The In Shape setting lets you define the shape of the fade-in to a clip for a fade, or to clip 2 for a crossfade.
Selects a single continuous fade curve. This creates a general-purpose fade that can be edited by dragging the curve itself.
Selects an S-shaped curve, which inverts its beginning and end characteristics. This makes it possible to fade in faster at the start of the curve, and slower at the end. S-shaped curves are useful with material that is difficult to fade effectively. S-curves can be edited by dragging the curve in the curve editor.
Seven commonly used preset curves are provided for fast creation. These can be edited by dragging the end points of the curve in the curve editor portion of this dialog. The seven presets are as follows: