Trim

Select the video you have added to the program, and play it in the preview window, then drag the seekbar to a time point as you want, and click the button "[" to set it as a start, in the same way, click the button "]" to set an end. So that, the program will convert the part (as the red line in the progress bar shows) you have trimmed.

Crop

Move your mouse on the preview window, then left-click and hold to choose a rectangle area in the video. So that, the program will convert the area (in the grey box) you have cropped.

To cancel the cropped area, please right-click and hold on the preview window, then move your mouse in any direction.