Flanico.user.js

// ==UserScript==
// @name        Flanico
// @namespace   FlandreDaisuki
// @description A HTML5 based niconico player
// @include     http://www.nicovideo.jp/watch/*
// @match       http://www.nicovideo.jp/watch/*
// @exclude     
// @version     2015.07.14
// @grant       none
// ==/UserScript==
'use strict';

function queryToObject(query) {
    var pattern = [
        ['%', /\%25/g],
        ['&', /\%26/g],
        ['/', /\%2F/g],
        [':', /\%3A/g],
        ['=', /\%3D/g],
        ['?', /\%3F/g]
    ];
    for (var i = 0; i < pattern.length; i++) {
        query = query.replace(pattern[i][1], pattern[i][0]);
    }
    var retobj = {};
    query.split('&').forEach(function(str) {
        var keyvalue = /(^[\w|\_]+)=(.*)/.exec(str);
        if (/\%/.test(keyvalue[2])) {
            keyvalue[2] = decodeURIComponent(keyvalue[2]);
        }
        retobj[keyvalue[1]] = keyvalue[2];
    });
    return retobj;
}

function cleanChild(elem) {
    while(elem.children.length > 0){
        elem.removeChild(elem.children.item(0));
    }
}

window.Flanico = {};
//get flv data
Flanico.watchAPIData = JSON.parse(document.querySelector('#watchAPIDataContainer').innerHTML);
Flanico.flvinfo = queryToObject(Flanico.watchAPIData.flashvars.flvInfo);

//set my area
Flanico.stage = document.createElement('div');
Flanico.stage.id = 'FlanicoStage';
Flanico.stage.style.height = '100%';
Flanico.stage.style.width = '100%'

//replace flash to my area
cleanChild(document.querySelector('#playerAlignmentArea'));
document.querySelector('#playerAlignmentArea').appendChild(Flanico.stage);

//add just HTML5 video
Flanico.video = document.createElement('video');
Flanico.video.innerHTML = 'HTML5 media not support';
Flanico.videoSource = document.createElement('source');
Flanico.videoSource_low = document.createElement('source');
if ( Flanico.flvinfo.url.slice( -3 ) === 'low' ) {
    Flanico.videoSource.src = Flanico.flvinfo.url.slice( 0, -3 );
    Flanico.videoSource_low.src = Flanico.flvinfo.url;
} else {
    Flanico.videoSource.src = Flanico.flvinfo.url;
    Flanico.videoSource_low.src = Flanico.flvinfo.url + 'low';
}

Flanico.video.appendChild(Flanico.videoSource_low);
Flanico.video.appendChild(Flanico.videoSource);
Flanico.stage.appendChild(Flanico.video);
Flanico.video.controls = true;

// remove chrome notification
document.querySelector('.notify_update_flash_player').remove();