index.player.js

/**
 * Created by xieting on 2017/11/8.
 */

module.exports = PearPlayer;

var debug = require('debug')('pear:player');
var inherits = require('inherits');
var render = require('render-media');
var PearDownloader = require('./src/index.downloader');
var WebTorrent = require('webtorrent');

inherits(PearPlayer, PearDownloader);

function PearPlayer(selector, token, opts) {

    var self = this;
    if (!(self instanceof PearPlayer)) return new PearPlayer(selector, token, opts);
    if (typeof token === 'object') return PearPlayer(selector, '', token);
    if (!opts) opts = {};
    if (typeof selector === 'string') {
        self.video = document.querySelector(selector);        
    } else if (Object.prototype.toString.call(selector) === '[object HTMLVideoElement]') {
        self.video = selector;
    } else {
        throw new Error('illegal video selector');
    }
    opts.selector = selector;
    opts.render = render;
    opts.sequencial = true;                           //player必须有序下载buffer
    opts.interval = 3000;
    if (!opts.algorithm) opts.algorithm = 'pull';     //algorithm默认‘pull’

    //monitor
    self.canPlayDelayStart = (new Date()).getTime();

    if (opts.BTMode && opts.magnetURI) {

        var client = new WebTorrent();

        return client.add(opts.magnetURI, function (torrent) {
            // Got torrent metadata!
            // debug('Client is downloading:', torrent.infoHash)

            torrent.files.forEach(function (file) {

                render.render(file, opts.selector, {autoplay: opts.autoplay});
            })
        })

    }

    PearDownloader.call(self, opts.src || self.video.src, token, opts);

    self.setupListeners();
}

PearPlayer.prototype.setupListeners = function () {
    var self = this;

    self.video.addEventListener('canplay', function () {

        self.canPlayDelayEnd = (new Date()).getTime();
        var canPlayDelay = (self.canPlayDelayEnd - self.canPlayDelayStart);
        self.emit('canplay', canPlayDelay);


    });

    self.video.addEventListener('loadedmetadata', function () {

        var dispatcher = self.dispatcher;

        if (dispatcher) {
            var bitrate = Math.ceil(dispatcher.fileSize/self.video.duration);
            var windowLength = Math.ceil(bitrate * 15 / dispatcher.pieceLength);       //根据码率和时间间隔来计算窗口长度
            // console.warn('dispatcher._windowLength:'+dispatcher._windowLength);
            // self.normalWindowLength = self._windowLength;
            if (windowLength < 3) {
                windowLength = 3;
            } else if (self._windowLength > 15) {
                windowLength = 15;
            }
            dispatcher._windowLength = windowLength;
            dispatcher.interval = 5000;
            // console.warn('dispatcher._windowLength:'+dispatcher._windowLength);
            // self._colddown = 5/self._slideInterval*self._interval2BufPos + 5;                        //窗口滑动的冷却时间
            // self._colddown = self._windowLength*2;
            // self._colddown = 5;
            self.emit('metadata', {'bitrate': bitrate, 'duration': self.video.duration});
        }


    });

}

PearPlayer.isWebRTCSupported = function () {
    return PearDownloader.isWebRTCSupported();
};

PearPlayer.isMSESupported = function () {
    return isMSESupported();
};

function isMSESupported() {

    return !!(window['MediaSource'] || window['WebKitMediaSource']);

}