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Record video in lower resolution than original using MediaRecorder

I'm creating a video recorder script using JavaScript and the MediaRecorder API. I'm using a video capture as source. The video output is 1920 x 1080 but I'm trying to shrink this resolution to 640 x 360 (360p).
I will write all the code below. I tried many configurations and variants of HTML and JS, and according to this site my video source can fit that size I'm trying to force.
The video source is from this elgato camlink 4k
UPDATE
Instead of using exact in video constraints, replace it with ideal and it will see if this resolution is available in the device.
The elgato camlink device don't support 360p apparently, I tested with external webcam which does support 360p and using ideal it works.
Using windows camera settings you can see there is no other resolutions available on elgato camlink only HD and FHD.
The HTML tag:
<video id="videoEl" width="640" height="360" autoplay canplay resize></video>
This is the getUSerMedia() script:
const video = document.getElementById('videoEl');
const constraints = {
audio: { deviceId: audioDeviceId },
video: {
deviceId: videoDeviceId,
width: { exact: 640 },
height: { exact: 360 },
frameRate: 30
}
};
this.CameraStream = await navigator.mediaDevices.getUserMedia(constraints);
video.srcObject = this.CameraStream;
Before that I choose the video source using navigator.mediaDevices.enumerateDevices();
Then I tried some options for the MediaRecorder constructor:
this.MediaRecorder = new MediaRecorder(this.CameraStream)
this.MediaRecorder = new MediaRecorder(this.CameraStream, { mimeType: 'video/webm' })
Found this mimeType in this Forum
this.MediaRecorder = new MediaRecorder(this.CameraStream, { mimeType: 'video/x-matroska;codecs=h264' })
And the event listener
this.MediaRecorder.addEventListener('dataavailable', event => {
this.BlobsRecorded.push(event.data);
});
MediaRecorder on stop
As I mention before, I tried some variants of options:
const options = { type: 'video/x-matroska;codecs=h264' };
const options = { type: 'video/webm' };
const options = { type: 'video/mp4' }; // not supported
const finalVideo = URL.createObjectURL(
new Blob(this.BlobsRecorded, options)
);
Note
Everything is working perfectly, I just leave the code to let you see the used constraints and for illustrative purposes. If there is something missing let me know to put it here.
Thank you for your time.

Can't clearTimer in async interval

I'm trying to modify an implementation of some TensorFlow face detection algorithms using Java.
At the moment, I've added a button that properly stops/starts the video streaming from my camera. Also, when the video is playing, I detect the faces on it every 100ms with an async interval.
The problem appears when I Stop and then restart the video streaming because multiple detections are generated. I'm assuming it's related to the interval considering that I print the detections and the interval var to console and there are more than one detections in the same interval and the interval doesn't reset to zero after clearInterval(DetTim) when the video gets paused.
My code is as follows (I'm omitting a load of models and the StartVideo function):
const video = document.getElementById('video')
const PlayButton = document.getElementById('play-button')
var DetTim = null
video.addEventListener('play', () => {
const canvas = faceapi.createCanvasFromMedia(video)
document.body.append(canvas)
const displaySize = { width: video.width, height: video.height }
faceapi.matchDimensions(canvas, displaySize)
if (!video.paused){
DetTim = setInterval(async () => {
console.log(DetTim)
const detections = await faceapi.detectAllFaces(video, new
faceapi.TinyFaceDetectorOptions())
const resizedDetections = faceapi.resizeResults(detections, displaySize)
canvas.getContext('2d').clearRect(0, 0, canvas.width, canvas.height)
faceapi.draw.drawDetections(canvas, resizedDetections)
}, 100)
} else {
clearInterval(DetTim)
console.log(DetTim)
}
})
PlayButton.addEventListener("click", (e) =>{
if (video.paused) {
video.play()
e.target.textContent = '▌ ▌'
} else {
video.pause()
e.target.textContent = '▶'
}
})
Also, here are some screenshots related to the problem. In the first shot, the code works properly as it has just been initialized. In the second one, multiple detections (blue rectangles) have been drawn over the canvas after multiple starts/stops clicks.
First Shot
Second Shot

As CBroe mentioned in a comment:
I would either handle both in the click event, or both in the play and pause event. Mixing both, does not sound like a good idea.
I ended up handling the click event within the play event and it solved the issue.

