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AVIVO HD vs. Purevideo HD: What You Need to Know about High-Definition Video

Playing HD DVD And Blu-ray Movies On The PC

It is no secret that the movie industry is unhappy about video piracy. And while I could easily write volumes on the politics of the subject, that would have very little effect on the user experience. So for now, let's concentrate on how the whole digital rights management thing affects the little guy - you and I, the lowly PC users.

Although the information has been out there for some time, there is still a great deal of confusion regarding digital rights management on the new optical formats, both for HD DVD and Blu-ray. I think it's worth a re-cap because the hardware is becoming commercially available; it's not just theory anymore.

The problem is that there are no simple answers, just a lot of caveats and conditions. If you were to ask "what do I need to play HD movies on the PC?" the only correct answer is: "that depends".

What does it depend on, then? Well, right now your PC HD experience depends primarily on the signal type you plan to use...

Signal Type: Analog Vs. Digital

Digital technology allows us to make perfect copies of media. Every copy of a digital audio file - music or video - is perfectly identical to the original. However, if you were to make a copy of an analog file, say by recording a radio broadcast to a cassette tape, the copy would never be as good as the original broadcast. In the analog world, this is known as generation loss.

Because of generation loss, analog signals are much less intimidating to the movie and music industry. As a result, analog signals have fewer constraints than digital signals.

Analog Output

First, the good news about analog output:

Today you could buy an HD DVD or Blu-ray drive, put it in your PC, install HD movie playing software, and play a movie at 1080p resolution using your analog VGA output!
No special HDCP compliant hardware is required!

Of course, your CPU would have to be fast enough to decode the data. If not, you would need a fast enough Avivo or Purevideo HD video card to assist the video decoding process (more on that soon). But the basics are a HD/Blu-ray drive and an HD software player. That's it.

And now for the bad news about analog output... well, three bits of bad news, actually:

Firstly, analog Component video is limited to 1080i (interlaced) resolution. The full 1080p (progressive) resolution is not available on analog component video. It is available on an analog VGA output, however.

Second, the movie industry has the option of enabling a couple of different flags on future HD/Blu-ray disks that will limit your analog use. One such flag is called the Image Constraint Token, or ICT. Once the ICT is enabled, a 1080p source video will be purposefully degraded in resolution before it gets to your television or monitor. That means you won't see the original source file that is 1920x1080 pixels in size. What you will see instead is an image degraded to one half that resolution, with one quarter of the image data, 960x540 pixels in size. ICT is expected to be enabled sometime around the year 2010, but it could happen tomorrow. No guarantees, folks.

Thirdly, there is another flag that the movie industry can adopt whenever it chooses to: this one is called the DOT, or Digital Only Token. If the DOT flag is set on an HD/Blu-ray disk, that disk will not work on an analog output, period. That's right, DOT flagged HD/Blu-ray disks will not work on VGA output, component output or even the standard Xbox 360's, which have no digital output option at all (The Xbox360 'elite' has a digital HDMI cable output, however).

It's a bit scary but its a few years away yet. Clearly though, digital is the future, so let's examine what we need to get digital output working with HD DVD and Blu-ray disks.