The group of companies behind the Blu-ray Disc format outlined some of the future enhancements and additions it is planning for the format this week.

Blu-ray Disc is being positioned as a successor to DVD for high-definition content. DVDs don't have the storage capacity to accommodate an entire movie in high-definition format but Blu-ray Disc does. That's largely because it uses blue lasers to read and write data on the disc, rather than the red lasers used by DVD. A blue laser makes a smaller spot on the disc surface which means the space required for one bit of data is smaller and so more can be fitted onto a 12-centimetre disc.

Another format, HD-DVD (High Definition/High Density-DVD), is being promoted by NEC and Toshiba for the same application and is battling with Blu-ray Disc for the market. Players based on that format will be available in 2005, the two companies said at a seminar in Tokyo in July.

The first part of the Blu-ray Disc format to be standardized was that for rewritable discs. The first version of the BD-RE format covers single-layer discs with 23GB, 25GB and 27GB capacities and dual-layer discs with 50GB capacity. Products supporting that format are on sale in Japan. Sony began selling a recorder last year and Matsushita Electric Industrial, better known as Panasonic, followed with the launch of its first recorder last week. The target market for both is recording of high-definition television.

Format incompatibility hits early adopters

The path for early adopters isn't easy. The Sony machine uses 23GB discs while the Panasonic machine uses 25GB or 50GB discs. The result is that the Sony discs can be used for recording and playback in both machines but the same is not true of the Panasonic discs, according to Panasonic. The Sony machine can read the 25GB disc, after a 90 second delay to recognise the disc, but recording onto the Panasonic discs using the Sony machine is impossible. This will change in future, Sony said.

Sony was one of a small number of companies at the event that was demonstrating prototype Blu-ray Disc machines. Its device was a Blu-ray Disc player for BD-ROM format discs. BD-ROM is a new format that hasn't been commercially launched yet and has been developed for prerecorded content.

Version 1.0 of the BD-ROM physical format was approved in June this year and work is continuing on several other aspects of it, such as the codec that will be used for video compression. Current BD-RE machines use MPEG-2, but the format group is considering the adoption of MPEG-4 AVC FRExt or Microsoft's VC9 codec. Both of these are more efficient than MPEG-2 so more video can be stored on the disc. The HD-DVD group has already made MPEG-4 and VC9 a part of its format.

A decision on the inclusion of these was due in July but has been delayed slightly, said Makoto Morise, assistant general manager at Panasonic. He said he expects a decision soon that will call for the inclusion of at least one of the two codecs.

Development roadmap defined

The group is also looking at higher read/write speeds than the standard 36Mbps. Its format roadmap calls for a 2x version of the write-once BD-R format to be approved in September this year and a 2x version of the BD-RE format to be approved in October.

A 4x version of BD-R is also tentatively scheduled for next year and the group said it is looking at 6x discs as a future technology. However, standing in the way of faster discs is more than just format finalization. Higher speeds demand stronger lasers and there is no word on when those may be available.

Also being looked at for the future is a quad-layer version of BD-R that will be able to hold around 100GB of data.

Other prototypes on display on Tuesday included a Blu-ray Disc recorder from Samsung. It is based on the ATSC (Advanced Television Systems Committee) high-definition broadcasting format in use in the US and South Korea. Samsung plans to have the machine on sale in those markets by the end of this year, said Ko Jungwan, a principal engineer at Samsung's audio-visual application lab. The machine will also be capable of CD and DVD playback, he said.

The presentation in Tokyo and those in the US last week were held to explain the format and promote a new association that will be open to any company in the industry. Wide support is important for any new standard and especially so for Blu-ray Disc because its competing against HD-DVD in a market where consumers have shown in the past a strong preference for a single standard.

Wooing Hollywood

Both the Blu-ray Disc and HD-DVD groups see the support of content providers, especially movie studios, as vital and the events in the US last week included promotions to Hollywood studios, said Morise. For such companies a key issue is the time and cost of producing a single disc. Blu-ray Disc and HD-DVD groups generally agree on production cost and both say they expect the discs to cost a little more than DVDs to produce.

There are bigger differences between the two standards in the time taken to produce a disc. Disc-maker Memory-Tech said in July that it can already produce HD-DVDs in volume and at yields of over 90 per cent. It said it takes 3.5 seconds to make a single HD-DVD compared with around 3 seconds for a DVD.

In contrast, Sony said in presentations in the US last week that it is aiming for a production time of 4 seconds and indicated that it expects to achieve this in about a year from now. Panasonic's estimate for disc production is 5 seconds, according to the same presentation. For a single disc the difference isn't much but it can become substantial when the global disc production industry, which produces hundreds of millions of discs per year, is considered.

Following the Tokyo event, which drew participants from several Asian nations including Japan, South Korea and Taiwan, the group will prepare to accept applications for membership. It is planning its first major meeting in Tokyo on October 4 and its first board meeting in November at an undisclosed location.