// ==UserScript==
// @name         雨课堂追帧
// @version      0.1.1
// @description  雨课堂直播追帧：保持延迟在 3s 内
// @author       panda2134
// @match        *://*.yuketang.cn/*
// @run-at       document-idle
// @grant        none
// @namespace https://greasyfork.org/users/379925
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    function checkLatency() {
        var player = document.getElementById('player');
        var latency = player.buffered.end(0) - player.currentTime;
        var MAX_LATENCY = 3.00;
        console.log('Latency:' + latency);
        if (latency > MAX_LATENCY) {
            console.log('追帧');
            player.playbackRate = 1.1;
            player.ontimeupdate = function() {
                if(player.buffered.end(0) - player.currentTime < 1) {
                    player.playbackRate = 1.00;
                }
            };
        }
    }
    setInterval(checkLatency, 500);
})();