I had interesting discussions today about HD content on DVD media.
While first look at things such as 3X DVD-ROM may give the impression of a dead-born idea, a second look brings different result if taking in consideration the strong movie industry desire for VGA sunset, managed copy, and others, while cutting transition cost, especially on the manufacturing of media, not so much of playback devices.
Would a HD on DVD DVD playback device make sense? Not really alone. But adding HD on DVD support to new generation blue laser devices (HD DVD or BD indifferently) is a very cheap improvement. This would smooth the transition for the content provider to HD. HD DVD and BD remain a quite scary costfull change. HD DVD and BD logical layer on a physical DVD is much more attractive.
Passed the business advantage, does the idea still make technical sense? In terms of speed, bandwidth is available at 3 times the original DVD speed, a speed largerly achieved for years. The jump performance model, that is, the time taken by the drive to perform a seek (non-linear access) influencing the require drive minimum buffer / video minimum atomic unit, need to be adapted, but nothing impossible here. The improved codec efficiency, the added content interactivity, remains. The capacity is not that different regarding video. With 3 dual layer DVDs, which is not a too unusual package, you reach the capacity of a single layer BD media. When BD or/and HD DVD total cost per Gb goes below the one of DVD, and hopefully one of the two new generation format dominate the market, changing to blue laser media should be a natural thing.
A niche market for high-end PC could be considerated. DVD devices there are already capable of more that 3X speed, and the software which will need to understand the new HD logical content can be very easily updated – unlike fw of CE device.
HD 1x playback is performed at 4,5 Mb/s. A dual layer DVD contains 8.5 Gb. This should permit about 30 minute video per DVD. Notice this computation assume worst case scenario, high efficiency codecs usually do not require the 4,5 Mb/s most of the time.