When I try to fetch MediaSource object via blob link or send GET XMLHttpRequest I'm getting the error net::ERR_FILE_NOT_FOUND. This happened for youtube or instagram MediaSource links. eg
var xhr = new XMLHttpRequest;
xhr.open('get', url);
xhr.responseType = 'arraybuffer';
xhr.onload = function () {
some_Further_CallBack(xhr.response);
};
xhr.send();
I'm completelly stuck, please say me what I'm doing wrong.
The blob: URL when created from a MediaSource can not be fetched from that URL. Note that even when it's created from a Blob, it's not the same Blob object that you fetch.
The best is to keep your MediaSource instance available in a variable, but in cases you can't (e.g because you're not the author of the page), you can add some hooks on the URL methods to save the original object and retrieve it later as exposed in this answer of mine. But note that you'd need this script to be ran BEFORE the page's use of URL.creatObjectURL(), which means that in your case you will probably need an user-script to inject it as soon as possible.