Blu-ray vs. HD-DVD: Just the Facts
Part 2: Capacity
Ok, here is one topic that has caused a tremendous amount of debate. Blu-ray offers 50Gb of storage using dual layer discs while HD-DVD offers 30GB using dual layer discs. The HD-DVD camps states the 30GB is more than enough to deliver master quality video and audio as well as bonus content through the use of more efficient codecs (Mainly VC1 on dual layer discs). Blu-ray discs have been authored in VC1, AVC, and MPEG2 mainly on single layer discs and a few dual layer discs.
While it does appear that HD-DVD’s 30GB capacity is sufficient for most of the releases to date, the ability to offer master quality video and lossless audio in continents other than North America may prove difficult. Europe consists of about nine different core languages. If a disc is to be sold in Europe it should contain lossless audio tracks in all key languages. This was a key decision factor in certain studios choosing Blu-ray over HD-DVD.
One additional item that has not reared its head is that with HDMI 1.3 comes the ability to offer 10bit - 36bit color depths. Each time the bit-depth is increased the amount of space required on the disc goes up drastically. Current DVD’s utilize 8-bit color, if a disc is created that uses 10-bit color it will require 20% more disc space. This may prove to be tasking for HD-DVDs limited capacity.
