Struggling with chroma key + crop

Hi everyone !

I’m making a split screen of 9 vidéos (3X3). For your information, I recorded a concrete football pitch from a high point of view and there was 9 groups of people who came at different moments of the day, there were positionned at differents places of the pitch and waved hello at the camera. I want to merge these videos to make the illusion the 9 teams where there at the same moment and waved together.

I used Crop filter which works perfectly. Unfortunately, some people are overlapping the crop areas, and they look without arms or legs… I tried Chroma Key filter by selecting the grey pitch as a reference and It work well for the upper layer, but after it goes wrong. I know the Crop filter needs to be below the chroma key filter but whith 9 layers it doesn’t work.

I fear it’s a problem of order in the processing of the filters :

  1. Video 1 Chroma key
  2. Video 1 Crop
  3. Video 2 Chroma key
  4. Video 2 Crop

Is it possible to force Shotcut FIRST to apply Chroma key on the 9 videos and THEN to crop ? Like :

  1. Video 1 Chroma key
  2. Video 2 Chroma key
  3. Video 3 Chroma key

  4. 5 ) Video 1 Crop
  5. Video 2 Crop

Thanks a lot for reading me !