Develop Reference

How can I use my slider to adjust the volume of my device?

I am trying to use a slider to adjust the volume of a project I am working on and I cannot find a way to sync the slider to my computers settings. If that is impossible is there a way to convert the value, and divide it so that it would vary between 0.0 and 1 as a decimal to then input it separately into the code?
Here is the volume controller and the place where the music gets recognized.
<script src="https://sdk.scdn.co/spotify-player.js"></script>
<script>
window.onSpotifyWebPlaybackSDKReady = () => {
const token = '';
const player = new Spotify.Player({
name: 'Web Player',
getOAuthToken: cb => { cb(token); },
volume: 0.5
});
And here is the slider
<div class="slidecontainer">
<input type="range" min="0" max="100" value="50" class="slider" id="myRange">
<p>Value: <span id="VolumeValue"></span></p>
</div>
<script>
var slider = document.getElementById("myRange");
var output = document.getElementById("VolumeValue");
output.innerHTML = slider.value;
slider.oninput = function() {
output.innerHTML = this.value;
}
</script>
If you haven't guessed already I am fairly new to programming so any help would be appreciated.

When you're declaring your Spotify player variable inside of the onSpotifyWebPlaybackSDKReady callback, it's only visible there and you can't call the setVolume method somewhere else to apply slider values.
One option would be to store the player variable in the window object:
window.onSpotifyWebPlaybackSDKReady = () => {
window.spotifyPlayer = new Spotify.Player({
...
})
};
This would allow you to access it in a slider change event handler:
slider.oninput = function() {
// Assuming you stick to your range 0..100, then this would calculate values 0..1
window.spotifyPlayer.setVolume(this.value / 100);
}

Control audio with a slider

How to control volume with mouse action when user pull the volume progress up or down in a custom made audio player (Vanilla JS preferred)

You can use an input element with type="range", then listen for the input event or change event to update the volume. The change event will fire when the user stops moving the slider. The input event will fire as the slider is being moved.
Example:
let audio = new Audio("https://www.soundhelix.com/examples/mp3/SoundHelix-Song-1.mp3");
// update the volume when the slider is moved
volume.addEventListener("input", (e) => {
audio.volume = e.currentTarget.value / 100;
});
play.addEventListener("click", (e) => {
return audio.paused ? audio.play() : audio.pause();
});
<input type="range" id="volume" value="100">
<button type="button" id="play">
Play/Pause Audio
</button>

Set Default Volume in script

I have a website that loops music on load, but it is too loud. I have a slider bar to change the music volume, but how would I default it to 25% of the slider?
WEBSITE
<audio id=music loop autoplay src="peep.mp3">
<p>If you are reading this, it is because your browser does not support the audio element.</p>
</audio>
<input id="vol-control" type="range" min="0" max="100" step="1" oninput="SetVolume(this.value)" onchange="SetVolume(this.value)"></input>
<script>
function SetVolume(val)
{
var player = document.getElementById('music');
console.log('Before: ' + player.volume);
player.volume = val / 100;
console.log('After: ' + player.volume);
}
</script>

Just create a script that set the volume:
var audio = document.getElementById("music");
audio.volume = 0.25;

If you are using the audio tags, just get the DOM Node in Javascript and manipulate the volume property
var audio = document.querySelector('audio');
// Getting
console.log(volume); // 1
// Setting
audio.volume = 0.5; // Reduce the Volume by Half
The number that you set should be in the range 0.0 to 1.0, where 0.0 is the quietest and 1.0 is the loudest.

input is a Void element and as such does not needs a closing </input>
You're using max, min, well, use also value.
Avoid using inline JavaScript. Keep you logic away from your markup.
init your function like setVolume()
use camelCase setVolume instead of PascalCase SetVolume, since it's a normal function, not a Method, Class or constructor...
const audio = document.getElementById('audio'),
input = document.getElementById('volume'),
setVolume = () => audio.volume = input.value / 100;
input.addEventListener("input", setVolume);
setVolume();
<audio id=audio loop autoplay src="//upload.wikimedia.org/wikipedia/en/4/45/ACDC_-_Back_In_Black-sample.ogg">Audio is not supported on your browser. Update it.</audio>
<input id=volume type=range min=0 max=100 value=25 step=1>
I think you'd also like this example.

