Hardware Reference
In-Depth Information
to play. Most newer region-free modified players know how to query the disc first to cir-
cumvent this check as well.
DVD-ROM drives used in PCs originally did not have RPC in the hardware, placing that
responsibility instead on the software used to play DVD video discs on the PC. The play-
er software would usually lock the region code to the first disc that was played and then
from that point on, play only discs from that region. Reinstalling the software enabled the
regioncodetobereset,andnumerouspatches werepostedonwebsites toenableresetting
the region code even without reinstalling the software. Because of the relative ease of de-
featingtheregion-codingrestrictionswithDVD-ROMdrives,startingonJanuary1,2000,
all DVD-ROM and rewritable DVD drives were required to have RPC-II, which embeds
the region coding directly into the drive.
RPC-II (or RPC-2) places the region lock in the drive, and not in the playing or MPEG-2
decoding software. You can set the region code in RPC-II drives up to five times total,
which basically means you can change it up to four times after the initial setting. Usually,
the change can be made via the player software you are using, or you can download
region-change software from the drive manufacturer. Upon making the fourth change
(which is the fifth setting), the drive is locked on the last region set.
Region Codes Used by BD
A different region code scheme that divides the world into three regions is used by BD:
• Region A includes North America, Central America, South America, Korea, Japan,
and South East Asia.
• Region B includes Europe, the Middle East, Africa, Australia, and New Zealand.
• Region C includes Russia, India, China, and the rest of the world.
A BD without a region code can be played by players with any region code.
CSS
TheCSSprovidesthemainprotectionforDVD-Videodiscs.Itwasn'tuntilthisprotection
was implemented that the Motion Picture Association of America (MPAA) agreed to re-
lease movies in the DVD format, which is the main reason the rollout of DVD had been
significantly delayed.
CSSoriginallywasdevelopedbyMatsushita(Panasonic)andisusedtodigitallyscramble
and encrypt the audio and video data on a DVD-Video disc. Descrambling requires a pair
of40-bit(5-byte)keys(numericcodes).Oneofthekeysisuniquetothedisc,whereasthe
other is unique to the video title set (VTS file) being descrambled. The disc and title keys
are stored in the lead-in area of the disc in an encrypted form. The CSS scrambling and