webrtc speed issues when i capture screen

am developing a 4 peers webrtc video chat!
everything is fine at this point , so i add a screen sharing future to the website!
when ever i press screenshare , the connection becomes so slow ! i thought it's because 4 peers connection , but this happens only when i share my screen .
i tried to use RemoveStream function that sends the camera stream, but the streams still lagging .
this is the function that runs after i press screenshare button
async function startCapture() {
var audioStream = await navigator.mediaDevices.getUserMedia({audio:true});
var audioTrack = audioStream.getAudioTracks()[0];
let captureStream = null;
try {
captureStream = await navigator.mediaDevices.getDisplayMedia(gdmOptions);
captureStream.addTrack( audioTrack );
} catch(err) {
console.error("Error: " + err);
}
// return captureStream;
if(rtcPeerConn){
rtcPeerConn.removeStream(myStream);
rtcPeerConn.addStream(captureStream);
}
if(rtcPeerConn1){
rtcPeerConn1.removeStream(myStream);
rtcPeerConn1.addStream(captureStream);
}
if(rtcPeerConn2){
rtcPeerConn2.removeStream(myStream);
rtcPeerConn2.addStream(captureStream);
}
if(rtcPeerConn3){
rtcPeerConn3.removeStream(myStream);
rtcPeerConn3.addStream(captureStream);
}
myStream.getTracks().forEach(function(track) {
track.stop();
});
myStream = captureStream;
success(myStream);
}
i even tried to remove tracks from the first stream like this
async function startCapture() {
myStream.getTracks().forEach(function(track) {
track.stop();
});
var audioStream = await navigator.mediaDevices.getUserMedia({audio:true});
var audioTrack = audioStream.getAudioTracks()[0];
let captureStream = null;
try {
captureStream = await navigator.mediaDevices.getDisplayMedia(gdmOptions);
captureStream.addTrack( audioTrack );
} catch(err) {
console.error("Error: " + err);
}
if(rtcPeerConn){
rtcPeerConn.removeStream(myStream);
rtcPeerConn.addStream(captureStream);
}
if(rtcPeerConn1){
rtcPeerConn1.removeStream(myStream);
rtcPeerConn1.addStream(captureStream);
}
if(rtcPeerConn2){
rtcPeerConn2.removeStream(myStream);
rtcPeerConn2.addStream(captureStream);
}
if(rtcPeerConn3){
rtcPeerConn3.removeStream(myStream);
rtcPeerConn3.addStream(captureStream);
}
myStream = captureStream;
success(myStream);
}
as you see i used removeStream function to avoid sending useless streams , but still nothing changed.

What are the constraints you are placing on getDisplayMedia? Perhaps you are sending "too much" video content, and thus slowing everything down.
[edit]
According to your comment, you are recording audio from the screen, and also audio from the mic. Perhaps remove the audio track from the screen recording?
You can also use options to reduce the size of the video: (this requires using getUserMedia instead of getDisplayMedia)
video:{
width: { min: 100, ideal: width, max: 1920 },
height: { min: 100, ideal: height, max: 1080 },
frameRate: {ideal: framerate}
}
Perhaps a lower framerate? Try reducing the size and see if that helps too :)