How to display video tag in a canvas element [duplicate]

is it possible to display a html5-video as part of the canvas?
basically the same way as you draw an Image in the canvas.
context.drawVideo(vid, 0, 0);
thanks!

var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var video = document.getElementById('video');
video.addEventListener('play', function () {
var $this = this; //cache
(function loop() {
if (!$this.paused && !$this.ended) {
ctx.drawImage($this, 0, 0);
setTimeout(loop, 1000 / 30); // drawing at 30fps
}
})();
}, 0);
I guess the above code is self Explanatory, If not drop a comment below, I will try to explain the above few lines of code
Edit :
here's an online example, just for you :)
Demo
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var video = document.getElementById('video');
// set canvas size = video size when known
video.addEventListener('loadedmetadata', function() {
canvas.width = video.videoWidth;
canvas.height = video.videoHeight;
});
video.addEventListener('play', function() {
var $this = this; //cache
(function loop() {
if (!$this.paused && !$this.ended) {
ctx.drawImage($this, 0, 0);
setTimeout(loop, 1000 / 30); // drawing at 30fps
}
})();
}, 0);
<div id="theater">
<video id="video" src="http://upload.wikimedia.org/wikipedia/commons/7/79/Big_Buck_Bunny_small.ogv" controls></video>
<canvas id="canvas"></canvas>
<label>
<br />Try to play me :)</label>
<br />
</div>

Here's a solution that uses more modern syntax and is less verbose than the ones already provided:
const canvas = document.querySelector("canvas");
const ctx = canvas.getContext("2d");
const video = document.querySelector("video");
video.addEventListener("play", () => {
function step() {
ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
requestAnimationFrame(step);
}
requestAnimationFrame(step);
});
Some useful links:
MDN Documentation for window.requestAnimationFrame()
Can I use requestAnimationFrame?

