Before digital editing software in the 1990s, linear video editing was widely used as the conventional method for constructing video programs. This tape-to-tape process is now considered archaic but is still useful for quick basic edits. Another advantage of linear is it isn't constrained by hardware or format issues. Tools used for linear editing besides two video tape recorders include video switchers and graphics generators. Before digital technology, linear editing was simply known as "video editing."
Videotape is a sequence of picture frames moving at about 30 frames per second. An edit decision list documents where edit ins and outs are to be made on video tape based on timecode, which is expressed as hours, minutes, seconds and frames. A timecode of 01:02::03:01 means the frame is located at the first hour, second minute, third second of the video tape. Timecode is used for logging, synchronization and editing. It is a standard function for television broadcast video tape recorders. Timecode is recorded on an audio track or the video track.
Timecode was a primitive process used to produce second-generation video, making the final product lower video quality than the raw footage, known as source material. The first non-linear video editing system was the CMX 600, produced by CBS and Memorex in the 1970s. By 1988 video editing software by Avid for the MacIntosh II introduced the digital timeline and bins for storing video clips. The editor could now easily organize video clips and have direct access to any frame. Advancements in compression software in 1990 by Eidos eliminated the need for expensive hardware.
Non-linear video editing became standard in the 1990s, making the craft easier, quicker, more flexible and more affordable. Video editing software programs by Avid, Final Cut and Adobe allow you to capture and store video and audio then edit it on a timeline. Using the functions of cut, copy and paste, it's easy to move video clips around without affecting the original source files. Another advantage to using software is effects such as transitions and fades can be added while editing.