Blu-ray and HD DVD output resolution reduced for analog HDTV connections

Some high-definition television sets will not be able to display the next-generation DVD formats in their highest resolution. Blu-ray and HD DVD players will degrade the image output from 1920×1080 to 960×540, a quarter of its full resolution, when hooked up by an analog connection.

Ars Technica reports that backers of the Advanced Access Content System (AACS), the system adopted by Blu-ray and HD DVD to prevent piracy, have made a deal with hardware manufacturers to disallow the full signal of a disc to be transferred to a HDTV, unless through a protected digital input, such as HDMI.

The deal was negotiated in an effort to limit illegal copies being made in the highest resolution. This means that some current HDTV owners will have to make do with a lesser quality picture as the first-generation HDTVs were only equipped with an analog input.

The AACS was developed by eight companies, including IBM, Intel, Microsoft, Panasonic, Sony, Toshiba, The Walt Disney Company and Warner Bros. Studios, who will support an Image Constraint Token (ICT) flag that will be incorporated into the data of each disk.

Blu-ray and HD DVD players will recognize this flag and reduce the output resolution if the ICT is turned on. If the ICT is turned off the players will continue to output at the highest resolution.

Incorporating the ICT for HD image degradation over analog connections is not compulsory. Studios and content providers are at liberty to choose whether individual discs enforce the lower resolution output or not.