add overlay to video

overlay_ffmpeg.sh

ffmpeg -i intro.mp4 -i overlay.png \
-filter_complex "[1:v]scale=520:-1,format=rgba,colorchannelmixer=aa=0.5[fg];[0][fg]overlay=1380:920:enable='between(t,0,20)'" \
-pix_fmt yuv420p -c:v libx264 -preset fast -crf 22  -c:a libmp3lame \
output.mp4

ffmpeg -i intro.mp4 -i overlay.png \
-filter_complex "[1:v]format=rgba,colorchannelmixer=aa=0.7[fg];[0][fg]overlay" \
-pix_fmt yuv420p -c:a copy \
output.mp4


ffmpeg -i intro.mp4 -i overlay.png \
-filter_complex "[0:v][1:v] overlay=25:25:enable='between(t,0,20)'" \
-pix_fmt yuv420p -c:a copy \
output.mp4

ffmpeg -i intro.mp4 -i overlay.png \
-filter_complex "[0:v];[bg][1:v]overlay=10:10:all_opacity='0.5'" \
-pix_fmt yuv420p -c:a copy \
output.mp4