Trying to load video through javascript - javascript

I want to dynamically load videos from a server to a client using javascript DOM manipulation. I tried this code but the callback function onload doesn't run and in addition in the network tab in the request headers accept field is "/".
function doAjaxVideo(param, lambda) {
let video = document.createElement("video");
let sourceElem = document.createElement("source");
sourceElem.src = param;
sourceElem.type = "video/webm";
video.appendChild(sourceElem);
video.autoplay = "true";
video.onload = () => lambda();
}
doAjaxVideo("/video.webm", function() { console.log("Ready!") }
Any suggestions on how to tweak this so it works? Or maybe another way of doing it.
Image of network tab in devtools

You can try onloadeddata. https://www.w3schools.com/jsref/event_onloadeddata.asp
Because you want it to take action when the data is loaded, not the video element itself.

Related

Getting video audio from another domain for visualisation

On my web page I'm looking to get an audio level visualisation from a video source created on another domain, both of which I control. I am considering using the this library, which contains the following example code:
var myMeterElement = document.getElementById('my-peak-meter');
var myAudio = document.getElementById('my-audio');
var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var sourceNode = audioCtx.createMediaElementSource(myAudio);
sourceNode.connect(audioCtx.destination);
var meterNode = webAudioPeakMeter.createMeterNode(sourceNode, audioCtx);
webAudioPeakMeter.createMeter(myMeterElement, meterNode, {});
myAudio.addEventListener('play', function() {
audioCtx.resume();
});
Because the source is from another domain, I cannot access the element directly with getElement. I understand the postMessage() function allows the sending cross-origin data, however am not sure how to apply it to a scenario like this, or whether this will even work. Any suggestions?

Using requested XHR data while actually loading

maybe i just got it wrong but... im requesting "large" files via ajax (180mb - 500mb). i thought that im able to fetch and use the data with the method URL.createObjectURL while its actually loading? i need the requested data within 5 seconds but its acutually loading 16 seconds.
ajax request
xhr.onload (worked within 5 seconds or faster, locally, but not live)
within the onload (or progress, onreadystatechange (i tried)) i used URL.createObjectURL(xhr.response) to get the data
var nxtclp = new XMLHttpRequest();
nxtclp.onload = function() {
get_src = URL.createObjectURL(nxtclp.response);
that.preloadSource = get_src;
};
nxtclp.open("GET", "media/vid.mp4");
nxtclp.responseType = "blob";
nxtclp.send();
is there any way to playback data while loading ?
Use autoplay attribute at <video> element
autoplay
A Boolean attribute; if specified, the video automatically begins to
play back as soon as it can do so without stopping to finish loading
the data.
<video controls autoplay src="http://mirrors.creativecommons.org/movingimages/webm/ScienceCommonsJesseDylan_240p.webm">
</video>
alternatively, using javascript
var video = document.createElement("video");
video.autoplay = true;
video.controls = true;
video.onloadedmetadata = (e) => {
console.log(video.readyState);
document.body.appendChild(e.path[0])
}
video.src = "http://mirrors.creativecommons.org/movingimages/webm/ScienceCommonsJesseDylan_240p.webm";
<body>
</body>

Connecting MediaElementAudioSourceNode to AudioContext.destination doesn't work

Here's a fiddle to show the problem. Basically, whenever the createMediaElementSource method of an AudioContext object is called, the output of the audio element is re-routed into the returned MediaElementAudioSourceNode. This is all fine and according to spec; however, when I then try to reconnect the output to the speakers (using the destination of the AudioContext), nothing happens.
Am I missing something obvious here? Maybe it has to do with cross-domain audio files? I just couldn't find any information on the topic on Google, and didn't see a note of it in the specs.
Code from the fiddle is:
var a = new Audio();
a.src = "http://webaudioapi.com/samples/audio-tag/chrono.mp3";
a.controls = true;
a.loop = true;
a.autoplay = true;
document.body.appendChild(a);
var ctx = new AudioContext();
// PROBLEM HERE
var shouldBreak = true;
var src;
if (shouldBreak) {
// this one stops playback
// it should redirect output from audio element to the MediaElementAudioSourceNode
// but src.connect(ctx.destination) does not fix it
src = ctx.createMediaElementSource(a);
src.connect(ctx.destination);
}
Yes, the Web Audio API requires that the audio adhere to the Same-Origin Policy. If the audio you're attempting to play is not from the same origin then the appropriate Access-Control headers are required. The resource in your example does not have the required headers.