Using canvas to display Videos
Displaying a video is much the same as displaying an image. The minor differences are to do with onload events and the fact that you need to render the video every frame or you will only see one frame not the animated frames.
The demo below has some minor differences to the example. A mute function (under the video click mute/sound on to toggle sound) and some error checking to catch IE9+ and Edge if they don't have the correct drivers.
Keeping answers current.
The previous answers by user372551 is out of date (December 2010) and has a flaw in the rendering technique used. It uses the setTimeout and a rate of 33.333..ms which setTimeout will round down to 33ms this will cause the frames to be dropped every two seconds and may drop many more if the video frame rate is any higher than 30. Using setTimeout will also introduce video shearing created because setTimeout can not be synced to the display hardware.
There is currently no reliable method that can determine a videos frame rate unless you know the video frame rate in advance you should display it at the maximum display refresh rate possible on browsers. 60fps
The given top answer was for the time (6 years ago) the best solution as requestAnimationFrame was not widely supported (if at all) but requestAnimationFrame is now standard across the Major browsers and should be used instead of setTimeout to reduce or remove dropped frames, and to prevent shearing.
The example demo.
Loads a video and set it to loop. The video will not play until the you click on it. Clicking again will pause. There is a mute/sound on button under the video. The video is muted by default.
Note users of IE9+ and Edge. You may not be able to play the video format WebM as it needs additional drivers to play the videos. They can be found at tools.google.com Download IE9+ WebM support
// This code is from the example document on stackoverflow documentation. See HTML for link to the example.
// This code is almost identical to the example. Mute has been added and a media source. Also added some error handling in case the media load fails and a link to fix IE9+ and Edge support.
// Code by Blindman67.
// Original source has returns 404
// var mediaSource = "http://video.webmfiles.org/big-buck-bunny_trailer.webm";
// New source from wiki commons. Attribution in the leading credits.
var mediaSource = "http://upload.wikimedia.org/wikipedia/commons/7/79/Big_Buck_Bunny_small.ogv"
var muted = true;
var canvas = document.getElementById("myCanvas"); // get the canvas from the page
var ctx = canvas.getContext("2d");
var videoContainer; // object to hold video and associated info
var video = document.createElement("video"); // create a video element
video.src = mediaSource;
// the video will now begin to load.
// As some additional info is needed we will place the video in a
// containing object for convenience
video.autoPlay = false; // ensure that the video does not auto play
video.loop = true; // set the video to loop.
video.muted = muted;
videoContainer = { // we will add properties as needed
video : video,
ready : false,
};
// To handle errors. This is not part of the example at the moment. Just fixing for Edge that did not like the ogv format video
video.onerror = function(e){
document.body.removeChild(canvas);
document.body.innerHTML += "<h2>There is a problem loading the video</h2><br>";
document.body.innerHTML += "Users of IE9+ , the browser does not support WebM videos used by this demo";
document.body.innerHTML += "<br><a href='https://tools.google.com/dlpage/webmmf/'> Download IE9+ WebM support</a> from tools.google.com<br> this includes Edge and Windows 10";
}
video.oncanplay = readyToPlayVideo; // set the event to the play function that
// can be found below
function readyToPlayVideo(event){ // this is a referance to the video
// the video may not match the canvas size so find a scale to fit
videoContainer.scale = Math.min(
canvas.width / this.videoWidth,
canvas.height / this.videoHeight);
videoContainer.ready = true;
// the video can be played so hand it off to the display function
requestAnimationFrame(updateCanvas);
// add instruction
document.getElementById("playPause").textContent = "Click video to play/pause.";
document.querySelector(".mute").textContent = "Mute";
}
function updateCanvas(){
ctx.clearRect(0,0,canvas.width,canvas.height);
// only draw if loaded and ready
if(videoContainer !== undefined && videoContainer.ready){
// find the top left of the video on the canvas
video.muted = muted;
var scale = videoContainer.scale;
var vidH = videoContainer.video.videoHeight;
var vidW = videoContainer.video.videoWidth;
var top = canvas.height / 2 - (vidH /2 ) * scale;
var left = canvas.width / 2 - (vidW /2 ) * scale;
// now just draw the video the correct size
ctx.drawImage(videoContainer.video, left, top, vidW * scale, vidH * scale);
if(videoContainer.video.paused){ // if not playing show the paused screen
drawPayIcon();
}
}
// all done for display
// request the next frame in 1/60th of a second
requestAnimationFrame(updateCanvas);
}
function drawPayIcon(){
ctx.fillStyle = "black"; // darken display
ctx.globalAlpha = 0.5;
ctx.fillRect(0,0,canvas.width,canvas.height);
ctx.fillStyle = "#DDD"; // colour of play icon
ctx.globalAlpha = 0.75; // partly transparent
ctx.beginPath(); // create the path for the icon
var size = (canvas.height / 2) * 0.5; // the size of the icon
ctx.moveTo(canvas.width/2 + size/2, canvas.height / 2); // start at the pointy end
ctx.lineTo(canvas.width/2 - size/2, canvas.height / 2 + size);
ctx.lineTo(canvas.width/2 - size/2, canvas.height / 2 - size);
ctx.closePath();
ctx.fill();
ctx.globalAlpha = 1; // restore alpha
}
function playPauseClick(){
if(videoContainer !== undefined && videoContainer.ready){
if(videoContainer.video.paused){
videoContainer.video.play();
}else{
videoContainer.video.pause();
}
}
}
function videoMute(){
muted = !muted;
if(muted){
document.querySelector(".mute").textContent = "Mute";
}else{
document.querySelector(".mute").textContent= "Sound on";
}
}
// register the event
canvas.addEventListener("click",playPauseClick);
document.querySelector(".mute").addEventListener("click",videoMute)
body {
font :14px arial;
text-align : center;
background : #36A;
}
h2 {
color : white;
}
canvas {
border : 10px white solid;
cursor : pointer;
}
a {
color : #F93;
}
.mute {
cursor : pointer;
display: initial;
}
<h2>Basic Video & canvas example</h2>
<p>Code example from Stackoverflow Documentation HTML5-Canvas<br>
Basic loading and playing a video on the canvas</p>
<canvas id="myCanvas" width = "532" height ="300" ></canvas><br>
<h3><div id = "playPause">Loading content.</div></h3>
<div class="mute"></div><br>
<div style="font-size:small">Attribution in the leading credits.</div><br>
Canvas extras
Using the canvas to render video gives you additional options in regard to displaying and mixing in fx. The following image shows some of the FX you can get using the canvas. Using the 2D API gives a huge range of creative possibilities.
Image relating to answer Fade canvas video from greyscale to color
See video title in above demo for attribution of content in above inmage.

You need to update currentTime video element and then draw the frame in canvas. Don't init play() event on the video.
You can also use for ex. this plugin https://github.com/tstabla/stVideo

I started with the answer from 2018 about requestAnimationFrame. However, it has three problems.
unnecessarily complex
there is a new way to handle this task (since about 2020)
attaching an event listener to the play event invites performance issues
First, the event listener can simply be connected to the function that does your desired processing and schedules the next call to itself. There's no need to wrap it in an anonymous function with another call to requestAnimationFrame.
Second, don't use requestAnimationFrame. That function schedules the next call to your callback as quickly as the browser can handle (generally 60Hz), which results in a significant processing workload. video.requestVideoFrameCallback only calls your callback when the video proceeds to its next frame. This reduces the workload when a video runs at less than 60 FPS and obviates the need for any processing at all while the video isn't playing, significantly improving performance.
Third, an event listener attached to the play event will fire whenever you tell the video to video.play(), which you'll do every time you load a new video into the video element and tell it to start playing, and also when you resume playback after using video.pause(). Thus, the video is drawn on the canvas (plus whatever other processing you're doing) once for each time the video has been told to play(), which quickly accumulates.
If you're sure you'll only be playing one video which you'd like to pause and resume, you can toggle play/pause by changing the playback rate, e.g. video.playbackRate = !video.playbackRate. If you'll be loading multiple videos into this element, it's better to forego the play event listener entirely and insert a manual call to step() when you load your first video to get that started. Note that this is active on the video element, not on specific loaded videos, so you'll need to either set and check a flag to ensure that you only call step() when loading the first video, or cancel any active video frame request before making a new one (shown below).
let animation_handle;
const canvas = document.querySelector("canvas");
const ctx = canvas.getContext("2d");
const video = document.querySelector("video");
video.addEventListener('loadeddata', video_load_callback, false);
function video_load_callback() {
video.cancelVideoFrameCallback(animation_handle);
step()
}
function step() { // update the canvas when a video proceeds to next frame
ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
animation_handle = video.requestVideoFrameCallback(step);
}

