44 Going Split ScreenDiagonal

#44 Going Split ScreenDiagonal

Layering is one way to show two videos in the same screen, as discussed above. Let's explore anothera diagonal split screen (Figure 44a)that you create by applying a "garbage matte" effect to one clip that exposes the clip in the track under it. Here's how it works.

Figure 44a. Here we see the upper-left corner of one clip and the bottom-right corner of another. This effect is a natural for this concert.

Garbage Mattes

The garbage matte is a freeform trapezoid that you draw around a section of your video or video layer. Once the garbage matte is in place, the editor discards everything outside the matte in that layer, like, well, garbage. Garbage mattes are most commonly used with chroma key effects to exclude edge detritus, but they also play a useful general-purpose role any time you want to exclude portions of a frame. Premiere Pro has Four-, Eight-, and Sixteen-Point garbage mattes.

1.	In Premiere Pro, place two clips at the same location on the timeline, one on Video 1 and the other on Video 2 (see Figure 42a). In this example, I'm combining a close-up of the hands of a pianist over a long shot of her playing.
2.	Apply the Four-Point Garbage Matte to the top clip (Video Effects > Keying Folder).
3.	In the Effect Controls panel, click the Four-Point Garbage Matte effect to make it active. You should see circular positioning handles on each corner (Figure 44b). Figure 44b. Premiere Pro hides regions outside the garbage matte, revealing the clip under it. To create this effect, drag the handle from the lower-left corner until it forms a straight line.
4.	In the Program Monitor, grab the lower-left corner of the garbage matte and drag it toward the center until there's a straight line from the upper-left corner to the lower-right corner. This obscures the lower-left portion of the top clip, letting the bottom clip show through.