HTML5 / JavaScript camera blurry, only on front facing camera, only on my app

I have built a visitor management system and have recently swapped to a surface device as the driver. The html5 webcam stream is showing as blurry / out of focus on the front facing camera. If I swap to the rear camera however it is fine. And if i use the front facing camera on another public site that uses another webcam feature, it works absolutely fine.
Here is a capture of the camera element, it looks like some form of deliberate blurring as appose to the camera just being bad...
https://ibb.co/Dzf67nC/
I have tried scanning through the code and cannot find anything that scales the camera stream at all that may cause bluring or focus changing
Below is my photo.js file that provides the stream to my visitor sign in page and also handles the capturing of screenshots.
// References to all the element we will need.
var video = document.querySelector('#camera-stream'),
image = document.querySelector('#snap'),
my_photo = document.querySelector('#my-photo'),
container = document.querySelector('.camera-container'),
//start_camera = document.querySelector('#start-camera'),
controls = document.querySelector('.controls'),
take_photo_btn = document.querySelector('#take-photo'),
delete_photo_btn = document.querySelector('#delete-photo'),
download_photo_btn = document.querySelector('#download-photo'),
imgeurl = document.querySelector('#imagesource'),
open_camera = document.querySelector('#open-camera'),
error_message = document.querySelector('#error-message');
// The getUserMedia interface is used for handling camera input.
// Some browsers need a prefix so here we're covering all the options
navigator.getMedia = ( navigator.getUserMedia ||
navigator.webkitGetUserMedia ||
navigator.mozGetUserMedia ||
navigator.msGetUserMedia);
// Mobile browsers cannot play video without user input,
// so here we're using a button to start it manually.
open_camera.addEventListener("click", function(e){
if($('#my-photo').attr('src') == '') {
e.preventDefault();
container.classList.add("visible");
// Start video playback manually.
//video.play();
//showVideo();
if(!navigator.getMedia){
displayErrorMessage("Your browser doesn't have support for the navigator.getUserMedia interface.");
}
else{
// Request the camera.
navigator.getMedia(
{
video: true
},
// Success Callback
function(stream){
// Create an object URL for the video stream and
// set it as src of our HTLM video element.
video.srcObject=stream;
// Play the video element to start the stream.
video.play();
video.onplay = function() {
showVideo();
};
},
// Error Callback
function(err){
displayErrorMessage("There was an error with accessing the camera stream: " + err.name, err);
}
);
}
}
});
open_camera.click();
take_photo_btn.addEventListener("click", function(e){
e.preventDefault();
var count=4;
var counter=setInterval(timer, 500); //1000 will run it every 1 second
$('.countdown-container').addClass('visible');
function timer(){
count=count-1;
if (count <= 0)
{
$('.countdown-number').html('<i class="far fa-smile"></i>');
clearInterval(counter);
//counter ended, do something here
return;
}
$('.countdown-number').text(count);
//Do code for showing the number of seconds here
}
setTimeout(function(){
$('.countdown-container').removeClass('visible');
$('.countdown-number').text('Get Ready');
},2500);
setTimeout(function(){
video.pause(snap);
var snap = takeSnapshot();
// Show image.
image.setAttribute('src', snap);
imgeurl.value = snap;
image.classList.add("visible");
//tumbnail image
my_photo.setAttribute('src', snap);
my_photo.value = snap;
// Enable delete and save buttons
delete_photo_btn.classList.remove("disabled");
download_photo_btn.classList.remove("disabled");
take_photo_btn.classList.add("disabled");
},3000);
// Set the href attribute of the download button to the snap url.
// Pause video playback of stream.
});
delete_photo_btn.addEventListener("click", function(e){
e.preventDefault();
// Hide image.
image.setAttribute('src', "");
image.classList.remove("visible");
my_photo.setAttribute('src', "");
// Disable delete and save buttons
delete_photo_btn.classList.add("disabled");
download_photo_btn.classList.add("disabled");
take_photo_btn.classList.remove("disabled");
// Resume playback of stream.
video.play();
});
function showVideo(){
// Display the video stream and the controls.
//hideUI();
video.classList.add("visible");
controls.classList.add("visible");
}
function takeSnapshot(){
// Here we're using a trick that involves a hidden canvas element.
var hidden_canvas = document.querySelector('canvas'),
context = hidden_canvas.getContext('2d');
var width = video.videoWidth,
height = video.videoHeight;
if (width && height) {
// Setup a canvas with the same dimensions as the video.
hidden_canvas.width = width;
hidden_canvas.height = height;
// Make a copy of the current frame in the video on the canvas.
context.drawImage(video, 0, 0, width, height);
// Turn the canvas image into a dataURL that can be used as a src for our photo.
return hidden_canvas.toDataURL('image/png');
}
}
download_photo_btn.addEventListener("click", function(e){
e.preventDefault();
container.classList.remove("visible");
my_photo.classList.add("visible");
});
function displayErrorMessage(error_msg, error){
error = error || "";
if(error){
console.log(error);
}
error_message.innerText = error_msg;
hideUI();
error_message.classList.add("visible");
}
function hideUI(){
// Helper function for clearing the app UI.
controls.classList.remove("visible");
//start_camera.classList.remove("visible");
video.classList.remove("visible");
snap.classList.remove("visible");
error_message.classList.remove("visible");
}
The camera should be a lot crisper than it is. No errors or anything in the console.

Create thumbnail from video file via file input

I am attempting to create a thumbnail preview from a video file (mp4,3gp) from a form input type='file'. Many have said that this can be done server side only. I find this hard to believe since I just recently came across this Fiddle using HTML5 Canvas and Javascript.
Thumbnail Fiddle
The only problem is this requires the video to be present and the user to click play before they click a button to capture the thumbnail. I am wondering if there is a way to get the same results without the player being present and user clicking the button. For example: User click on file upload and selects video file and then thumbnail is generated. Any help/thoughts are welcome!

Canvas.drawImage must be based on html content.
source
here is a simplier jsfiddle
//and code
function capture(){
var canvas = document.getElementById('canvas');
var video = document.getElementById('video');
canvas.getContext('2d').drawImage(video, 0, 0, video.videoWidth, video.videoHeight);
}
The advantage of this solution is that you can select the thumbnail you want based on the time of the video.

