Flash Video Encoder provides the following editing options to crop and resize video clips before encoding them:
Cropping alters the dimensions of a video clip. You can eliminate areas of the video to emphasize a particular focal point within the frame such as highlighting a character by removing ancillary imagery or removing unwanted backdrops.
Trimming edits the beginning and ending points (the in and out points) of a video. For example, you can adjust the trim of a video clip to begin playback 30 seconds into the full clip, removing unwanted frames.