It is no mystery that Blu-ray got off to a slow start, a fact probably attributable to the long and protracted battle with HD-DVD, but now the company has a few new foes that might stymie its recent advances: broadband and on demand. Broadband allows for streaming content and downloadable content while on demand serves up content on the fly in a manner similar to streaming. Throw in the advanced DVR capabilities of most set top boxes (STBs) and it would seem that Blu-ray has its work cut out for it.
So, how will Blu-ray respond? By increasing the storage capacity of their discs from 25 GB (gigabytes) per layer to 33.4 GB. In order to understand this strategy and to decide whether or not it will work, it helps to look at the facts and see the direction in which broadband is heading.
Video Sizes: a Tale of Bits and Bytes
Current HD broadcasting and transmission standards tend to peak at around 20 Mbps (Megabits per second). Note that the use of the word bits versus the use of the word bytes. One byte is 8 bits, meaning that 20 Mbps is around 2.5 MBps (Megabytes per second), the key difference in the nomenclature being the capitalization of the B or the lack of capitalization. A 90 minute movie with an amazing 60 minutes of extras would take up no more than 22.5 GB of data (2.5 MBps * 60 * (90 + 60)) plus a small amount of overhead for menus and languages, but that is a worst case scenario that would never happen in the real world.
Compression techniques used in modern video CODECs ensure that peak rates are rarely the norm, and are only seen for very brief periods of time. For most programs, a data rate of around half the peak data rate is average, with fast action sequences usually requiring a more data every second. The result is that the aforementioned 22.5 GB disc would likely be half that size, or less than half the size of single-layer/single-sided Blu-ray disc. Bear in mind that this still assumes that the video is being stored in full 1080p, which not all videos area. Perhaps this is why the Blu-ray association claims that up to 9 hours of content can be stored on a single Blu-ray disc.
Bringing this back to broadband, 2.5 MBps downstream, the peak/theoretical maximum of 1080p using modern video CODECs is still 20 Mbps, though probably only half of that would be seen in real world situations. Even 10 Mbps is fairly substantial, there are consumer-grade VDSL services such as AT&T’s U-verse that offer consumers speeds of up to 24 Mbps, cable Internet data services from Comcast scale up to 16 Mbps, and Verizon’s FiOS customers can currently choose broadband packages with up to 50 Mbps. This certainly gives Blu-ray discs an advantage, but there are a few problems.
Error Rates
One problem that discs have, and are unlikely to ever escape from, is that of permanent errors. If a Blu-ray disc were to become scratched, which many eventually do, it could permanently mar a critical portion of its surface. Digital content comes with error correction technology that ensure constant delivery of accurate data.
Size vs. Speed
The storage capacity of Blu-ray’s newest discs are certainly impressive, and it might be possible for a dual-layer disc to hold an entire season of a television show in stunning high-definition. The problem is that while 33.4 GB per layer sounds impressive today, it will be laughable in only a few years. This is a problem that has always afflicted disc technology from the very beginning, and is one of the best reasons to consider broadband access the winner. Let professionally managed server farms do the storing, and as broadband speeds increase it will only be a matter of time until even 10 Mbps is hardly noticeable. In fact, the previously mentioned AT&T U-verse package actually bundles the ability to stream up to two HD channels to a custom STB without interfering with the 24 Mbps of service, and Verizon has similar offerings that are even faster.
The Verdict
Blu-ray’s size increase might net it another short-term victory, but only if studios can offer exclusive content. It would seem that exclusive content might be all that keeps discs of any kind afloat in a world that is increasingly connected by broadband. In such a world, discs are not likely to ever be a major factor because they increase in capabilities and capacities in relatively large jumps, while cloud-based services delivered via broadband scale much more linearly and transparently. On the other hand, Blu-ray could offer higher than high-definition features, such as HD3D, but the penetration of compatible televisions is relatively low. If this penetration increases, the equation might change temporarily, but broadband seems to be better positioned for media content delivery than a mere disc.
