I'm trying to overlay a 15 second video transition on the beginning of an image sequence (png sequence with an alpha to reveal the image below), which I can do fine with the overlay filter. But I want to hold the first frame of the image sequence for 5 seconds before playing the animation. I've tried trim/select but I can't seem to get it be a duration of 5 seconds, I also can't seem to concat it back with the other video to do the transition. So my questions are:
How do I get the first frame and hold it for 5 seconds, the method below works but doesn't seem like the best method?
The first frames of both sequences are repeated 149 times, so that there are 150 instances (30 fps x 5s). The 0 at the end of loop is the starting index of the frame(s) to loop. The middle 1 is the number of frames to loop starting at the index in the 3rd argument.