Golf Shot Tracer

This is a video editor that tracks the ball in golf shot videos to create a trajectory, and the process proceeds in the following order:

1. **Import Screen**: When you open the app, it displays Import Video, Continue Work, and Recent Work. It imports using the system video selector and creates a copy in the app's dedicated space without modifying the original. Once the import is complete, you will move to the Marking screen. The Import menu is not available on the Edit screen.

2. **Start Point Tab**: Use the frame slider and Previous/Next buttons to mark the ball just before the shot. Once you mark the start point, you will move to the Move Marking tab.

3. **Move Marking Tab**: You can set correction points only in key frames where the ball is visible. Touching or dragging over the video displays a circular magnifying glass, and releasing your finger confirms the point. Grabbing and moving near an already marked point allows for fine adjustment at 1/3 speed. You can zoom in and move the entire video with two fingers; however, two-finger gestures or canceled touches will not be marked.

4. **Landing Point Tab**: If a landing point is found, you can specify the location; if not found, you can skip it. Pressing the Start/Destination tab again returns you to the magnifying glass view of the previously designated frames and locations. **Time Adjustment** changes the automatic/manual arrival times in a separate window, distinguishing it from the designated location frames.

5. **Next · Calculate Trajectory**: After specifying the start point, press the Next button at the bottom to enter the calculation and confirmation screen. It performs motion, brightness, and continuity-based tracking and camera calibration while preserving the manual points. You can restart the calculation from this screen if you cancel or fail. If you are not satisfied with the result, return to **Edit Marking** to calibrate and recalculate.

6. **Confirm · Save**: Set the save range using the handles at both ends. Playback is limited to this range, and the trajectory is displayed using the same renderer.

7. **Select Save Method**: The default quality saves without ads. For high quality, you must explicitly select an ad; the video is saved after the ad closes following a reward callback.

Manually designated points, start points, and destination points are displayed as circles, while automatic points are displayed as squares. Deleting the start point also deletes the designated point and tracking result for that shot, so a confirmation window is displayed, and you can restore them using Undo. If you redefine the landing point after deleting it, the landing time handle is also regenerated.