If you've done a waypoint mission and saved it then that will be as close as you can get to doing an exact recreation. If you were free flying it then it becomes more difficult, but not impossible. I've done this several times. Here's an outline of how I did it:
1. All my flight records are uploaded to AirData, this give mes the ability to retrieve the data in a .csv file.
2. Retrieve the flight data .csv file and open in Excel.
3. Scan through the data and eliminate rows of useless data such as the take off and landing, initial positioning, return flight, etc.
4. Add a new column to the left of the first data column. Count the number of data rows and divide by 95. In the column just created fill in a series from 1 to the number you just calculated, and repeat this all the way to the last data record.
5. Select all the rows and columns with data and convert this to a Table.
6. Filter the table on the first column using a value at the approximate midpoint of the number series. Now you should have the data needed for a Litchi Waypoint mission, there should be less than 100 rows in the filtered table - Litchi has a 100 waypoint limit.
7. Open the Litchi Mission Hub and create a test mission with a few waypoints, doesn't matter too much were, you're just looking for the data table structure. You should fill in a Gimbal angle (I use -25 which eliminates most of the ski and makes for a good exposure of the ground level YMMV), Curve size (use small value - batch edit to 10% works well). Ensure the Setting for Heading Mode = Custom(WD), Path Mode (Curved Turns), and Gimble Pitch Mode = Interpolate. Save the mission.
8. Now export the mission from Litchi as a .csv file and open it in Excel.
9. From the original flight data, copy the data in the rows latitude, longitude, height_above_takeoff(feet), and gimbal_heading(degrees) and paste these into the Litchi mission table columns latitude, longitude, altitude(ft), and heading(deg). If you did a lot of gimbal pitch adjustment also copy the gimbal_pitch(degrees) into the gimbalpitchangle column.
10. Now copy down the rest of the data columns values in the Litchi table to fill out the table for all the waypoints. You should have less than 100 waypoint rows in this table
11. Save the Litchi mission data table in .csv format
12. Import the mission in the .csv table into the Litchi Mission Hub.
13. Your basic mission should be now laid out in the Mission Hub. You will need to adjust the default speed setting of the mission to a value that matches the original or possibly at one or more waypoint. Batch adjust the curve size to about 50% or whatever seems appropriate or at each waypoint.
14. You may need to add a lead-in or lead-out waypoint or two (the reason for <100 waypoints initially) to make for a smoother video. Other adjustments may be necessary.
15. Save your mission and fly it. I always test fly first in VLM just to check the work.
It's a close process but not perfect, winds affect the aircraft speed so if you're trying to do some side-by-side videos you may have to chop the video into segments to synchronize the footage.
Here are some example video of using this process.
Don