html audio tag, duration always infinity

I've been working on using the html audio tag to play some audio files. The audio plays alright, but the duration property of the audio tag is always returning infinity.
I tried the accepted answer to this question but with the same result. Tested with Chrome, IE and Firefox.
Is this a bug with the audio tag, or am I missing something?
Some of the code I'm using to play the audio files.
javascript function when playbutton is pressed
function playPlayerV2(src) {
document.getElementById("audioplayerV2").addEventListener("loadedmetadata", function (_event) {
console.log(player.duration);
});
var player = document.getElementById("audioplayer");
player.src = "source";
player.load();
player.play();
}
the audio tag in html
<audio controls="true" id="audioplayerV2" style="display: none;" preload="auto">
note: I'm hiding the standard audio player with the intend of using custom layout and make use of the player via javascript, this does not seem to be related to my problem.
try this
var getDuration = function (url, next) {
var _player = new Audio(url);
_player.addEventListener("durationchange", function (e) {
if (this.duration!=Infinity) {
var duration = this.duration
_player.remove();
next(duration);
};
}, false);
_player.load();
_player.currentTime = 24*60*60; //fake big time
_player.volume = 0;
_player.play();
//waiting...
};
getDuration ('/path/to/audio/file', function (duration) {
console.log(duration);
});
I think this is due to a chrome bug. Until it's fixed:
if (video.duration === Infinity) {
video.currentTime = 10000000;
setTimeout(() => {
video.currentTime = 0; // to reset the time, so it starts at the beginning
}, 1000);
}
let duration = video.duration;
This works for me
const audio = document.getElementById("audioplayer");
audio.addEventListener('loadedmetadata', () => {
if (audio.duration === Infinity) {
audio.currentTime = 1e101
audio.addEventListener('timeupdate', getDuration)
}
})
function getDuration() {
audio.currentTime = 0
this.voice.removeEventListener('timeupdate', getDuration)
console.log(audio.duration)
},
In case you control the server and can make it to send proper media header - this what helped the OP.
I faced this problem with files stored in Google Drive when getting them in Mobile version of Chrome. I cannot control Google Drive response and I have to somehow deal with it.
I don't have a solution that satisfies me yet, but I tried the idea from both posted answers - which basically is the same: make audio/video object to seek the real end of the resource. After Chrome finds the real end position - it gives you the duration. However the result is unsatisfying.
What this hack really makes - it forces Chrome to load the resource into the memory completely. So, if the resource is too big, or connection is too slow you end up waiting a long time for the file to be downloaded behind the scenes. And you have no control over that file - it is handled by Chrome and once it decides that it is no longer needed - it will dispose it, so the bandwidth may be spent ineficciently.
So, in case you can load the file yourself - it is better to download it (e.g. as blob) and feed it to your audio/video control.
If this is a Twilio mp3, try the .wav version. The mp3 is coming across as a stream and it fools the audio players.
To use the .wav version, just change the format of the source url from .mp3 to .wav (or leave it off, wav is the default)
Note - the wav file is 4x larger, so that's the downside to switching.
Not a direct answer but in case anyone using blobs came here, I managed to fix it using a package called webm-duration-fix
import fixWebmDuration from "webm-duration-fix";
...
fixedBlob = await fixWebmDuration(blob);
...
//If you want to modify the video file completely, you can use this package "webmFixDuration" Other methods are applied at the display level only on the video tag With this method, the complete video file is modified
webmFixDuration github example
mediaRecorder.onstop = async () => {
const duration = Date.now() - startTime;
const buggyBlob = new Blob(mediaParts, { type: 'video/webm' });
const fixedBlob = await webmFixDuration(buggyBlob, duration);
displayResult(fixedBlob);
};

