STOP!
Enough of this nonsense. It’s time to set the record straight, to clear up the air about what 1080p is and isn’t.
First off, there is no 1080p HDTV transmission format. There is a 1080p/24 production format in wide use for prime time TV shows and some feature films. But these programs must be converted to 1080i/30 (that’s interlaced, not progressive scan) before airing on any terrestrial, satellite, or cable TV network.
What’s that, you say? Those 1080p/24 could be broadcast as a digital signal? That’s true, except that none of the consumer HDTV sets out there would support the non-standard horizontal scan rate required. And you sure wouldn’t want to watch 24Hz video for any length of time; the flicker would drive you crazy after a few seconds.
No, you’d need to have your TV refresh images at either a 2x (48Hz) or 3x (72Hz) frame rate, neither of which is supported by most HDTVs. If the HDTV has a computer (PC) input, that might work. But if you are receiving the signals off-air or using a DVI HDCP or HDMI connection, you’ll be outta luck.
What about live HDTV? That is captured, edited, and broadcast as 1080i/30. No exceptions. At present, there are no off-the-shelf broadcast cameras that can handle 1080p/60, a true progressive format with fast picture refresh rates. It’s just too much digital data to handle and requires way too much bandwidth or severe MPEG compression. (Consider that uncompressed 1920x1080i requires about 1.3 gigabits per second to move around. 1080p/60 would double that data rate.)
How about Blu-ray and HD-DVD? If either format is used to store and play back live HD content, it will have to be 1920x1080i (interlaced again) to be compatible with the bulk of consumer TVs. And any progressive-scan content will also have to be interlaced for viewing on the majority of HDTV sets.
Here’s why. To cut manufacturing costs, most HDTV sets run their horizontal scan at a constant 33.8 kHz, which is what’s needed for 1080i (or 540p). 1080p scans pictures twice as fast at 67.6 kHz. But most of today’s HDTVs don’t even support external 720p signal sources, which requires a 44.9 kHz higher scan rate.
In the consumer TV business today, it’s all about cutting prices and moving as many sets as possible through big distribution channels. So, I ask you: Why would HDTV manufacturers want to add to the price of their sets by supporting 1080p/60, a format that no HDTV network uses?
Here’s something else to think about. The leading manufacturer of LCD TVs does not support the playback of 1080p content on its own 1920x1080 products, whether the signal is in the YPbPr component or RGB format. Only the industrial monitor version of this same LCD HDTV can accept a 1920x1080p RGB signal.
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