The expansion of hdtv is High-definition television. The hdtv means television signals broadcast with a higher resolution than traditional formats like NTSC, SÉCAM, PAL. The hdtv is broadcasted digitally, except for early analog formats in Europe and Japan.

Historically, the term high-definition television was also used to refer to television standards developed in the 1930s to replace the early experimental systems, although, not so long afterwards, Philo T. Farnsworth, John Logie Baird and Vladimir Zworkin had each developed competing TV systems but resolution was not the issue that separated their substantially different technologies. It was patent interference lawsuits and deployment issues given the tumultuous financial climate of the late 20′s and 30′s. Most patents were expiring by the end of WW2 leaving the market wide open and no worldwide standard for television agreed upon. The world used analog PAL, NTSC, SECAM and other standards for over half a century.

The terms HD ready and HD compatible are being used around the industrial world for marketing purposes. They indicate that a TV or display is able to accept video over an HDMI connection, using a new connector design, the main purpose of which seems to be to ensure that digital video is only passed over an interface which, by agreement, incorporates copyright protection. Even HD-ready sets do not necessarily have enough pixels to display video to the 1080-line (1920×1080) or 720-line (1280×720) HD standards in full resolution without interpolation, and HD-compatible sets are often just standard-definition sets with an HDMI input. This is a confusing use of the terms HD and hdtv.

MPEG-2 is most commonly used as the compression codec for digital hdtv broadcasts. The hdtv is capable of “theater quality” audio because it uses the Dolby Digital (AC-3) format to support “5.1″ surround sound.
Read the rest of this entry »