Timewarps can be created in two ways in the timeline:
Implicit timewarps always take precedence over explicit timewarps. If you create an implicit timewarp on a source clip that has an explicit speed change specified, the explicit speed change is ignored.
Working with Implicit Timewarps in Batch
Implicit timewarps are added to the record clip when an edit causes a difference in source and record durations, and when Auto Timewarp is enabled (see Timewarp). For example, if you perform a four-point edit with ripple off and the source clip duration is shorter than the record clip duration, a fit-to-fill edit occurs and the clip is timewarped to fit the new duration.
A fit-to-fill timewarp occurs during a fit-to-fill edit (when both source in and out points, and record in and out points are specified). The speed change is automatically calculated based on source and record durations. A portion of the record clip is replaced by a portion of the source clip such that the source material is timewarped to fit the duration of the record material being replaced. The heads and tails of the source clip are retained.
You can create an explicit timewarp in the timeline by applying it to an existing segment.
To create an explicit timewarp:
An unrendered timewarp for the clip is created and the Timewarp quick menu appears.
(a) Timewarp Type box (b) Speed field (c) Transition Render Mode box (d) Anchor box (e) Timewarp Processing option box
The speed value changes to a negative number, indicating the frames are reversed.
You can also create a timewarp that uses a variable mix value in the Timewarp Editor. See Creating Variable Speed Timewarps.