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Youtube Auto Resolution Selection

Auto selects the resolution (automatic highest resolution is default) for video quality

当前为 2017-05-18 提交的版本，查看 最新版本。

  1. // ==UserScript==
  2. // @name         Youtube Auto Resolution Selection
  3. // @version      1.4
  4. // @namespace    http://userscripts.org/users/zackton
  5. // @description  Auto selects the resolution (automatic highest resolution is default) for video quality
  6. // @include      *.youtube.com/*
  7. // @include      *.youtube.com/
  8. // @grant        none
  9. // ==/UserScript==
  10.  
  11. // Content inject so Chrome can access HTML5 player
  12. function contentEval(source) {
  13. 	if ('function' == typeof source) {
  14. 		source = '(' + source + ')();'
  15. 	}
  16. 	var script = document.createElement('script');
  17. 	script.setAttribute("type", "application/javascript");
  18. 	script.textContent = source;
  19. 	document.body.appendChild(script);
  20. 	document.body.removeChild(script);
  21. }
  22.  
  23. contentEval(function(){
  24.  
  25. var YP = new Object();
  26.  
  27. // Quality options from Youtube API
  28. YP.quality_options = ['highres', 'hd1080', 'hd720', 'large', 'medium', 'small', 'default'];
  29.  
  30.  // Playback quality (delete the qualities you don't want. e.g. if you want 720p max, delete the highres and hd1080 lines)
  31.  YP.quality = 'default';
  32.  YP.quality = 'small';
  33.  YP.quality = 'medium';
  34.  YP.quality = 'large';
  35.  YP.quality = 'hd720';
  36.  YP.quality = 'hd1080';
  37.  YP.quality = 'highres';
  38.  
  39.  
  40. // Number of times to check for player before giving up
  41. YP.max_attempts = 20;
  42.  
  43. // Initialize player, and make sure API is ready
  44. YP.init = function() {
  45. 			if (document.getElementById('movie_player')) {
  46. 			// Normal video player
  47. 			this.player = document.getElementById('movie_player');
  48. 		}
  49. 		else if (document.getElementById('movie_player-flash')) {
  50. 			// Channel video player
  51. 			this.player = document.getElementById('movie_player-flash');
  52. 		}
  53. 		else {
  54. 			return false;
  55. 		}
  56. 	
  57. 		// Check for HTML5 player
  58. 		this.html5 = this.player.getElementsByTagName('video').length ? true : false;
  59.  
  60. 		// Make sure player API is ready
  61. 		if (typeof this.player.pauseVideo === 'undefined') {
  62. 			return false;
  63. 		}
  64. 	
  65. 		// Pause to avoid flicker caused be loading a different quality
  66. 		this.player.pauseVideo();
  67. 	
  68. 		// In Chrome Flash player, player.setQualityLevel() doesn't seem to work unless video has started playing (or is paused)
  69. 		// In Firefox HTML5 player, player.getPlayerState() returns -1 even if player is paused
  70. 		if (!this.html5 && this.player.getPlayerState() < 1) {
  71. 			return false;
  72. 		}
  73. 	
  74. 		// Everything is good to go
  75. 		return true;
  76. 	};
  77. 	
  78. 	// Set video quality to YP.quality or highest available
  79. 	YP.setQuality = function() {
  80. 		// Get available quality levels
  81. 		var levels = this.player.getAvailableQualityLevels();
  82. 		// Set playback quality
  83. 		if (levels.indexOf(this.quality) >= 0) {
  84. 			this.player.setPlaybackQuality(this.quality);
  85. 		}
  86. 		else {
  87. 			this.player.setPlaybackQuality(levels[0]);
  88. 		}
  89. 		// Play video
  90. 		this.player.playVideo();
  91. 	}
  92. 	
  93. 	// Start execution
  94. 	YP.start = function(attempts) {
  95. 		// Initialize self (look for player)
  96. 		if (this.init()) {
  97. 			this.setQuality();
  98. 			return true;
  99. 		}
  100. 		// Give up (page has no player)
  101. 		if (attempts > this.max_attempts) {
  102. 			return false;
  103. 		}
  104. 		// Try again until initialize sucessful (maybe page still loading)
  105. 		setTimeout(function() {
  106. 			YP.start(++attempts);
  107. 		}, 200);
  108. 	}
  109. 	
  110. 	// Main
  111. 	YP.start(0);
  112. 	
  113. });