New Chips Enable High-Def Recording on DVDs
For the last few years most of the world's biggest consumer electronics companies have been arguing over a format for high-definiton video discs. The drama over HD DVD versus Blu-ray Disc has confused consumers and held back adoption and, it turns out, might have been unnecessary after all.
Both of the new high-def formats were developed because conventional DVDs don't have the capacity to hold an HD movie in the MPEG2 format used for most of the world's HDTV broadcasting. While a DVD holds just 4.7G-bytes of data per layer, an HD DVD disc can hold 15G bytes and a Blu-ray Disc 25G bytes, enough to store a high-def movie or soccer match.
But in the last few months chips have become available that can transcode an off-the-air MPEG2 signal in real time into the much more efficient MPEG4 AVC format.
The chips have found their way into new HD DVD and Blu-ray Disc players and can increase their storage capacity by several times. For example, new machines from Sony Corp. can store about 8 hours of HDTV on a single-sided Blu-ray Disc using MPEG4 AVC -- about four times the amount of video than was possible with MPEG2.
But they also make it possible to store about 2 hours of HDTV on a conventional DVD. With hardware prices for HD DVD and Blu-ray Disc recorders typically at US$1,000 or more, some consumers may think it's better to stick with the cheap, tried and tested DVD.
Not surprisingly, that's disputed by companies pushing the new, more expensive recorders. They are offering machines that play one of the two new optical disc formats -- HD DVD or Blu-ray Disc -- as well as the "enhanced" conventional DVD.
Panasonic said the dual capability is useful because the Blu-ray Disc media is still quite expensive, so consumers will be able to choose which DVD format to use depending on their needs. "For precious recordings that they want to preserve in high-quality they can use Blu-ray Disc, and for others put them on DVD, said Manabu Sukegawa [cq], managing director of Panasonic's marketing division.
Toshiba said the 3 to 4 times capacity jump from DVD to HD DVD means much more high-def video can be stored on the new discs, and that that alone gives them merit over conventional DVDs.
While the enhanced DVD technology is being offered in new-generation machines from Toshiba, Panasonic and Sony, it remains to be seen whether they'll turn up in cheaper, DVD-only recorders. For now, Toshiba seems to be the only company contemplating this. It said it will watch market reaction and then make a decision.
Even with a fall-back to DVD there's a catch: there's no agreement on format for the "enhanced" conventional DVD, so Toshiba's HD REC and Panasonic's AVCREC formats are incompatible. HD Rec comes from the DVD Forum, the standards group responsible for DVD and the new HD DVD formats, while AVCREC comes from the Blu-ray Disc Association.
HD REC lays down a 4M bps (bits per second) MPEG4 AVC stream, while AVCREC in the Panasonic machines records at a higher 5.7M bps. That should mean a better picture but also less recording space on each DVD.
While the consumer electronics giants battled over their new formats, several smaller groups have been pushing high-def recording on DVD or formats based on the technology.
London-based New Medium Enterprises Inc. has a format called VMD (Versatile Multilayer Disc) that increases a disc capacity by adding more recording layers. A multilayer VMD disc can store about 30G bytes of information, about equivalent to HD DVD. In Taiwan, a group of companies developed FVD (Forward Versatile Disc), which added recording layers and an advanced compression system to enable high-def recording on a DVD-like disc.
However, without the support of major movie studios, all of which have a stake in Blu-ray Disc or HD DVD, the alternative formats have had trouble breaking into the mainstream market.