Even though the intent of the Blu-Ray association is to open BD for more serious commercial backup users, this announcement for a 4-layer BD specification (topping at 128GB R.O.M.) has home theater potential.
The current BD disks easily handle 1080p HD movie content, including some typical “bonus” features on a single disk, thanks to 25GB (single layer) and 50GB (double layer) capacity.
The BDXL format, with up to 128GB, could potentially enable the next generation of home video playback. The downside, of course, would be that a new generation of players (and monitors) would also be required. However, staying within the Blu-Ray family would be a boon for compatibility and licensing issues (sorry, Toshiba).
How would the math work? Would 128GB be sufficient for 4K? Fortunately the answer is a simple yes. Rather than studying bit rates and compression, if we simply look at pixels and scale up we can determine feasibility.
1080p = 1920 * 1080 = 2.07 Million Pixels
4K = 4096 * 2160 = 8.85 Million Pixels
8.85 / 2.07 = 4.28 times more pixels in 4K
You can see the difference visually below (image from Wikipedia)
Today’s BD movies average around 19-27 GB in size, for the “feature” movie:
27GB * 4.28 = 115.43 GB required for 4K
As you can see, the math works out nicely. Now all we need to do is sit back for a couple years and listen for announcements.
