Reduced to its most basic definition, editing is the process of combining video and audio elements from various sources into a coherent whole. For example, you may have one videotape that has footage of the mayor waving to a crowd and then walking into his office and another that has an interview with the mayor in which he talks about his bid for reelection. Through editing, you can combine these video and audio sources, discarding material you don't need.

Using a switcher in a studio production situation, as discussed in Chapter 9, can be thought of as a form of real-time editing. Here, too, you are selecting various sources of video (cameras, satellite feeds, graphics, etc.) at appropriate times to create a coherent production. Postproduction editing, however, is usually a more deliberative process in which much more time is taken in selecting and combining various sources of video. As its name implies, postproduction editing takes place after the video material has been gathered. A postproduction editor may take many hours to create a finished product that is only a few minutes in length.

Two basic editing processes can be used in postproduction editing. Linear editing uses videotape both as the source of the footage to be used and as the recording medium. In essence, linear editing is recording from one videotape onto another. In nonlinear editing, all of the video footage is stored in digital form on a random access medium (such as a hard drive), then edited using a computer. Nonlinear editing offers the random access to stored information described in Chapter 10, and it also overcomes many of the temporal limitations of linear editing, as you will see. Nonlinear systems such as the one shown in Figure 11.1 have been rapidly replacing tape-based systems.

However, many tape-based editing systems are still in use and likely will be for some time. For that reason, this chapter discusses linear editing as well.

The disciplines of editing include thorough planning before the editing even begins and attention to aesthetic considerations. The techniques of editing, while differing according to the equipment being used, still involve general practices that are addressed in this chapter as it covers the following:

• Types of editing situations, including the difference between on-line and off-line editing (11.1)
• The importance of planning and making decisions about editing before entering the editing suite (11.2)
• The basic process of nonlinear editing, including capturing, editing, and outputting (11.3)
• The difference between assemble and insert editing (11.4)
• The basic processes of linear editing (11.4)
• The importance of understanding editing aesthetics, including continuity and ethical considerations (11.5)