AfterDawn: Glossary

When used in reference to DVD-Video, PGC stands for Program Chain.

A program chain is a group of cells or collection of programs that are linked together, creating a sequential presentation. A user may select a program chain while using a DVD-Video.

Each cell is a basic unit of playback for video and audio data. Additionally, each cell is uniquely identified by its starting and ending sector address on the disc. The PGC therefore define the order in which all the cells are played back and how they are to be played back, based on the user's settings or the DVD player's setting.

Multiple PGCs can be "chained" together to form a Video Title Set.

Each PGC can contain 128 pre-commands, which are executed before the playback of th first cell in the PGC, and can contain 128 post-commands, which are executed after the playback of the last cell in the PGC.