Records YouTube live streams and videos directly from the browser
// ==UserScript==
// @name YouTube - Recorder
// @namespace https://greasyfork.org/ja/users/941284-ぐらんぴ
// @version 2025-12-09
// @description Records YouTube live streams and videos directly from the browser
// @author ぐらんぴ
// @match https://*.youtube.com/*
// @icon https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant none
// @run-at document-start
// @require https://greasyfork.org/scripts/433051-trusted-types-helper/code/Trusted-Types%20Helper.js
// @license MIT
// ==/UserScript==
let S = {
bitsPerSecond: 20000000, // default 20 Mbps
format: 'mp4' // 'webm' or 'mp4'
};
let $s = (el) => document.querySelector(el), $sa = (el) => document.querySelectorAll(el), $c = (el) => document.createElement(el)
let recorder, chunks, isRecording = false, seconds = 0, timerInterval;
window.addEventListener("yt-navigate-finish", e => {
if (e.detail.pageType == "watch") {
let btn = $c('button');
btn.textContent = ` [RECORD]`;
btn.className = "GRMP";
btn.style.cursor = "pointer";
btn.style.color = "white";
btn.style.background = "none";
btn.style.border = "none";
btn.style.cursor = "pointer";
btn.addEventListener("click", () => {
const video = $s("video");
if (!video) {
alert("Video element not found.");
return;
}
if (video.paused || video.readyState < 3) {
video.play().catch(err => console.warn("Video play failed:", err));
}
if (!isRecording) {
try {
let stream;
let recorderStream;
if (navigator.userAgent.indexOf('Firefox') > -1) { // Firefox
const audioCtx = new AudioContext();
const sourceNode = audioCtx.createMediaElementSource(video);
const destinationNode = audioCtx.createMediaStreamDestination();
sourceNode.connect(audioCtx.destination); // keep audio playback
sourceNode.connect(destinationNode); // send to recorder
stream = video.mozCaptureStream ? video.mozCaptureStream() : video.captureStream();
recorderStream = new MediaStream([
...stream.getVideoTracks(),
...destinationNode.stream.getAudioTracks()
]);
} else { // Chromium
recorderStream = video.captureStream();
}
if (!recorderStream) {
alert("Failed to capture stream");
return;
}
// MIME 候補（MP4 を優先する場合と WEBM のみ）
const mp4Candidates = [
'video/mp4;codecs="avc1.42E01E, mp4a.40.2"',
'video/mp4;codecs="avc1.42E01E"',
'video/mp4'
];
const webmCandidates = [
'video/webm;codecs=vp9,opus',
'video/webm;codecs=vp8,opus',
'video/webm'
];
// format 設定に基づいて MIME を選択
let mime = null;
function chooseMimeByFormat(format) {
try {
if (format === 'mp4') {
for (const m of mp4Candidates) {
try { if (MediaRecorder.isTypeSupported && MediaRecorder.isTypeSupported(m)) return m; } catch (e) {}
}
// mp4 がサポートされない場合は webm を試す（フォールバック）
for (const m of webmCandidates) {
try { if (MediaRecorder.isTypeSupported && MediaRecorder.isTypeSupported(m)) return m; } catch (e) {}
}
return null;
} else { // 'webm' 指定
for (const m of webmCandidates) {
try { if (MediaRecorder.isTypeSupported && MediaRecorder.isTypeSupported(m)) return m; } catch (e) {}
}
return null;
}
} catch (e) {
return null;
}
}
mime = chooseMimeByFormat(String(S.format || 'webm').toLowerCase());
// ユーザーに通知: MP4 を要求したがサポートされない場合
if (String(S.format || 'webm').toLowerCase() === 'mp4') {
// mp4 を要求したが mime が webm になった場合は通知
const mp4Supported = (function () {
try {
for (const m of mp4Candidates) {
if (MediaRecorder.isTypeSupported && MediaRecorder.isTypeSupported(m)) return true;
}
} catch (e) {}
return false;
})();
if (!mp4Supported) {
// mp4 未サポート。ユーザーに知らせる（だが録画は続行）
console.warn('Browser does not support MediaRecorder MP4 output. Falling back to WebM.');
}
}
const options = mime
? { mimeType: mime, bitsPerSecond: Number(S.bitsPerSecond) || undefined }
: (Number(S.bitsPerSecond) ? { bitsPerSecond: Number(S.bitsPerSecond) } : undefined);
recorder = options ? new MediaRecorder(recorderStream, options) : new MediaRecorder(recorderStream);
chunks = [];
recorder.ondataavailable = e => { if (e.data && e.data.size) chunks.push(e.data); };
recorder.onstop = () => {
clearInterval(timerInterval);
btn.textContent = ` [RECORD]`;
// 実際のチャンクから Blob を作成（MIME は最初のチャンクの type を参照）
const blobType = (chunks[0] && chunks[0].type) ? chunks[0].type : (mime || 'video/webm');
const blob = new Blob(chunks, { type: blobType });
// 拡張子決定: 実際の blob.type を優先、なければ S.format を参照
let ext = 'webm';
if (blob.type.includes('mp4') || blob.type.includes('x-m4v') || blob.type.includes('quicktime')) ext = 'mp4';
else if (blob.type.includes('webm')) ext = 'webm';
else {
// blob.type が空や不明な場合は S.format を参照
ext = (String(S.format || 'webm').toLowerCase() === 'mp4') ? 'mp4' : 'webm';
}
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
const now = new Date();
const month = String(now.getMonth() + 1).padStart(2, '0');
const day = String(now.getDate()).padStart(2, '0');
try {
a.download = location.search.slice(3) + "_" + month + "-" + day + "." + ext;
} catch (e) {
a.download = location.hostname + "_" + month + "-" + day + "." + ext;
}
a.click();
setTimeout(() => URL.revokeObjectURL(url), 10000);
// もしユーザーが MP4 を期待していて実際は WEBM だった場合、簡単な案内を表示
if (String(S.format || 'webm').toLowerCase() === 'mp4' && ext !== 'mp4') {
// 一度だけ表示（console と alert）
console.warn('Requested MP4 but recorded format is not MP4.');
}
};
recorder.start();
isRecording = true;
seconds = 0;
btn.textContent = formatTime(seconds);
timerInterval = setInterval(() => {
seconds++;
btn.textContent = formatTime(seconds);
}, 1000);
} catch (e) { alert("Recording failed: " + e); }
} else {
recorder.stop();
isRecording = false;
clearInterval(timerInterval);
btn.textContent = ` [RECORD]`;
}
});
if (!$s('.GRMP')) {
if ($s('.ytp-right-controls') == null) {
const intervalId = setInterval(() => {
console.log('a')
if (!$s('.ytp-right-controls')) return;
clearInterval(intervalId);
$s('.ytp-right-controls').appendChild(btn);
}, 500);
} else $s('.ytp-right-controls').appendChild(btn);
}
function formatTime(sec) {
const m = String(Math.floor(sec / 60)).padStart(2, '0');
const s = String(sec % 60).padStart(2, '0');
return ` [${m}:${s}]`;
}
}
});