gopchop cuts and merges MPEG2 video streams. gopchop uses
 a method to cut streams that does not require re-encoding,
 and therefore is fast and not prone to the artifacts
 and degradation of quality inherent in re-encoding.
 However, cuts are limited to I-frames or
 group-of-picture (GOP) boundaries. These frames occur
 frequently enough, and often times at scene transitions,
 so that gopchop's method is adequate for many applications.
 .
 The typical use is manually editing commercials out of
 recorded television programs.
 .
 Another application is splitting .VOB files from
 dual-layer DVD rips so that the content can be
 re-authored such that each half will fit on one
 single-layer DVD recordable.