High-definition discs explained What is high-definition DVD?
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Blu-ray high-definition DVD, backed by Sony
High-definition DVD players boast pictures that, providing you are watching a high-definition disc, are far superior to standard-definition DVDs.
Rival formats
There were two rival high-definition DVD formats: Blu-ray, backed primarily by Sony, and HD-DVD, supported by Toshiba among others. But now that Toshiba has decided to withdraw from the battle and stop producing players Blu-ray has won the day.
Drawbacks
However, HD players have their drawbacks. On the players we've tested, basic features such as resume from standby are missing, they’re generally more complex and sluggish, use more power and are pretty noisy. High-definition players also cost about 10 times more than a standard player.
HD-ready TV compatibility
More seriously, the move to high-definition DVD has created a mismatch between new discs and most existing HD equipment. New high-definition TVs and DVD players are better equipped to cope with the new technology but a deluge of logos and labels has made it difficult to identify which bits of equipment will work best.
Despite labels such as HD full and 1080HD, if you've bought a new flat-panel HDTV in the past couple of years, it may not display Blu-ray movies properly. As if that isn't bad enough, the first high-definition DVD players on the market are already obsolete.
Mismatched speeds
The problem is a mismatch between the number of pictures per second recorded onto the discs, and the number which players and TVs output and display on a screen – see below.
None of the first wave of players and only a few TVs on the market match the speed of the discs.
The result is juddery movements during fast-motion or camera panning scenes.
We first revealed the problem in February 2007, and hoped it would be a temporary glitch.
If high-definition discs were manufactured at slightly faster, traditional European speeds, they would work with the players and TVs already on the market.
The difference in speed is however so minimal that most people are unaware of the effect on normal DVDs.
