HD-DVD vs. Blu-Ray

Several companies have developed alternatives to the existing DVD standard. The two forerunners are HD-DVD and Blu-ray. Competition between the two has escalated, drawing inevitable comparisons to the struggle between VHS and Betamax. Here are the highlights:
  • Both formats use blue lasers rather than red.
  • Both have the same options for video and audio compression.
  • Blu-ray offers significantly more storage space -- 50 GB on a dual-layer disc versus HD-DVD's 30 GB.
  • The DVD Forum, which creates DVD standards, has approved HD-DVD and has not approved Blu-ray.
  • HD-DVD is less expensive than Blu-ray, partly because HD-DVDs can be produced on existing equipment, and Blu-ray discs can't. HD-DVD players are selling for around $399 (Toshiba HD-A2), and the cheapest Blu-ray player is selling for around $699 (PlayStation3).
  • HD-DVD players hit the market on April 18, 2006, two months before the first Blu-ray player hit the U.S. market in June 2006.

    • HD-DVD Facts

    HD-DVD Capacity:
    15 GB single layer, 30 GB dual layer

    DVD Capacity:
    4.7 GB single layer, 8.4 GB dual layer

    Compression:
    MPEG-2, MPEG-4, VC-1

    High-definition Playback, 15 GB:
    4 hours

    High-definition playback, 50 GB:
    8 hours

Along with other companies, Toshiba, Microsoft and Intel have sided with HD-DVD. Microsoft plans to release an add-on HD-DVD drive for its Xbox 360 in November 2006. The Blu-ray Disc Association, on the other hand, has electronics companies like Sony (which plans to release the Blu-ray-equipped PS3 in November) and Pioneer, computer companies like Dell and Apple and entertainment companies like Disney and Fox on its board of directors. Most of the motion picture industry seems to support Blu-ray, in part because the need for new manufacturing equipment might cut down on piracy.

The Xbox 360 HD-DVD player
Photo courtesy Amazon
The Xbox 360 HD-DVD player

Even though Blu-ray seems to have the backing of more of the industry, the battle isn't over. Some companies, like Hewlett Packard, previously supported only Blu-ray but now support both formats. Critics of Blu-ray point out that it may have more capacity than any movie could ever use, even with special features. Many people theorize that HD-DVD will be the winner solely because it is so much cheaper.

For lots more information about high-definition video and related technology, check out the links on the next page.

Something Rotten in the State of HD
If you visit sites devoted to HD-DVD and Blu-ray, you might notice that something seems a little fishy with the supposed playback times. According to Toshiba, a 30 GB HD-DVD will hold 8 hours of HD video. According to the Blu-ray disc association, a 50 GB Blu-ray disc will hold 4.5 hours of HD video. So how could a disk that's twice as big hold about half as much information?

The likeliest culprits for those numbers not adding up are bit rate and encoding. A file recorded at a low bit rate will take less space. In addition, many early Blu-ray tests used MPEG-2 encoding, which is less efficient than MPEG-4.