Page 91 - SKU-000506274_TEXT.indd

70 P a r t I I Producing Your YouTube Videos

Understanding Video Resolution

The physical size of a video picture is measured in terms of pixels. A pixel is, quite
simply, the smallest discrete picture element. The physical size of a pixel is different
on different video capture and display devices, so a picture that’s 800 pixels wide
might be bigger on one computer display than on another. The point, however, is
that you measure resolution in pixels; the more pixels in a picture, the higher reso-
lution—and the better the quality.

Standard Versus High Definition

A standard definition television (SDTV) picture has a resolution of 640 pixels wide
by 480 pixels tall—or what we call 640×480 resolution. It doesn’t matter what physi-
cal size the TV screen is; a 15" screen has the same 640×480 resolution as a 35"
screen.

Notice that I used the term standard definition. This is different from the new high
definition television (HDTV) standard—or, to be more precise, standards, plural.
There are actually several different resolutions used in HDTV broadcasts and dis-
plays, all of which are much higher quality than the older standard resolution pic-
ture.

The two most common HD resolutions are 720×1280 (known as 720p resolution)
and 1080×1920 (used in both 1080i and 1080p displays). As you can tell from the
numbers, HD packs a lot more pixels in the same screen area, resulting in much
sharper pictures.

Note

HDTV also features a wider screen. A standard definition screen has an
aspect ratio of 4:3—that is, the width is 4/3 the height. An HDTV screen
has an aspect ratio of 16:9—the width is 16/9 the height. When you view
a 16:9 picture on a 4:3 display, you see black bars above and below the
picture, a feature known as letterboxing.

YouTube Resolution

Are you confused yet? There’s no need to be. The bottom line is that YouTube lets
you use just about any video resolution available, from standard definition to high
definition—and then some.

It hasn’t always been that way. When YouTube first launched, it played back every
single video, no matter the original resolution, at 320×240 pixels. Now, that resolu-