ffmpeg -f lavfi -i "color=r=60:c=black:s=1600x1200:d=120" -i coil.webm -t 120 -vsync 0 -c:v libx264 -crf 20 -an -filter_complex "
[1:v]loop=3:1800:0,split=4[s0][s1][s2][s3];
[s0]setpts=PTS-22.5/TB[t0];
[s1]setpts=PTS-15/TB,transpose=1[t1];
[s2]setpts=PTS-7.5/TB,transpose=1,transpose=1[t2];
[s3]transpose=2[t3];
[0:v][t1]overlay=x=240:y=0[corner1];
[corner1][t2]overlay=x=280:y=140[corner2];
[corner2][t3]overlay=x=0:y=180[corner3];
[corner3][t4]overlay=x=0:y=0" output.mp4