bch-pip.user.js

// ==UserScript==
// @name         bandai channel picture in picture
// @namespace    https://rinsuki.github.io/
// @version      0.1
// @description  バンダイチャンネルのHTML5プレーヤーでPicture in Pictureを利用できるようにします
// @author       You
// @match        http://www.b-ch.com/ttl/index_html5.php?*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    var b = document.createElement("button")
    b.innerText = "Picture in Picture"
    b.onclick = () => {
        var video = document.getElementById("bchplayer_html5_api")
        console.log(video.webkitPresentationMode)
        video.webkitSetPresentationMode(video.webkitPresentationMode == "inline" ? "picture-in-picture" : "inline")
    }
    document.getElementById("player-info").appendChild(b)
})();