I would like to display a video from a Javascript Blob/File object in the HTML5 video tag.
This code only works for small videos :
var reader = new FileReader();
reader.onload = function(e) {
document.getElementById("video").src=reader.result;
}
reader.readAsDataURL(vid);
I cannot use this for big videos (> 10MB). Is there a solution to display a big video from a blob object in HTML 5?
I've found. It was so simple that I didnt even see it...
/**
* @param {Blob} videoFile
* @param {HTMLVideoElement} videoEl
* @returns {void}
*/
function display( videoFile, videoEl ) {
// Preconditions:
if( !( videoFile instanceof Blob ) ) throw new Error( '`videoFile` must be a Blob or File object.' ); // The `File` prototype extends the `Blob` prototype, so `instanceof Blob` works for both.
if( !( videoEl instanceof HTMLVideoElement ) ) throw new Error( '`videoEl` must be a <video> element.' );
//
const newObjectUrl = URL.createObjectURL( videoFile );
// URLs created by `URL.createObjectURL` always use the `blob:` URI scheme: https://w3c.github.io/FileAPI/#dfn-createObjectURL
const oldObjectUrl = videoEl.currentSrc;
if( oldObjectUrl && oldObjectUrl.startsWith('blob:') ) {
// It is very important to revoke the previous ObjectURL to prevent memory leaks. Un-set the `src` first.
// See https://developer.mozilla.org/en-US/docs/Web/API/URL/createObjectURL
videoEl.src = ''; // <-- Un-set the src property *before* revoking the object URL.
URL.revokeObjectURL( oldObjectUrl );
}
// Then set the new URL:
videoEl.src = newObjectUrl;
// And load it:
videoEl.load(); // https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement/load
}
vid parameter?
In some case blobObject.data should be provided in createObjectURL() method. See this simple trick:
function playVideo(videoStream){ // as blob
var video = document.querySelector('video');
var videoUrl=window.URL.createObjectURL(videoStream.data);// blob.data gives actual data
video.src = videoUrl;
}
Blob type does not have a property named data, so your videoStream object is not actually Blob but some other type. See developer.mozilla.org/en-US/docs/Web/API/Blob