HTML5 video full preload in javascript

I have a high quality video which I cannot compress too much as it's going to be the base of a lot of image analysis whereby each frame will be redrawn into the canvas and then manipulated.
I'm trying to preload the whole thing before playing it as I can't have the video stop, buffer and continue. Is there an event which I can listen for which signifies that the whole video has preloaded before I commence playback?
Here's how I'm doing it in JS/jQuery:
this.canvas = this.el.find("canvas")[0];
this.video = this.el.find("video")[0];
this.ctx = this.canvas.getContext("2d");
this.video.autoplay = false;
this.video.addEventListener("play",this.draw)
this.video.addEventListener("timeupdate",this.draw)
this.video.addeventlistener("ended",this.trigger("complete",this))
This will load the entire video in JavaScript
var r = new XMLHttpRequest();
r.onload = function() {
myVid.src = URL.createObjectURL(r.response);
myVid.play();
};
if (myVid.canPlayType('video/mp4;codecs="avc1.42E01E, mp4a.40.2"')) {
r.open("GET", "slide.mp4");
}
else {
r.open("GET", "slide.webm");
}
r.responseType = "blob";
r.send();
canplaythrough is the event that should fire when enough data has downloaded to play without buffering.
From the Opera teams excellent (although maybe very slightly dated now) resource Everything you need to know about HTML5 video and audio
If the load is successful, whether using the src attribute or using source elements, then as data is being downloaded, progress events are fired. When enough data has been loaded to determine the video's dimensions and duration, a loadedmetadata event is fired. When enough data has been loaded to render a frame, the loadeddata event is fired. When enugh data has been loaded to be able to play a little bit of the video, a canplay event is fired. When the browser determines that it can play through the whole video without stopping for downloading more data, a canplaythrough event is fired; this is also when the video starts playing if it has a autoplay attribute.
'canplaythrough' support matrix available here: https://caniuse.com/mdn-api_htmlmediaelement_canplaythrough_event
You can get around the support limitations by binding the load element to the same function, as it will trigger on those.
Download the video using fetch
Convert the response to a blob
Create an object URL from the blob (e.g. blob:http://localhost:8080/df3c4336-2d9f-4ba9-9714-2e9e6b2b8888)
async function preloadVideo(src) {
const res = await fetch(src);
const blob = await res.blob();
return URL.createObjectURL(blob);
}
Usage:
const video = document.createElement("video");
video.src = await preloadVideo("https://example.com/video.mp4");
Hope this could help you
var xhrReq = new XMLHttpRequest();
xhrReq.open('GET', 'yourVideoSrc', true);
xhrReq.responseType = 'blob';
xhrReq.onload = function() {
if (this.status === 200) {
var vid = URL.createObjectURL(this.response);
video.src = vid;
}
}
xhrReq.onerror = function() {
console.log('err' ,arguments);
}
xhrReq.onprogress = function(e){
if(e.lengthComputable) {
var percentComplete = ((e.loaded/e.total)*100|0) + '%';
console.log('progress: ', percentComplete);
}
}
xhrReq.send();
and then , if your video src has another domain ,you have to handle CORS .
So far the most trustable solution we found was to play it and wait for the buffer to be fully loaded.
Which means if the video is long, you will have to wait for almost all the video length.
That isn't cool, i know.
Wondering if someone has figured out some other magically reliable way of doing it ( ideally using something like PreloadJS which automatically falls back to flash when HTML5 video isn't supported ).
You can use this nice plugin:
https://github.com/GianlucaGuarini/jquery.html5loader
In its API there is a onComplete event that is triggered when the plugin finishes to load all the sources
Does this work?
video.onloadeddata = function(){
video.onseeked = function(){
if(video.seekable.end(0) >= video.duration-0.1){
alert("Video is all loaded!");
} else {
video.currentTime=video.buffered.end(0); // Seek ahead to force more buffering
}
};
video.currentTime=0; // first seek to trigger the event
};

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