Understanding MPEG-2 Compression
  February 6, 2001

by Phil De Lancie

As a distribution medium, DVD-Video offers the potential for quality that is far closer to the original than VHS. But to realize that potential, the look and feel that has been painstakingly created in production and post must be maintained through the DVD title preparation process. That process might include steps that are familiar, such as transfer from film to video (telecine), standards conversion (NTSC to PAL or vice versa), editing for home video release, or even shooting additional material for value-added "featurettes." But it will also include the relatively new and often unfamiliar step of video compression, which is a critical determinant of the ultimate quality. Film-makers armed with an understanding of compression and the factors that affect it will know what to expect when they see the results on their own work, and will be better positioned to influence the fidelity with which that work is translated to DVD.

Contents:
    —   Why Compression?
    —   VBR Encoding
    —   Preserving Quality