WHITNEY HOUSTON - One Wish - The Holiday Album - Music

Click Here to Order WHITNEY HOUSTON - One Wish - The Holiday Album

Click Here for More Information about WHITNEY HOUSTON - One Wish - The Holiday Album.

Did you know

1. Each DVD-Video disc contains one or more region codes, denoting the area(s) of the world in which distribution and playback are intended. The commercial DVD-Video player specification dictates that a player must only play discs that contain its region code. In theory, this allows the motion picture studios to control the various aspects of a release (including content, date and price) on a region-by-region basis. In practice, many DVD players allow playback of any disc, or can be modified to do so. Entirely independent of encryption, region coding pertains to regional lockout, which originated in the video game industry.

2. A CD is read by focusing a 780 nm wavelength semiconductor laser through the bottom of the polycarbonate layer. The difference in height between pits and lands is a sixth of the wavelength of the laser light, leading to a third-wavelength phase difference between the light reflected from a pit and from its surrounding land. The sixth, 125 nm, (and not a quarter) of the wavelength was chosen to have a good trade-off between the push-pull radial tracking signal and the full-aperture read-out signal. The interference reduces the intensity of the reflected light compared to when the laser is reflected by just a land. By measuring this intensity with a photodiode, one is able to read the data from the disc. The pits and lands themselves do not represent the zeroes and ones of binary data. Instead a change from pit to land or land to pit indicates a one, while no change indicates a zero. This in turn is decoded by reversing the Eight-to-Fourteen Modulation used in mastering the disc, finally revealing the raw data stored on the disc.