Custom progress bar for <audio> and <progress> HTML5 elements

I am mind boggled at working out how to create a custom seekbar for an audio player using the tag and simple Javascript.
Current Code:
<script>
function play() {
document.getElementById('player').play();
}
function pause() {
document.getElementById('player').pause();
}
</script>
<audio src="sample.mp3" id="player"></audio>
<button onClick="javascript:play()" >Play</button>
<button onClick="javascript:pause()" >Pause</button>
<progress id="seekbar"></progress>
Would it be possible to link the progress bar so that when i play a song the progress is shown?

Yes, it is possible using the timeupdate event of the audio tag. You receive this event every time the position of the playback is updated. Then, you can update your progress bar using the currentTime and duration properties of the audio element.
You can see a working example in this fiddle

If you want smooth progress bar,try somethink like that
HTML:
<div class="hp_slide">
<div class="hp_range"></div>
</div>
CSS:
.hp_slide{
width:100%;
background:white;
height:25px;
}
.hp_range{
width:0;
background:black;
height:25px;
}
JS:
var player = document.getElementById('player');
player.addEventListener("timeupdate", function() {
var currentTime = player.currentTime;
var duration = player.duration;
$('.hp_range').stop(true,true).animate({'width':(currentTime +.25)/duration*100+'%'},250,'linear');
});
Pretty rough,but works

Here's a simple vanilla example:
const url = "https://upload.wikimedia.org/wikipedia/en/a/a9/Webern_-_Sehr_langsam.ogg";
const audio = new Audio(url);
const playBtn = document.querySelector("button");
const progressEl = document.querySelector('input[type="range"]');
let mouseDownOnSlider = false;
audio.addEventListener("loadeddata", () => {
progressEl.value = 0;
});
audio.addEventListener("timeupdate", () => {
if (!mouseDownOnSlider) {
progressEl.value = audio.currentTime / audio.duration * 100;
}
});
audio.addEventListener("ended", () => {
playBtn.textContent = "▶️";
});
playBtn.addEventListener("click", () => {
audio.paused ? audio.play() : audio.pause();
playBtn.textContent = audio.paused ? "▶️" : "⏸️";
});
progressEl.addEventListener("change", () => {
const pct = progressEl.value / 100;
audio.currentTime = (audio.duration || 0) * pct;
});
progressEl.addEventListener("mousedown", () => {
mouseDownOnSlider = true;
});
progressEl.addEventListener("mouseup", () => {
mouseDownOnSlider = false;
});
button {
font-size: 1.5em;
}
<button>▶️</button>
<input type="range" value="0" min="0" max="100" step="1">
The approach is to use an input[type="range"] slider to reflect the progress and allow the user to seek through the track. When the range changes, set the audio.currentTime attribute, using the slider as a percent (you could also adjust the max attribute of the slider to match the audio.duration).
In the other direction, I update the slider's progress on timeupdate event firing.
One corner case is that if the user scrolls around with their mouse down on the slider, the timeupdate event will keep firing, causing the progress to hop around between wherever the user's cursor is hovering and the current audio progress. I use a boolean and the mousedown/mouseup events on the slider to prevent this from happening.
See also JavaScript - HTML5 Audio / custom player's seekbar and current time for an extension of this code that displays the time.

First of all, don't use the progress element, it's a shitty element (for now) and styling it is a huge pain in... well it's boring (look at a little project I made, look at it (and it's juste webkit/moz)).
Anyway, you should read the doc on MDN, it's very easy and with a lot of examples. What you are looking for is the currentTime attribute, here a little snippet :
var audio = document.querySelector('#player')
audio.currentTime = 60 // will go to the 60th second
So what you need is to use the cross-multiplication (div is the element you use as a progress bar) :
Where I clicked on div | THE TIME I WANT TO KNOW
————————————————————————————————————————
Total length of div | The total time of my video/audio (audio.seekable.end())