Auto selects the resolution (automatic highest resolution is default) for video quality
// ==UserScript==
// @name Youtube Auto Resolution Selection
// @version 1.4
// @namespace http://userscripts.org/users/zackton
// @description Auto selects the resolution (automatic highest resolution is default) for video quality
// @include *.youtube.com/*
// @include *.youtube.com/
// @grant none
// ==/UserScript==
// Content inject so Chrome can access HTML5 player
function contentEval(source) {
if ('function' == typeof source) {
source = '(' + source + ')();'
}
var script = document.createElement('script');
script.setAttribute("type", "application/javascript");
script.textContent = source;
document.body.appendChild(script);
document.body.removeChild(script);
}
contentEval(function(){
var YP = new Object();
// Quality options from Youtube API
YP.quality_options = ['highres', 'hd1080', 'hd720', 'large', 'medium', 'small', 'default'];
// Playback quality (delete the qualities you don't want. e.g. if you want 720p max, delete the highres and hd1080 lines)
YP.quality = 'default';
YP.quality = 'small';
YP.quality = 'medium';
YP.quality = 'large';
YP.quality = 'hd720';
YP.quality = 'hd1080';
YP.quality = 'highres';
// Number of times to check for player before giving up
YP.max_attempts = 20;
// Initialize player, and make sure API is ready
YP.init = function() {
if (document.getElementById('movie_player')) {
// Normal video player
this.player = document.getElementById('movie_player');
}
else if (document.getElementById('movie_player-flash')) {
// Channel video player
this.player = document.getElementById('movie_player-flash');
}
else {
return false;
}
// Check for HTML5 player
this.html5 = this.player.getElementsByTagName('video').length ? true : false;
// Make sure player API is ready
if (typeof this.player.pauseVideo === 'undefined') {
return false;
}
// Pause to avoid flicker caused be loading a different quality
this.player.pauseVideo();
// In Chrome Flash player, player.setQualityLevel() doesn't seem to work unless video has started playing (or is paused)
// In Firefox HTML5 player, player.getPlayerState() returns -1 even if player is paused
if (!this.html5 && this.player.getPlayerState() < 1) {
return false;
}
// Everything is good to go
return true;
};
// Set video quality to YP.quality or highest available
YP.setQuality = function() {
// Get available quality levels
var levels = this.player.getAvailableQualityLevels();
// Set playback quality
if (levels.indexOf(this.quality) >= 0) {
this.player.setPlaybackQuality(this.quality);
}
else {
this.player.setPlaybackQuality(levels[0]);
}
// Play video
this.player.playVideo();
}
// Start execution
YP.start = function(attempts) {
// Initialize self (look for player)
if (this.init()) {
this.setQuality();
return true;
}
// Give up (page has no player)
if (attempts > this.max_attempts) {
return false;
}
// Try again until initialize sucessful (maybe page still loading)
setTimeout(function() {
YP.start(++attempts);
}, 200);
}
// Main
YP.start(0);
});