have not worked on recorder yet.
But found this post that may help. It is an API.
https://hacks.mozilla.org/2016/04/record-almost-everything-in-the-browser-with-mediarecorder/

MeteorJS - How to record sound from phone mic?

I was able to get sound byte data from the browser, but when I build it for the phone and try it out it doesn't work.
I have checked around and people had luck with cordova-plugin-media-capture however, it seems to record audio and archive it on the device.
I need to somehow get the audio data and manipulate it myself on the phone.
What I am currently doing to get audio on a non-mobile device
navigator.mediaDevices.getUserMedia({audio: true}).then(onMediaSuccess).catch(onMediaError);
function onMediaSuccess(stream) {
mediaRecorder = new MediaStreamRecorder(stream);
mediaRecorder.mimeType = 'audio/wav';
mediaRecorder.ondataavailable = handleDataAvailable;
mediaRecorder.start();
function handleDataAvailable(blob) {
toBuffer(blob, function(err, buffer) {
if (err)
throw err
ws.publish(`com.app.audioStream__`, {payload: buffer});
});
}
}
However, it seems get user media is having no effect.
I have tried using navigator.device.capture.captureAudio, but it is slightly difficult to debug it on my phone and see what the console outputs.
When I do use the method though, it prompts some UI managed by cordova that wants me to rec a sound and stop it then writes it to a file. I am looking for actively reading the mic.
Edit:
I have even tried with cordova-diagnostic-plugin
// check and request microphone access
cordova.plugins.diagnostic.getMicrophoneAuthorizationStatus(function(status) {
if (status !== "GRANTED") {
cordova.plugins.diagnostic.requestMicrophoneAuthorization(function(status) {
//...
return;
});
}
}, function() {
throw new Meteor.error('failed to get permission for microphone');
});
which results in a blank screen.
SO far there has been no easy way for me to prompt mic permissions.

Is HTML5's getUserMedia for audio recording working now?

I had searched a lot of DEMO and examples about getUserMedia , but most are just camera capturing, not microphone.
So I downloaded some examples and tried on my own computer , camera capturing is work ,
But when I changed
navigator.webkitGetUserMedia({video : true},gotStream);
to
navigator.webkitGetUserMedia({audio : true},gotStream);
The browser ask me to allow microphone access first, and then it failed at
document.getElementById("audio").src = window.webkitURL.createObjectURL(stream);
The message is :
GET blob:http%3A//localhost/a5077b7e-097a-4281-b444-8c1d3e327eb4 404 (Not Found)
This is my code: getUserMedia_simple_audio_test
Did I do something wrong? Or only getUserMedia can work for camera now ?

It is currently not available in Google Chrome. See Issue 112367.
You can see in the demo, it will always throw an error saying
GET blob:http%3A//whatever.it.is/b0058260-9579-419b-b409-18024ef7c6da 404 (Not Found)
And also you can't listen to the microphone either in
{
video: true,
audio: true
}

It is currently supported in Chrome Canary. You need to type about:flags into the address bar then enable Web Audio Input.
The following code connects the audio input to the speakers. WATCH OUT FOR THE FEEDBACK!
<script>
// this is to store a reference to the input so we can kill it later
var liveSource;
// creates an audiocontext and hooks up the audio input
function connectAudioInToSpeakers(){
var context = new webkitAudioContext();
navigator.webkitGetUserMedia({audio: true}, function(stream) {
console.log("Connected live audio input");
liveSource = context.createMediaStreamSource(stream);
liveSource.connect(context.destination);
});
}
// disconnects the audio input
function makeItStop(){
console.log("killing audio!");
liveSource.disconnect();
}
// run this when the page loads
connectAudioInToSpeakers();
</script>
<input type="button" value="please make it stop!" onclick="makeItStop()"/>

(sorry, I forgot to login, so posting with my proper username...)
It is currently supported in Chrome Canary. You need to type about:flags into the address bar then enable Web Audio Input.
The following code connects the audio input to the speakers. WATCH OUT FOR THE FEEDBACK!
http://jsfiddle.net/2mLtM/
<script>
// this is to store a reference to the input so we can kill it later
var liveSource;
// creates an audiocontext and hooks up the audio input
function connectAudioInToSpeakers(){
var context = new webkitAudioContext();
navigator.webkitGetUserMedia({audio: true}, function(stream) {
console.log("Connected live audio input");
liveSource = context.createMediaStreamSource(stream);
liveSource.connect(context.destination);
});
}
// disconnects the audio input
function makeItStop(){
console.log("killing audio!");
liveSource.disconnect();
}
// run this when the page loads
connectAudioInToSpeakers();
</script>
<input type="button" value="please make it stop!" onclick="makeItStop()"/>

It's working, you just need to add toString parameter after audio : true
Check this article - link