What does it mean to be encoding when making a DVD?

Answer 1

There are several kinds of encoding involved in producing a DVD. First of all, in most cases, the video and audio content of the movie, or other subject of the DVD, preexists in analog form (although this is becoming less common). Since DVDs are a digital recording medium, the content must be encoded in digital form. This is done with an analog to digital converter, an electronic device which, logically enough, accepts analog input and produces a digitized version of that input at its output. At a sublevel to the above, various kinds of special audio encoding, such as Dolby Stereo, may also be employed. While it would be theoretically possible to record the digital signals thereby produced directly onto the DVD, a second step is normally employed. The second encoding step, then, is called "compression". In compression, various mathematical algorithms are applied to the digital data (either in a computer or in specialized digital hardware) to reduce the number of bytes that the data will take up on the DVD. This allows the DVD to contain a longer (possibly much longer) amount of material. There are two types of compression: lossless and lossy. The latter results in more space savings, but degrades the picture and sound to a greater degree. A third type or class of encoding that might be employed is called encryption. This is yet another set of digital algorithms that scramble or encode the data to restrict access to authorized users or classes of players.