Use the Interleave tool to interleave the frames of two source clips. You specify how to interleave the two clips in the Spacing field. For example, a spacing value of two mixes two frames of the second source clip after every frame of the first source clip.

To interleave two clips:

1. With Video selected from the A/V Tools box, click Interleave.
2. Set the spacing for the interleave in the Spacing field.
3. Select the source clips.
4. Select the destination for the result clip.