High-def ‘down-converting’ forced

[thunderhawk]

High-def ‘down-converting’ forced

Some buyers of HD DVD and Blu-ray Disc players might not get everything they bargained for.

In a deal reached this week after tense negotiations, the eight-company consortium behind the Advanced Access Content System, created for use by both high-def formats to prevent unauthorized copying, has agreed to require hardware makers to bar some high-def signals from being sent from players to displays over analog connections, sources said.

Instead, the affected analog signal must be “down-converted” from the full 1920x1080 lines of resolution the players are capable of outputting to 960x540 lines—a resolution closer to standard DVDs than to high-def. Standard DVDs are typically encoded at 720 horizontal by 480 vertical lines of resolution.

The 960x540 standard stipulated in the AACS agreement represents 50% higher resolution than standard-def, but only one-quarter the resolution of full high-def. Whether a particular movie is down-converted will be up to the studio.

The players will be required to recognize and respond to a digital flag, called an Image Constraint Token, inserted into the movie data.

If the flag is set to “on,” the player must down-convert the analog signal. If set to “off,” the player can pass the full high-def signal over the analog connections.

The studios are divided over whether to require such down-conversion and are likely to follow separate policies.

Hardware makers had generally resisted the requirement, but under the new deal, ICT recognition will be included in the AACS license that all device makers and playback software vendors will have to sign.

Estimates differ on how many consumers might be affected by the new requirement.

Many first-generation HDTV sets are equipped only with analog inputs, because at the time they were manufactured, there was no agreed-on industry standard for copy-protected digital connections between devices.

Now that there is, however, the studios are anxious to move all signal traffic to protected digital inputs and outputs.

Although movies in both Blu-ray and HD DVD will be encrypted while on the disc, the digital encryption is lost once the signal is converted to analog. Some studios fear that pirates will be able to capture and record the unencrypted analog signal, which could then be re-converted into a pristine, unprotected digital copy.

Down-converting the analog signal from high-def to something closer to standard-definition would at least prevent pirates from starting with the highest-quality image.

The effect, however, will be to deny those HDTV owners with analog-only sets the full capabilities of the new disc formats.

As part of the deal with hardware makers, the studios will be required to disclose on a movie’s packaging whether the image will be down-converted.

Supporters of Image Constraint argue that few consumers will be able to tell the difference between down-converted analog and high-def.

Many so-called HDTV sets are actually capable of displaying only 720 lines of resolution, regardless of the source, so viewers would not be getting full high-def anyway, even over digital connections.

Once the analog image is down-sampled to 540 lines, moreover, players will be permitted to use a signal processor to “up-convert” it to 720 or 1,080 lines.

Although such up-conversion does not restore the detail lost through down-sampling, it does improve overall picture sharpness.

No studio would comment on whether it plans to take advantage of the Image Constraint option.

Within the AACS consortium, however, Warner Home Video was consistently the strongest proponent of the idea, according to sources familiar with the negotiations.

20th Century Fox Home Entertainment is not a member of AACS, but has argued against the idea in other forums.

AACS-member Disney, as well as non-members NBC Universal and Paramount, are likely to take advantage of the option, according to sources with knowledge of the studios’ thinking.

Although Sony is a member of AACS, where it sometimes clashed with Warner on the issue, sources said it is still unclear whether Sony Pictures Home Entertainment will take advantage of the ICT option now that it is in place.

Source:
http://www.videobusiness.com/article/CA6300812.html