The Digital Television Standard is Broken

By Peter K. Sheerin

America’s HDTV standard is horrendously complex and will produce confusion instead of high-definition images unless it is fixed. This article describes what is wrong, why it is wrong, and how to fix it.

Something has to be done about the so-called High-Definition Television standard currently being promulgated in the U.S. Having strayed far from its original goal of vastly improving the resolution and clarity of television broadcasts, HDTV has become a monstrosity of convoluted standards (28 different picture standards instead of today’s one). The current implementation needs to be re-evaluated and modified—perhaps slightly and perhaps drastically. There is no way that the average American household will embrace the technology given is convoluted development and competing interests. Twenty-eight video formats is far too many, and most of them do not really provide a high-definition viewing experience. This, coupled by the ability for broadcasters to broadcast low-definition signals instead and use the “leftover” bandwidth for other uses (such as data transmission or other channels) will leave this nation with a television standard that is not only convoluted but which doesn’t provide the image quality necessary to improve its usability.

This situation must be fixed by ripping all of the poor-quality formats from the HDTV standard, mandating that stations broadcasting the new digital signals actually broadcast a full-definition signal and not subdivide it for data services or other stations. To do otherwise would cheat the public of the best use of the precious, publicly-held spectrum.

Sub(standard) Channels

One of the worst aspects of the HDTV standard is that it allows station owners to broadcast multiple low-definition signals instead of one high-quality image (or one low-definition image and then resell the “leftover” space). If you thought navigating all those channels on your cable system or satellite dish was confusing, just wait until you have to deal with channels 26.1, 26.2, 26.3, and 26.4. Think I'm kidding? Station WETA is doing just that—and warning viewers that they “cannot give specific instructions for each make and model and suggest you refer to your owners manual for more information on channel navigation for your receiver.” Can you imagine anything so silly?

Interlaced Needs to Go

In crafting the standard, one of the worst aspects of today’s 50-year old analog television standard is retained and even included in the so-called highest resolution modes. Interlacing divides each image divides each image frame into two fields, each of which contains every-other scan line of the original frame. This causes a significant reduction in resolution, introduces blurry motion artifacts, and flicker. The computer industry briefly produced monitors that worked in this way, and the poor resulting image quality quickly relegated this design to the scrap heap. Why then, should we put up with this in the HDTV standard? Some may say for compatibility, but if so, it should only exist in the lowest-definition signal, not the highest.

More details on my suggested reform will follow, but basically the implementation needs to be simplified and made as robust as possible. This means no more than a handful of formats—1080 progressive × 30 (or 60) fps for standard TV broadcasts, 1080 progressive × 24 fps for motion picture broadcasts (exclusively for movies originally shot on film), and perhaps one other format for backwards compatibility. No more should today’s archaic NTSC-resolution signal be allowed to masquerade as an HDTV broadcast. And the broadcast standard (whether the current VSB-8 or something else) must enable HDTV signals to be received by both stationary and mobile receivers—period. And the encoding standard must provide sufficient bandwidth to allow high-quality images to be broadcast—the signals must not be constrained so much that the blocky motion artifacts typical of high-motion video are visible even faintly visible.

28 Standards, What Do You Get?

The Advanced Television Systems Committee (ATSC) created a standard that allows broadcasters to choose which among the below formats to broadcast. Some of these formats are appropriate and deserve to be kept. These are the 30 frames-per-second (fps) 1080p mode (for primary television broadcasting), the 24 fps 1080p mode (for broadcasting film content originally shot at 24 fps without artifact-creating conversions), the 60 fps 720p mode (necessary for the possible broadcast of stereoscopic video), and possibly the 30 fps 720p mode as a bridge to ease the transmission of HDTV signals over older cable systems that don’t have enough bandwidth for the full resolution signals.

Common Name	Resolution	Frame Rate*	High-Definition^†	Worth Saving?
1080p	1920×1080	30 p
	1920×1080	29.97 p
	1920×1080	24 p
	1920×1080	23.976 p
1080i	1920×1080	30 i
	1920×1080	29.97 i
720p	1280×720	60 p
	1280×720	59.94 p
	1280×720	30 p
	1280×720	29.97 p
	1280×720	24 p
	1280×720	23.976 p
	704×480	60 p
	704×480	59.94 p
	704×480	30 p
	704×480	29.97 p
	704×480	24 p
	704×480	23.976 p
	704×480	30 i
	704×480	29.97 i
480p	640×480	60 p
	640×480	59.94 p
	640×480	30 p
	640×480	29.97 p
	640×480	24 p
	640×480	23.976 p
480i	640×480	30 i
	640×480	29.97 i

* The “i” suffix indicates an interlaced mode; the “p” suffix indicates the better, progressive mode.
^† My opinion on whether a format represents a high-quality signal.

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