About high-definition (HD) video

About high-definition (HD) video


High-definition (HD) video refers to any video format
with a resolution higher than standard-definition (SD)
video formats. Typically, standard-definition refers
to digital formats with resolutions close to those of analog TV standards, such
as NTSC and PAL (around 480 or 576 vertical lines, respectively). The most
common HD formats have resolutions of 1280 x 720 or 1920 x 1080, with a
widescreen aspect ratio of 16:9.
HD video formats include interlaced and noninterlaced varieties. Typically,
the highest-resolution formats are interlaced at the higher frame rates, because
noninterlaced video at this resolution would require a prohibitively high data
rate.
HD video formats are designated by their vertical resolution, scan mode, and
frame or field rate (depending on the scan mode). For example, 1080i60 denotes interlaced scanning of 60 interlaced
1920 x 1080 fields per second, whereas 720p30 denotes
progressive scanning of 30 noninterlaced 1280 x 720 frames per second. In both
cases, the frame rate is approximately 30 frames per second. For more
information on high-definition video, see www.adobe.com/go/learn_dv_primer_highdef.
Programs in Adobe Creative Suite 3 Production Premium (Adobe Premiere Pro,
Adobe After Effects, Adobe Soundbooth, and Adobe Encore) includes presets that
are designed for working with various HD formats. Some of the most common HD
video formats you may encounter include the following:
DVCPRO HD
Panasonic’s high-definition variant of its DVCPRO format, which also
includes DVCPRO25 and DVCPRO50. Whereas DVCPRO25 and DVCPRO50 support data rates
of 25Mbits/s (megabits per second) and 50Mbit/s, respectively, DVCPRO HD
supports a data rate of 100Mbit/s, from which it gets its other name, DVCPRO100.

HDCAM
Sony’s high-definition version of its Digital Betacam format. A variant
called HDCAM SR uses a tape with a higher particle density
to record video with greater color sampling and at higher bit rates. However,
HDCAM SR is supported by decks only, and not camcorders.

HDV
Developed jointly by several companies, HDV employs a form of MPEG‑2
compression to enable high-definition video to be encoded onto standard miniDV
cassette media.

H.264
Also known as MPEG‑4 part 10 and AVC
(Advanced Video Coding), H.264 can deliver video over a range of bitrates
more efficiently than previous standards. For example, H.264 can deliver the
same quality as MPEG‑2 at half the data rate. H.264 is built into the Apple
QuickTime 7 multimedia architecture, and it’s supported by both HD‑DVD and
Blu‑ray Disc, two newer DVD formats.

Uncompressed HD
High-definition video in an uncompressed format. Without compression to
reduce the video’s data rate, uncompressed video requires relatively fast
computer processors, hard disks, and a specialized capture device.

WM9 HDTV
Microsoft’s high-definition delivery format is among numerous formats
included in the Windows Media 9 (WM9) framework. By employing an aggressive
compression scheme, WM9 HDTV permits high-definition video encoding and playback
at relatively low data rates.

A Digital Video Primer:
Understanding and Using
High-Definition Video
Introduction

A Digital Video Primer:
Understanding and Using
High-Definition Video

Introduction

This document is for digital media professionals interested in moving to high-definition production, post-production, and distribution. It focuses on the powerful Adobe desktop applications Adobe After Effects and Adobe Premiere Pro, but it also includes information about how many other tools and products can be integrated into a high-definition video production workflow.

The two goals of this document are to help you understand what’s involved in making the transition to authoring and distributing high-definition content, and to help you get the best results from that transition.
What is high definition?
After years of anticipation, high definition (HD) video production has become widespread. Over-the-air HDTV is rapidly building an audience, and high definition DVD development is proceeding quickly. Even people not producing for an HD audience are using HD formats during production and post-production. For example, the pioneering DVD company, Criterion, uses HD on D5 tape for digital intermediates from their telecine captures. Suddenly, companies are finding that they have HD content to distribute and are looking for ways to distribute it.

The myth is that HD is very expensive and difficult to author. The reality is that HD has become cheaper and easier to use than standard definition (SD) was only a few years ago. Today, you can build a complete entry-level HD production system, including storage, software, and camera, for under U.S.$20,000. Higher-end and uncompressed HD editing systems can be much more expensive, but they are also declining in price as more options enter the market.

Types of HD

High definition simply means more than standard definition (SD). The highest resolution SD format is PAL, with 576 lines. Thus, almost any video frame with a vertical size greater than 576 lines is considered HD. If a final video is destined for playback on a computer monitor or a custom device, you can create your own frame dimensions. However, most HD video is either 1920 x 1080 or 1280 x 720, with a 16:9 aspect ratio.

http://www.adobe.com/designcenter/productionstudio/articles/prs1ip_hdprimer/prs1ip_hdprimer.pdf