Посмотрите это в Firefox - установите Greasemonkey и добавьте этот скрипт . Позволяет переключаться между соотношениями (4: 3 и 16: 9).
Код обновляется с этого (для Firefox и Chrome)
// ==UserScript== // @name Youtube Aspect Remake // @description Adds buttons to toggle 4:3 and 16:9 aspect ratios on youtube, probs to the great work of scupizzaboy who mades this script. I've just changed the buttons to make them more adapt at the new youtube design. Original Script: http://userscripts.org/scripts/show/101165 // @namespace NoXPhasma // @include http://youtube.*/* // @include http://*.youtube.*/* // @include https://youtube.*/* // @include https://*.youtube.*/* // @version 9 // @date 2012-15-03 // ==/UserScript== function setAspectWide() { document = unsafeWindow.document; var player = document.getElementById('movie_player'); var flashvars = player.getAttribute('flashvars').split('&'); for (var i = 0; i < flashvars.length; i++) { if (flashvars[i].indexOf('keywords') == 0) { var keywords = flashvars[i].split('=')[1].split(','); var found = false; for (var j = 0; j < keywords.length; j++) { if (decodeURIComponent(keywords[j]) == 'yt:stretch=4:3') { keywords[j] = encodeURIComponent('yt:stretch=16:9'); found = true; } } if (found == false) { keywords.push(encodeURIComponent('yt:stretch=16:9')); } flashvars[i] = 'keywords=' + keywords.join(','); } } player.setAttribute('flashvars', flashvars.join('&')); player.src += ""; } function setAspectNarrow() { document = unsafeWindow.document; var player = document.getElementById('movie_player'); var flashvars = player.getAttribute('flashvars').split('&'); for (var i = 0; i < flashvars.length; i++) { if (flashvars[i].indexOf('keywords') == 0) { var keywords = flashvars[i].split('=')[1].split(','); var found = false; for (var j = 0; j < keywords.length; j++) { if (decodeURIComponent(keywords[j]) == 'yt:stretch=16:9') { keywords[j] = encodeURIComponent('yt:stretch=4:3'); found = true; } } if (found == false) { keywords.push(encodeURIComponent('yt:stretch=4:3')); } flashvars[i] = 'keywords=' + keywords.join(','); } } player.setAttribute('flashvars', flashvars.join('&')); player.src += ""; } function fixWindowBox() { document = unsafeWindow.document; var player = document.getElementById('movie_player'); var flashvars = player.getAttribute('flashvars').split('&'); for (var i = 0; i < flashvars.length; i++) { if (flashvars[i].indexOf('keywords') == 0) { var keywords = flashvars[i].split('=')[1].split(','); var found = false; for (var j = 0; j < keywords.length; j++) { if (decodeURIComponent(keywords[j]) == 'yt:crop=16:9') { found = true; } } if (found == false) { keywords.push(encodeURIComponent('yt:crop=16:9')); } flashvars[i] = 'keywords=' + keywords.join(','); } } player.setAttribute('flashvars', flashvars.join('&')); player.src += ""; } var target = document.getElementById('watch-actions'); var group = document.createElement('span'); group.setAttribute("class", "yt-uix-button-group"); target.appendChild(group); var button = document.createElement('input'); button.setAttribute("class", "start yt-uix-tooltip-reverse yt-uix-button yt-uix-button-default yt-uix-tooltip"); button.setAttribute("style", 'width:17px;height:2.77em;padding:0px 6px'); button.setAttribute("value", '4:3'); button.setAttribute("title", "Stretch to 4:3"); button.addEventListener('click', setAspectNarrow, false); group.appendChild(button); var button = document.createElement('input'); button.setAttribute("class", "middle yt-uix-tooltip-reverse yt-uix-button yt-uix-button-default yt-uix-tooltip"); button.setAttribute("style", 'width:24px;height:2.77em;padding:0px 6px'); button.setAttribute("value", '16:9'); button.setAttribute("title", "Stretch to 16:9"); button.addEventListener('click', setAspectWide, false); group.appendChild(button); var button = document.createElement('input'); button.setAttribute("class", "end yt-uix-tooltip-reverse yt-uix-button yt-uix-button-default yt-uix-tooltip"); button.setAttribute("style", 'width:24px;height:2.77em;padding:0px 6px'); button.setAttribute("value", 'Zoom'); button.setAttribute("title", "Fix Windowboxing"); button.addEventListener('click', fixWindowBox, false); group.appendChild(button);