Editing MPEG Files and the Basics of Frame EditingGroup of Picture Editing
If you wish to edit MPEG files, it is important to understand the basics of MPEG compression and the main differences between “frame editing” and “Group of Picture (GOP) editing.”
Let’s first start by stating that MPEG compression was not developed with the intention of supporting precise editing. Instead, MPEG serves as a high-powered compression tool made for pre-edited video. Nevertheless, with some fundamental knowledge and appropriate tools, it is possible to perform highly accurate edits of MPEG files.
Fundamentals of MPEG Compression
The main characteristic that complicates editing of MPEG video is the way in which MPEG encodes a compressed file. MPEG uses what’s referred to as “reference frames” and “difference frames.” For every 15 frames of movie footage, the normal standard of compression is 1 reference frame for every 14 difference frames. The difference frames only encode changes such as foreground movement, and therefore much less storage space than the preceding
