I want to capture a window and overlay it on another video.
This is my command:
ffmpeg -i MainVideo.avi -f gdigrab -framerate 25 -video_size 300x200 -i title="MyWindow" -filter_complex "setpts=PTS-STARTPTS[b];[b][1:v]overlay=(main_w-overlay_w):main_h-overlay_h[v]" -map "[v]" -c:v libx264 -r 25 out.mp4
background of my window is black.
How can I replace this black color with transparency?
is this possible by ffmpeg? (I think it is possible by chromakey/colorkey filters but I'm not sure, and I don't know how to use those filters)