Recently needed this so I wrote a function, to take in a video file and a desired timestamp, and return an image blob at that time of the video.
Sample Usage:
try {
// get the frame at 1.5 seconds of the video file
const cover = await getVideoCover(file, 1.5);
// print out the result image blob
console.log(cover);
} catch (ex) {
console.log("ERROR: ", ex);
}
Function:
function getVideoCover(file, seekTo = 0.0) {
console.log("getting video cover for file: ", file);
return new Promise((resolve, reject) => {
// load the file to a video player
const videoPlayer = document.createElement('video');
videoPlayer.setAttribute('src', URL.createObjectURL(file));
videoPlayer.load();
videoPlayer.addEventListener('error', (ex) => {
reject("error when loading video file", ex);
});
// load metadata of the video to get video duration and dimensions
videoPlayer.addEventListener('loadedmetadata', () => {
// seek to user defined timestamp (in seconds) if possible
if (videoPlayer.duration < seekTo) {
reject("video is too short.");
return;
}
// delay seeking or else 'seeked' event won't fire on Safari
setTimeout(() => {
videoPlayer.currentTime = seekTo;
}, 200);
// extract video thumbnail once seeking is complete
videoPlayer.addEventListener('seeked', () => {
console.log('video is now paused at %ss.', seekTo);
// define a canvas to have the same dimension as the video
const canvas = document.createElement("canvas");
canvas.width = videoPlayer.videoWidth;
canvas.height = videoPlayer.videoHeight;
// draw the video frame to canvas
const ctx = canvas.getContext("2d");
ctx.drawImage(videoPlayer, 0, 0, canvas.width, canvas.height);
// return the canvas image as a blob
ctx.canvas.toBlob(
blob => {
resolve(blob);
},
"image/jpeg",
0.75 /* quality */
);
});
});
});
}

Recently needed this and did quite some testing and boiling it down to the bare minimum, see https://codepen.io/aertmann/pen/mAVaPx
There are some limitations where it works, but fairly good browser support currently: Chrome, Firefox, Safari, Opera, IE10, IE11, Android (Chrome), iOS Safari (10+).
video.preload = 'metadata';
video.src = url;
// Load video in Safari / IE11
video.muted = true;
video.playsInline = true;
video.play();

You can use this function that I've written. You just need to pass the video file to it as an argument. It will return the dataURL of the thumbnail(i.e image preview) of that video. You can modify the return type according to your need.
const generateVideoThumbnail = (file: File) => {
return new Promise((resolve) => {
const canvas = document.createElement("canvas");
const video = document.createElement("video");
// this is important
video.autoplay = true;
video.muted = true;
video.src = URL.createObjectURL(file);
video.onloadeddata = () => {
let ctx = canvas.getContext("2d");
canvas.width = video.videoWidth;
canvas.height = video.videoHeight;
ctx.drawImage(video, 0, 0, video.videoWidth, video.videoHeight);
video.pause();
return resolve(canvas.toDataURL("image/png"));
};
});
};
Please keep in mind that this is a async function. So make sure to use it accordingly.
For instance:
const handleFileUpload = async (e) => {
const thumbnail = await generateVideoThumbnail(e.target.files[0]);
console.log(thumbnail)
}

The easiest way to display a thumbnail is using the <video> tag itself.
<video src="http://www.w3schools.com/html/mov_bbb.mp4"></video>
Use #t in the URL, if you want the thumbnail of x seconds.
E.g.:
<video src="http://www.w3schools.com/html/mov_bbb.mp4#t=5"></video>
Make sure that it does not include any attributes like autoplay or controls and it should not have a source tag as a child element.
With a little bit of JavaScript, you may also be able to play the video, when the thumbnail has been clicked.
document.querySelector('video').addEventListener('click', (e) => {
if (!e.target.controls) { // Proceed, if there are no controls
e.target.src = e.target.src.replace(/#t=\d+/g, ''); // Remove the time, which is set in the URL
e.target.play(); // Play the video
e.target.controls = true; // Enable controls
}
});
<video src="http://www.w3schools.com/html/mov_bbb.mp4#t=5"></video>

With jQuery Lib you can use my code here. $video is a Video element.This function will return a string
function createPoster($video) {
//here you can set anytime you want
$video.currentTime = 5;
var canvas = document.createElement("canvas");
canvas.width = 350;
canvas.height = 200;
canvas.getContext("2d").drawImage($video, 0, 0, canvas.width, canvas.height);
return canvas.toDataURL("image/jpeg");;
}
Example usage:
$video.setAttribute("poster", createPoster($video));

I recently stumbled on the same issue and here is how I got around it.
firstly it will be easier if you have the video as an HTML element, so you either have it in the HTML like this
<video src="http://www.w3schools.com/html/mov_bbb.mp4"></video>
or you take from the input and create an HTML element with it.
The trick is to set the start time in the video tag to the part you want to seek and have as your thumbnail, you can do this by adding #t=1.5 to the end of the video source.
<video src="http://www.w3schools.com/html/mov_bbb.mp4#t=1.5"></video>
where 1.5 is the time you want to seek and get a thumbnail of.
This, however, makes the video start playing from that section of the video so to avoid that we add an event listener on the video's play button(s) and have the video start from the beginning by setting video.currentTime = 0
const video = document.querySelector('video');
video.addEventListener('click', (e)=> {
video.currentTime = 0 ;
video.play();
})