Explaining YouTube’s VERY Cool New Aspect Ratio Changes

YouTube very quietly made a very cool and rather major improvement in their desktop video players today. I noticed it immediately this morning and now have confirmation both from testing with my own YT videos (for which I know all the native metadata) and via informal statements from Google.

YouTube is now adjusting the YT player size to match videos’ native aspect ratios. This is a big deal, and very much welcome.

Despite the fact that I’m publicly critical from time to time regarding various elements of YouTube content-related policies, this does not detract from the fact that I’m one of YT’s biggest fans. I spend a lot of time in YT, and I consider it to be a news, information, education, and entertainment wonder of the world. Its scale is staggering large — so we can’t reasonably expect perfection — and frankly I don’t even want to think about life without YT.

Excuse me while I put on my video engineering hat for a moment …

One of the more complicated facets of video — played out continuously on YouTube — is aspect ratios. A modern high definition TV (HDTV) video is normally displayed at a 16 (horizontal) by 9 (vertical) aspect ratio – significantly wider than high. The older standard definition TV ratio is 4:3 — just a bit wider than high, and visually very close to the traditional 35mm film aspect ratio of 3:2.

When displaying video, the typical techniques to display different aspect ratios on different fixed ratio display systems have been to either modify the actual contents of the visible video frames themselves, or to fit more of the original frames into the display area by reducing their overall relative sizes and providing “fillers” for any remaining areas of the display. 

The “modification of contents” technique usually has the worst results. Techniques such as “pan and scan” were traditionally used to show only portions of widescreen movie frames on standard 4:3 TVs, simply cutting off much of the action. Ugh. 

But eventually, especially as 4:3 television screens became larger in many homes, the much superior “letterboxing” technique came into play, displaying black bars on the top and bottom of the screen to permit the entire (or at least most) of widescreen film frames to be displayed on a 4:3 cathode ray tube. In the early days of this process, it was common to see squiggles and such in those bars — networks and local stations were concerned that viewers would assume that something was wrong with their televisions if empty black bars were present without some sort of explanations — and sometimes broadcasters would even provide such explanations at the start of the film — sometimes they still do even with HDTV! Very widescreen films shown on 16:9 displays today may still use letterboxing to permit viewing more of the frame that would otherwise exceed the 16:9 ratio.

When 16:9 HDTV arrived, the opposite of the standard definition TV problem appeared. Now to properly display a traditional 4:3 standard TV image, you needed to put black bars on the right and left side of the screen — “pillarboxing” is the name usually given to this technique, and it’s widely used on many broadcast, satellite, streaming, and other video channels. It is in fact by far the preferred technique to display 4:3 content on a fixed aspect ratio 16:9 physical display.

After YouTube switched from a 4:3 video player to their standard 16:9 player years ago, you started seeing some YT uploaders zooming in on 4:3 videos to make them “fake” 16:9 videos before uploading, to fill the 16:9 player — resulting in grainy and noisy images, with significant portions of the original video chopped off. The same thing is done by some TV broadcasters and other video channels, documentary creators, and others who have this uncontrollable urge to fill the entire screen, no matter what! These drive me nuts.

Up until today, YouTube handled the display of native 4:3 videos by using the pillarbox technique within their 16:9 player. Completely reasonable, but of necessity wasting significant areas of the screen taken up by the black pillarbox bars.

This all changed this morning. The YouTube player now adapts to the native aspect ratio of the video being played, instead of always being a fixed 16:9. This means for example that a native 4:3 video now displays in a 4:3 player, with no pillarboxing required — and with significant viewable screen real estate recovered to actually display video rather than pillarboxing bars. In effect, these videos today are displaying similarly to how they would have in the early days of YT — fully filling the video display area — as had been the case before YT switched to fixed aspect ratio 16:9 players. Excellent! 

The same goes for other aspect ratios, in particular such as 16:9 used by most more recent videos, so 16:9 videos will continue to display in a 16:9 player.

One aspect (no pun intended) to keep in mind. The player will apparently adapt to the native video resolution as uploaded. So if a video was uploaded as 4:3, you’ll get a 4:3 player. But if (for example) a 4:3 video was already converted to 16:9 by pillarboxing before being uploaded, YouTube’s encoding pipeline is going to consider this to be a native 16:9 video and display it in a 16:9 player with the black bar pillars intact. Bottom line: If you have 4:3 material to upload, don’t change its aspect ratio, just upload it as native 4:3, pretty please!

Since I watch a fair bit of older videos on YouTube that tend to be in 4:3 aspect ratio, the changes YT made today are great for me. But having the YT player adjust to various native aspect ratios is going to be super for all YT users in the long run. It may take a little time for you to adapt to seeing the player size and shape vary from video to video, but you’ll get used to it. And trust me, you’ll come to love it.

Great work by YouTube. My thanks to the entire YouTube team!